:root {
    --navy: #071c4d;
    --blue: #1457ff;
    --blue-dark: #0637b5;
    --cyan: #22d3ee;
    --ink: #101828;
    --muted: #667085;
    --surface: #ffffff;
    --line: #dbe5ff;
    --success: #12b76a;
    --danger: #f04438;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html,
body {
    width: 100%;
    height: 100%;
    overflow: hidden;
    color: var(--ink);
    background: #eef4ff;
    font-family: Inter, "Segoe UI", Arial, sans-serif;
}

button,
a {
    font: inherit;
}

.presentation {
    position: relative;
    width: 100vw;
    height: 100dvh;
    overflow: hidden;
    background:
        radial-gradient(circle at 10% 20%, rgba(34, 211, 238, 0.16), transparent 26%),
        radial-gradient(circle at 90% 80%, rgba(20, 87, 255, 0.14), transparent 28%),
        linear-gradient(135deg, #f8fbff 0%, #edf3ff 100%);
}

.presentation::before {
    content: "";
    position: absolute;
    inset: 0;
    pointer-events: none;
    opacity: 0.3;
    background-image: linear-gradient(rgba(20, 87, 255, 0.06) 1px, transparent 1px), linear-gradient(90deg, rgba(20, 87, 255, 0.06) 1px, transparent 1px);
    background-size: 48px 48px;
    mask-image: linear-gradient(to bottom, transparent, #000 25%, #000 75%, transparent);
}

.deck-topbar {
    position: absolute;
    z-index: 50;
    top: 0;
    left: 0;
    right: 0;
    height: 66px;
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    align-items: center;
    padding: 0 3.5vw;
}

.back-link,
.icon-button,
.control-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: var(--navy);
    text-decoration: none;
    border: 0;
    cursor: pointer;
}

.back-link {
    justify-self: start;
    gap: 9px;
    font-size: 0.84rem;
    font-weight: 700;
}

.back-link:hover {
    color: var(--blue);
}

.deck-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--navy);
    font-size: 0.78rem;
    font-weight: 800;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.deck-brand img {
    width: 34px;
    height: 34px;
    object-fit: contain;
}

.icon-button {
    justify-self: end;
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.75);
    border: 1px solid rgba(20, 87, 255, 0.12);
    border-radius: 12px;
}

.slides {
    position: relative;
    z-index: 2;
    width: 100%;
    height: 100%;
}

.slide {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    display: grid;
    align-content: center;
    padding: 76px clamp(42px, 7vw, 118px) 88px;
    visibility: hidden;
    opacity: 0;
    transform: translateX(5%) scale(0.985);
    transition: opacity 0.42s ease, transform 0.42s ease, visibility 0.42s;
}

.slide.previous {
    transform: translateX(-5%) scale(0.985);
}

.slide.active {
    visibility: visible;
    opacity: 1;
    transform: translateX(0) scale(1);
}

.slide-heading {
    max-width: 980px;
    margin-bottom: clamp(24px, 4vh, 44px);
}

.kicker {
    margin-bottom: 10px;
    color: var(--blue);
    font-size: clamp(0.72rem, 1.1vw, 0.9rem);
    font-weight: 900;
    letter-spacing: 0.13em;
    text-transform: uppercase;
}

h2 {
    color: var(--navy);
    font-size: clamp(2rem, 4vw, 4.3rem);
    line-height: 1.04;
    letter-spacing: -0.045em;
}

h3 {
    color: var(--navy);
}

.lead {
    margin-top: 20px;
    color: var(--muted);
    font-size: clamp(1rem, 1.5vw, 1.35rem);
    line-height: 1.65;
}

.reveal {
    opacity: 0;
    transform: translateY(22px);
}

.active .reveal {
    animation: reveal-up 0.58s cubic-bezier(0.2, 0.8, 0.2, 1) forwards;
}

.active .reveal:nth-child(2) { animation-delay: 0.08s; }
.active .reveal:nth-child(3) { animation-delay: 0.16s; }
.active .reveal:nth-child(4) { animation-delay: 0.24s; }
.active .reveal:nth-child(5) { animation-delay: 0.32s; }
.active .reveal:nth-child(6) { animation-delay: 0.4s; }

@keyframes reveal-up {
    to { opacity: 1; transform: translateY(0); }
}

.title-slide {
    grid-template-columns: minmax(0, 1.25fr) minmax(280px, 0.65fr);
    align-items: center;
    gap: 7vw;
    background: linear-gradient(115deg, transparent 56%, rgba(20, 87, 255, 0.06) 56%);
}

.hero-title {
    max-width: 850px;
    color: var(--navy);
    font-size: clamp(3rem, 6.7vw, 7.4rem);
    line-height: 0.92;
    letter-spacing: -0.07em;
}

.hero-title span {
    color: var(--blue);
    text-shadow: 0 8px 30px rgba(20, 87, 255, 0.22);
}

.hero-subtitle {
    margin: 22px 0 32px;
    color: var(--muted);
    font-size: clamp(1rem, 1.7vw, 1.5rem);
}

.speaker-card {
    width: fit-content;
    display: flex;
    align-items: center;
    gap: 13px;
    padding: 11px 18px 11px 11px;
    background: rgba(255, 255, 255, 0.82);
    border: 1px solid rgba(20, 87, 255, 0.14);
    border-radius: 16px;
    box-shadow: 0 14px 32px rgba(7, 28, 77, 0.08);
}

.speaker-avatar {
    width: 46px;
    height: 46px;
    display: grid;
    place-items: center;
    color: #fff;
    background: var(--blue);
    border-radius: 13px;
}

.speaker-card strong,
.speaker-card span {
    display: block;
}

.speaker-card strong { color: var(--navy); }
.speaker-card span { margin-top: 2px; color: var(--muted); font-size: 0.78rem; }

.title-visual {
    position: relative;
    justify-self: center;
}

.title-visual img {
    position: relative;
    z-index: 2;
    display: block;
    max-width: 100%;
    max-height: 72vh;
    border-radius: 22px;
    box-shadow: 0 30px 80px rgba(7, 28, 77, 0.28);
}

.orbit {
    position: absolute;
    border: 1px solid rgba(20, 87, 255, 0.25);
    border-radius: 50%;
    animation: spin 12s linear infinite;
}

.orbit::after {
    content: "";
    position: absolute;
    top: 50%;
    width: 10px;
    height: 10px;
    background: var(--cyan);
    border-radius: 50%;
    box-shadow: 0 0 18px var(--cyan);
}

.orbit-one { inset: -28px; }
.orbit-two { inset: -58px; animation-direction: reverse; animation-duration: 18s; }

@keyframes spin { to { transform: rotate(360deg); } }

.agenda-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}

.agenda-card,
.pillar-card,
.countdown-card,
.product-card,
.support-card {
    position: relative;
    background: rgba(255, 255, 255, 0.88);
    border: 1px solid rgba(20, 87, 255, 0.13);
    border-radius: 22px;
    box-shadow: 0 18px 45px rgba(7, 28, 77, 0.09);
}

.agenda-card {
    min-height: 235px;
    padding: 28px;
    overflow: hidden;
}

.agenda-card > span {
    position: absolute;
    top: 15px;
    right: 18px;
    color: rgba(20, 87, 255, 0.12);
    font-size: 3.2rem;
    font-weight: 900;
}

.agenda-card i {
    width: 54px;
    height: 54px;
    display: grid;
    place-items: center;
    margin-bottom: 30px;
    color: #fff;
    font-size: 1.35rem;
    background: linear-gradient(135deg, var(--blue), var(--blue-dark));
    border-radius: 16px;
}

.agenda-card h3 { font-size: 1.5rem; }
.agenda-card p { margin-top: 10px; color: var(--muted); line-height: 1.55; }

.degree-timeline {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 14px;
}

.career-timeline-wrap {
    position: relative;
    padding-bottom: 88px;
}

.career-timeline-wrap .degree-timeline {
    position: relative;
    z-index: 2;
}

.summer-focus .year-block:not(:nth-child(3)):not(:nth-child(4)) {
    opacity: 0.55;
}

.semester-six {
    border-color: #fdb022;
    box-shadow: 0 12px 28px rgba(247, 144, 9, 0.15);
}

.summer-marker {
    position: absolute;
    z-index: 4;
    bottom: 0;
    left: 75%;
    min-width: 245px;
    padding: 14px 20px;
    text-align: center;
    color: var(--navy);
    background: #fff8e7;
    border: 2px solid #fdb022;
    border-radius: 17px;
    box-shadow: 0 14px 30px rgba(247, 144, 9, 0.18);
    transform: translateX(-50%);
}

.summer-marker::before {
    content: "";
    position: absolute;
    bottom: 100%;
    left: 50%;
    width: 3px;
    height: 26px;
    background: #fdb022;
}

.summer-marker i {
    margin-right: 8px;
    color: #f79009;
}

.summer-marker span {
    font-weight: 900;
}

.summer-marker small {
    display: block;
    margin-top: 3px;
    color: #b54708;
    font-size: 0.72rem;
    font-weight: 700;
}

.year-block {
    position: relative;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 7px;
    padding-top: 35px;
}

.year-label {
    position: absolute;
    top: 0;
    left: 0;
    color: var(--muted);
    font-size: 0.75rem;
    font-weight: 800;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.semester {
    min-height: 135px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 7px;
    color: var(--navy);
    font-weight: 800;
    background: rgba(255, 255, 255, 0.82);
    border: 1px solid var(--line);
    border-radius: 17px;
}

.semester i { color: var(--blue); font-size: 1.4rem; }
.semester strong { color: var(--blue); font-size: 0.7rem; text-transform: uppercase; }
.year-block.opportunity { padding: 35px 6px 6px; background: rgba(20, 87, 255, 0.08); border-radius: 22px; }
.semester.placement, .semester.internship { border-color: rgba(20, 87, 255, 0.28); box-shadow: 0 12px 24px rgba(20, 87, 255, 0.09); }

.full-career-timeline {
    position: relative;
    min-height: 360px;
    padding-top: 12px;
}

.semester-scale {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    display: grid;
    grid-template-columns: repeat(8, 1fr);
    gap: 7px;
}

.semester-scale span {
    padding: 13px 6px;
    text-align: center;
    color: var(--navy);
    font-size: 0.82rem;
    font-weight: 900;
    background: rgba(255, 255, 255, 0.82);
    border: 1px solid var(--line);
    border-radius: 11px;
}

.preparation-band {
    position: absolute;
    top: 76px;
    left: 0;
    width: 50%;
    min-height: 188px;
    padding: 24px 26px;
    color: #fff;
    background: linear-gradient(135deg, var(--blue), var(--blue-dark));
    border-radius: 22px;
    box-shadow: 0 18px 40px rgba(20, 87, 255, 0.22);
}

.preparation-band > strong {
    font-size: 1.3rem;
}

.preparation-band > small {
    display: block;
    margin-top: 18px;
    color: rgba(255, 255, 255, 0.75);
    font-weight: 700;
}

.preparation-topics {
    display: flex;
    gap: 12px;
    margin-top: 20px;
}

.preparation-topics span {
    flex: 1;
    padding: 13px 10px;
    text-align: center;
    font-weight: 900;
    background: rgba(255, 255, 255, 0.13);
    border: 1px solid rgba(255, 255, 255, 0.18);
    border-radius: 12px;
}

