:root {
            --bg: #f8f7f4;
            --bg-soft: #f5f3ee;
            --panel: rgba(255, 255, 255, 0.78);
            --panel-strong: rgba(255, 252, 248, 0.94);
            --panel-light: rgba(255, 255, 255, 0.54);
            --text: #1e2336;
            --text-muted: #70778c;
            --text-dim: #8d92a1;
            --line: rgba(30, 35, 54, 0.1);
            --line-strong: rgba(30, 35, 54, 0.18);
            --gold: #f3b54a;
            --amber: #ff9163;
            --primary: #2f53ea;
            --primary-deep: #2138a5;
            --blue: #335cff;
            --cyan: #b8c6ff;
            --teal: #47a8a0;
            --violet: #dfe5ff;
            --rose: #af2e3d;
            --shadow: 0 24px 70px rgba(11, 16, 32, 0.09);
            --shadow-soft: 0 14px 36px rgba(11, 16, 32, 0.07);
            --radius-sm: 14px;
            --radius-md: 22px;
            --radius-lg: 32px;
            --font-serif: "Noto Serif SC", serif;
            --font-sans: "Inter", -apple-system, BlinkMacSystemFont, sans-serif;
        }

        html[data-zda-theme="dark"] {
            --bg: #0f172a;
            --bg-soft: #172033;
            --panel: rgba(30, 41, 59, 0.88);
            --panel-strong: rgba(30, 41, 59, 0.98);
            --panel-light: rgba(51, 65, 85, 0.62);
            --text: #f8fafc;
            --text-muted: #cbd5e1;
            --text-dim: #94a3b8;
            --line: rgba(148, 163, 184, 0.22);
            --line-strong: rgba(148, 163, 184, 0.32);
            --primary: #a855f7;
            --primary-deep: #c084fc;
            --blue: #818cf8;
            --cyan: #93c5fd;
            --teal: #5fc8bd;
            --violet: #334155;
            --rose: #ff8d98;
            --shadow: 0 24px 70px rgba(2, 6, 23, 0.34);
            --shadow-soft: 0 14px 36px rgba(2, 6, 23, 0.28);
        }

        * { margin: 0; padding: 0; box-sizing: border-box; }
        html { scroll-behavior: smooth; }
        html.modal-scroll-locked { scroll-behavior: auto; }
        html.generation-scroll-locked, html.generation-scroll-locked body,
        html.payment-scroll-locked, html.payment-scroll-locked body { overflow: hidden; }
        html:not(.app-ready) body > *:not(.boot-screen) { visibility: hidden; }

        body {
            font-family: var(--font-sans);
            background: #faf9f6;
            color: var(--text);
            line-height: 1.7;
            overflow-x: hidden;
            min-height: 100vh;
            position: relative;
        }

        a { color: inherit; }
        button, input { font: inherit; }

        .index-scale-shell {
            width: 100%;
            min-height: 100vh;
        }
        .index-scale-content {
            width: 100%;
            transform-origin: top left;
        }
        html.scaled-index-page .index-scale-shell {
            height: var(--index-page-scaled-height, auto);
            overflow-x: hidden;
        }
        html.scaled-index-page .index-scale-content {
            width: 920px;
            transform: scale(var(--index-page-scale, 1));
        }

        .boot-screen {
            position: fixed;
            inset: 0;
            z-index: 10000;
            display: grid;
            place-items: center;
            background: #faf9f6;
            color: var(--text);
            font-size: 14px;
            font-weight: 800;
        }
        html.app-ready .boot-screen { display: none; }

        .noise-overlay {
            position: fixed; inset: 0; pointer-events: none; z-index: 10; opacity: 0.07; mix-blend-mode: soft-light;
            background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 240 240' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='1.15' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.8'/%3E%3C/svg%3E");
        }

        .gradient-bg { position: fixed; inset: 0; z-index: -3; overflow: hidden; }
        .gradient-orb { position: absolute; border-radius: 50%; filter: blur(100px); opacity: 0.48; animation: float 20s ease-in-out infinite; transition: opacity 1s ease; }
        .orb-1 { width: 560px; height: 560px; top: -120px; left: -80px; background: radial-gradient(circle, rgba(184, 198, 255, 0.24), transparent 72%); }
        .orb-2 { width: 460px; height: 460px; top: 18%; right: -140px; background: radial-gradient(circle, rgba(255, 209, 183, 0.26), transparent 70%); animation-delay: -6s; }
        .orb-3 { width: 420px; height: 420px; bottom: -120px; left: 28%; background: radial-gradient(circle, rgba(71, 168, 160, 0.14), transparent 72%); animation-delay: -12s; }

