/* ViVek intro landing — modern product page */

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

html {
    scroll-behavior: smooth;
}

body.intro-page {
    background: var(--bg-primary);
    color: var(--text-primary);
    font-family: var(--font-sans);
    min-height: 100vh;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

/* ── Ambient background ── */
.intro-bg {
    position: fixed;
    inset: 0;
    z-index: 0;
    pointer-events: none;
    overflow: hidden;
}

.intro-bg__mesh {
    position: absolute;
    inset: -20%;
    background:
        radial-gradient(ellipse 55% 45% at 15% 20%, rgba(255, 111, 97, 0.11), transparent 55%),
        radial-gradient(ellipse 50% 40% at 85% 15%, rgba(61, 184, 176, 0.09), transparent 50%),
        radial-gradient(ellipse 60% 50% at 70% 80%, rgba(255, 111, 97, 0.06), transparent 55%);
    animation: introMeshDrift 22s ease-in-out infinite alternate;
}

.intro-bg__grid {
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(255, 255, 255, 0.025) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.025) 1px, transparent 1px);
    background-size: 48px 48px;
    mask-image: radial-gradient(ellipse 80% 70% at 50% 30%, black 20%, transparent 75%);
}

@keyframes introMeshDrift {
    from { transform: translate(0, 0) scale(1); }
    to { transform: translate(-2%, 2%) scale(1.03); }
}

/* ── Header ── */
.intro-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px clamp(20px, 4vw, 48px);
    transition: background 0.35s ease, border-color 0.35s ease, box-shadow 0.35s ease;
}

.intro-header.is-scrolled {
    background: rgba(19, 17, 16, 0.82);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.25);
}

.intro-brand {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
    color: inherit;
}

.intro-brand__mark {
    width: 36px;
    height: 36px;
    flex-shrink: 0;
}

.intro-brand:hover .intro-brand__mark.vivek-logo {
    background-color: var(--accent-hover, #ff8579);
}

.intro-brand__text {
    font-weight: 600;
    font-size: 1.05rem;
    letter-spacing: -0.02em;
}

.intro-nav {
    display: flex;
    align-items: center;
    gap: 10px;
}

.intro-btn {
    appearance: none;
    border: 1px solid transparent;
    background: transparent;
    color: var(--text-secondary);
    font-family: inherit;
    font-size: 0.9rem;
    font-weight: 500;
    padding: 9px 18px;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: color 0.2s, background 0.2s, border-color 0.2s, transform 0.2s, box-shadow 0.2s;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.intro-btn:hover {
    color: var(--text-primary);
}

.intro-btn--ghost {
    border-color: var(--border);
}

.intro-btn--ghost:hover {
    border-color: var(--border-hover);
    background: rgba(255, 255, 255, 0.04);
}

.intro-btn--primary {
    background: var(--accent);
    color: #fff;
    border-color: var(--accent);
    font-weight: 600;
    box-shadow: 0 4px 20px rgba(255, 111, 97, 0.28);
}

.intro-btn--primary:hover {
    background: var(--accent-hover);
    transform: translateY(-1px);
    box-shadow: 0 6px 24px rgba(255, 111, 97, 0.38);
    color: #fff;
}

.intro-btn--lg {
    padding: 13px 26px;
    font-size: 0.95rem;
    border-radius: var(--radius-md);
}

/* ── Layout shell ── */
.intro-main {
    position: relative;
    z-index: 1;
}

.intro-section {
    padding: clamp(64px, 10vw, 120px) clamp(20px, 4vw, 48px);
    max-width: 1200px;
    margin: 0 auto;
}

.intro-section--hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 100px;
    padding-bottom: 80px;
}

/* ── Hero ── */
.intro-hero {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: clamp(40px, 6vw, 72px);
    align-items: center;
    width: 100%;
}

.intro-hero__copy {
    max-width: 560px;
}

.intro-eyebrow {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-family: var(--font-mono);
    font-size: 0.72rem;
    font-weight: 500;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--vivek-secondary);
    background: var(--vivek-secondary-muted);
    border: 1px solid rgba(61, 184, 176, 0.25);
    padding: 6px 12px;
    border-radius: 999px;
    margin-bottom: 24px;
}

.intro-eyebrow__dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--vivek-secondary);
    animation: introPulse 2s ease-in-out infinite;
}

@keyframes introPulse {
    0%, 100% { opacity: 1; transform: scale(1); }
    50% { opacity: 0.5; transform: scale(0.85); }
}

.intro-headline {
    font-size: clamp(2.25rem, 5vw, 3.35rem);
    font-weight: 700;
    line-height: 1.1;
    letter-spacing: -0.03em;
    margin-bottom: 20px;
}

.intro-headline__accent {
    background: linear-gradient(135deg, var(--accent) 0%, #ff9a8b 45%, var(--vivek-secondary) 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.intro-subhead {
    font-size: clamp(1rem, 2vw, 1.15rem);
    line-height: 1.65;
    color: var(--text-secondary);
    margin-bottom: 32px;
    max-width: 48ch;
}