.preparation-topics i {
    margin-right: 6px;
    color: var(--cyan);
}

.si-interview-window {
    position: absolute;
    top: 76px;
    left: 50%;
    width: 12.5%;
    min-width: 220px;
    min-height: 108px;
    display: flex;
    align-items: center;
    gap: 13px;
    padding: 18px;
    color: var(--navy);
    background: #fff8e7;
    border: 2px dashed #f79009;
    border-radius: 17px;
    box-shadow: 0 14px 30px rgba(247, 144, 9, 0.15);
    transform: translateX(-12px);
}

.si-interview-window i,
.timeline-summer-internship i {
    color: #f79009;
    font-size: 1.5rem;
}

.si-interview-window strong,
.si-interview-window span,
.timeline-summer-internship strong,
.timeline-summer-internship span {
    display: block;
}

.si-interview-window span,
.timeline-summer-internship span {
    margin-top: 5px;
    color: var(--muted);
    font-size: 0.76rem;
    line-height: 1.35;
}

.timeline-summer-internship {
    position: absolute;
    top: 76px;
    left: 75%;
    min-width: 230px;
    min-height: 108px;
    display: flex;
    align-items: center;
    gap: 13px;
    padding: 18px;
    color: var(--navy);
    background: #fff;
    border: 2px solid #fdb022;
    border-radius: 17px;
    box-shadow: 0 14px 30px rgba(247, 144, 9, 0.15);
    transform: translateX(-50%);
}

.timeline-summer-internship::before {
    content: "";
    position: absolute;
    bottom: 100%;
    left: 50%;
    width: 3px;
    height: 30px;
    background: #fdb022;
}

.big-takeaway {
    width: fit-content;
    margin: 32px auto 0;
    padding: 13px 20px;
    color: var(--navy);
    font-weight: 800;
    background: rgba(34, 211, 238, 0.13);
    border: 1px solid rgba(34, 211, 238, 0.35);
    border-radius: 100px;
}

.big-takeaway i { margin-right: 8px; color: var(--blue); }

.summer-track {
    display: grid;
    grid-template-columns: auto 1fr auto 1fr auto 1fr auto;
    align-items: center;
    margin: 30px 2vw 50px;
}

.track-point {
    min-width: 120px;
    text-align: center;
}

.track-point span,
.track-point small { display: block; }
.track-point span { color: var(--navy); font-size: 1.25rem; font-weight: 900; }
.track-point small { margin-top: 7px; color: var(--muted); }
.track-point i { margin-bottom: 8px; color: #f79009; font-size: 2.5rem; }

.track-point.featured {
    padding: 24px 22px;
    background: #fff;
    border: 2px solid #fdb022;
    border-radius: 22px;
    box-shadow: 0 17px 38px rgba(247, 144, 9, 0.16);
}

.track-line { height: 4px; background: #cdd9f3; }
.track-line.active { background: linear-gradient(90deg, var(--blue), #fdb022); }

.question-banner,
.answer-line {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 25px;
    padding: 22px 28px;
    color: #fff;
    background: linear-gradient(135deg, var(--navy), var(--blue-dark));
    border-radius: 20px;
    box-shadow: 0 20px 40px rgba(7, 28, 77, 0.18);
}

.question-banner span,
.answer-line span { font-size: clamp(1rem, 1.6vw, 1.35rem); }
.question-banner strong,
.answer-line strong { font-size: clamp(1.2rem, 2vw, 1.8rem); }

.countdown-grid {
    display: grid;
    grid-template-columns: 1fr auto 1fr auto 1fr;
    align-items: center;
    gap: 22px;
}

.countdown-card {
    min-height: 235px;
    padding: 30px;
}

.countdown-card > span { color: var(--blue); font-weight: 900; }
.countdown-card strong { display: block; margin: 20px 0 10px; color: var(--navy); font-size: 2rem; }
.countdown-card p { color: var(--muted); line-height: 1.55; }
.countdown-card.accent { color: #fff; background: linear-gradient(145deg, var(--blue), var(--blue-dark)); }
.countdown-card.accent span, .countdown-card.accent strong, .countdown-card.accent p { color: #fff; }
.countdown-card.muted { opacity: 0.78; }
.flow-arrow { color: var(--blue); font-size: 1.4rem; }
.answer-line { max-width: 900px; margin: 28px auto 0; }

.statement-slide {
    justify-items: center;
    text-align: center;
}

.statement-mark {
    width: 86px;
    height: 86px;
    display: grid;
    place-items: center;
    margin-bottom: 28px;
    color: #fff;
    font-size: 2.2rem;
    background: linear-gradient(135deg, var(--blue), var(--cyan));
    border-radius: 26px;
    box-shadow: 0 20px 45px rgba(20, 87, 255, 0.24);
}

.statement {
    max-width: 1080px;
    font-size: clamp(2.6rem, 5.8vw, 6rem);
}

.statement-sub {
    max-width: 780px;
    margin-top: 25px;
    color: var(--muted);
    font-size: clamp(1rem, 1.7vw, 1.4rem);
}

.pillar-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 25px;
}

.pillar-card {
    min-height: 290px;
    padding: 30px;
}

.pillar-icon {
    width: 60px;
    height: 60px;
    display: grid;
    place-items: center;
    margin-bottom: 25px;
    color: #fff;
    font-size: 1.4rem;
    background: var(--blue);
    border-radius: 18px;
}

.pillar-card > span { color: var(--blue); font-size: 0.76rem; font-weight: 900; text-transform: uppercase; }
.pillar-card h3 { margin: 8px 0 13px; font-size: 1.8rem; }
.pillar-card p { color: var(--muted); line-height: 1.6; }

.formula {
    margin-top: 28px;
    text-align: center;
    color: var(--navy);
    font-size: clamp(1rem, 1.6vw, 1.3rem);
}

.formula b { color: var(--blue); }

.split-layout {
    display: grid;
    grid-template-columns: 1fr 0.9fr;
    align-items: center;
    gap: 8vw;
}

.check-list {
    display: grid;
    gap: 15px;
    margin-top: 30px;
    list-style: none;
}

.check-list li {
    display: flex;
    align-items: center;
    gap: 12px;
    color: #344054;
    font-size: clamp(0.95rem, 1.35vw, 1.2rem);
}

.check-list i {
    width: 28px;
    height: 28px;
    display: grid;
    place-items: center;
    flex: 0 0 auto;
    color: #fff;
    font-size: 0.75rem;
    background: var(--success);
    border-radius: 50%;
}

.code-visual {
    padding: 18px;
    background: linear-gradient(145deg, rgba(20, 87, 255, 0.18), rgba(34, 211, 238, 0.12));
    border-radius: 28px;
}

.code-window {
    min-height: 340px;
    padding: 24px;
    color: #d9e6ff;
    background: #07152f;
    border-radius: 18px;
    box-shadow: 0 25px 50px rgba(7, 21, 47, 0.28);
}

.window-dots { color: #f97066; letter-spacing: 5px; }
.code-window code { display: block; margin-top: 55px; font: 600 clamp(1rem, 1.65vw, 1.35rem)/2.1 Consolas, monospace; }
.code-window em { color: var(--cyan); font-style: normal; }

.fundamentals-map {
    position: relative;
    width: min(760px, 80vw);
    height: min(440px, 48vh);
    margin: 0 auto;
}

.fund-center,
.fund-node {
    position: absolute;
    display: grid;
    place-items: center;
    text-align: center;
    background: #fff;
    border: 1px solid var(--line);
    box-shadow: 0 16px 35px rgba(7, 28, 77, 0.1);
}

.fund-center {
    z-index: 3;
    top: 50%;
    left: 50%;
    width: 170px;
    height: 170px;
    color: #fff;
    font-size: 1.35rem;
    font-weight: 900;
    background: linear-gradient(135deg, var(--blue), var(--blue-dark));
    border-radius: 50%;
    transform: translate(-50%, -50%);
}

.fund-node {
    width: 180px;
    height: 100px;
    gap: 7px;
    color: var(--navy);
    font-weight: 800;
    border-radius: 18px;
}

.fund-node i { color: var(--blue); font-size: 1.4rem; }
.node-os { top: 0; left: 50%; transform: translateX(-50%); }
.node-db { top: 50%; right: 0; transform: translateY(-50%); }
.node-net { bottom: 0; left: 50%; transform: translateX(-50%); }
.node-oop { top: 50%; left: 0; transform: translateY(-50%); }

.fundamentals-map::before,
.fundamentals-map::after {
    content: "";
    position: absolute;
    top: 50%;
    left: 50%;
    background: var(--line);
    transform: translate(-50%, -50%);
}

.fundamentals-map::before { width: 70%; height: 2px; }
.fundamentals-map::after { width: 2px; height: 70%; }

.ai-evolution {
    display: grid;
    grid-template-columns: repeat(11, auto);
    align-items: center;
    justify-content: center;
    gap: 12px;
}

.evolution-step {
    width: clamp(145px, 14vw, 205px);
    min-height: 215px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 20px 15px;
    text-align: center;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 20px;
    box-shadow: 0 14px 32px rgba(7, 28, 77, 0.08);
}

.evolution-step span { color: var(--blue); font-size: 0.75rem; font-weight: 900; }
.evolution-step i { margin: 20px 0; color: var(--blue); font-size: 1.8rem; }
.evolution-step strong { color: var(--navy); }
.evolution-step small { margin-top: 8px; color: var(--muted); line-height: 1.35; }
.evolution-arrow { color: var(--blue); font-size: 1.5rem; }
.evolution-caption { margin-top: 28px; text-align: center; color: var(--muted); font-size: 1.15rem; }
.evolution-caption b { color: var(--blue); }

.agent-loop {
    position: relative;
    width: min(450px, 42vw);
    aspect-ratio: 1;
    margin: auto;
}

.loop-center,
.loop-node {
    position: absolute;
    z-index: 2;
    display: grid;
    place-items: center;
    color: var(--navy);
    font-weight: 900;
    background: #fff;
    border: 1px solid var(--line);
    box-shadow: 0 12px 28px rgba(7, 28, 77, 0.11);
}

.loop-center {
    top: 50%;
    left: 50%;
    width: 135px;
    height: 135px;
    color: #fff;
    background: var(--blue);
    border-radius: 50%;
    transform: translate(-50%, -50%);
}

.loop-center i { font-size: 1.8rem; }
.loop-center span { font-size: 1.1rem; }
.loop-node { width: 105px; height: 60px; border-radius: 15px; }
.loop-plan { top: 0; left: 50%; transform: translateX(-50%); }
.loop-act { top: 50%; right: 0; transform: translateY(-50%); }
.loop-check { bottom: 0; left: 50%; transform: translateX(-50%); }
.loop-improve { top: 50%; left: 0; transform: translateY(-50%); }
.loop-ring { position: absolute; inset: 45px; border: 3px dashed rgba(20, 87, 255, 0.35); border-radius: 50%; animation: spin 14s linear infinite; }

.system-diagram {
    min-height: 300px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 35px;
    padding: 34px;
    background: rgba(255, 255, 255, 0.68);
    border: 1px solid var(--line);
    border-radius: 26px;
}

.system-users,
.server-node,
.database-node,
.diagram-users,
.load-balancer {
    min-width: 155px;
    min-height: 150px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 9px;
    text-align: center;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 20px;
    box-shadow: 0 15px 32px rgba(7, 28, 77, 0.09);
}

.system-users i,
.server-node i,
.database-node i,
.diagram-users i,
.load-balancer i { color: var(--blue); font-size: 2rem; }
.system-users span,
.server-node span { color: var(--muted); font-size: 0.8rem; }
.request-arrow { color: var(--blue); text-align: center; }
.request-arrow span { display: block; margin-bottom: 9px; color: var(--muted); font-size: 0.75rem; }
.request-arrow i { font-size: 1.5rem; }