        /* 动态背景层 */
        .theme-bg { position: absolute; inset: 0; opacity: 0; transition: opacity 1s ease; pointer-events: none; z-index: -1; }
        .bg-general { background-image: linear-gradient(rgba(30, 35, 54, 0.045) 1px, transparent 1px), linear-gradient(90deg, rgba(30, 35, 54, 0.045) 1px, transparent 1px); background-size: 52px 52px; mask-image: radial-gradient(circle at center, rgba(0, 0, 0, 0.92), transparent 78%); }
        body[data-scroll-theme="general"] .bg-general { opacity: 0.42; }
        .bg-science { background-image: radial-gradient(circle at 20% 30%, rgba(71, 168, 160, 0.15) 2px, transparent 4px), radial-gradient(circle at 70% 60%, rgba(71, 168, 160, 0.1) 3px, transparent 5px), radial-gradient(circle at 40% 80%, rgba(71, 168, 160, 0.08) 2px, transparent 3px), radial-gradient(circle at 80% 20%, rgba(71, 168, 160, 0.12) 2px, transparent 4px); background-size: 200px 200px; }
        body[data-scroll-theme="science"] .bg-science { opacity: 1; }
        .bg-history { background-image: repeating-linear-gradient(90deg, rgba(138, 63, 45, 0.04) 0px, rgba(138, 63, 45, 0.04) 1px, transparent 1px, transparent 40px), radial-gradient(circle at center, rgba(220, 180, 140, 0.1) 0%, transparent 80%); }
        body[data-scroll-theme="history"] .bg-history { opacity: 1; }
        .bg-mind { background-image: radial-gradient(circle at 50% 50%, rgba(255, 145, 99, 0.04) 0%, transparent 50%), radial-gradient(circle at 20% 80%, rgba(184, 198, 255, 0.05) 0%, transparent 40%); background-size: 100% 100%; }
        body[data-scroll-theme="mind"] .bg-mind { opacity: 1; }
        .bg-tech { background-image: linear-gradient(rgba(51, 92, 255, 0.06) 1px, transparent 1px), linear-gradient(90deg, rgba(51, 92, 255, 0.06) 1px, transparent 1px); background-size: 40px 40px; }
        body[data-scroll-theme="tech"] .bg-tech { opacity: 1; }

        .scroll-figure { position: absolute; width: 220px; height: 220px; opacity: 0.12; transition: opacity 0.7s ease, transform 0.7s ease, border-radius 0.7s ease, background 0.7s ease; }
        .figure-left { left: 4vw; top: 32vh; transform: translateX(-40px) rotate(-8deg); }
        .figure-right { right: 5vw; top: 54vh; transform: translateX(40px) rotate(8deg); }
        body[data-scroll-theme] .figure-left, body[data-scroll-theme] .figure-right { opacity: 0.18; transform: translateX(0) rotate(0); }

        @keyframes float {
            0%, 100% { transform: translate3d(0, 0, 0) scale(1); }
            25% { transform: translate3d(20px, -18px, 0) scale(1.04); }
            50% { transform: translate3d(-16px, 28px, 0) scale(0.97); }
            75% { transform: translate3d(26px, 18px, 0) scale(1.02); }
        }

        /* 导航栏 */
        .navbar {
            position: fixed; top: 0; left: 0; width: 100%; z-index: 1000;
            background: rgba(255, 255, 255, 0.45);
            backdrop-filter: saturate(180%) blur(32px); -webkit-backdrop-filter: saturate(180%) blur(32px);
            border-bottom: 1px solid rgba(255, 255, 255, 0.6);
            transition: background 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease, transform 0.58s cubic-bezier(0.45, 0, 0.2, 1), opacity 0.42s ease;
        }
        .navbar.scrolled {
            background: rgba(255, 255, 255, 0.75); box-shadow: 0 4px 30px rgba(0, 0, 0, 0.05);
        }

        .nav-container, .section-container, .footer-container { width: min(1280px, calc(100% - 48px)); margin: 0 auto; }
        .nav-container { display: flex; align-items: center; justify-content: space-between; height: 82px; }
        .logo { display: flex; align-items: center; gap: 12px; border: none; background: transparent; color: inherit; text-decoration: none; cursor: pointer; }
        .logo-symbol { display: block; width: 82px; height: 42px; object-fit: contain; }
        .logo-name { font-family: var(--font-serif); font-size: 24px; font-weight: 700; letter-spacing: 0.04em; }