.intro-cta-row {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-bottom: 36px;
}

.intro-trust {
    display: flex;
    flex-wrap: wrap;
    gap: 10px 20px;
}

.intro-trust__item {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.82rem;
    color: var(--text-secondary);
}

.intro-trust__item svg {
    width: 16px;
    height: 16px;
    color: var(--vivek-secondary);
    flex-shrink: 0;
}

/* ── Product mock ── */
.intro-mock {
    position: relative;
    width: 100%;
    cursor: pointer;
}

.intro-mock__glow {
    position: absolute;
    inset: -12% -8%;
    background: radial-gradient(circle, rgba(255, 111, 97, 0.12), transparent 65%);
    filter: blur(40px);
    pointer-events: none;
    z-index: 0;
}

.intro-mock__stage {
    position: relative;
    z-index: 1;
    width: 100%;
    height: 330px;
    touch-action: manipulation;
}

.intro-mock__frame {
    display: none !important;
    width: 100%;
    height: 100%;
    overflow: auto;
    background: rgba(28, 25, 23, 0.92);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: var(--radius-xl);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    box-shadow:
        0 0 0 1px rgba(255, 255, 255, 0.04) inset,
        0 24px 80px rgba(0, 0, 0, 0.45);
}

.intro-mock__frame.is-active {
    display: block !important;
}

.intro-mock__frame[hidden] {
    display: none !important;
}

.intro-mock__indicators {
    display: flex;
    justify-content: center;
    gap: 6px;
    margin-top: 14px;
    position: relative;
    z-index: 2;
}

.intro-mock__indicator {
    width: 6px;
    height: 6px;
    border-radius: 999px;
    border: none;
    padding: 0;
    background: rgba(255, 255, 255, 0.18);
    cursor: pointer;
    transition: width 0.25s ease, background 0.25s ease;
}

.intro-mock__indicator.is-active {
    width: 18px;
    background: var(--accent);
}

.intro-mock__chrome {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
    background: rgba(0, 0, 0, 0.2);
}

.intro-mock__chrome-mark {
    flex-shrink: 0;
    width: 32px;
    height: 20px;
    border-radius: 5px;
    border: 1px solid rgba(255, 255, 255, 0.1);
    background: linear-gradient(180deg, rgba(255, 255, 255, 0.06), rgba(255, 255, 255, 0.02));
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.05);
}

.intro-mock__title {
    flex: 1;
    text-align: center;
    font-family: var(--font-mono);
    font-size: 0.72rem;
    color: var(--text-secondary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.intro-mock__chrome-tag {
    flex-shrink: 0;
    font-family: var(--font-mono);
    font-size: 0.62rem;
    font-weight: 500;
    letter-spacing: 0.04em;
    text-transform: uppercase;
    color: var(--vivek-secondary);
    background: var(--vivek-secondary-muted);
    border: 1px solid rgba(61, 184, 176, 0.2);
    padding: 4px 8px;
    border-radius: 6px;
}

.intro-mock__viewport,
.intro-mock__track,
.intro-mock__slide {
    display: none;
}

.intro-mock__body {
    padding: 18px 20px 20px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    height: calc(100% - 49px);
    box-sizing: border-box;
}

.intro-mock__body--chat,
.intro-mock__body--mindmap,
.intro-mock__body--worksheet,
.intro-mock__body--flashcards,
.intro-mock__body--google {
    min-height: 0;
}

.intro-mock__context {
    align-self: flex-start;
    font-family: var(--font-mono);
    font-size: 0.68rem;
    color: var(--vivek-secondary);
    background: var(--vivek-secondary-muted);
    border: 1px solid rgba(61, 184, 176, 0.2);
    padding: 5px 10px;
    border-radius: 999px;
}

.intro-mock__bubble {
    max-width: 92%;
    padding: 12px 14px;
    border-radius: 14px;
    font-size: 0.88rem;
    line-height: 1.55;
    animation: introFadeUp 0.6s ease backwards;
}

.intro-mock__bubble--user {
    align-self: flex-end;
    background: var(--vivek-brand-muted);
    border: 1px solid rgba(255, 111, 97, 0.25);
    color: var(--text-primary);
    animation-delay: 0.15s;
}

.intro-mock__bubble--ai {
    align-self: flex-start;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    color: var(--text-secondary);
    animation-delay: 0.45s;
}

.intro-mock__typing {
    display: inline-flex;
    gap: 4px;
    align-items: center;
    padding: 4px 0;
}

.intro-mock__typing span {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--text-secondary);
    animation: introTyping 1.2s ease-in-out infinite;
}

.intro-mock__typing span:nth-child(2) { animation-delay: 0.15s; }
.intro-mock__typing span:nth-child(3) { animation-delay: 0.3s; }