.overloaded-system { gap: 90px; }
.crowd { text-align: center; color: var(--navy); }
.crowd > i { display: block; margin-bottom: 12px; color: var(--blue); font-size: 4rem; }
.request-stream { margin-top: 25px; color: var(--danger); font-size: 1.6rem; letter-spacing: 4px; animation: pulse 1s ease-in-out infinite; }

@keyframes pulse { 50% { opacity: 0.35; transform: translateX(5px); } }

.server-node.danger { border: 2px solid var(--danger); animation: shake 1.5s ease-in-out infinite; }
.server-node.danger i, .server-node.danger strong { color: var(--danger); }
.server-node.danger small { color: var(--muted); }
.heat-bar { width: 80%; height: 8px; overflow: hidden; background: #fee4e2; border-radius: 10px; }
.heat-bar span { display: block; width: 95%; height: 100%; background: var(--danger); }

@keyframes shake { 0%, 90%, 100% { transform: translateX(0); } 93% { transform: translateX(-4px); } 96% { transform: translateX(4px); } }

.problem-chips,
.benefit-row {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-top: 26px;
}

.problem-chips span,
.benefit-row span {
    padding: 11px 16px;
    color: var(--navy);
    font-weight: 700;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 100px;
}

.problem-chips i { color: var(--danger); margin-right: 7px; }
.benefit-row i { color: var(--success); margin-right: 7px; }

.load-balancer-diagram {
    min-height: 315px;
    display: grid;
    grid-template-columns: auto auto auto 80px auto;
    align-items: center;
    justify-content: center;
    gap: 30px;
}

.diagram-arrow { color: var(--blue); font-size: 1.7rem; }
.load-balancer { color: #fff; background: linear-gradient(145deg, var(--blue), var(--blue-dark)); border: 0; }
.load-balancer i, .load-balancer span { color: #fff; }
.load-balancer span { font-size: 0.75rem; opacity: 0.82; }
.branch-lines { height: 170px; display: flex; flex-direction: column; justify-content: space-around; }
.branch-lines span { width: 80px; height: 3px; background: var(--blue); }
.server-stack { display: grid; gap: 14px; }
.mini-server { min-width: 150px; padding: 16px; color: var(--navy); font-weight: 800; background: #fff; border: 1px solid var(--line); border-radius: 13px; box-shadow: 0 10px 22px rgba(7, 28, 77, 0.07); }
.mini-server i { margin-right: 8px; color: var(--success); }

.traffic-analogy {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    align-items: center;
    gap: 30px;
    min-height: 330px;
    padding: 35px;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 26px;
}

.traffic-source { display: grid; gap: 18px; color: var(--blue); font-size: 2rem; }
.traffic-control { width: 85px; height: 85px; display: grid; place-items: center; color: #fff; font-size: 2rem; background: var(--blue); border-radius: 50%; }
.traffic-roads { display: grid; gap: 18px; }
.traffic-roads span { padding: 10px 18px; color: var(--navy); font-weight: 800; background: #eef4ff; border-left: 5px solid var(--success); border-radius: 8px; }

.college-roadmap {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    align-items: stretch;
    gap: 25px;
}

.roadmap-half {
    min-height: 330px;
    padding: 38px;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 25px;
    box-shadow: 0 18px 42px rgba(7, 28, 77, 0.08);
}

.roadmap-years { color: var(--blue); font-weight: 900; text-transform: uppercase; }
.roadmap-icon { width: 62px; height: 62px; display: grid; place-items: center; margin: 28px 0 20px; color: #fff; font-size: 1.5rem; background: var(--blue); border-radius: 18px; }
.roadmap-half h3 { font-size: 2rem; }
.roadmap-half p { margin-top: 15px; color: var(--muted); font-size: 1.05rem; line-height: 1.75; }
.build-half { color: #fff; background: linear-gradient(145deg, var(--navy), var(--blue-dark)); }
.build-half .roadmap-years, .build-half h3, .build-half p { color: #fff; }
.build-half p { opacity: 0.78; }
.build-half .roadmap-icon { color: var(--blue); background: #fff; }
.roadmap-chevron { display: grid; place-items: center; color: var(--blue); font-size: 2rem; }

.comparison-grid {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    align-items: center;
    gap: 30px;
}

.comparison-card {
    min-height: 350px;
    padding: 35px;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 25px;
}

.comparison-label { color: var(--muted); font-size: 0.8rem; font-weight: 900; text-transform: uppercase; }
.comparison-card ul { display: grid; gap: 18px; margin-top: 30px; list-style: none; }
.comparison-card li { display: flex; align-items: center; gap: 14px; color: var(--navy); font-size: 1.15rem; font-weight: 800; }
.comparison-card li i { width: 42px; height: 42px; display: grid; place-items: center; color: var(--muted); background: #f2f4f7; border-radius: 12px; }
.comparison-vs { width: 54px; height: 54px; display: grid; place-items: center; color: #fff; font-weight: 900; background: var(--blue); border-radius: 50%; }
.active-path { color: #fff; background: linear-gradient(145deg, var(--blue), var(--blue-dark)); }
.active-path .comparison-label, .active-path li { color: #fff; }
.active-path li i { color: var(--blue); background: #fff; }

.rubyx-intro {
    display: grid;
    grid-template-columns: 0.65fr 1.35fr;
    align-items: center;
    gap: 7vw;
}

.rubyx-logo-block {
    min-height: 320px;
    display: grid;
    place-items: center;
    background: linear-gradient(145deg, var(--navy), var(--blue-dark));
    border-radius: 32px;
    box-shadow: 0 28px 58px rgba(7, 28, 77, 0.24);
}

.rubyx-logo-block img { width: min(220px, 60%); filter: brightness(0) invert(1); }
.rubyx-pillars { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; margin-top: 40px; }
.rubyx-pillar { display: grid; grid-template-columns: auto 1fr; column-gap: 13px; padding: 19px; background: #fff; border: 1px solid var(--line); border-radius: 17px; }
.rubyx-pillar i { grid-row: span 2; align-self: center; color: var(--blue); font-size: 1.5rem; }
.rubyx-pillar strong { color: var(--navy); }
.rubyx-pillar span { color: var(--muted); font-size: 0.8rem; }

.rubyx-merged-layout {
    display: grid;
    grid-template-columns: 0.7fr 1.3fr;
    gap: 28px;
}

.rubyx-summary-card {
    min-height: 365px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding: 38px;
    color: #fff;
    background: linear-gradient(145deg, var(--navy), var(--blue-dark));
    border-radius: 28px;
    box-shadow: 0 25px 55px rgba(7, 28, 77, 0.22);
}

.rubyx-summary-card > img {
    width: min(220px, 75%);
    margin: 0 auto 38px;
    filter: brightness(0) invert(1);
}

.rubyx-summary-points {
    display: grid;
    gap: 12px;
}

.rubyx-summary-points span {
    padding: 12px 14px;
    font-weight: 800;
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.14);
    border-radius: 12px;
}

.rubyx-summary-points i {
    width: 25px;
    color: var(--cyan);
}

.rubyx-products-compact {
    display: grid;
    gap: 18px;
}

.compact-product {
    min-height: 172px;
    display: grid;
    grid-template-columns: 155px 1fr;
    align-items: center;
    gap: 25px;
    padding: 22px;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 22px;
    box-shadow: 0 16px 38px rgba(7, 28, 77, 0.08);
}

.compact-product-icon {
    height: 128px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    color: #fff;
    font-size: 2rem;
    background: linear-gradient(135deg, var(--blue), var(--cyan));
    border-radius: 17px;
}

.compact-product-icon.seller-icon {
    background: linear-gradient(135deg, var(--navy), var(--blue));
}

.compact-product span {
    color: var(--blue);
    font-size: 0.72rem;
    font-weight: 900;
    letter-spacing: 0.1em;
    text-transform: uppercase;
}

.compact-product h3 {
    margin: 7px 0 8px;
    font-size: 1.55rem;
}

.compact-product p {
    color: var(--muted);
    line-height: 1.5;
}

.rubyx-dual-focus {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 28px;
}

.rubyx-focus-card {
    min-height: 390px;
    padding: 34px;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 27px;
    box-shadow: 0 20px 48px rgba(7, 28, 77, 0.1);
}

.startup-focus {
    color: #fff;
    background: linear-gradient(145deg, var(--navy), var(--blue-dark));
    border-color: transparent;
}

.focus-heading {
    display: flex;
    align-items: center;
    gap: 17px;
}

.focus-icon {
    width: 64px;
    height: 64px;
    display: grid;
    place-items: center;
    flex: 0 0 auto;
    color: #fff;
    font-size: 1.55rem;
    background: var(--blue);
    border-radius: 18px;
}

.startup-focus .focus-icon {
    color: var(--blue);
    background: #fff;
}

.focus-heading span {
    color: var(--blue);
    font-size: 0.72rem;
    font-weight: 900;
    letter-spacing: 0.1em;
    text-transform: uppercase;
}

.startup-focus .focus-heading span {
    color: var(--cyan);
}

.focus-heading h3 {
    margin-top: 5px;
    font-size: 1.65rem;
}

.startup-focus h3 {
    color: #fff;
}

.rubyx-focus-card > p {
    margin: 27px 0;
    color: var(--muted);
    font-size: 1.02rem;
    line-height: 1.6;
}

.startup-focus > p {
    color: rgba(255, 255, 255, 0.75);
}

.institute-points,
.startup-products {
    display: grid;
    gap: 12px;
}

.institute-points span {
    padding: 13px 15px;
    color: var(--navy);
    font-weight: 800;
    background: #f4f7ff;
    border-radius: 12px;
}

.institute-points i {
    width: 27px;
    color: var(--blue);
}

.startup-products {
    grid-template-columns: repeat(2, 1fr);
}

.startup-products > div {
    min-height: 126px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding: 18px;
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.14);
    border-radius: 15px;
}

.startup-products i {
    margin-bottom: 15px;
    color: var(--cyan);
    font-size: 1.5rem;
}

.startup-products span {
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.65rem;
    font-weight: 900;
    text-transform: uppercase;
}

.startup-products strong {
    margin-top: 5px;
    color: #fff;
}

.product-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 28px;
}

.product-card {
    min-height: 360px;
    padding: 36px;
    overflow: hidden;
}

.product-number { position: absolute; top: 14px; right: 24px; color: rgba(20, 87, 255, 0.11); font-size: 5rem; font-weight: 900; }
.product-visual { width: 100%; height: 165px; display: flex; align-items: center; justify-content: center; gap: 18px; margin-bottom: 25px; color: #fff; font-size: 3rem; background: linear-gradient(135deg, var(--blue), var(--cyan)); border-radius: 20px; }
.seller-product .product-visual { background: linear-gradient(135deg, var(--navy), var(--blue)); }
.product-card h3 { font-size: 1.8rem; }
.product-card p { max-width: 470px; margin-top: 12px; color: var(--muted); font-size: 1.05rem; line-height: 1.6; }

.founder-support {
    display: grid;
    grid-template-columns: 1fr 50px 1fr 50px 1fr;
    align-items: center;
}

.support-card { min-height: 270px; padding: 32px; text-align: center; }
.support-card i { width: 65px; height: 65px; display: grid; place-items: center; margin: 0 auto 24px; color: #fff; font-size: 1.45rem; background: var(--blue); border-radius: 18px; }
.support-card h3 { font-size: 1.5rem; }
.support-card p { margin-top: 12px; color: var(--muted); line-height: 1.55; }
.support-connector { height: 3px; background: linear-gradient(90deg, var(--blue), var(--cyan)); }