        .nav-links { display: flex; gap: 32px; }
        .nav-links button { position: relative; border: none; background: transparent; color: var(--text-muted); font-size: 14px; font-weight: 600; cursor: pointer; transition: color 0.3s ease; }
        .nav-links button::after {
            content: ""; position: absolute; left: 0; bottom: -6px; width: 0; height: 2px;
            border-radius: 999px; background: linear-gradient(90deg, var(--cyan), var(--gold)); transition: width 0.3s ease;
        }
        .nav-links button:hover { color: var(--text); }
        .nav-links button:hover::after { width: 100%; }

        .nav-actions { display: flex; align-items: center; gap: 16px; }

        /* 主屏与输入区域 */
        .hero {
            width: min(1280px, calc(100% - 48px)); margin: 0 auto;
            min-height: 100vh; padding: 120px 0 60px;
            display: flex; flex-direction: column; justify-content: center; position: relative;
        }
        html.scaled-index-page .hero {
            justify-content: flex-start;
            padding-top: 350px;
        }
        .hero-copy { position: relative; z-index: 20; margin-bottom: 50px; }
        .hero-title, .section-title { font-family: var(--font-serif); letter-spacing: 0.02em; }
        .hero-title { font-size: clamp(38px, 4vw, 86px); line-height: 1.07; font-weight: 700; margin-bottom: 26px; }
        .title-line { display: block; }
        .title-line .accent { background: linear-gradient(135deg, #2f53ea, #ff9163); -webkit-background-clip: text; color: transparent; margin-left: 0.22em; }
        .type-line { display: inline-block; color: #47a8a0; margin-left: 0.22em; }
        #typewriter::after { content: "|"; margin-left: 6px; color: rgba(71, 168, 160, 0.76); animation: blink 1s infinite; }
        @keyframes blink { 0%, 50% { opacity: 1; } 51%, 100% { opacity: 0; } }
        .hero-desc, .section-desc { text-align:center ; color: var(--text-muted); font-size: 17px; line-height: 1.85; }
        .hero-desc { margin-bottom: 0;text-align:left ; }
        .highlight { color: var(--text); font-weight: 700; background: linear-gradient(180deg, transparent 45%, rgba(184, 198, 255, 0.28) 46%, rgba(255, 209, 183, 0.24) 100%); }

        .hero-stage { position: relative; scroll-margin-top: 104px; z-index: 20; width: 100%; }

        .stage-shell {
            position: relative; overflow: hidden; border-radius: 22px; padding: 24px;
            background: rgba(255, 255, 255, 0.4);
            backdrop-filter: blur(24px); -webkit-backdrop-filter: blur(24px);
            border: 1px solid rgba(255, 255, 255, 0.8);
            box-shadow: 0 24px 60px rgba(11, 16, 32, 0.08), inset 0 1px 0 rgba(255, 255, 255, 0.8);
        }
        .input-dock {
            position: relative; z-index: 2; padding: 18px; border-radius: 20px;
            border: 1px solid rgba(255, 255, 255, 0.5);
            background: rgba(255, 255, 255, 0.85);
            box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.9);
        }
        .input-label { display: block; color: var(--text); font-size: 14px; font-weight: 700; margin-bottom: 12px; }
        .input-row { display: flex; gap: 12px; margin-bottom: 0; }
        .input-row input {
            flex: 1; min-width: 0; border-radius: 16px;
            border: 1px solid rgba(30, 35, 54, 0.08);
            background: rgba(255, 255, 255, 0.6);
            color: var(--text); padding: 16px 18px; outline: none; font-size: 14px; transition: all 0.3s ease;
        }
        .input-row input:focus { border-color: rgba(47, 83, 234, 0.28); box-shadow: 0 0 0 4px rgba(184, 198, 255, 0.24); }
        .input-row input::placeholder { color: rgba(112, 119, 140, 0.68); }

