:root {
            --mint: #94e3c2;
            --teal-deep: #0a3d3d;
            --bg: #050505;
            --surface: rgba(255, 255, 255, 0.03);
            --border: rgba(255, 255, 255, 0.08);
            --text: #f2f7f5;
            --text-dim: rgba(242, 247, 245, 0.62);
        }

        html[data-theme="wcag-aaa"] {
            --mint: #ffff00;
            --text-dim: rgba(255, 255, 255, 0.85);
        }

        * { box-sizing: border-box; }

        body {
            font-family: 'Outfit', sans-serif;
            background: var(--bg);
            color: var(--text);
            margin: 0;
            min-height: 100vh;
        }

        body::before {
            content: '';
            position: fixed;
            inset: 0;
            background:
                radial-gradient(ellipse 60% 45% at 15% -5%, rgba(148, 227, 194, 0.13), transparent 60%),
                radial-gradient(ellipse 50% 40% at 90% 110%, rgba(0, 128, 128, 0.16), transparent 60%);
            pointer-events: none;
            z-index: 0;
        }

        .page { position: relative; z-index: 1; max-width: 1240px; margin: 0 auto; padding: 0 1.4rem 4rem; }

        /* ===== TOP BAR ===== */
        .topbar {
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 1rem;
            padding: 1.3rem 0;
        }
        .topbar .brand { display: flex; align-items: center; gap: 0.9rem; text-decoration: none; color: var(--text); }
        .topbar .brand img { height: 44px; width: auto; display: block; }
        .topbar .brand span { font-weight: 600; letter-spacing: 0.02em; font-size: 1.02rem; color: var(--text-dim); }
        .back-link {
            color: var(--teal-deep);
            background: var(--mint);
            text-decoration: none;
            font-weight: 600;
            font-size: 0.92rem;
            padding: 0.55rem 1.3rem;
            border-radius: 999px;
            transition: transform 0.25s ease, box-shadow 0.25s ease;
            white-space: nowrap;
        }
        .back-link:hover { transform: translateY(-2px); box-shadow: 0 8px 24px rgba(148, 227, 194, 0.3); }

        /* ===== HOME / VÝBĚR LEKCE ===== */
        .hero { text-align: center; padding: 3.2rem 0 2.6rem; }
        .hero h1 {
            font-size: clamp(2rem, 4.5vw, 3.2rem);
            font-weight: 800;
            letter-spacing: -0.02em;
            margin: 0 0 1rem;
            background: linear-gradient(120deg, #ffffff 20%, var(--mint) 80%);
            -webkit-background-clip: text;
            background-clip: text;
            -webkit-text-fill-color: transparent;
        }
        .hero p { color: var(--text-dim); font-size: 1.08rem; max-width: 44rem; margin: 0 auto; line-height: 1.65; }

        .lessons { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 1.4rem; margin-top: 1.4rem; }
        .lesson-card {
            background: var(--surface);
            border: 1px solid var(--border);
            border-radius: 1.6rem;
            padding: 0;
            overflow: hidden;
            cursor: pointer;
            text-align: left;
            color: var(--text);
            font-family: inherit;
            font-size: inherit;
            backdrop-filter: blur(14px);
            -webkit-backdrop-filter: blur(14px);
            transition: transform 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275), border-color 0.3s ease, box-shadow 0.3s ease;
        }
        .lesson-card:hover, .lesson-card:focus-visible {
            transform: translateY(-8px);
            border-color: rgba(148, 227, 194, 0.45);
            box-shadow: 0 18px 44px rgba(148, 227, 194, 0.12);
            outline: none;
        }
        .lesson-card .cover { display: block; position: relative; aspect-ratio: 16 / 9; overflow: hidden; background: #0d1b1a; }
        .lesson-card .cover img { width: 100%; height: 100%; object-fit: cover; object-position: top; display: block; opacity: 0.88; transition: transform 0.6s ease; }
        .lesson-card:hover .cover img { transform: scale(1.04); }
        .lesson-card .cover::after {
            content: '';
            position: absolute; inset: 0;
            background: linear-gradient(180deg, transparent 45%, rgba(5, 5, 5, 0.85));
        }
        .lesson-card .body { display: block; padding: 1.3rem 1.5rem 1.6rem; }
        .lesson-card .title { display: block; margin: 0 0 0.45rem; font-size: 1.32rem; font-weight: 700; letter-spacing: -0.01em; }
        .lesson-card .meta { color: var(--text-dim); font-size: 0.9rem; display: flex; align-items: center; gap: 0.5rem; }
        .lesson-card .meta .dot { width: 5px; height: 5px; border-radius: 50%; background: var(--mint); display: inline-block; }
        .lesson-card .cta {
            display: inline-block;
            margin-top: 1.05rem;
            color: var(--mint);
            font-weight: 600;
            font-size: 0.95rem;
        }