.action-plan {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 18px;
}

.action-item {
    min-height: 145px;
    display: grid;
    grid-template-columns: auto 1fr;
    align-items: center;
    gap: 23px;
    padding: 24px;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 20px;
    box-shadow: 0 14px 30px rgba(7, 28, 77, 0.07);
}

.action-item > span { color: rgba(20, 87, 255, 0.18); font-size: 3rem; font-weight: 900; }
.action-item h3 { font-size: 1.3rem; }
.action-item p { margin-top: 7px; color: var(--muted); }

.qna-slide {
    justify-items: center;
    text-align: center;
    background: radial-gradient(circle at center, rgba(20, 87, 255, 0.12), transparent 50%);
}

.qna-orb { width: 100px; height: 100px; display: grid; place-items: center; margin-bottom: 28px; color: #fff; font-size: 2.7rem; background: linear-gradient(135deg, var(--blue), var(--cyan)); border-radius: 50%; box-shadow: 0 0 0 18px rgba(20, 87, 255, 0.08), 0 0 0 36px rgba(20, 87, 255, 0.04); animation: float 3s ease-in-out infinite; }
@keyframes float { 50% { transform: translateY(-10px); } }
.qna-slide h2 { font-size: clamp(4rem, 10vw, 10rem); }
.qna-copy { margin-top: 20px; color: var(--muted); font-size: clamp(1rem, 2vw, 1.5rem); }
.qna-footer { display: flex; align-items: center; gap: 12px; margin-top: 45px; color: var(--navy); font-weight: 800; }
.qna-footer img { width: 45px; }

.deck-controls {
    position: absolute;
    z-index: 60;
    right: 3.5vw;
    bottom: 22px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.control-button {
    width: 44px;
    height: 44px;
    background: rgba(255, 255, 255, 0.9);
    border: 1px solid rgba(20, 87, 255, 0.15);
    border-radius: 13px;
    box-shadow: 0 8px 22px rgba(7, 28, 77, 0.1);
}

.control-button.primary { color: #fff; background: var(--blue); }
.control-button:disabled { opacity: 0.35; cursor: not-allowed; }

.slide-status {
    min-width: 170px;
    display: flex;
    justify-content: space-between;
    gap: 20px;
    color: var(--muted);
    font-size: 0.76rem;
    font-weight: 800;
    text-transform: uppercase;
}

.slide-status b { color: var(--blue); }

.progress-track {
    position: absolute;
    z-index: 70;
    bottom: 0;
    left: 0;
    right: 0;
    height: 5px;
    background: rgba(20, 87, 255, 0.08);
}

.progress-track span {
    display: block;
    width: 0;
    height: 100%;
    background: linear-gradient(90deg, var(--blue), var(--cyan));
    transition: width 0.35s ease;
}

.keyboard-hint {
    position: absolute;
    z-index: 40;
    bottom: 27px;
    left: 3.5vw;
    color: #98a2b3;
    font-size: 0.72rem;
}

kbd {
    display: inline-grid;
    place-items: center;
    min-width: 24px;
    height: 24px;
    margin-right: 4px;
    color: var(--muted);
    font-family: inherit;
    background: #fff;
    border: 1px solid #d0d5dd;
    border-radius: 6px;
    box-shadow: 0 2px 0 #d0d5dd;
}

@media (max-width: 1100px) {
    .agenda-grid { grid-template-columns: repeat(2, 1fr); }
    .agenda-card { min-height: 180px; }
    .agenda-card i { margin-bottom: 15px; }
    .ai-evolution { grid-template-columns: repeat(5, 1fr); }
    .evolution-arrow { display: none; }
    .evolution-step { width: auto; min-height: 180px; }
    .rubyx-pillars { margin-top: 24px; }
}

@media (max-width: 820px) {
    .deck-brand span,
    .back-link span,
    .keyboard-hint { display: none; }
    .slide { padding: 70px 24px 84px; overflow-y: auto; }
    .title-slide,
    .split-layout,
    .rubyx-intro,
    .rubyx-merged-layout,
    .rubyx-dual-focus { grid-template-columns: 1fr; gap: 28px; }
    .title-visual { display: none; }
    .agenda-grid,
    .pillar-grid,
    .product-grid,
    .action-plan { grid-template-columns: 1fr 1fr; }
    .degree-timeline { grid-template-columns: repeat(2, 1fr); }
    .countdown-grid { grid-template-columns: 1fr; }
    .flow-arrow { transform: rotate(90deg); justify-self: center; }
    .summer-track { grid-template-columns: 1fr; gap: 10px; }
    .track-line { width: 4px; height: 25px; justify-self: center; }
    .fundamentals-map { transform: scale(0.78); }
    .ai-evolution { grid-template-columns: repeat(2, 1fr); }
    .agent-loop { width: min(380px, 80vw); }
    .system-diagram { flex-wrap: wrap; min-height: auto; }
    .load-balancer-diagram { grid-template-columns: 1fr; gap: 16px; }
    .diagram-arrow { transform: rotate(90deg); justify-self: center; }
    .branch-lines { display: none; }
    .server-stack { grid-template-columns: repeat(3, 1fr); }
    .college-roadmap,
    .comparison-grid,
    .founder-support { grid-template-columns: 1fr; }
    .roadmap-chevron { transform: rotate(90deg); }
    .comparison-vs { justify-self: center; }
    .support-connector { width: 3px; height: 30px; justify-self: center; }
    .rubyx-pillars { grid-template-columns: 1fr; }
    .compact-product { grid-template-columns: 120px 1fr; }
    .compact-product-icon { height: 110px; }
}

@media (max-width: 560px) {
    .slide { align-content: start; padding-top: 78px; }
    .agenda-grid,
    .pillar-grid,
    .product-grid,
    .action-plan,
    .degree-timeline,
    .ai-evolution { grid-template-columns: 1fr; }
    .hero-title { font-size: 3.2rem; }
    .agenda-card,
    .pillar-card,
    .product-card { min-height: auto; }
    .semester { min-height: 105px; }
    .question-banner,
    .answer-line { align-items: flex-start; flex-direction: column; }
    .fundamentals-map { width: 540px; margin-left: calc((100% - 540px) / 2); transform: scale(0.62); }
    .problem-chips,
    .benefit-row { flex-wrap: wrap; }
    .server-stack { grid-template-columns: 1fr; }
    .traffic-analogy { grid-template-columns: 1fr; }
    .traffic-source { grid-template-columns: repeat(3, 1fr); }
    .traffic-control { justify-self: center; }
    .compact-product { grid-template-columns: 1fr; }
    .startup-products { grid-template-columns: 1fr; }
    .deck-controls { left: 20px; right: 20px; justify-content: flex-end; }
    .slide-status { min-width: 130px; }
}

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Segment-specific visual systems */
.presentation {
    transition: background 0.6s ease, color 0.4s ease;
}

.presentation[data-theme="career-timeline"] {
    background:
        radial-gradient(circle at 90% 12%, rgba(255, 184, 77, 0.27), transparent 25%),
        radial-gradient(circle at 8% 85%, rgba(255, 111, 97, 0.14), transparent 28%),
        linear-gradient(130deg, #fffaf1, #fff4e4 55%, #ffe9cf);
}

.presentation[data-theme="what-to-learn"] {
    background:
        radial-gradient(circle at 50% 110%, rgba(125, 92, 255, 0.32), transparent 42%),
        linear-gradient(135deg, #faf8ff, #eee9ff);
}

.presentation[data-theme="ai-era"] {
    color: #f4f7ff;
    background:
        radial-gradient(circle at 18% 18%, rgba(20, 87, 255, 0.35), transparent 28%),
        radial-gradient(circle at 82% 80%, rgba(34, 211, 238, 0.2), transparent 30%),
        linear-gradient(145deg, #030817, #07152f 52%, #061d3f);
}

.presentation[data-theme="system-design"] {
    color: #e8fff7;
    background:
        linear-gradient(rgba(17, 239, 178, 0.045) 1px, transparent 1px),
        linear-gradient(90deg, rgba(17, 239, 178, 0.045) 1px, transparent 1px),
        radial-gradient(circle at 50% 50%, rgba(18, 183, 106, 0.12), transparent 40%),
        #061a1b;
    background-size: 42px 42px, 42px 42px, auto, auto;
}

.presentation[data-theme="college-roadmap"] {
    background:
        radial-gradient(circle at 12% 12%, rgba(40, 199, 111, 0.2), transparent 26%),
        radial-gradient(circle at 90% 80%, rgba(15, 118, 110, 0.18), transparent 30%),
        linear-gradient(135deg, #f6fff9, #e7faef);
}

.presentation[data-theme="rubyx"] {
    background:
        radial-gradient(circle at 88% 12%, rgba(34, 211, 238, 0.2), transparent 26%),
        linear-gradient(135deg, #eef4ff, #dfeaff);
}

.presentation[data-theme="q-a"] {
    background:
        radial-gradient(circle at center, rgba(34, 211, 238, 0.22), transparent 35%),
        linear-gradient(145deg, #040b20, #0b2d68);
}

.presentation[data-theme="ai-era"]::before,
.presentation[data-theme="system-design"]::before,
.presentation[data-theme="q-a"]::before {
    opacity: 0.25;
    background-image:
        linear-gradient(rgba(255, 255, 255, 0.05) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.05) 1px, transparent 1px);
}

.presentation[data-theme="ai-era"] .deck-topbar,
.presentation[data-theme="system-design"] .deck-topbar,
.presentation[data-theme="q-a"] .deck-topbar,
.presentation[data-theme="ai-era"] .back-link,
.presentation[data-theme="system-design"] .back-link,
.presentation[data-theme="q-a"] .back-link,
.presentation[data-theme="ai-era"] .deck-brand,
.presentation[data-theme="system-design"] .deck-brand,
.presentation[data-theme="q-a"] .deck-brand {
    color: #f4f7ff;
}

.presentation[data-theme="ai-era"] .deck-brand img,
.presentation[data-theme="system-design"] .deck-brand img,
.presentation[data-theme="q-a"] .deck-brand img {
    filter: brightness(0) invert(1);
}

.presentation[data-theme="ai-era"] .icon-button,
.presentation[data-theme="system-design"] .icon-button,
.presentation[data-theme="q-a"] .icon-button,
.presentation[data-theme="ai-era"] .control-button:not(.primary),
.presentation[data-theme="system-design"] .control-button:not(.primary),
.presentation[data-theme="q-a"] .control-button:not(.primary) {
    color: #fff;
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.16);
}

.presentation[data-theme="ai-era"] .slide-status,
.presentation[data-theme="system-design"] .slide-status,
.presentation[data-theme="q-a"] .slide-status,
.presentation[data-theme="ai-era"] .keyboard-hint,
.presentation[data-theme="system-design"] .keyboard-hint,
.presentation[data-theme="q-a"] .keyboard-hint {
    color: rgba(255, 255, 255, 0.58);
}

/* Career: editorial roadmap */
.slide[data-section="Career Timeline"] {
    overflow: hidden;
}

.slide[data-section="Career Timeline"]::before {
    content: "";
    position: absolute;
    z-index: -1;
    top: -17vw;
    right: -10vw;
    width: 42vw;
    height: 42vw;
    border: 2px solid rgba(240, 120, 30, 0.16);
    border-radius: 50%;
    box-shadow:
        0 0 0 45px rgba(240, 120, 30, 0.045),
        0 0 0 90px rgba(240, 120, 30, 0.03);
}

.slide[data-section="Career Timeline"] .kicker {
    color: #d95f0e;
}

.slide[data-section="Career Timeline"] h2 {
    color: #3d2416;
    font-family: Georgia, "Times New Roman", serif;
    font-weight: 700;
    letter-spacing: -0.05em;
}