        /* ==== 修改1：醒目的输入框高亮动画 ==== */
        @keyframes strongPulse {
            0% { border-color: var(--primary); box-shadow: 0 0 0 0 rgba(47, 83, 234, 0.5); background: #fff; }
            50% { border-color: var(--primary); box-shadow: 0 0 0 12px rgba(47, 83, 234, 0); background: #fff; transform: translateY(-1px); }
            100% { border-color: rgba(30, 35, 54, 0.08); box-shadow: 0 0 0 0 rgba(47, 83, 234, 0); background: rgba(255, 255, 255, 0.6); transform: translateY(0); }
        }
        .input-row input.pulse-active {
            animation: strongPulse 1.2s cubic-bezier(0.2, 0.8, 0.2, 1);
        }

        .btn-generate {
            border: none; border-radius: 999px; cursor: pointer; display: inline-flex; align-items: center; justify-content: center;
            background: #1c2030; color: #fff; padding: 12px 28px; font-size: 14px; font-weight: 600;
            box-shadow: 0 8px 20px rgba(28, 32, 48, 0.15); transition: all 0.28s ease;
        }
        .btn-generate:hover { background: #16243d; transform: translateY(-2px); box-shadow: 0 10px 24px rgba(7, 17, 35, 0.24); }

        .hero-copy, .topic-atlas, .story-loop, .universe-showcase, .pricing, .faq, .about, .footer, .modal-overlay, .noise-overlay, .gradient-bg {
            transition: opacity 0.5s ease, transform 0.58s cubic-bezier(0.45, 0, 0.2, 1);
        }
        body.generation-exit .navbar { transform: translateY(-110%); opacity: 0; }
        body.generation-exit .hero-copy,
        body.generation-exit .topic-atlas,
        body.generation-exit .story-loop,
        body.generation-exit .universe-showcase,
        body.generation-exit .pricing,
        body.generation-exit .faq,
        body.generation-exit .about,
        body.generation-exit .footer,
        body.generation-exit .modal-overlay,
        body.generation-exit .noise-overlay,
        body.generation-exit .gradient-bg {
            opacity: 0;
            transform: translateY(16px);
            pointer-events: none;
        }
        body.generation-exit .stage-shell { opacity: 0; transition: opacity 0.26s ease; }
        .handoff-bubble {
            position: fixed;
            z-index: 3000;
            display: flex;
            align-items: center;
            min-height: 56px;
            max-width: min(460px, calc(100vw - 32px));
            padding: 14px 18px;
            border-radius: 18px;
            color: #1e2336;
            background: #eef2ff;
            border: 1px solid rgba(47, 83, 234, 0.14);
            box-shadow: 0 18px 50px rgba(11, 16, 32, 0.12);
            font-size: 15px;
            font-weight: 650;
            line-height: 1.72;
            overflow: hidden;
            text-overflow: ellipsis;
            white-space: nowrap;
            transition: left 0.72s cubic-bezier(0.2, 0.8, 0.2, 1), top 0.72s cubic-bezier(0.2, 0.8, 0.2, 1), width 0.72s cubic-bezier(0.2, 0.8, 0.2, 1), min-height 0.72s cubic-bezier(0.2, 0.8, 0.2, 1), padding 0.72s cubic-bezier(0.2, 0.8, 0.2, 1), border-radius 0.72s cubic-bezier(0.2, 0.8, 0.2, 1), background 0.72s ease;
        }

        .section-header { text-align: center; margin: 0 auto 54px; }
        .section-title { font-size: clamp(34px, 3vw, 54px); line-height: 1.18; margin-bottom: 16px; }
        .section-tag, .flow-index {
            display: inline-flex; align-items: center; gap: 6px; color: #b4710b;
            background: linear-gradient(135deg, rgba(243, 181, 74, 0.18), rgba(243, 181, 74, 0.05));
            border: 1px solid rgba(243, 181, 74, 0.35); padding: 6px 16px; border-radius: 999px;
            font-size: 12px; font-weight: 800; text-transform: uppercase; letter-spacing: 0.08em;
            box-shadow: 0 4px 12px rgba(243, 181, 74, 0.08);
        }
        .section-header .section-tag { margin: 0 auto 16px; }
        .about-copy .section-tag { margin-bottom: 24px; align-self: flex-start; }

