/* ─── Variables ─────────────────────────────────────── */
    :root {
        --bg: #f6f7fb;
        --surface: #ffffff;
        --surface2: #eef1f7;
        --border: rgba(15, 23, 42, 0.12);
        --bar-track: rgba(15, 23, 42, 0.08);
        --accent: #3b6bff;
        --accent2: #7a4dff;
        --accent3: #0ea37f;
        --accent4: #f59e0b;
        --accent5: #e84563;
        --text: #13182a;
        --muted: #5e6b85;
        --radius: 14px;
        --hero-grad-1: #360143;
        --hero-grad-2: #2a81fc;
    }

    html[data-theme="dark"] {
        --bg: #0d0f1a;
        --surface: #13162b;
        --surface2: #1a1e35;
        --border: rgba(255, 255, 255, .07);
        --bar-track: rgba(255, 255, 255, .06);
        --accent: #4f8dff;
        --accent2: #8b5cf6;
        --accent3: #06d6a0;
        --accent4: #f59e0b;
        --accent5: #f43f5e;
        --text: #e8eaf6;
        --muted: #7680a0;
        --hero-grad-1: #360143;
        --hero-grad-2: #2a81fc;
    }

    /* ─── Reset / Base ─────────────────────────────────── */
    *,
    *::before,
    *::after {
        box-sizing: border-box;
        margin: 0;
        padding: 0;
    }

    html {
        scroll-behavior: smooth;
    }

    body {
        font-family: 'DM Sans', sans-serif;
        background: var(--bg);
        color: var(--text);
        min-height: 100vh;
        overflow-x: hidden;
    }

    ::selection {
        background: var(--accent);
        color: #fff;
    }

    /* ─── Background decoration ────────────────────────── */
    body::before {
        content: '';
        position: fixed;
        inset: 0;
        background:
            radial-gradient(ellipse 80vw 60vh at 20% -10%, rgba(59, 107, 255, .12) 0%, transparent 60%),
            radial-gradient(ellipse 60vw 50vh at 80% 100%, rgba(122, 77, 255, .12) 0%, transparent 55%);
        pointer-events: none;
        z-index: 0;
    }

    html[data-theme="dark"] body::before {
        background:
            radial-gradient(ellipse 80vw 60vh at 20% -10%, rgba(79, 141, 255, .12) 0%, transparent 60%),
            radial-gradient(ellipse 60vw 50vh at 80% 100%, rgba(139, 92, 246, .1) 0%, transparent 55%);
    }

    .section-header {
        text-align: center;
        padding: 40px 24px 48px;
    }

    .intro {
        max-width: 960px;
        margin: 0 auto;
        line-height: 1.7;
        font-size: 16px;
         font-family: Arial, sans-serif;
    }

    .liste{
        margin-left: 30px;
        margin-bottom: 20px;
        margin-top: 10px;
    }

    .page-hero {
        background: linear-gradient(180deg, var(--hero-grad-1), var(--hero-grad-2));
        color: #fff;
        text-align: center;
        padding: 40px 20px;
        box-shadow: 0 5px 20px rgb(54, 66, 109);
        position: relative;
        z-index: 1;
        margin-bottom: 40px;
    }

    .page-hero h1 {
        font-family: 'Syne', sans-serif;
        font-size: clamp(2rem, 5vw, 3rem);
        margin: 0;
    }

    .page-hero p {
        max-width: 760px;
        margin: 14px auto 0;
        font-size: 1.05rem;
        line-height: 1.6;
        color: rgba(255, 255, 255, 0.93);
    }

    /* ─── Layout ────────────────────────────────────────── */
    .page-wrapper {
        max-width: 960px;
        margin: 0 auto;
        padding: 0 24px 80px;
        position: relative;
        z-index: 1;

    }

    /* ─── Hero ──────────────────────────────────────────── */
    .hero {
        text-align: center;
        padding: 64px 0 48px;
    }