@keyframes introTyping {
    0%, 60%, 100% { opacity: 0.25; transform: translateY(0); }
    30% { opacity: 1; transform: translateY(-3px); }
}

.intro-mock__composer {
    margin-top: auto;
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 12px;
    background: rgba(0, 0, 0, 0.25);
    border: 1px solid var(--border);
    border-radius: 12px;
    animation: introFadeUp 0.6s ease 0.7s backwards;
}

.intro-mock__composer-text {
    flex: 1;
    font-size: 0.82rem;
    color: var(--text-secondary);
}

.intro-mock__composer-send {
    width: 32px;
    height: 32px;
    border-radius: 8px;
    background: var(--accent);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
}

.intro-mock__caption {
    margin-top: auto;
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.78rem;
    color: var(--text-secondary);
}

.intro-mock__caption svg {
    width: 14px;
    height: 14px;
    color: var(--accent);
    flex-shrink: 0;
}

/* Mind map slide — matches dark markmap viewer */
.intro-mock__body--mindmap {
    padding: 18px 20px 16px;
    gap: 10px;
}

.intro-mock__mindmap-viewer {
    position: relative;
    flex: 1;
    min-height: 0;
    background: #121212;
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.06);
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    animation: introFadeUp 0.55s ease 0.1s backwards;
}

.intro-mock__mm-grid {
    position: absolute;
    inset: 0;
    background-image:
        radial-gradient(rgba(255, 255, 255, 0.04) 1px, transparent 1px);
    background-size: 18px 18px;
    pointer-events: none;
}

.intro-mock__mm-toolbar {
    position: absolute;
    top: 10px;
    right: 10px;
    display: flex;
    gap: 6px;
    z-index: 2;
}

.intro-mock__mm-tool {
    width: 28px;
    height: 28px;
    border-radius: 8px;
    background: rgba(42, 42, 42, 0.92);
    border: 1px solid #333;
    color: #e0e0e0;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.35);
}

.intro-mock__mm-tool svg {
    width: 14px;
    height: 14px;
}

.intro-mock__mindmap-svg {
    width: 100%;
    height: 100%;
    max-height: 200px;
    position: relative;
    z-index: 1;
}

.intro-mock__mm-link {
    stroke: #666;
    stroke-width: 1.5;
    fill: none;
}

.intro-mock__mm-node {
    fill: #2A2A2A;
    stroke: #ccc;
    stroke-width: 1.5;
}

.intro-mock__mm-node--root {
    fill: #FF6F61;
    stroke: #FF8A7A;
    stroke-width: 2;
    filter: drop-shadow(0 0 6px rgba(255, 111, 97, 0.45));
}

.intro-mock__mm-node--sm {
    fill: #1E1E1E;
}

.intro-mock__mm-label {
    fill: #B0B0B0;
    font-family: 'JetBrains Mono', 'Courier New', monospace;
    font-size: 9px;
    text-anchor: middle;
}

.intro-mock__mm-label--root {
    fill: #E0E0E0;
    font-size: 10px;
    font-weight: 600;
}

.intro-mock__mm-label--sm {
    font-size: 8px;
}

/* Worksheet slide — matches Form.io worksheet viewer */
.intro-mock__body--worksheet {
    padding: 18px 20px 16px;
    gap: 10px;
}

.intro-mock__ws-viewport {
    flex: 1;
    min-height: 0;
    border-radius: 12px;
    overflow: hidden;
    border: 1px solid rgba(255, 255, 255, 0.06);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.25);
    animation: introFadeUp 0.55s ease 0.1s backwards;
}

.intro-mock__ws-shell {
    height: 100%;
    display: flex;
    flex-direction: column;
    background: #f1f3f4;
    overflow: hidden;
}

.intro-mock__ws-header {
    background: linear-gradient(135deg, #673ab7, #5e35b1);
    color: #fff;
    padding: 14px 16px 12px;
    flex-shrink: 0;
}

.intro-mock__ws-header h3 {
    margin: 0 0 5px;
    font-size: 0.95rem;
    font-weight: 500;
    letter-spacing: -0.02em;
}

.intro-mock__ws-header p {
    margin: 0;
    font-size: 0.68rem;
    opacity: 0.9;
    line-height: 1.45;
}

.intro-mock__ws-body {
    flex: 1;
    padding: 12px 14px 14px;
    overflow: hidden;
}

.intro-mock__ws-question {
    border: 1px solid #dadce0;
    border-radius: 8px;
    padding: 11px 12px;
    margin-bottom: 8px;
    background: #fff;
    transition: box-shadow 0.2s ease, border-color 0.2s ease;
}

.intro-mock__ws-question--animated {
    animation: introFadeUp 0.5s ease backwards;
}

.intro-mock__ws-question--animated:nth-child(1) { animation-delay: 0.12s; }
.intro-mock__ws-question--animated:nth-child(2) { animation-delay: 0.24s; }
.intro-mock__ws-question--animated:nth-child(3) { animation-delay: 0.36s; }