        /* ===== PROHLÍDKA ===== */
        #tour { display: none; }
        body.mode-tour #home { display: none; }
        body.mode-tour #tour { display: block; }

        .tour-head { display: flex; align-items: baseline; justify-content: space-between; gap: 1rem; flex-wrap: wrap; margin: 0.6rem 0 1.1rem; }
        .tour-head h1 { font-size: clamp(1.4rem, 3vw, 2rem); font-weight: 800; letter-spacing: -0.01em; margin: 0; }
        .tour-head .counter { color: var(--text-dim); font-size: 1rem; font-variant-numeric: tabular-nums; }
        .tour-head .counter strong { color: var(--mint); font-weight: 700; }

        .progress-track { height: 4px; border-radius: 999px; background: rgba(255, 255, 255, 0.08); overflow: hidden; margin-bottom: 1.4rem; }
        .progress-fill { height: 100%; width: 0; background: linear-gradient(90deg, var(--mint), #4fd1a5); border-radius: 999px; transition: width 0.45s cubic-bezier(0.22, 1, 0.36, 1); }

        .stage-wrap {
            background: var(--surface);
            border: 1px solid var(--border);
            border-radius: 1.6rem;
            backdrop-filter: blur(14px);
            -webkit-backdrop-filter: blur(14px);
            overflow: hidden;
        }
        .stage {
            position: relative;
            background:
                radial-gradient(ellipse 70% 90% at 50% 0%, rgba(148, 227, 194, 0.06), transparent),
                #0b1514;
            display: flex;
            align-items: center;
            justify-content: center;
            min-height: 320px;
            max-height: 68vh;
            padding: 1.6rem;
        }
        .stage img {
            max-width: 100%;
            max-height: calc(68vh - 3.2rem);
            width: auto;
            height: auto;
            border-radius: 0.7rem;
            box-shadow: 0 24px 60px rgba(0, 0, 0, 0.55), 0 0 0 1px rgba(255, 255, 255, 0.06);
            opacity: 1;
            transition: opacity 0.35s ease;
        }
        .stage img.fading { opacity: 0; }

        .caption-panel { padding: 1.5rem 1.8rem 1.7rem; border-top: 1px solid var(--border); }
        .caption-panel .step-section {
            display: block;
            color: var(--mint);
            font-size: 0.82rem;
            font-weight: 700;
            letter-spacing: 0.08em;
            text-transform: uppercase;
            margin: 0 0 0.55rem;
        }
        .caption-panel .step-title { font-size: clamp(1.1rem, 2.4vw, 1.45rem); font-weight: 600; line-height: 1.45; margin: 0; }
        .caption-panel .step-text { color: var(--text-dim); font-size: 1rem; line-height: 1.7; margin: 0.85rem 0 0; max-width: 72rem; }
        .caption-panel .step-text:empty { display: none; }
        .caption-panel .provenance { color: var(--text-dim); font-size: 0.88rem; margin-top: 0.9rem; display: flex; align-items: center; gap: 0.55rem; flex-wrap: wrap; }
        .caption-panel .try-live {
            margin-left: auto;
            color: var(--teal-deep);
            background: var(--mint);
            text-decoration: none;
            font-weight: 700;
            font-size: 0.88rem;
            padding: 0.45rem 1.1rem;
            border-radius: 999px;
            transition: transform 0.25s ease, box-shadow 0.25s ease;
            white-space: nowrap;
        }
        .caption-panel .try-live:hover { transform: translateY(-2px); box-shadow: 0 8px 24px rgba(148, 227, 194, 0.3); }
        .caption-panel .try-live[hidden] { display: none; }
        .caption-panel .provenance .badge {
            background: rgba(148, 227, 194, 0.12);
            border: 1px solid rgba(148, 227, 194, 0.25);
            color: var(--mint);
            border-radius: 999px;
            padding: 0.18rem 0.75rem;
            font-weight: 600;
            font-size: 0.8rem;
        }