    .hero-chip {
        display: inline-flex;
        align-items: center;
        gap: 8px;
        font-size: .78rem;
        font-weight: 500;
        color: var(--accent);
        background: rgba(79, 141, 255, .1);
        border: 1px solid rgba(79, 141, 255, .25);
        border-radius: 20px;
        padding: 5px 14px;
        margin-bottom: 20px;
        letter-spacing: .04em;
    }

    .hero-chip .dot {
        width: 6px;
        height: 6px;
        border-radius: 50%;
        background: var(--accent);
        animation: pulse 2s infinite;
    }

    @keyframes pulse {

        0%,
        100% {
            opacity: 1;
            transform: scale(1)
        }

        50% {
            opacity: .5;
            transform: scale(.8)
        }
    }

    h1 {
        font-family: 'Syne', sans-serif;
        font-size: clamp(2.2rem, 5vw, 3.4rem);
        font-weight: 800;
        line-height: 1.1;
        margin-bottom: 18px;
    }

    h1 em {
        font-style: normal;
        background: linear-gradient(135deg, var(--accent), var(--accent2));
        background-clip: text;
        -webkit-background-clip: text;
        -webkit-text-fill-color: transparent;
    }

    .hero-desc {
        font-size: 1.05rem;
        color: var(--muted);
        max-width: 560px;
        margin: 0 auto;
        line-height: 1.65;
    }

    /* ─── Section title ─────────────────────────────────── */
    .section-label {
        display: flex;
        align-items: center;
        gap: 10px;
        font-family: 'Syne', sans-serif;
        font-size: .8rem;
        font-weight: 700;
        letter-spacing: .1em;
        text-transform: uppercase;
        color: var(--muted);
        margin-bottom: 14px;
    }

    .section-label::after {
        content: '';
        flex: 1;
        height: 1px;
        background: var(--border);
    }

    h2 {
        font-family: 'Syne', sans-serif;
        font-size: 1.35rem;
        font-weight: 700;
        margin-bottom: 6px;
    }

    /* ─── Card ──────────────────────────────────────────── */
    .card {
        background: var(--surface);
        border: 1px solid var(--border);
        border-radius: var(--radius);
        padding: 28px;
        margin-bottom: 24px;
        font-size: 1.08rem;
    }

    .card-sm {
        padding: 18px 22px;
    }

    .section-desc {
        font-size: 1rem;
        color: var(--muted);
        margin-bottom: 18px;
        line-height: 1.65;
    }

    .hint-text {
        font-size: .95rem;
        color: var(--muted);
        line-height: 1.65;
    }

    /* ─── DEMO 1 : Tokeniseur live ───────────────────────── */
    .tokenizer-input-row {
        display: flex;
        gap: 10px;
        align-items: flex-start;
        flex-wrap: wrap;
    }

    .tokenizer-input-row textarea {
        flex: 1;
        min-width: 220px;
        background: var(--surface2);
        border: 1px solid var(--border);
        color: var(--text);
        font-family: 'DM Sans', sans-serif;
        font-size: 1rem;
        border-radius: 10px;
        padding: 14px 16px;
        resize: vertical;
        min-height: 88px;
        outline: none;
        transition: border-color .2s;
    }

    .tokenizer-input-row textarea:focus {
        border-color: var(--accent);
    }

    textarea::placeholder {
        color: var(--muted);
    }

    .text-area {
        width: 100%;
        background: var(--surface2);
        border: 1px solid var(--border);
        color: var(--text);
        font-family: 'DM Sans', sans-serif;
        font-size: 1rem;
        border-radius: 10px;
        padding: 14px 16px;
        resize: vertical;
        outline: none;
        margin-bottom: 16px;
        transition: border-color .2s;
    }