.intro-mock__ws-question:hover {
    border-color: #673ab7;
    box-shadow: 0 4px 14px rgba(103, 58, 183, 0.12);
}

.intro-mock__ws-question label {
    display: block;
    font-size: 0.76rem;
    font-weight: 500;
    color: #202124;
    line-height: 1.45;
    margin-bottom: 8px;
}

.intro-mock__ws-input {
    height: 26px;
    border-radius: 6px;
    border: 1px solid #dadce0;
    background: linear-gradient(180deg, #fff, #f8f9fa);
}

.intro-mock__ws-input--tall {
    height: 38px;
}

.intro-mock__ws-options {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.intro-mock__ws-option {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.72rem;
    color: #3c4043;
    padding: 4px 6px;
    border-radius: 6px;
}

.intro-mock__ws-option--selected {
    background: rgba(103, 58, 183, 0.08);
    color: #202124;
}

.intro-mock__ws-radio {
    width: 14px;
    height: 14px;
    border-radius: 50%;
    border: 2px solid #dadce0;
    flex-shrink: 0;
    position: relative;
}

.intro-mock__ws-option--selected .intro-mock__ws-radio {
    border-color: #673ab7;
}

.intro-mock__ws-option--selected .intro-mock__ws-radio::after {
    content: '';
    position: absolute;
    inset: 2px;
    border-radius: 50%;
    background: #673ab7;
}

.intro-mock__ws-submit {
    display: inline-block;
    margin-top: 2px;
    background: #673ab7;
    color: #fff;
    border: none;
    border-radius: 999px;
    padding: 8px 18px;
    font-size: 0.72rem;
    font-weight: 500;
    box-shadow: 0 4px 12px rgba(103, 58, 183, 0.35);
    cursor: default;
    animation: introFadeUp 0.5s ease 0.48s backwards;
}

/* Flashcards slide — matches generated deck viewer */
.intro-mock__body--flashcards {
    padding: 18px 20px 16px;
    gap: 10px;
}

.intro-mock__fc-viewport {
    position: relative;
    flex: 1;
    min-height: 0;
    border-radius: 12px;
    overflow: hidden;
    border: 1px solid rgba(255, 255, 255, 0.06);
    animation: introFadeUp 0.55s ease 0.1s backwards;
}

.intro-mock__fc-bg {
    position: absolute;
    inset: 0;
    background: linear-gradient(-45deg, #0f0c29, #302b63, #24243e, #6a11cb, #2575fc);
    background-size: 400% 400%;
    animation: introFcGradient 14s ease infinite;
}

@keyframes introFcGradient {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

.intro-mock__fc-shell {
    position: relative;
    z-index: 1;
    height: 100%;
    display: flex;
    flex-direction: column;
    padding: 12px 14px 14px;
    color: #f8f9ff;
}

.intro-mock__fc-header {
    text-align: center;
    margin-bottom: 8px;
}

.intro-mock__fc-header--animated {
    animation: introFadeUp 0.5s ease 0.1s backwards;
}

.intro-mock__fc-header h3 {
    margin: 0 0 3px;
    font-size: 0.9rem;
    font-weight: 600;
    letter-spacing: -0.02em;
    text-shadow: 0 2px 12px rgba(0, 0, 0, 0.3);
}

.intro-mock__fc-header p {
    margin: 0;
    font-size: 0.66rem;
    opacity: 0.88;
}

.intro-mock__fc-progress {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 8px;
}

.intro-mock__fc-progress--animated {
    animation: introFadeUp 0.5s ease 0.2s backwards;
}

.intro-mock__fc-progress-track {
    flex: 1;
    height: 5px;
    background: rgba(255, 255, 255, 0.15);
    border-radius: 999px;
    overflow: hidden;
}

.intro-mock__fc-progress-fill {
    height: 100%;
    background: linear-gradient(90deg, #a855f7, #38bdf8);
    border-radius: 999px;
    box-shadow: 0 0 10px rgba(168, 85, 247, 0.55);
}

.intro-mock__fc-progress-label {
    font-size: 0.66rem;
    font-weight: 600;
    min-width: 2.4rem;
    text-align: right;
    opacity: 0.9;
}

.intro-mock__fc-card-stage {
    flex: 1;
    min-height: 0;
    display: flex;
    align-items: center;
    margin-bottom: 8px;
    perspective: 900px;
}

.intro-mock__fc-card {
    width: 100%;
    min-height: 108px;
    border-radius: 16px;
    transform: rotateX(2deg);
    box-shadow: 0 16px 40px rgba(0, 0, 0, 0.4), 0 0 0 1px rgba(255, 255, 255, 0.08);
}

.intro-mock__fc-card--animated {
    animation: introFcCardPop 0.55s cubic-bezier(0.34, 1.4, 0.64, 1) 0.28s backwards;
}