        .controls { display: flex; align-items: center; justify-content: space-between; gap: 1rem; margin-top: 1.3rem; flex-wrap: wrap; }
        .controls .group { display: flex; align-items: center; gap: 0.7rem; }
        .nav-btn {
            font-family: inherit;
            font-size: 0.96rem;
            font-weight: 600;
            border: 1px solid var(--border);
            background: var(--surface);
            color: var(--text);
            border-radius: 999px;
            padding: 0.68rem 1.6rem;
            cursor: pointer;
            backdrop-filter: blur(10px);
            transition: border-color 0.25s ease, transform 0.2s ease, background 0.25s ease;
        }
        .nav-btn:hover:not(:disabled), .nav-btn:focus-visible { border-color: rgba(148, 227, 194, 0.5); transform: translateY(-2px); outline: none; }
        .nav-btn:disabled { opacity: 0.35; cursor: default; }
        .nav-btn.primary { background: var(--mint); color: var(--teal-deep); border-color: transparent; }
        .nav-btn.primary:hover:not(:disabled) { box-shadow: 0 8px 24px rgba(148, 227, 194, 0.3); }
        .nav-btn.playing { background: rgba(148, 227, 194, 0.15); color: var(--mint); border-color: rgba(148, 227, 194, 0.4); }

        .kbd-hint { color: var(--text-dim); font-size: 0.82rem; }
        .kbd-hint kbd {
            font-family: inherit;
            background: rgba(255, 255, 255, 0.07);
            border: 1px solid var(--border);
            border-radius: 0.4rem;
            padding: 0.1rem 0.45rem;
            font-size: 0.78rem;
        }

        /* ===== FILMSTRIP ===== */
        .filmstrip {
            display: flex;
            gap: 0.6rem;
            overflow-x: auto;
            padding: 1.1rem 0.2rem 0.6rem;
            scrollbar-width: thin;
            scrollbar-color: rgba(148, 227, 194, 0.35) transparent;
        }
        .filmstrip::-webkit-scrollbar { height: 6px; }
        .filmstrip::-webkit-scrollbar-thumb { background: rgba(148, 227, 194, 0.3); border-radius: 999px; }
        .thumb {
            flex: 0 0 auto;
            width: 118px;
            aspect-ratio: 16 / 10;
            border-radius: 0.6rem;
            overflow: hidden;
            border: 2px solid transparent;
            background: #0d1b1a;
            padding: 0;
            cursor: pointer;
            opacity: 0.55;
            transition: opacity 0.25s ease, border-color 0.25s ease, transform 0.2s ease;
        }
        .thumb img { width: 100%; height: 100%; object-fit: cover; object-position: top; display: block; }
        .thumb:hover, .thumb:focus-visible { opacity: 0.9; transform: translateY(-2px); outline: none; }
        .thumb.active { opacity: 1; border-color: var(--mint); }

        .status-msg { text-align: center; color: var(--text-dim); padding: 4rem 1rem; font-size: 1.05rem; }

        @media (max-width: 640px) {
            .stage { padding: 0.9rem; min-height: 220px; }
            .caption-panel { padding: 1.1rem 1.2rem 1.3rem; }
            .kbd-hint { display: none; }
        }

        @media (prefers-reduced-motion: reduce) {
            *, *::before, *::after { transition: none !important; animation: none !important; }
        }