.slide[data-section="Career Timeline"] .degree-timeline {
    position: relative;
    gap: 0;
    padding: 26px 0;
}

.slide[data-section="Career Timeline"] .degree-timeline::before {
    content: "";
    position: absolute;
    top: 126px;
    left: 2%;
    right: 2%;
    height: 5px;
    background: linear-gradient(90deg, #f5b971, #ef7c2d, #d94928);
    border-radius: 10px;
    transform: translateY(-50%);
    box-shadow: 0 5px 16px rgba(217, 95, 14, 0.18);
}

.slide[data-section="Career Timeline"] .year-block {
    gap: 12px;
    padding: 35px 10px 0;
}

.slide[data-section="Career Timeline"] .year-label {
    left: 10px;
    color: #9a5b32;
}

.slide[data-section="Career Timeline"] .semester {
    position: relative;
    z-index: 2;
    min-height: 130px;
    background: rgba(255, 253, 248, 0.94);
    border: 0;
    box-shadow: 0 16px 35px rgba(108, 57, 24, 0.12);
}

.slide[data-section="Career Timeline"] .semester::before {
    content: "";
    position: absolute;
    top: 50%;
    left: -9px;
    width: 12px;
    height: 12px;
    background: #ef7c2d;
    border: 4px solid #fff8ed;
    border-radius: 50%;
    transform: translateY(-50%);
}

.slide[data-section="Career Timeline"] .year-block.opportunity {
    background: rgba(232, 91, 52, 0.1);
    border: 1px solid rgba(217, 73, 40, 0.18);
}

.slide[data-section="Career Timeline"] .big-takeaway {
    color: #6f3213;
    background: #fff1d6;
    border-color: rgba(217, 95, 14, 0.25);
}

.slide[data-section="Career Timeline"] .question-banner {
    background: linear-gradient(115deg, #3d2416, #9b3e18);
}

.slide[data-section="Career Timeline"] .semester-scale span {
    color: #6f3213;
    background: rgba(255, 253, 248, 0.92);
    border-color: rgba(217, 95, 14, 0.16);
}

.slide[data-section="Career Timeline"] .preparation-band {
    background: linear-gradient(120deg, #492919, #d95f0e);
    box-shadow: 0 20px 45px rgba(145, 63, 16, 0.24);
}

.slide[data-section="Career Timeline"] .preparation-topics span {
    background: rgba(255, 255, 255, 0.12);
}

.slide[data-section="Career Timeline"] .preparation-topics i {
    color: #ffd166;
}

.slide[data-section="Career Timeline"] .si-interview-window,
.slide[data-section="Career Timeline"] .timeline-summer-internship,
.slide[data-section="Career Timeline"] .summer-marker {
    background: #fffaf0;
}

.active[data-section="Career Timeline"] .degree-timeline {
    animation: career-track-in 0.8s ease both;
}

@keyframes career-track-in {
    from { opacity: 0; transform: translateX(-45px); }
    to { opacity: 1; transform: translateX(0); }
}

/* Skills: dimensional learning stack */
.slide[data-section="What to Learn"]::before {
    content: "";
    position: absolute;
    z-index: -1;
    inset: 12% 8%;
    background: conic-gradient(from 90deg, rgba(125, 92, 255, 0.12), rgba(34, 211, 238, 0.08), rgba(125, 92, 255, 0.12));
    filter: blur(35px);
    border-radius: 50%;
    animation: breathe 5s ease-in-out infinite;
}

@keyframes breathe {
    50% { transform: scale(1.08); opacity: 0.72; }
}

.slide[data-section="What to Learn"] .kicker {
    color: #7548e8;
}

.slide[data-section="What to Learn"] h2 {
    color: #271653;
}

.slide[data-section="What to Learn"] .pillar-grid {
    perspective: 1100px;
}

.slide[data-section="What to Learn"] .pillar-card {
    min-height: 315px;
    overflow: hidden;
    background: rgba(255, 255, 255, 0.72);
    border: 1px solid rgba(117, 72, 232, 0.18);
    backdrop-filter: blur(14px);
    transform-style: preserve-3d;
}

.slide[data-section="What to Learn"] .pillar-card::after {
    content: "";
    position: absolute;
    right: -60px;
    bottom: -60px;
    width: 150px;
    height: 150px;
    background: radial-gradient(circle, rgba(117, 72, 232, 0.24), transparent 65%);
}

.slide[data-section="What to Learn"] .pillar-card:nth-child(2) {
    transform: translateY(-20px);
}

.slide[data-section="What to Learn"] .pillar-icon {
    background: linear-gradient(145deg, #7548e8, #4f2db8);
    box-shadow: 0 12px 28px rgba(117, 72, 232, 0.3);
}

.slide[data-section="What to Learn"] .formula {
    color: #3a236e;
}

/* AI: neon evolution lab */
.slide[data-section="AI Era"] h2,
.slide[data-section="AI Era"] .statement {
    color: #f8fbff;
}

.slide[data-section="AI Era"] .kicker {
    color: var(--cyan);
}

.slide[data-section="AI Era"]::before {
    content: "";
    position: absolute;
    z-index: -1;
    top: 14%;
    left: 7%;
    width: 300px;
    height: 300px;
    background: rgba(20, 87, 255, 0.16);
    border: 1px solid rgba(34, 211, 238, 0.22);
    border-radius: 42% 58% 62% 38%;
    filter: blur(2px);
    animation: ai-blob 9s ease-in-out infinite alternate;
}

@keyframes ai-blob {
    to { transform: translate(60vw, 18vh) rotate(140deg) scale(0.72); border-radius: 65% 35% 38% 62%; }
}

.slide[data-section="AI Era"] .ai-evolution {
    position: relative;
    gap: 8px;
}

.slide[data-section="AI Era"] .ai-evolution::before {
    content: "";
    position: absolute;
    z-index: -1;
    top: 50%;
    left: 3%;
    right: 3%;
    height: 2px;
    background: linear-gradient(90deg, transparent, var(--cyan), var(--blue), var(--cyan), transparent);
    box-shadow: 0 0 20px rgba(34, 211, 238, 0.6);
}

.slide[data-section="AI Era"] .evolution-step {
    position: relative;
    min-height: 230px;
    color: #f5f8ff;
    background: rgba(7, 28, 77, 0.72);
    border: 1px solid rgba(34, 211, 238, 0.24);
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.28), inset 0 1px rgba(255, 255, 255, 0.08);
    backdrop-filter: blur(18px);
}

.slide[data-section="AI Era"] .evolution-step:nth-of-type(4n + 1) {
    transform: translateY(-17px);
}

.slide[data-section="AI Era"] .evolution-step:nth-of-type(4n + 3) {
    transform: translateY(17px);
}

.slide[data-section="AI Era"] .evolution-step::after {
    content: "";
    position: absolute;
    inset: -1px;
    z-index: -1;
    opacity: 0;
    background: linear-gradient(145deg, rgba(34, 211, 238, 0.25), transparent 45%);
    border-radius: inherit;
    animation: ai-node-glow 3s ease-in-out infinite;
}

.slide[data-section="AI Era"] .evolution-step span,
.slide[data-section="AI Era"] .evolution-step i {
    color: var(--cyan);
}

.slide[data-section="AI Era"] .evolution-step strong {
    color: #fff;
}

.slide[data-section="AI Era"] .evolution-step small,
.slide[data-section="AI Era"] .evolution-caption,
.slide[data-section="AI Era"] .statement-sub {
    color: rgba(230, 239, 255, 0.68);
}

.slide[data-section="AI Era"] .evolution-arrow {
    color: var(--cyan);
    text-shadow: 0 0 14px var(--cyan);
}

@keyframes ai-node-glow {
    50% { opacity: 1; }
}

.slide[data-section="AI Era"].statement-slide {
    background: radial-gradient(circle at center, rgba(20, 87, 255, 0.2), transparent 45%);
}

.slide[data-section="AI Era"] .statement-mark {
    animation: float 3s ease-in-out infinite, neon-pulse 2s ease-in-out infinite;
}

@keyframes neon-pulse {
    50% { box-shadow: 0 0 55px rgba(34, 211, 238, 0.6), 0 0 100px rgba(20, 87, 255, 0.28); }
}

/* System design: live network topology */
.slide[data-section="System Design"] h2 {
    color: #eafff7;
    font-family: Consolas, "Segoe UI", sans-serif;
    letter-spacing: -0.055em;
}

.slide[data-section="System Design"] .kicker {
    color: #39efb2;
}

.slide[data-section="System Design"] .system-diagram {
    position: relative;
    overflow: hidden;
    background: rgba(2, 25, 25, 0.74);
    border: 1px solid rgba(57, 239, 178, 0.22);
    box-shadow: inset 0 0 55px rgba(57, 239, 178, 0.035), 0 25px 55px rgba(0, 0, 0, 0.25);
    backdrop-filter: blur(12px);
}

.slide[data-section="System Design"] .system-users,
.slide[data-section="System Design"] .server-node,
.slide[data-section="System Design"] .database-node,
.slide[data-section="System Design"] .diagram-users,
.slide[data-section="System Design"] .load-balancer,
.slide[data-section="System Design"] .mini-server {
    color: #ecfff8;
    background: rgba(4, 47, 43, 0.88);
    border-color: rgba(57, 239, 178, 0.25);
    box-shadow: 0 0 28px rgba(18, 183, 106, 0.1), inset 0 1px rgba(255, 255, 255, 0.05);
}

.slide[data-section="System Design"] .system-users i,
.slide[data-section="System Design"] .server-node i,
.slide[data-section="System Design"] .database-node i,
.slide[data-section="System Design"] .diagram-users i,
.slide[data-section="System Design"] .load-balancer i {
    color: #39efb2;
}

.slide[data-section="System Design"] .system-users strong,
.slide[data-section="System Design"] .server-node strong,
.slide[data-section="System Design"] .database-node strong,
.slide[data-section="System Design"] .diagram-users strong,
.slide[data-section="System Design"] .load-balancer strong {
    color: #fff;
}

.slide[data-section="System Design"] .system-users span,
.slide[data-section="System Design"] .server-node span,
.slide[data-section="System Design"] .request-arrow span,
.slide[data-section="System Design"] .load-balancer span {
    color: rgba(224, 255, 245, 0.58);
}

.slide[data-section="System Design"] .request-arrow {
    position: relative;
    width: 130px;
    height: 55px;
    display: grid;
    place-items: center;
}

.slide[data-section="System Design"] .request-arrow i {
    color: rgba(57, 239, 178, 0.34);
}

.slide[data-section="System Design"] .request-arrow::after {
    content: "●";
    position: absolute;
    top: 25px;
    left: 0;
    color: #39efb2;
    font-size: 0.7rem;
    text-shadow: 0 0 12px #39efb2;
    animation: packet-flow 1.6s linear infinite;
}

@keyframes packet-flow {
    from { transform: translateX(0); opacity: 0; }
    15%, 85% { opacity: 1; }
    to { transform: translateX(120px); opacity: 0; }
}

.slide[data-section="System Design"] .crowd > i {
    color: #39efb2;
    filter: drop-shadow(0 0 18px rgba(57, 239, 178, 0.45));
}

.slide[data-section="System Design"] .crowd strong {
    color: #fff;
}

.slide[data-section="System Design"] .request-stream {
    color: #ff6b6b;
    text-shadow: 0 0 16px rgba(255, 107, 107, 0.65);
}

.slide[data-section="System Design"] .server-node.danger {
    background: rgba(77, 16, 20, 0.7);
    border-color: #ff6b6b;
    box-shadow: 0 0 45px rgba(255, 73, 73, 0.22);
}