        /* 知识概览 Topic Atlas */
        .topic-atlas { min-height: 100vh; display: flex; flex-direction: column; justify-content: center; padding: 84px 0 36px; }
        .topic-grid { display: grid; grid-template-columns: repeat(5, minmax(220px, 1fr)); gap: 18px; }
        .topic-grid .topic-list { transition: opacity 0.36s ease, transform 0.36s ease; }
        .topic-grid.topic-swapping .topic-list { opacity: 0; transform: translateY(8px); }
        .topic-card { position: relative; min-height: 280px; padding: 22px; border-radius: 22px; border: 1px solid var(--line); background: rgba(255, 255, 255, 0.72); box-shadow: var(--shadow-soft); overflow: hidden; }
        .topic-card-visual { position: absolute; top: 20px; right: 18px; width: 92px; height: 92px; opacity: 0.22; transition: opacity 0.4s ease, transform 0.4s ease; }
        .topic-card-visual svg { width: 100%; height: 100%; fill: none; stroke: currentColor; stroke-width: 3; stroke-linecap: round; stroke-linejoin: round; }
        .topic-card:hover .topic-card-visual { opacity: 0.34; transform: translateY(-4px); }
        .topic-card-visual.general { color: var(--primary); background: linear-gradient(rgba(51, 92, 255, 0.28) 1px, transparent 1px), linear-gradient(90deg, rgba(51, 92, 255, 0.28) 1px, transparent 1px); background-size: 16px 16px; border-radius: 18px; }
        .topic-card-visual.science { color: var(--teal); border: 2px solid rgba(71, 168, 160, 0.42); border-radius: 50%; box-shadow: inset 0 0 0 24px rgba(71, 168, 160, 0.08); }
        .topic-card-visual.history { color: var(--rose); border-radius: 26px 8px 26px 8px; border: 2px solid rgba(175, 46, 61, 0.24); background: repeating-linear-gradient(0deg, rgba(255, 145, 99, 0.14) 0 2px, transparent 2px 16px); }
        .topic-card-visual.mind { color: var(--amber); border-radius: 50% 46% 54% 42%; background: radial-gradient(circle at 35% 35%, rgba(255, 209, 183, 0.74), transparent 28%), radial-gradient(circle at 62% 62%, rgba(184, 198, 255, 0.58), transparent 34%); }
        .topic-card-visual.tech { color: var(--primary-deep); border-radius: 18px; background: linear-gradient(rgba(47, 83, 234, 0.22) 1px, transparent 1px), linear-gradient(90deg, rgba(47, 83, 234, 0.22) 1px, transparent 1px), rgba(234, 239, 255, 0.72); background-size: 18px 18px; }
        .topic-card-copy { position: relative; z-index: 1; margin-bottom: 22px; }
        .topic-label { display: inline-flex; margin-bottom: 14px; color: var(--primary); font-size: 12px; font-weight: 800; }
        .topic-card h3 { font-family: var(--font-serif); font-size: 26px; margin-bottom: 10px; }
        .topic-list { position: relative; z-index: 1; display: grid; gap: 10px; }
        .topic-chip { border: 1px solid rgba(30, 35, 54, 0.1); border-radius: 14px; background: rgba(248, 247, 244, 0.84); color: var(--text); cursor: pointer; padding: 8px 12px; text-align: left; font-size: 13px; font-weight: 700; transition: background 0.28s ease, border-color 0.28s ease, transform 0.28s ease; display: inline-block; white-space: nowrap; overflow: hidden; text-overflow: ellipsis;}
        .topic-chip:hover { border-color: rgba(47, 83, 234, 0.18); background: rgba(234, 239, 255, 0.7); transform: translateX(3px); }
        html.scaled-index-page .topic-card:nth-child(n + 4) { display: none; }

        /* 数据流区域 */
        .story-loop { height: 400vh; position: relative; padding: 0; }
        .story-loop-sticky { position: sticky; top: 0; height: 100vh; display: flex; flex-direction: column; justify-content: center; overflow: hidden; }
        html.scaled-index-page .story-loop { padding: 40px 0 84px; height: auto; }
        html.scaled-index-page .story-loop-sticky { position: static; display: block; height: auto; overflow: visible; }

        .data-flow { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 42px 58px; position: relative; z-index: 1; margin-top: 24px; }
        .flow-card {
            position: relative; border-radius: 18px; padding: 20px; min-height: 220px;
            border: 1px solid rgba(30, 35, 54, 0.08); background: rgba(255, 255, 255, 0.4);
            box-shadow: none; opacity: 0.35; filter: grayscale(1);
            transform: translateY(16px); transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1); z-index: 2;
        }
        .flow-card.active { border: 1px solid rgba(47, 83, 234, 0.2); background: rgba(255, 255, 255, 0.95); box-shadow: 0 24px 60px rgba(47, 83, 234, 0.08); opacity: 1; filter: grayscale(0); transform: translateY(0); }
        html.scaled-index-page .flow-card { border: 1px solid rgba(47, 83, 234, 0.2); background: rgba(255, 255, 255, 0.95); box-shadow: 0 24px 60px rgba(47, 83, 234, 0.08); opacity: 1; filter: grayscale(0); transform: translateY(0); }