@keyframes introFcCardPop {
    from { opacity: 0; transform: scale(0.92) translateY(14px); }
    to { opacity: 1; transform: rotateX(2deg) scale(1) translateY(0); }
}

.intro-mock__fc-face {
    position: relative;
    min-height: 108px;
    border-radius: 16px;
    padding: 18px 14px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
}

.intro-mock__fc-face--front {
    background: linear-gradient(145deg, rgba(255, 255, 255, 0.98), rgba(237, 231, 246, 0.96));
    color: #1a1a2e;
}

.intro-mock__fc-face-label {
    position: absolute;
    top: 10px;
    left: 12px;
    font-size: 0.52rem;
    font-weight: 700;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    opacity: 0.55;
}

.intro-mock__fc-face-text {
    font-size: 1.75rem;
    font-weight: 700;
    line-height: 1.2;
}

.intro-mock__fc-tap-hint {
    margin-top: 6px;
    font-size: 0.6rem;
    opacity: 0.5;
}

.intro-mock__fc-controls {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    justify-content: center;
}

.intro-mock__fc-controls--animated {
    animation: introFadeUp 0.5s ease 0.38s backwards;
}

.intro-mock__fc-btn {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    border-radius: 999px;
    padding: 7px 12px;
    font-size: 0.66rem;
    font-weight: 600;
}

.intro-mock__fc-btn svg {
    width: 12px;
    height: 12px;
}

.intro-mock__fc-btn--primary {
    background: linear-gradient(135deg, #a855f7, #6366f1);
    color: #fff;
    box-shadow: 0 6px 18px rgba(99, 102, 241, 0.45);
}

.intro-mock__fc-btn--ghost {
    background: rgba(255, 255, 255, 0.12);
    color: #fff;
    backdrop-filter: blur(6px);
}

/* Google Drive slide */
.intro-mock__body--google {
    padding: 18px 20px 16px;
    gap: 10px;
}

.intro-mock__gd-connected {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 12px;
    border-radius: 12px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
}

.intro-mock__gd-connected--animated {
    animation: introFadeUp 0.5s ease 0.08s backwards;
}

.intro-mock__gd-avatar {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: linear-gradient(135deg, #4285f4, #34a853);
    color: #fff;
    font-size: 0.8rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.intro-mock__gd-connected strong {
    display: block;
    font-size: 0.78rem;
    color: var(--text-primary);
}

.intro-mock__gd-connected span:last-of-type {
    font-size: 0.68rem;
    color: var(--text-secondary);
}

.intro-mock__gd-badge {
    margin-left: auto;
    font-size: 0.62rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--vivek-secondary);
    background: var(--vivek-secondary-muted);
    border: 1px solid rgba(61, 184, 176, 0.25);
    padding: 4px 8px;
    border-radius: 999px;
}

.intro-mock__gd-picker {
    flex: 1;
    min-height: 0;
    display: flex;
    flex-direction: column;
    gap: 6px;
    padding: 10px;
    border-radius: 12px;
    background: rgba(0, 0, 0, 0.22);
    border: 1px solid var(--border);
    overflow: hidden;
}

.intro-mock__gd-picker--animated {
    animation: introFadeUp 0.5s ease 0.18s backwards;
}

.intro-mock__gd-path {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 0.7rem;
    color: var(--text-secondary);
    padding-bottom: 6px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
    margin-bottom: 2px;
}

.intro-mock__gd-path svg {
    width: 14px;
    height: 14px;
    color: #6ba3f7;
}

.intro-mock__gd-sep {
    opacity: 0.5;
}

.intro-mock__gd-file {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 10px;
    border-radius: 10px;
    border: 1px solid transparent;
    transition: background 0.2s ease, border-color 0.2s ease;
}

.intro-mock__gd-file--selected {
    background: rgba(66, 133, 244, 0.12);
    border-color: rgba(66, 133, 244, 0.28);
}

.intro-mock__gd-file-icon {
    width: 32px;
    height: 32px;
    border-radius: 8px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    color: var(--text-secondary);
}

.intro-mock__gd-file-icon svg {
    width: 16px;
    height: 16px;
}

.intro-mock__gd-file-icon--pdf {
    background: rgba(234, 67, 53, 0.12);
    color: #f28b82;
    border-color: rgba(234, 67, 53, 0.2);
}

.intro-mock__gd-file-icon--folder {
    background: rgba(251, 188, 5, 0.12);
    color: #fdd663;
    border-color: rgba(251, 188, 5, 0.2);
}

.intro-mock__gd-file-meta {
    flex: 1;
    min-width: 0;
}

.intro-mock__gd-file-meta strong {
    display: block;
    font-size: 0.76rem;
    color: var(--text-primary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.intro-mock__gd-file-meta span {
    font-size: 0.64rem;
    color: var(--text-secondary);
}