    .text-area:focus {
        border-color: var(--accent);
    }

    .text-area--sm {
        min-height: 70px;
    }

    .text-area--lg {
        min-height: 100px;
    }

    .tokenizer-controls {
        display: flex;
        flex-direction: column;
        gap: 8px;
    }

    select {
        background: var(--surface2);
        border: 1px solid var(--border);
        color: var(--text);
        font-family: 'DM Sans', sans-serif;
        font-size: .88rem;
        border-radius: 10px;
        padding: 10px 14px;
        outline: none;
        cursor: pointer;
        transition: border-color .2s;
    }

    select:focus {
        border-color: var(--accent);
    }

    .btn {
        display: inline-flex;
        align-items: center;
        gap: 7px;
        font-family: 'DM Sans', sans-serif;
        font-size: .9rem;
        font-weight: 500;
        padding: 11px 20px;
        border-radius: 10px;
        border: none;
        cursor: pointer;
        transition: all .18s;
        white-space: nowrap;
    }

    .btn-primary {
        background: linear-gradient(135deg, var(--accent), var(--accent2));
        color: #fff;
    }

    .btn-primary:hover {
        opacity: .88;
        transform: translateY(-1px);
    }

    .btn-ghost {
        background: var(--surface2);
        color: var(--muted);
        border: 1px solid var(--border);
    }

    .btn-ghost:hover {
        color: var(--text);
        border-color: rgba(255, 255, 255, .2);
    }

    /* Stats bar */
    .stats-bar {
        display: flex;
        gap: 20px;
        flex-wrap: wrap;
        padding: 14px 0 18px;
    }

    .stat {
        display: flex;
        flex-direction: column;
    }

    .stat-val {
        font-family: 'Syne', sans-serif;
        font-size: 1.5rem;
        font-weight: 700;
    }

    .stat-label {
        font-size: .75rem;
        color: var(--muted);
    }

    #statTokens {
        color: var(--accent);
    }

    /* Token pills */
    .token-display {
        min-height: 60px;
        display: flex;
        flex-wrap: wrap;
        gap: 6px;
        align-items: flex-start;
        padding: 16px;
        background: var(--surface2);
        border-radius: 10px;
        border: 1px solid var(--border);
    }

    .token-placeholder {
        color: var(--muted);
        font-size: .9rem;
        font-style: italic;
    }

    .token-pill {
        font-family: 'DM Mono', 'Courier New', monospace;
        font-size: .83rem;
        padding: 4px 9px;
        border-radius: 6px;
        cursor: default;
        transition: transform .15s, box-shadow .15s;
        animation: popIn .2s ease both;
        border-bottom: 2px solid transparent;
    }

    .token-pill:hover {
        transform: translateY(-2px) scale(1.06);
        box-shadow: 0 4px 14px rgba(0, 0, 0, .4);
    }

    @keyframes popIn {
        from {
            opacity: 0;
            transform: scale(.8)
        }

        to {
            opacity: 1;
            transform: scale(1)
        }
    }

    /* space indicator */
    .space-dot::before {
        content: '·';
        opacity: .4;
    }

    /* Legend */
    .legend {
        display: flex;
        gap: 14px;
        flex-wrap: wrap;
        margin-top: 12px;
    }

    .legend-item {
        display: flex;
        align-items: center;
        gap: 6px;
        font-size: .78rem;
        color: var(--muted);
    }

    .legend-swatch {
        width: 12px;
        height: 12px;
        border-radius: 3px;
    }

    /* ─── DEMO 2 : Comparaison encodages ──────────────────── */
    .encoding-grid {
        display: grid;
        grid-template-columns: 1fr 1fr 1fr;
        gap: 14px;
    }

    @media(max-width:640px) {
        .encoding-grid {
            grid-template-columns: 1fr;
        }
    }

    .enc-card {
        background: var(--surface2);
        border: 1px solid var(--border);
        border-radius: 10px;
        padding: 16px;
    }

    .enc-title {
        font-family: 'Syne', sans-serif;
        font-size: .82rem;
        font-weight: 700;
        letter-spacing: .05em;
        text-transform: uppercase;
        margin-bottom: 10px;
    }