.slide[data-section="System Design"] .server-node.danger small {
    color: rgba(255, 231, 231, 0.65);
}

.slide[data-section="System Design"] .problem-chips span,
.slide[data-section="System Design"] .benefit-row span,
.slide[data-section="System Design"] .big-takeaway {
    color: #ddfff3;
    background: rgba(4, 47, 43, 0.78);
    border-color: rgba(57, 239, 178, 0.22);
}

.slide[data-section="System Design"] .load-balancer-diagram {
    position: relative;
    padding: 30px;
    background: rgba(2, 25, 25, 0.68);
    border: 1px solid rgba(57, 239, 178, 0.2);
    border-radius: 28px;
    box-shadow: 0 25px 55px rgba(0, 0, 0, 0.24);
}

.slide[data-section="System Design"] .load-balancer {
    position: relative;
    background: linear-gradient(145deg, #08785e, #045241);
    box-shadow: 0 0 45px rgba(57, 239, 178, 0.22);
}

.slide[data-section="System Design"] .load-balancer::before {
    content: "";
    position: absolute;
    inset: -14px;
    border: 1px solid rgba(57, 239, 178, 0.3);
    border-radius: 28px;
    animation: topology-pulse 2.2s ease-out infinite;
}

@keyframes topology-pulse {
    to { transform: scale(1.13); opacity: 0; }
}

.slide[data-section="System Design"] .branch-lines span {
    position: relative;
    overflow: hidden;
    background: rgba(57, 239, 178, 0.22);
}

.slide[data-section="System Design"] .branch-lines span::after {
    content: "";
    position: absolute;
    inset: 0;
    width: 35%;
    background: linear-gradient(90deg, transparent, #39efb2, transparent);
    animation: branch-flow 1.8s linear infinite;
}

.slide[data-section="System Design"] .branch-lines span:nth-child(2)::after { animation-delay: 0.4s; }
.slide[data-section="System Design"] .branch-lines span:nth-child(3)::after { animation-delay: 0.8s; }

@keyframes branch-flow {
    from { transform: translateX(-100%); }
    to { transform: translateX(340%); }
}

.slide[data-section="System Design"] .mini-server i {
    color: #39efb2;
}

.active[data-section="System Design"] .server-node,
.active[data-section="System Design"] .database-node,
.active[data-section="System Design"] .load-balancer {
    animation: node-arrive 0.7s cubic-bezier(0.2, 0.8, 0.2, 1) both;
}

@keyframes node-arrive {
    from { opacity: 0; transform: scale(0.72); }
    to { opacity: 1; transform: scale(1); }
}

/* College: growth journey */
.slide[data-section="College Roadmap"]::before {
    content: "";
    position: absolute;
    z-index: -1;
    right: -8%;
    bottom: -40%;
    width: 70%;
    height: 75%;
    background: #c9f2d7;
    border-radius: 50% 50% 0 0;
    transform: rotate(-8deg);
}

.slide[data-section="College Roadmap"] .kicker {
    color: #087a55;
}

.slide[data-section="College Roadmap"] h2 {
    color: #113d2d;
    font-family: Georgia, "Times New Roman", serif;
}

.slide[data-section="College Roadmap"] .college-roadmap {
    position: relative;
}

.slide[data-section="College Roadmap"] .roadmap-half {
    position: relative;
    overflow: hidden;
    border: 0;
    box-shadow: 0 20px 45px rgba(18, 93, 62, 0.12);
}

.slide[data-section="College Roadmap"] .learn-half {
    background: rgba(255, 255, 255, 0.9);
}

.slide[data-section="College Roadmap"] .build-half {
    background: linear-gradient(145deg, #0b5b43, #07845e);
}

.slide[data-section="College Roadmap"] .roadmap-icon {
    background: #0a8f65;
    box-shadow: 0 12px 28px rgba(10, 143, 101, 0.24);
}

.slide[data-section="College Roadmap"] .roadmap-chevron {
    color: #0a8f65;
    animation: journey-arrow 1.4s ease-in-out infinite;
}

@keyframes journey-arrow {
    50% { transform: translateX(8px); }
}

/* Rubyx: premium brand stage */
.slide[data-section="Rubyx"]::before {
    content: "";
    position: absolute;
    z-index: -1;
    top: -180px;
    right: -100px;
    width: 520px;
    height: 520px;
    border: 1px solid rgba(20, 87, 255, 0.16);
    border-radius: 50%;
    box-shadow: 0 0 0 55px rgba(20, 87, 255, 0.04), 0 0 0 110px rgba(20, 87, 255, 0.025);
    animation: spin 24s linear infinite;
}

.slide[data-section="Rubyx"] .kicker {
    color: #1457ff;
}

.slide[data-section="Rubyx"] .rubyx-focus-card,
.slide[data-section="Rubyx"] .support-card {
    backdrop-filter: blur(14px);
}

.slide[data-section="Rubyx"] .institute-focus {
    background: rgba(255, 255, 255, 0.78);
}

.slide[data-section="Rubyx"] .startup-focus {
    background: linear-gradient(145deg, #071c4d, #174dc0);
    box-shadow: 0 25px 60px rgba(7, 28, 77, 0.24);
}

.active[data-section="Rubyx"] .startup-products > div {
    animation: product-float 3s ease-in-out infinite;
}

.active[data-section="Rubyx"] .startup-products > div:nth-child(2) {
    animation-delay: 0.5s;
}

@keyframes product-float {
    50% { transform: translateY(-7px); }
}

/* Q&A: immersive closing stage */
.slide[data-section="Q&A"] h2,
.slide[data-section="Q&A"] .qna-copy,
.slide[data-section="Q&A"] .qna-footer {
    color: #fff;
}

.slide[data-section="Q&A"] .qna-orb {
    box-shadow:
        0 0 0 20px rgba(34, 211, 238, 0.08),
        0 0 0 42px rgba(34, 211, 238, 0.04),
        0 0 90px rgba(34, 211, 238, 0.48);
}

.qna-layout {
    width: min(1180px, 100%);
    display: grid;
    grid-template-columns: minmax(0, 1.25fr) minmax(290px, 0.75fr);
    align-items: center;
    gap: clamp(45px, 7vw, 100px);
}

.qna-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

.jobs-qr-card {
    position: relative;
    padding: 24px;
    text-align: center;
    background: rgba(255, 255, 255, 0.92);
    border: 1px solid rgba(20, 87, 255, 0.14);
    border-radius: 28px;
    box-shadow: 0 25px 60px rgba(7, 28, 77, 0.14);
}

.jobs-qr-card::before {
    content: "";
    position: absolute;
    inset: -10px;
    z-index: -1;
    border: 1px solid rgba(34, 211, 238, 0.3);
    border-radius: 35px;
    animation: qr-pulse 2.5s ease-out infinite;
}

@keyframes qr-pulse {
    to { transform: scale(1.05); opacity: 0; }
}

.qr-badge {
    width: fit-content;
    margin: 0 auto 15px;
    padding: 7px 12px;
    color: #087a55;
    font-size: 0.72rem;
    font-weight: 900;
    background: #e8fff5;
    border-radius: 100px;
}

.qr-badge i {
    margin-right: 5px;
}

.jobs-qr-card > img {
    display: block;
    width: min(245px, 75%);
    aspect-ratio: 1;
    margin: 0 auto 16px;
    object-fit: contain;
    background: #fff;
    border: 10px solid #fff;
    border-radius: 18px;
    box-shadow: 0 12px 28px rgba(7, 28, 77, 0.12);
}

.jobs-qr-card h3 {
    color: var(--navy);
    font-size: 1.35rem;
}

.jobs-qr-card p {
    max-width: 320px;
    margin: 8px auto 14px;
    color: var(--muted);
    font-size: 0.86rem;
    line-height: 1.5;
}

.scan-hint {
    color: var(--blue);
    font-size: 0.72rem;
    font-weight: 800;
}

.scan-hint i {
    margin-right: 5px;
}

/* Segment-specific entrance motion */
.active[data-section="AI Era"] .reveal {
    animation-name: ai-reveal;
}

.active[data-section="System Design"] .reveal {
    animation-name: system-reveal;
}

.active[data-section="College Roadmap"] .reveal {
    animation-name: college-reveal;
}

@keyframes ai-reveal {
    from { opacity: 0; transform: translateY(12px) scale(0.94); filter: blur(8px); }
    to { opacity: 1; transform: translateY(0) scale(1); filter: blur(0); }
}

@keyframes system-reveal {
    from { opacity: 0; transform: translateX(-28px); }
    to { opacity: 1; transform: translateX(0); }
}

@keyframes college-reveal {
    from { opacity: 0; transform: translateY(35px) rotate(-1deg); }
    to { opacity: 1; transform: translateY(0) rotate(0); }
}

/* Light professional revision for AI, systems and closing */
.presentation[data-theme="ai-era"] {
    color: var(--ink);
    background:
        radial-gradient(circle at 14% 16%, rgba(34, 211, 238, 0.18), transparent 26%),
        radial-gradient(circle at 88% 82%, rgba(20, 87, 255, 0.12), transparent 30%),
        linear-gradient(135deg, #fbfdff, #edf5ff);
}

.presentation[data-theme="system-design"] {
    color: var(--ink);
    background:
        linear-gradient(rgba(20, 87, 255, 0.045) 1px, transparent 1px),
        linear-gradient(90deg, rgba(20, 87, 255, 0.045) 1px, transparent 1px),
        radial-gradient(circle at 82% 12%, rgba(18, 183, 106, 0.12), transparent 28%),
        #f8fcff;
    background-size: 42px 42px, 42px 42px, auto, auto;
}

.presentation[data-theme="q-a"] {
    color: var(--ink);
    background:
        radial-gradient(circle at center, rgba(34, 211, 238, 0.18), transparent 35%),
        linear-gradient(145deg, #f9fcff, #e6f1ff);
}

.presentation[data-theme="ai-era"]::before,
.presentation[data-theme="system-design"]::before,
.presentation[data-theme="q-a"]::before {
    opacity: 0.22;
    background-image:
        linear-gradient(rgba(20, 87, 255, 0.05) 1px, transparent 1px),
        linear-gradient(90deg, rgba(20, 87, 255, 0.05) 1px, transparent 1px);
}

.presentation[data-theme="ai-era"] .deck-topbar,
.presentation[data-theme="system-design"] .deck-topbar,
.presentation[data-theme="q-a"] .deck-topbar,
.presentation[data-theme="ai-era"] .back-link,
.presentation[data-theme="system-design"] .back-link,
.presentation[data-theme="q-a"] .back-link,
.presentation[data-theme="ai-era"] .deck-brand,
.presentation[data-theme="system-design"] .deck-brand,
.presentation[data-theme="q-a"] .deck-brand {
    color: var(--navy);
}

.presentation[data-theme="ai-era"] .deck-brand img,
.presentation[data-theme="system-design"] .deck-brand img,
.presentation[data-theme="q-a"] .deck-brand img {
    filter: none;
}

.presentation[data-theme="ai-era"] .icon-button,
.presentation[data-theme="system-design"] .icon-button,
.presentation[data-theme="q-a"] .icon-button,
.presentation[data-theme="ai-era"] .control-button:not(.primary),
.presentation[data-theme="system-design"] .control-button:not(.primary),
.presentation[data-theme="q-a"] .control-button:not(.primary) {
    color: var(--navy);
    background: rgba(255, 255, 255, 0.9);
    border-color: rgba(20, 87, 255, 0.14);
}