        .flow-1 { grid-column: 1; grid-row: 1; }
        .flow-2 { grid-column: 2; grid-row: 1; }
        .flow-3 { grid-column: 3; grid-row: 1; }
        .flow-4 { grid-column: 4; grid-row: 1; }
        .flow-5 { grid-column: 4; grid-row: 2; }
        .flow-6 { grid-column: 3; grid-row: 2; }
        .flow-7 { grid-column: 2; grid-row: 2; }
        .flow-8 { grid-column: 1; grid-row: 2; }

        .flow-arrow {
            position: absolute; right: -58px; top: 50%; width: 58px; height: 3px;
            background: rgba(30, 35, 54, 0.1); transform: translateY(-50%);
            pointer-events: none; z-index: -1; transition: background 0.5s ease;
        }
        .flow-arrow::after {
            content: ""; position: absolute; right: -2px; top: 50%; border-left: 8px solid rgba(30, 35, 54, 0.1); border-top: 5px solid transparent; border-bottom: 5px solid transparent; transform: translateY(-50%); transition: border-left-color 0.5s ease, border-right-color 0.5s ease, border-top-color 0.5s ease;
        }
        .flow-5 .flow-arrow, .flow-6 .flow-arrow, .flow-7 .flow-arrow { right: auto; left: -58px; }
        .flow-5 .flow-arrow::after, .flow-6 .flow-arrow::after, .flow-7 .flow-arrow::after { right: auto; left: -2px; border-left: none; border-right: 8px solid rgba(30, 35, 54, 0.1); }
        .flow-4 .flow-arrow { right: 50%; left: 50%; top: 100%; bottom: auto; width: 3px; height: 42px; transform: translateX(-50%); }
        .flow-4 .flow-arrow::after { right: auto; left: 50%; top: auto; bottom: -2px; border-left: 5px solid transparent; border-right: 5px solid transparent; border-top: 8px solid rgba(30, 35, 54, 0.1); border-bottom: none; transform: translateX(-50%); }

        .flow-arrow.active { background: var(--primary); }
        .flow-arrow.active::after { border-left-color: var(--primary); }
        .flow-5 .flow-arrow.active::after, .flow-6 .flow-arrow.active::after, .flow-7 .flow-arrow.active::after { border-right-color: var(--primary); }
        .flow-4 .flow-arrow.active::after { border-top-color: var(--primary); }
        html.scaled-index-page .flow-arrow { background: var(--primary); }
        html.scaled-index-page .flow-arrow::after { border-left-color: var(--primary); }
        html.scaled-index-page .flow-5 .flow-arrow::after,
        html.scaled-index-page .flow-6 .flow-arrow::after,
        html.scaled-index-page .flow-7 .flow-arrow::after { border-right-color: var(--primary); }
        html.scaled-index-page .flow-4 .flow-arrow::after { border-top-color: var(--primary); }

        .flow-card h3 { color: var(--text); font-size: 16px; font-weight: 800; margin-bottom: 6px; }
        .flow-card p { font-size: 14px; line-height: 1.7; }
        .flow-index { margin-bottom: 16px; display: block; border: none; background: none; box-shadow: none; padding: 0; }

        /* 沉浸式大观 */
        .universe-showcase { position: relative; min-height: 100vh; padding: 80px 0 0; z-index: 10; margin-top: 40px; }

        #universe-panels { padding-bottom: 0; position: relative; }
        .universe-page-title {
            text-align: center; margin-bottom: 24px; padding: 4px 0 20px;
        }

        .universe-panel {
            position: relative;
            margin-bottom: 40px;
            display: flex; flex-direction: column; justify-content: center;
            padding: clamp(32px, 4vw, 56px) 5vw; min-height: calc(100vh - 230px);
            overflow: hidden; transform: translateZ(0);
        }
        .universe-panel:last-child { margin-bottom: 0; }

        .universe-inner { width: min(1280px, 100%); margin: 0 auto; }
        .universe-inner::-webkit-scrollbar { display: none; }