    .enc-tokens {
        display: flex;
        flex-wrap: wrap;
        gap: 5px;
    }

    .enc-token {
        font-family: 'Courier New', monospace;
        font-size: .75rem;
        padding: 3px 7px;
        border-radius: 5px;
        background: rgba(255, 255, 255, .06);
        color: var(--text);
    }

    .enc-count {
        font-size: .95rem;
        color: var(--muted);
        margin-top: 8px;
    }

    .info-box {
        margin-top: 18px;
        padding: 16px;
        background: var(--surface2);
        border-radius: 10px;
        border: 1px solid var(--border);
    }

    .info-text {
        font-size: .95rem;
        color: var(--muted);
        line-height: 1.65;
    }

    /* ─── DEMO 3 : Vocabulaire / Fréquences ──────────────── */
    .freq-row {
        display: grid;
        grid-template-columns: 1fr auto 80px;
        align-items: center;
        gap: 10px;
        padding: 8px 0;
        border-bottom: 1px solid var(--border);
    }

    .freq-row:last-child {
        border-bottom: none;
    }

    .freq-token {
        font-family: 'Courier New', monospace;
        font-size: 1.02rem;
    }

    .freq-count {
        font-size: .96rem;
        color: var(--muted);
        text-align: right;
    }

    .freq-bar-wrap {
        background: rgba(255, 255, 255, .05);
        border-radius: 4px;
        height: 8px;
        overflow: hidden;
    }

    .freq-bar-fill {
        height: 100%;
        border-radius: 4px;
        transition: width .6s ease;
    }

    .freq-btn {
        margin-bottom: 18px;
    }

    /* ─── DEMO 4 : Drôles de tokens ──────────────────────── */
    .curiosities {
        display: grid;
        grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
        gap: 14px;
    }

    .curiosity-card {
        background: var(--surface2);
        border: 1px solid var(--border);
        border-radius: 10px;
        padding: 16px;
    }

    .curiosity-title {
        font-family: 'Syne', sans-serif;
        font-size: .85rem;
        font-weight: 700;
        margin-bottom: 6px;
    }

    .curiosity-text {
        font-size: 1rem;
        color: var(--muted);
        line-height: 1.5;
    }

    .curiosity-token {
        display: inline-block;
        margin-top: 8px;
        font-family: 'Courier New', monospace;
        font-size: .78rem;
        background: rgba(79, 141, 255, .12);
        color: var(--accent);
        border: 1px solid rgba(79, 141, 255, .2);
        border-radius: 5px;
        padding: 3px 8px;
    }

    /* ─── DEMO 5 : Contexte & coût ──────────────────────── */
    .cost-inputs {
        display: flex;
        gap: 12px;
        flex-wrap: wrap;
        margin-bottom: 18px;
    }

    .cost-inputs label {
        flex: 1;
        min-width: 160px;
    }

    .cost-inputs span {
        display: block;
        font-size: .8rem;
        color: var(--muted);
        margin-bottom: 6px;
    }

    .cost-inputs input {
        width: 100%;
        background: var(--surface2);
        border: 1px solid var(--border);
        color: var(--text);
        font-family: 'DM Sans', sans-serif;
        font-size: .95rem;
        border-radius: 10px;
        padding: 10px 14px;
        outline: none;
        transition: border-color .2s;
    }

    .cost-inputs input:focus {
        border-color: var(--accent);
    }

    .model-block {
        margin-bottom: 18px;
    }

    .model-label {
        display: block;
        font-size: .9rem;
        color: var(--muted);
        margin-bottom: 8px;
    }

    .model-selector {
        display: flex;
        gap: 8px;
        flex-wrap: wrap;
    }

    .model-hint {
        font-size: .9rem;
        color: var(--muted);
        margin-top: 8px;
    }

    .cost-result {
        display: grid;
        grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
        gap: 14px;
    }