.presentation[data-theme="ai-era"] .slide-status,
.presentation[data-theme="system-design"] .slide-status,
.presentation[data-theme="q-a"] .slide-status,
.presentation[data-theme="ai-era"] .keyboard-hint,
.presentation[data-theme="system-design"] .keyboard-hint,
.presentation[data-theme="q-a"] .keyboard-hint {
    color: var(--muted);
}

.slide[data-section="AI Era"] h2,
.slide[data-section="AI Era"] .statement {
    color: var(--navy);
}

.slide[data-section="AI Era"]::before {
    background: rgba(20, 87, 255, 0.08);
    border-color: rgba(20, 87, 255, 0.14);
}

.slide[data-section="AI Era"] .evolution-step {
    color: var(--ink);
    background: rgba(255, 255, 255, 0.9);
    border-color: rgba(20, 87, 255, 0.18);
    box-shadow: 0 18px 42px rgba(7, 28, 77, 0.1);
}

.slide[data-section="AI Era"] .evolution-step strong {
    color: var(--navy);
}

.slide[data-section="AI Era"] .evolution-step small,
.slide[data-section="AI Era"] .evolution-caption,
.slide[data-section="AI Era"] .statement-sub {
    color: var(--muted);
}

.slide[data-section="AI Era"].statement-slide {
    background: radial-gradient(circle at center, rgba(20, 87, 255, 0.1), transparent 46%);
}

.slide[data-section="Q&A"] h2,
.slide[data-section="Q&A"] .qna-copy,
.slide[data-section="Q&A"] .qna-footer {
    color: var(--navy);
}

/* System architecture with recognizable virtual machines */
.slide[data-section="System Design"] h2 {
    color: var(--navy);
}

.slide[data-section="System Design"] .kicker {
    color: #087a55;
}

.architecture-stage,
.scaled-architecture {
    position: relative;
    min-height: 330px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: clamp(24px, 3.2vw, 58px);
    padding: 35px 42px;
    background: rgba(255, 255, 255, 0.78);
    border: 1px solid rgba(20, 87, 255, 0.12);
    border-radius: 30px;
    box-shadow: 0 25px 60px rgba(18, 52, 93, 0.1);
    backdrop-filter: blur(14px);
}

.architecture-stage::before,
.scaled-architecture::before {
    content: "";
    position: absolute;
    inset: 14px;
    pointer-events: none;
    border: 1px dashed rgba(20, 87, 255, 0.1);
    border-radius: 21px;
}

.client-group,
.traffic-cloud,
.traffic-source-modern {
    min-width: 175px;
    text-align: center;
}

.client-group .device {
    display: inline-grid;
    place-items: center;
    color: #fff;
    background: linear-gradient(145deg, var(--blue), #4d83ff);
    box-shadow: 0 12px 26px rgba(20, 87, 255, 0.2);
}

.client-group .laptop {
    width: 82px;
    height: 62px;
    font-size: 1.8rem;
    border-radius: 12px 12px 7px 7px;
}

.client-group .phone {
    width: 38px;
    height: 62px;
    margin-left: -8px;
    font-size: 1.25rem;
    border: 3px solid #fff;
    border-radius: 10px;
}

.client-group strong,
.client-group span,
.traffic-cloud strong,
.traffic-cloud span,
.traffic-source-modern strong {
    display: block;
}

.client-group strong,
.traffic-cloud strong,
.traffic-source-modern strong {
    margin-top: 16px;
    color: var(--navy);
}

.client-group span,
.traffic-cloud span {
    margin-top: 5px;
    color: var(--muted);
    font-size: 0.76rem;
}

.data-route {
    position: relative;
    width: clamp(100px, 10vw, 175px);
    height: 4px;
    background: linear-gradient(90deg, rgba(20, 87, 255, 0.15), rgba(20, 87, 255, 0.5));
    border-radius: 10px;
}

.data-route::after {
    content: "";
    position: absolute;
    top: 50%;
    right: -1px;
    width: 9px;
    height: 9px;
    border-top: 3px solid var(--blue);
    border-right: 3px solid var(--blue);
    transform: translateY(-50%) rotate(45deg);
}

.route-label {
    position: absolute;
    left: 50%;
    bottom: 13px;
    color: var(--muted);
    font-size: 0.68rem;
    font-weight: 800;
    letter-spacing: 0.08em;
    transform: translateX(-50%);
}

.packet {
    position: absolute;
    top: -4px;
    left: 0;
    width: 12px;
    height: 12px;
    background: var(--blue);
    border: 3px solid #dce8ff;
    border-radius: 50%;
    box-shadow: 0 0 13px rgba(20, 87, 255, 0.48);
    animation: vm-packet 2.2s linear infinite;
}

.packet-two { animation-delay: 0.7s; }
.packet-three { animation-delay: 1.4s; }

@keyframes vm-packet {
    from { transform: translateX(0); opacity: 0; }
    12%, 88% { opacity: 1; }
    to { transform: translateX(clamp(88px, 9vw, 160px)); opacity: 0; }
}

.short-route {
    width: clamp(70px, 7vw, 120px);
}

.vm-machine {
    position: relative;
    width: 210px;
    min-height: 245px;
    padding: 16px;
    color: var(--navy);
    background: linear-gradient(145deg, #f8fbff, #e9f0fa);
    border: 1px solid #cbd8eb;
    border-bottom: 7px solid #aebdd2;
    border-radius: 18px 18px 13px 13px;
    box-shadow:
        0 22px 38px rgba(18, 52, 93, 0.16),
        inset 0 1px #fff;
}

.vm-machine::before {
    content: "";
    position: absolute;
    top: 10px;
    bottom: 10px;
    left: 7px;
    width: 3px;
    background: linear-gradient(#d6e1ef, #fff, #d6e1ef);
    border-radius: 4px;
}

.vm-top {
    display: flex;
    align-items: center;
    gap: 7px;
    padding-left: 5px;
    color: var(--muted);
}

.vm-status {
    width: 9px;
    height: 9px;
    background: var(--success);
    border-radius: 50%;
    box-shadow: 0 0 10px rgba(18, 183, 106, 0.65);
    animation: status-blink 1.8s ease-in-out infinite;
}

@keyframes status-blink {
    50% { opacity: 0.45; }
}

.vm-screen {
    min-height: 105px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 10px;
    margin: 14px 0;
    color: #dff9ff;
    background:
        linear-gradient(rgba(34, 211, 238, 0.06) 1px, transparent 1px),
        #09254d;
    background-size: 100% 15px;
    border: 5px solid #d7e2ef;
    border-radius: 10px;
    box-shadow: inset 0 0 18px rgba(34, 211, 238, 0.13);
}

.vm-screen i {
    color: var(--cyan);
    font-size: 1.45rem;
}

.vm-specs {
    display: flex;
    justify-content: space-between;
    color: var(--muted);
    font-size: 0.66rem;
    font-weight: 800;
}

.vm-vents {
    display: flex;
    gap: 5px;
    margin-top: 14px;
}

.vm-vents i {
    width: 20px;
    height: 4px;
    background: #9fafc3;
    border-radius: 5px;
}

.database-system {
    min-width: 170px;
    text-align: center;
}

.database-disks {
    position: relative;
    width: 118px;
    height: 135px;
    margin: 0 auto 15px;
}

.database-disks i {
    position: absolute;
    left: 0;
    width: 118px;
    height: 56px;
    background: linear-gradient(145deg, #22a9e8, #1457ff);
    border: 2px solid #fff;
    border-radius: 50%;
    box-shadow: 0 14px 25px rgba(20, 87, 255, 0.16);
}

.database-disks i:nth-child(1) { top: 0; }
.database-disks i:nth-child(2) { top: 36px; }
.database-disks i:nth-child(3) { top: 72px; }
.database-system strong,
.database-system span { display: block; }
.database-system strong { color: var(--navy); }
.database-system span { margin-top: 5px; color: var(--muted); font-size: 0.72rem; }

.user-dots {
    width: 175px;
    display: grid;
    grid-template-columns: repeat(4, 28px);
    justify-content: center;
    gap: 8px;
    margin: 0 auto;
}

.user-dots i {
    position: relative;
    width: 28px;
    height: 28px;
    background: linear-gradient(145deg, #39c99b, #087a55);
    border-radius: 50% 50% 45% 45%;
    box-shadow: 0 7px 14px rgba(8, 122, 85, 0.14);
}

.user-dots i::after {
    content: "";
    position: absolute;
    bottom: -5px;
    left: 2px;
    right: 2px;
    height: 11px;
    background: #0a9268;
    border-radius: 10px 10px 5px 5px;
}

.packet-storm {
    position: relative;
    width: clamp(170px, 16vw, 280px);
    height: 100px;
}

.packet-storm i {
    position: absolute;
    top: calc(var(--packet-row, 1) * 13px);
    left: 0;
    width: 13px;
    height: 13px;
    background: #ff635d;
    border-radius: 4px;
    box-shadow: 0 0 12px rgba(255, 99, 93, 0.35);
    animation: storm-flow 1.1s linear infinite;
}

.packet-storm i:nth-child(1) { --packet-row: 0; animation-delay: 0s; }
.packet-storm i:nth-child(2) { --packet-row: 2; animation-delay: 0.15s; }
.packet-storm i:nth-child(3) { --packet-row: 4; animation-delay: 0.3s; }
.packet-storm i:nth-child(4) { --packet-row: 1; animation-delay: 0.45s; }
.packet-storm i:nth-child(5) { --packet-row: 3; animation-delay: 0.6s; }
.packet-storm i:nth-child(6) { --packet-row: 5; animation-delay: 0.75s; }

.packet-storm span {
    position: absolute;
    left: 50%;
    bottom: -16px;
    color: #d92d20;
    font-size: 0.72rem;
    font-weight: 800;
    transform: translateX(-50%);
}

@keyframes storm-flow {
    from { transform: translateX(0) rotate(0); opacity: 0; }
    12%, 88% { opacity: 1; }
    to { transform: translateX(clamp(155px, 15vw, 260px)) rotate(180deg); opacity: 0; }
}

.overloaded-vm {
    background: linear-gradient(145deg, #fff8f7, #ffe8e5);
    border-color: #ffaaa5;
    border-bottom-color: #e77d77;
    animation: machine-shake 1.4s ease-in-out infinite;
}

.vm-alert {
    padding: 7px 9px;
    color: #b42318;
    font-size: 0.72rem;
    font-weight: 900;
    text-align: center;
    background: #fee4e2;
    border-radius: 8px;
}

.resource-meter {
    display: grid;
    grid-template-columns: 28px 1fr 32px;
    align-items: center;
    gap: 7px;
    margin-top: 9px;
    color: #b42318;
    font-size: 0.66rem;
    font-weight: 900;
}

.resource-meter > div,
.vm-load {
    height: 7px;
    overflow: hidden;
    background: #f5c5c1;
    border-radius: 10px;
}

.resource-meter > div i {
    display: block;
    height: 100%;
    background: linear-gradient(90deg, #f79009, #f04438);
}

@keyframes machine-shake {
    0%, 88%, 100% { transform: translateX(0); }
    91% { transform: translateX(-4px); }
    94% { transform: translateX(4px); }
    97% { transform: translateX(-2px); }
}

.slide[data-section="System Design"] .problem-chips span,
.slide[data-section="System Design"] .benefit-row span,
.slide[data-section="System Design"] .big-takeaway {
    color: var(--navy);
    background: rgba(255, 255, 255, 0.88);
    border-color: rgba(20, 87, 255, 0.14);
}

.scaled-architecture {
    display: grid;
    grid-template-columns: 150px 120px 210px 140px minmax(420px, 1fr);
    gap: 16px;
}