.intro-mock__gd-check {
    width: 22px;
    height: 22px;
    border-radius: 50%;
    background: #4285f4;
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.intro-mock__gd-check svg {
    width: 12px;
    height: 12px;
}

.intro-mock__gd-import {
    display: flex;
    flex-direction: column;
    gap: 6px;
    font-size: 0.72rem;
    color: var(--text-secondary);
}

.intro-mock__gd-import--animated {
    animation: introFadeUp 0.5s ease 0.3s backwards;
}

.intro-mock__gd-import-bar {
    height: 5px;
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.08);
    overflow: hidden;
}

.intro-mock__gd-import-fill {
    height: 100%;
    width: 62%;
    border-radius: 999px;
    background: linear-gradient(90deg, #4285f4, #34a853);
    animation: introGdImport 2.2s ease-in-out infinite;
}

@keyframes introGdImport {
    0% { width: 38%; opacity: 0.7; }
    50% { width: 72%; opacity: 1; }
    100% { width: 38%; opacity: 0.7; }
}

.intro-mock__gd-actions {
    display: flex;
    gap: 8px;
    margin-top: auto;
}

.intro-mock__gd-btn {
    flex: 1;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 9px 12px;
    border-radius: 10px;
    font-size: 0.72rem;
    font-weight: 600;
}

.intro-mock__gd-btn svg {
    width: 14px;
    height: 14px;
}

.intro-mock__gd-btn--ghost {
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    color: var(--text-secondary);
}

.intro-mock__gd-btn--primary {
    background: linear-gradient(135deg, #4285f4, #3367d6);
    color: #fff;
    box-shadow: 0 4px 14px rgba(66, 133, 244, 0.35);
}

@keyframes introFadeUp {
    from { opacity: 0; transform: translateY(12px); }
    to { opacity: 1; transform: translateY(0); }
}

/* ── Section headers ── */
.intro-section-head {
    text-align: center;
    max-width: 640px;
    margin: 0 auto 48px;
}

.intro-section-label {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 12px;
}

.intro-section-title {
    font-size: clamp(1.75rem, 3.5vw, 2.25rem);
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: 12px;
}

.intro-section-desc {
    color: var(--text-secondary);
    font-size: 1rem;
    line-height: 1.6;
}

/* ── Bento grid ── */
.intro-bento {
    display: grid;
    grid-template-columns: repeat(12, 1fr);
    gap: 16px;
}

.intro-bento__card {
    background: rgba(28, 25, 23, 0.6);
    border: 1px solid rgba(255, 255, 255, 0.07);
    border-radius: var(--radius-lg);
    padding: 24px;
    transition: border-color 0.3s, transform 0.3s, box-shadow 0.3s;
    position: relative;
    overflow: hidden;
}

.intro-bento__card::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(255, 111, 97, 0.04), transparent 50%);
    opacity: 0;
    transition: opacity 0.3s;
    pointer-events: none;
}

.intro-bento__card:hover {
    border-color: rgba(255, 111, 97, 0.35);
    transform: translateY(-3px);
    box-shadow: 0 16px 48px rgba(0, 0, 0, 0.3);
}

.intro-bento__card:hover::before {
    opacity: 1;
}

.intro-bento__card--lg { grid-column: span 7; }
.intro-bento__card--md { grid-column: span 5; }
.intro-bento__card--sm { grid-column: span 4; }
.intro-bento__card--wide { grid-column: span 8; }
.intro-bento__card--narrow { grid-column: span 4; }

.intro-bento__icon {
    width: 40px;
    height: 40px;
    border-radius: 10px;
    background: var(--vivek-brand-muted);
    border: 1px solid rgba(255, 111, 97, 0.2);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 16px;
    color: var(--accent);
}

.intro-bento__icon--teal {
    background: var(--vivek-secondary-muted);
    border-color: rgba(61, 184, 176, 0.25);
    color: var(--vivek-secondary);
}

.intro-bento__title {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 8px;
}

.intro-bento__desc {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.55;
}

/* ── How it works ── */
.intro-steps {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    position: relative;
}

.intro-steps::before {
    content: '';
    position: absolute;
    top: 28px;
    left: 16%;
    right: 16%;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--border), var(--border), transparent);
}

.intro-step {
    text-align: center;
    position: relative;
}

.intro-step__num {
    width: 56px;
    height: 56px;
    margin: 0 auto 20px;
    border-radius: 50%;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: var(--font-mono);
    font-weight: 600;
    font-size: 1rem;
    color: var(--accent);
    position: relative;
    z-index: 1;
}

.intro-step__title {
    font-weight: 600;
    margin-bottom: 8px;
}

.intro-step__desc {
    font-size: 0.88rem;
    color: var(--text-secondary);
    line-height: 1.5;
    max-width: 28ch;
    margin: 0 auto;
}

/* ── Audience split ── */
.intro-audience {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.intro-audience__card {
    padding: 32px;
    border-radius: var(--radius-lg);
    border: 1px solid rgba(255, 255, 255, 0.07);
    background: rgba(28, 25, 23, 0.55);
    transition: border-color 0.3s, transform 0.3s;
}