    .cost-metric {
        background: var(--surface2);
        border: 1px solid var(--border);
        border-radius: 10px;
        padding: 16px;
    }

    .cost-metric-val {
        font-family: 'Syne', sans-serif;
        font-size: 1.3rem;
        font-weight: 700;
        margin-bottom: 4px;
    }

    .cost-metric-label {
        font-size: .94rem;
        color: var(--muted);
    }

    .ctx-visualizer {
        margin-top: 24px;
    }

    .ctx-desc {
        font-size: .92rem;
        color: var(--muted);
        margin-bottom: 14px;
    }

    .ctx-panel {
        background: var(--surface2);
        border-radius: 10px;
        padding: 16px;
        border: 1px solid var(--border);
    }

    .ctx-row {
        display: flex;
        justify-content: space-between;
        font-size: .85rem;
        color: var(--muted);
        margin-bottom: 8px;
    }

    .ctx-bar-bg {
        background: var(--bar-track);
        border-radius: 6px;
        height: 18px;
        overflow: hidden;
    }

    .ctx-bar {
        height: 100%;
        border-radius: 6px;
        background: linear-gradient(90deg, var(--accent), var(--accent2));
        width: 0%;
        transition: width .5s ease;
    }

    .ctx-message {
        font-size: .85rem;
        color: var(--muted);
        margin-top: 8px;
    }

    /* ─── Explainer / théorie ───────────────────────────── */
    .explainer-grid {
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 16px;
    }

    @media(max-width:580px) {
        .explainer-grid {
            grid-template-columns: 1fr;
        }
    }

    .exp-block {
        background: var(--surface2);
        border: 1px solid var(--border);
        border-radius: 10px;
        padding: 18px;
    }

    .exp-icon {
        font-size: 1.6rem;
        margin-bottom: 10px;
    }

    .exp-title {
        font-family: 'Syne', sans-serif;
        font-size: .95rem;
        font-weight: 700;
        margin-bottom: 6px;
    }

    .exp-text {
        font-size: 1rem;
        color: var(--muted);
        line-height: 1.6;
    }

    /* ─── Tabs ──────────────────────────────────────────── */
    .tabs {
        display: flex;
        gap: 4px;
        background: var(--surface2);
        border-radius: 10px;
        padding: 4px;
        margin-bottom: 20px;
        flex-wrap: wrap;
    }

    .tab-btn {
        flex: 1;
        min-width: 80px;
        background: none;
        border: none;
        color: var(--muted);
        font-family: 'DM Sans', sans-serif;
        font-size: .85rem;
        font-weight: 500;
        padding: 8px 14px;
        border-radius: 7px;
        cursor: pointer;
        transition: all .18s;
    }

    .tab-btn.active {
        background: var(--surface);
        color: var(--text);
        box-shadow: 0 2px 8px rgba(0, 0, 0, .3);
    }

    .tab-pane {
        display: none;
    }

    .tab-pane.active {
        display: block;
    }



    /* ─── Tooltip ──────────────────────────────────────── */
    [data-tooltip] {
        position: relative;
    }

    [data-tooltip]::after {
        content: attr(data-tooltip);
        position: absolute;
        bottom: calc(100% + 8px);
        left: 50%;
        transform: translateX(-50%);
        background: #1a1e35;
        color: var(--text);
        font-size: .76rem;
        line-height: 1.4;
        padding: 6px 10px;
        border-radius: 7px;
        border: 1px solid var(--border);
        white-space: nowrap;
        pointer-events: none;
        opacity: 0;
        transition: opacity .15s;
        z-index: 100;
    }

    [data-tooltip]:hover::after {
        opacity: 1;
    }



    /* ─── Animations d'entrée ───────────────────────────── */
    .fade-up {
        opacity: 0;
        transform: translateY(22px);
        transition: opacity .5s ease, transform .5s ease;
    }

    .fade-up.visible {
        opacity: 1;
        transform: translateY(0);
    }