        .universe-decor {
            position: absolute; width: 220px; height: 220px; opacity: 0; z-index: 0; pointer-events: none;
            transition: opacity 0.8s ease 0.2s, transform 0.9s cubic-bezier(0.2, 0.8, 0.2, 1);
        }
        .universe-decor svg { width: 100%; height: 100%; }
        .universe-decor.left { left: 2%; top: 25%; transform: translateX(-72px) rotate(-5deg); }
        .universe-decor.right { right: 2%; bottom: 15%; transform: translateX(72px) rotate(5deg); }
        .universe-panel.visible .universe-decor { opacity: 0.15; }
        .universe-panel.visible .universe-decor.left { transform: translateX(0) rotate(0deg); }
        .universe-panel.visible .universe-decor.right { transform: translateX(0) rotate(0deg); }
        .universe-panel.visible .universe-decor.left svg { animation: floatDecorLeft 8s ease-in-out infinite alternate 1s; }
        .universe-panel.visible .universe-decor.right svg { animation: floatDecorRight 9s ease-in-out infinite alternate 1s; }

        @keyframes floatDecorLeft { 0% { transform: translateY(0) rotate(0deg); } 100% { transform: translateY(-15px) rotate(3deg); } }
        @keyframes floatDecorRight { 0% { transform: translateY(0) rotate(0deg); } 100% { transform: translateY(15px) rotate(-3deg); } }

        .universe-panel[data-theme="science"] .universe-decor { color: var(--teal); }
        .universe-panel[data-theme="history"] .universe-decor { color: var(--rose); }
        .universe-panel[data-theme="mind"] .universe-decor { color: var(--amber); }
        .universe-panel[data-theme="tech"] .universe-decor { color: var(--primary); }
        .universe-panel[data-theme="general"] .universe-decor { color: var(--gold); }

        .universe-panel-header { display: flex; align-items: center; gap: 24px; margin-bottom: 42px; position: relative; z-index: 1; }
        .theme-icon { width: 84px; height: 84px; border-radius: 20px; display: flex; align-items: center; justify-content: center; position: relative; overflow: hidden; }
        .theme-icon.general { color: var(--primary); background: linear-gradient(rgba(51, 92, 255, 0.28) 1px, transparent 1px), linear-gradient(90deg, rgba(51, 92, 255, 0.28) 1px, transparent 1px); background-size: 16px 16px; border: 1px solid rgba(51,92,255,0.1); }
        .theme-icon.science { color: var(--teal); border: 2px solid rgba(71, 168, 160, 0.42); box-shadow: inset 0 0 0 24px rgba(71, 168, 160, 0.08); border-radius: 50%; }
        .theme-icon.history { color: var(--rose); border: 2px solid rgba(175, 46, 61, 0.24); background: repeating-linear-gradient(0deg, rgba(255, 145, 99, 0.14) 0 2px, transparent 2px 16px); }
        .theme-icon.mind { color: var(--amber); background: radial-gradient(circle at 35% 35%, rgba(255, 209, 183, 0.74), transparent 28%), radial-gradient(circle at 62% 62%, rgba(184, 198, 255, 0.58), transparent 34%); }
        .theme-icon.tech { color: var(--primary-deep); background: linear-gradient(rgba(47, 83, 234, 0.22) 1px, transparent 1px), linear-gradient(90deg, rgba(47, 83, 234, 0.22) 1px, transparent 1px), rgba(234, 239, 255, 0.72); background-size: 18px 18px; border: 1px solid rgba(47,83,234,0.1);}
        .theme-icon svg { width: 50%; height: 50%; fill: none; stroke: currentColor; stroke-width: 3; stroke-linecap: round; stroke-linejoin: round; }

        .theme-info { flex: 1; }
        .theme-label { font-size: 14px; font-weight: 800; color: var(--primary); margin-bottom: 8px; display: inline-block; padding: 4px 12px; background: rgba(255,255,255,0.7); border-radius: 999px; }
        .universe-panel[data-theme="science"] .theme-label { color: var(--teal); }
        .universe-panel[data-theme="history"] .theme-label { color: var(--rose); }
        .universe-panel[data-theme="mind"] .theme-label { color: var(--amber); }
        .universe-panel[data-theme="general"] .theme-label { color: #8a7a2d; }
        .theme-title { font-size: 32px; font-family: var(--font-serif); margin-bottom: 6px; }
        .theme-desc { color: var(--text-muted); font-size: 15px; max-width: 600px; }