.intro-audience__card:hover {
    border-color: rgba(255, 111, 97, 0.3);
    transform: translateY(-2px);
}

.intro-audience__card--teacher {
    background: linear-gradient(145deg, rgba(255, 111, 97, 0.08), rgba(28, 25, 23, 0.6));
}

.intro-audience__card--student {
    background: linear-gradient(145deg, rgba(61, 184, 176, 0.08), rgba(28, 25, 23, 0.6));
}

.intro-audience__badge {
    font-family: var(--font-mono);
    font-size: 0.68rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: 12px;
    color: var(--accent);
}

.intro-audience__card--student .intro-audience__badge {
    color: var(--vivek-secondary);
}

.intro-audience__title {
    font-size: 1.35rem;
    font-weight: 700;
    margin-bottom: 12px;
}

.intro-audience__list {
    list-style: none;
    margin-bottom: 24px;
}

.intro-audience__list li {
    font-size: 0.9rem;
    color: var(--text-secondary);
    padding: 6px 0 6px 22px;
    position: relative;
    line-height: 1.45;
}

.intro-audience__list li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 12px;
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--accent);
    opacity: 0.7;
}

.intro-audience__card--student .intro-audience__list li::before {
    background: var(--vivek-secondary);
}

/* ── Mission ── */
.intro-mission {
    background: rgba(28, 25, 23, 0.5);
    border: 1px solid rgba(255, 255, 255, 0.06);
    border-radius: var(--radius-xl);
    padding: clamp(32px, 5vw, 48px);
}

.intro-mission__lead {
    font-size: 1.05rem;
    line-height: 1.7;
    color: var(--text-secondary);
    margin-bottom: 20px;
}

.intro-mission__more {
    font-size: 0.95rem;
    line-height: 1.75;
    color: var(--text-secondary);
    opacity: 0.85;
}

.intro-mission__toggle {
    margin-top: 16px;
    background: none;
    border: none;
    color: var(--accent);
    font-family: inherit;
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    padding: 0;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.intro-mission__more[hidden] {
    display: none;
}

/* ── Footer ── */
.intro-footer {
    border-top: 1px solid var(--border);
    padding: 40px clamp(20px, 4vw, 48px) 100px;
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
}

.intro-footer__brand {
    font-weight: 600;
    font-size: 0.95rem;
}

.intro-footer__copy {
    font-size: 0.82rem;
    color: var(--text-secondary);
    margin-top: 4px;
}

.intro-footer__links {
    display: flex;
    gap: 20px;
}

.intro-footer__link {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-family: inherit;
    font-size: 0.88rem;
    cursor: pointer;
    text-decoration: none;
    transition: color 0.2s;
}

.intro-footer__link:hover {
    color: var(--text-primary);
}

/* ── Mobile sticky CTA ── */
.intro-mobile-cta {
    display: none;
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    z-index: 999;
    padding: 12px 16px calc(12px + env(safe-area-inset-bottom));
    background: rgba(19, 17, 16, 0.92);
    backdrop-filter: blur(16px);
    border-top: 1px solid var(--border);
    gap: 10px;
}

.intro-mobile-cta .intro-btn {
    flex: 1;
    justify-content: center;
}

/* ── Modal ── */
.intro-modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(4px);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    padding: 20px;
}

.intro-modal-overlay.is-open {
    display: flex;
}

.intro-modal {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 20px;
    max-width: 90vw;
    max-height: 90vh;
    box-shadow: 0 24px 64px rgba(0, 0, 0, 0.5);
}

.intro-modal__header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 16px;
}

.intro-modal__title {
    font-size: 1.1rem;
    font-weight: 600;
}

.intro-modal__close {
    appearance: none;
    border: none;
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    width: 36px;
    height: 36px;
    border-radius: 8px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
}

.intro-modal__close:hover {
    color: var(--text-primary);
}

.intro-modal__img {
    max-width: 80vw;
    max-height: 70vh;
    border-radius: var(--radius-md);
    border: 1px solid var(--border);
}

.intro-modal--auth {
    position: relative;
    width: 100%;
    max-width: 400px;
    max-height: min(90vh, 720px);
    overflow-y: auto;
    padding: 24px;
}

.intro-modal__close--auth {
    position: absolute;
    top: 16px;
    right: 16px;
    z-index: 2;
}

.intro-modal--auth .modal-title {
    margin-top: 0;
    margin-bottom: 20px;
    padding-right: 40px;
}

body.intro-page.intro-auth-open {
    overflow: hidden;
}

/* ── Scroll reveal ── */
.intro-reveal {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity 0.7s ease, transform 0.7s ease;
}

.intro-reveal.is-visible {
    opacity: 1;
    transform: translateY(0);
}

/* ── Hero entrance ── */
.intro-hero__copy > * {
    animation: introFadeUp 0.7s ease backwards;
}