.user-dots.compact {
    width: 115px;
    grid-template-columns: repeat(3, 24px);
}

.user-dots.compact i {
    width: 24px;
    height: 24px;
}

.incoming-route {
    position: relative;
    height: 4px;
    background: rgba(20, 87, 255, 0.25);
}

.incoming-route::after {
    content: "";
    position: absolute;
    right: 0;
    top: 50%;
    width: 10px;
    height: 10px;
    border-top: 3px solid var(--blue);
    border-right: 3px solid var(--blue);
    transform: translateY(-50%) rotate(45deg);
}

.incoming-route i {
    position: absolute;
    top: -4px;
    left: 0;
    width: 12px;
    height: 12px;
    background: var(--blue);
    border-radius: 50%;
    animation: incoming-flow 1.7s linear infinite;
}

.incoming-route i:nth-child(2) { animation-delay: 0.55s; }
.incoming-route i:nth-child(3) { animation-delay: 1.1s; }

@keyframes incoming-flow {
    from { transform: translateX(0); opacity: 0; }
    15%, 85% { opacity: 1; }
    to { transform: translateX(110px); opacity: 0; }
}

.load-balancer-gateway {
    position: relative;
    min-height: 190px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    color: #fff;
    background: linear-gradient(145deg, #1457ff, #0637b5);
    border-radius: 28px;
    box-shadow: 0 22px 45px rgba(20, 87, 255, 0.25);
}

.load-balancer-gateway > i {
    margin-bottom: 16px;
    font-size: 2.2rem;
}

.load-balancer-gateway span {
    margin-top: 7px;
    color: rgba(255, 255, 255, 0.72);
    font-size: 0.68rem;
}

.gateway-ring {
    position: absolute;
    inset: -12px;
    border: 2px solid rgba(20, 87, 255, 0.24);
    border-radius: 36px;
    animation: gateway-pulse 2s ease-out infinite;
}

@keyframes gateway-pulse {
    to { transform: scale(1.1); opacity: 0; }
}

.distribution-bus {
    height: 265px;
    display: flex;
    flex-direction: column;
    justify-content: space-around;
}

.bus-line {
    position: relative;
    display: block;
    width: 140px;
    height: 4px;
    overflow: hidden;
    background: rgba(18, 183, 106, 0.18);
    border-radius: 6px;
}

.bus-line::after {
    content: "";
    position: absolute;
    right: 0;
    top: 50%;
    width: 8px;
    height: 8px;
    border-top: 3px solid var(--success);
    border-right: 3px solid var(--success);
    transform: translateY(-50%) rotate(45deg);
}

.bus-line i {
    display: block;
    width: 35%;
    height: 100%;
    background: linear-gradient(90deg, transparent, var(--success), transparent);
    animation: bus-packet 1.8s linear infinite;
}

.line-two i { animation-delay: 0.4s; }
.line-three i { animation-delay: 0.8s; }

@keyframes bus-packet {
    from { transform: translateX(-100%); }
    to { transform: translateX(380%); }
}

.vm-fleet {
    position: relative;
    display: grid;
    grid-template-columns: 1fr;
    gap: 13px;
}

.vm-fleet::before {
    content: "Parallel VM instances";
    position: absolute;
    bottom: calc(100% + 8px);
    left: 0;
    color: #087a55;
    font-size: 0.68rem;
    font-weight: 900;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.fleet-vm {
    width: 100%;
    min-width: 270px;
    min-height: 76px;
    display: grid;
    grid-template-columns: 85px 1fr;
    grid-template-rows: auto 1fr;
    align-items: center;
    column-gap: 10px;
    padding: 9px 12px;
}

.fleet-vm .vm-top {
    grid-column: 1;
    grid-row: 1;
}

.fleet-vm .vm-screen {
    grid-column: 2;
    grid-row: 1 / 3;
    min-height: 57px;
    margin: 0;
    border-width: 3px;
}

.fleet-vm .vm-screen i {
    font-size: 1rem;
}

.vm-load {
    grid-column: 1;
    grid-row: 2;
    background: #dce7f4;
}

.vm-load i {
    display: block;
    height: 100%;
    background: linear-gradient(90deg, #12b76a, #39d98a);
}

.active[data-section="System Design"] .vm-machine {
    animation: vm-boot 0.75s cubic-bezier(0.2, 0.8, 0.2, 1) both;
}

.active[data-section="System Design"] .fleet-vm:nth-child(2) { animation-delay: 0.12s; }
.active[data-section="System Design"] .fleet-vm:nth-child(3) { animation-delay: 0.24s; }

@keyframes vm-boot {
    from { opacity: 0; transform: translateY(24px) scale(0.92); }
    to { opacity: 1; transform: translateY(0) scale(1); }
}

@media (max-width: 1100px) {
    .scaled-architecture {
        grid-template-columns: 120px 80px 180px 100px minmax(330px, 1fr);
    }

    .vm-machine {
        width: 180px;
    }
}

@media (max-width: 820px) {
    .architecture-stage,
    .scaled-architecture {
        display: flex;
        flex-direction: column;
    }

    .data-route,
    .incoming-route {
        width: 4px;
        height: 70px;
    }

    .data-route::after,
    .incoming-route::after {
        right: 50%;
        top: auto;
        bottom: 0;
        transform: translateX(50%) rotate(135deg);
    }

    .vm-fleet {
        grid-template-columns: 1fr;
        width: min(360px, 100%);
    }

    .distribution-bus {
        width: 4px;
        height: 80px;
    }

    .bus-line {
        display: none;
    }

    .qna-layout {
        grid-template-columns: 1fr;
    }

    .jobs-qr-card {
        width: min(390px, 100%);
        margin: 0 auto;
    }
}

/* Stable shared timeline for slides 3–5 */
.career-board {
    width: 100%;
    padding: 22px 24px 24px;
    background: rgba(255, 252, 246, 0.82);
    border: 1px solid rgba(217, 95, 14, 0.14);
    border-radius: 25px;
    box-shadow: 0 20px 46px rgba(108, 57, 24, 0.1);
    backdrop-filter: blur(10px);
}

.career-years-row {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    margin-bottom: 8px;
}

.career-years-row span {
    padding-left: 8px;
    color: #a45a2a;
    font-size: 0.7rem;
    font-weight: 900;
    letter-spacing: 0.1em;
    text-transform: uppercase;
}

.career-semester-row {
    position: relative;
    display: grid;
    grid-template-columns: repeat(8, minmax(0, 1fr));
    gap: 10px;
}

.career-semester-row::before {
    content: "";
    position: absolute;
    z-index: 0;
    top: 21px;
    left: 2%;
    right: 2%;
    height: 4px;
    background: linear-gradient(90deg, #f7bd80, #ed7a2d, #d9552d);
    border-radius: 8px;
}

.career-semester {
    position: relative;
    z-index: 1;
    min-height: 118px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 38px 8px 15px;
    color: #4f2b19;
    text-align: center;
    background: rgba(255, 255, 255, 0.94);
    border: 1px solid rgba(217, 95, 14, 0.1);
    border-radius: 15px;
    box-shadow: 0 10px 24px rgba(108, 57, 24, 0.08);
}

.career-semester::before {
    content: "";
    position: absolute;
    top: 14px;
    left: 50%;
    width: 14px;
    height: 14px;
    background: #ed7a2d;
    border: 4px solid #fff8ed;
    border-radius: 50%;
    box-shadow: 0 0 0 1px rgba(217, 95, 14, 0.15);
    transform: translateX(-50%);
}

.career-semester b {
    position: absolute;
    right: 10px;
    bottom: 2px;
    color: rgba(217, 95, 14, 0.08);
    font-size: 2.2rem;
    line-height: 1;
}

.career-semester > i {
    color: #1457ff;
    font-size: 1.25rem;
}

.career-semester small {
    color: #1457ff;
    font-size: 0.65rem;
    font-weight: 900;
    letter-spacing: 0.06em;
    text-transform: uppercase;
}

.opportunity-semester {
    background: linear-gradient(145deg, #fff, #fff2e7);
    border-color: rgba(217, 95, 14, 0.28);
    box-shadow: 0 12px 28px rgba(217, 95, 14, 0.13);
}

.muted-semester {
    opacity: 0.52;
}

.focus-semester {
    border: 2px solid #ed7a2d;
    box-shadow: 0 14px 30px rgba(217, 95, 14, 0.18);
}

.career-event-row {
    display: grid;
    grid-template-columns: repeat(8, minmax(0, 1fr));
    gap: 10px;
    margin-top: 20px;
}

.career-event {
    position: relative;
    display: flex;
    align-items: center;
    gap: 12px;
    min-height: 75px;
    padding: 14px 17px;
    color: #4f2b19;
    background: #fff;
    border: 1px solid rgba(217, 95, 14, 0.22);
    border-radius: 15px;
    box-shadow: 0 12px 26px rgba(108, 57, 24, 0.09);
}

.career-event > i {
    flex: 0 0 auto;
    color: #ed7a2d;
    font-size: 1.35rem;
}

.career-event strong,
.career-event span {
    display: block;
}

.career-event span {
    margin-top: 4px;
    color: #8b5e45;
    font-size: 0.7rem;
    line-height: 1.35;
}

.summer-event {
    grid-column: 6 / 8;
    width: 245px;
    justify-self: center;
    border: 2px solid #f3a11c;
    background: #fffaf0;
}

.summer-event::before,
.internship-event::before {
    content: "";
    position: absolute;
    bottom: 100%;
    left: 50%;
    width: 3px;
    height: 21px;
    background: #f3a11c;
    transform: translateX(-50%);
}

.internship-event::before {
    left: 0;
}

.compact-semesters .career-semester {
    min-height: 64px;
    justify-content: flex-end;
    padding: 31px 6px 9px;
    font-size: 0.78rem;
}

.preparation-events {
    align-items: stretch;
}

.preparation-event {
    grid-column: 1 / 5;
    display: block;
    color: #fff;
    background: linear-gradient(120deg, #4b291a, #d95f0e);
    border: 0;
    box-shadow: 0 18px 38px rgba(145, 63, 16, 0.22);
}

.event-title {
    display: flex;
    align-items: center;
    gap: 9px;
}

.event-title i {
    color: #ffd166;
}

.event-skills {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 8px;
    margin: 12px 0 10px;
}

.event-skills span {
    margin: 0;
    padding: 9px 8px;
    color: #fff;
    text-align: center;
    font-size: 0.72rem;
    font-weight: 800;
    background: rgba(255, 255, 255, 0.12);
    border: 1px solid rgba(255, 255, 255, 0.16);
    border-radius: 9px;
}

.event-skills i {
    margin-right: 4px;
    color: #ffd166;
}

.preparation-event small {
    color: rgba(255, 255, 255, 0.74);
    font-size: 0.66rem;
    font-weight: 700;
}

.interview-event {
    grid-column: 5 / 7;
    border: 2px dashed #ed7a2d;
    background: #fffaf0;
}

.internship-event {
    grid-column: 7 / 9;
    border: 2px solid #f3a11c;
    background: #fffaf0;
}

.internship-board {
    padding-bottom: 17px;
}

.preparation-board {
    padding-bottom: 20px;
}

.slide[data-section="Career Timeline"] .question-banner {
    margin-top: 20px;
}

.slide[data-section="Career Timeline"] .career-board + .big-takeaway {
    margin-top: 24px;
}

@media (max-width: 1000px) {
    .career-board {
        overflow-x: auto;
    }

    .career-years-row,
    .career-semester-row,
    .career-event-row {
        min-width: 900px;
    }
}