.intro-hero__copy .intro-eyebrow { animation-delay: 0.05s; }
.intro-hero__copy .intro-headline { animation-delay: 0.12s; }
.intro-hero__copy .intro-subhead { animation-delay: 0.2s; }
.intro-hero__copy .intro-cta-row { animation-delay: 0.28s; }
.intro-hero__copy .intro-trust { animation-delay: 0.36s; }

.intro-mock {
    animation: introFadeUp 0.8s ease 0.2s backwards;
}

/* ── Reduced motion ── */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
    .intro-reveal {
        opacity: 1;
        transform: none;
    }
}

/* Light theme (system default or user-selected light) */
body.intro-page.theme-light .intro-header.is-scrolled {
    background: rgba(250, 250, 249, 0.88);
    border-bottom: 1px solid rgba(0, 0, 0, 0.06);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.08);
}

body.intro-page.theme-light .intro-bg__grid {
    background-image:
        linear-gradient(rgba(0, 0, 0, 0.04) 1px, transparent 1px),
        linear-gradient(90deg, rgba(0, 0, 0, 0.04) 1px, transparent 1px);
}

body.intro-page.theme-light .intro-btn--ghost:hover {
    background: rgba(0, 0, 0, 0.04);
}

body.intro-page.theme-light .intro-mock__frame {
    background: rgba(255, 255, 255, 0.96);
    border-color: rgba(0, 0, 0, 0.08);
    box-shadow:
        0 0 0 1px rgba(0, 0, 0, 0.04) inset,
        0 24px 80px rgba(0, 0, 0, 0.1);
}

body.intro-page.theme-light .intro-mock__indicator {
    background: rgba(0, 0, 0, 0.15);
}

body.intro-page.theme-light .intro-mock__chrome {
    border-bottom-color: rgba(0, 0, 0, 0.06);
    background: rgba(0, 0, 0, 0.03);
}

body.intro-page.theme-light .intro-mock__chrome-mark {
    border-color: rgba(0, 0, 0, 0.1);
    background: linear-gradient(180deg, rgba(0, 0, 0, 0.04), rgba(0, 0, 0, 0.01));
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.6);
}

body.intro-page.theme-light .intro-mock__mindmap-viewer {
    background: #f5f5f4;
    border-color: rgba(0, 0, 0, 0.08);
}

body.intro-page.theme-light .intro-mock__mm-grid {
    background-image:
        radial-gradient(rgba(0, 0, 0, 0.06) 1px, transparent 1px);
}

body.intro-page.theme-light .intro-mock__mm-node--sm {
    fill: #e7e5e4;
}

body.intro-page.theme-light .intro-bento__card {
    background: rgba(255, 255, 255, 0.85);
    border-color: rgba(0, 0, 0, 0.08);
}

body.intro-page.theme-light .intro-bento__card:hover {
    box-shadow: 0 16px 48px rgba(0, 0, 0, 0.1);
}

body.intro-page.theme-light .intro-audience__card {
    background: rgba(255, 255, 255, 0.8);
    border-color: rgba(0, 0, 0, 0.08);
}

body.intro-page.theme-light .intro-audience__card--teacher {
    background: linear-gradient(145deg, rgba(255, 111, 97, 0.08), rgba(255, 255, 255, 0.9));
}

body.intro-page.theme-light .intro-audience__card--student {
    background: linear-gradient(145deg, rgba(61, 184, 176, 0.08), rgba(255, 255, 255, 0.9));
}

body.intro-page.theme-light .intro-mission {
    background: rgba(255, 255, 255, 0.75);
    border-color: rgba(0, 0, 0, 0.08);
}

/* ── Responsive ── */
@media (max-width: 960px) {
    .intro-hero {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .intro-hero__copy {
        max-width: none;
    }

    .intro-subhead {
        margin-left: auto;
        margin-right: auto;
    }

    .intro-cta-row,
    .intro-trust {
        justify-content: center;
    }

    .intro-mock {
        max-width: 480px;
        margin: 0 auto;
    }

    .intro-bento__card--lg,
    .intro-bento__card--md,
    .intro-bento__card--sm,
    .intro-bento__card--wide,
    .intro-bento__card--narrow {
        grid-column: span 12;
    }

    .intro-steps {
        grid-template-columns: 1fr;
        gap: 32px;
    }

    .intro-steps::before {
        display: none;
    }

    .intro-audience {
        grid-template-columns: 1fr;
    }

    .intro-nav .intro-btn--ghost:not(.intro-btn--primary) {
        display: none;
    }

    .intro-mobile-cta {
        display: flex;
    }

    .intro-footer {
        padding-bottom: calc(80px + env(safe-area-inset-bottom));
        flex-direction: column;
        text-align: center;
    }

    .intro-footer__links {
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .intro-brand__text {
        display: none;
    }
}