        .universe-content { display: grid; grid-template-columns: minmax(190px, 240px) minmax(0, 1fr); gap: clamp(28px, 4vw, 56px); position: relative; z-index: 1; align-items: start; }
        .universe-main { min-width: 0; }

        .universe-sidebar { min-width: 0; }
        .universe-sidebar h4, .universe-main h4 { font-size: 14px; color: var(--text-dim); margin-bottom: 18px; font-weight: 700; text-transform: uppercase; letter-spacing: 0.05em; }
        .universe-sidebar .topic-chips { display: flex; flex-direction: column; gap: 10px; margin-bottom: 18px; }
        .universe-case-rail {
            position: relative;
            height: 600px;
            overflow: hidden;
        }
        .universe-case-list { display: flex; flex-direction: column; gap: 16px; padding: 14px; }
        .universe-case-option {
            width: 100%;
            padding: 0;
            border: none;
            background: transparent;
            cursor: pointer;
            text-align: left;
            transition: transform 0.2s ease;
        }
        .universe-case-option:hover,
        .universe-case-option.active {
            transform: translateY(-1px);
        }
        .universe-case-option .video-placeholder.mini {
            width: 100%;
            box-shadow: none;
            pointer-events: none;
        }
        .universe-case-option .video-preview-frame { pointer-events: none; }
        .universe-case-option .play-button { width: 28px; height: 28px; }
        .universe-case-option .play-button svg { width: 14px; height: 14px; }
        .universe-case-option .video-duration { right: 6px; bottom: 5px; padding: 2px 5px; font-size: 9px; }
        .universe-case-copy { margin-top: 8px; }
        .universe-case-copy strong {
            display: -webkit-box;
            -webkit-box-orient: vertical;
            -webkit-line-clamp: 1;
            overflow: hidden;
            color: var(--text);
            font-size: 13px;
            line-height: 1.45;
        }
        .universe-case-copy span {
            display: -webkit-box;
            -webkit-box-orient: vertical;
            -webkit-line-clamp: 1;
            overflow: hidden;
            margin-top: 3px;
            color: var(--text-muted);
            font-size: 12px;
            line-height: 1.5;
        }
        .universe-case-option.active .universe-case-copy strong { color: var(--primary); }

        .showcase-spotlight { display: flex; flex-direction: column; gap: 18px; align-items: flex-start; }

        .spotlight-case { width: 100%; display: flex; flex-direction: column; border-top: 1px dashed rgba(30,35,54,0.1); padding-top: 18px; }
        .case-tag, .case-mode { padding: 8px 12px; border-radius: 999px; font-size: 11px; font-weight: 800; }
        .case-tag { background: rgba(255, 255, 255, 0.6); color: var(--text); border: 1px solid rgba(255,255,255,0.8); }

        .case-mode, .case-mode-text { cursor: help; text-transform: uppercase; letter-spacing: 0.05em; border: 1px solid transparent; transition: transform 0.2s; }
        .case-mode:hover, .case-mode-text:hover { transform: scale(1.05); }
        .case-mode[data-mode-type="s-c-r-s"], .case-mode-text[data-mode-type="s-c-r-s"] { background: rgba(255, 224, 209, 0.72); color: #8a3f2d; border-color: rgba(255, 224, 209, 0.9); }
        .case-mode[data-mode-type="timeline"], .case-mode-text[data-mode-type="timeline"] { background: rgba(209, 234, 255, 0.72); color: #2d5a8a; border-color: rgba(209, 234, 255, 0.9); }
        .case-mode[data-mode-type="question"], .case-mode-text[data-mode-type="question"] { background: rgba(245, 209, 255, 0.72); color: #7a2d8a; border-color: rgba(245, 209, 255, 0.9); }
        .case-mode[data-mode-type="contrast"], .case-mode-text[data-mode-type="contrast"] { background: rgba(209, 255, 224, 0.72); color: #2d8a4a; border-color: rgba(209, 255, 224, 0.9); }

        .case-title { font-size: 18px; font-weight: 800; margin-bottom: 6px; }
        .case-subtitle { color: var(--primary); font-size: 13px; font-weight: 600; margin-bottom: 12px; }
        .case-summary { font-size: 14px; line-height: 1.72; color: #666; }
        .case-summary h1, .case-summary h2, .case-summary h3,
        .case-detail h1, .case-detail h2, .case-detail h3 { margin: 16px 0 8px; color: #2c2c2c; line-height: 1.45; font-weight: 800; }
        .case-summary h1, .case-detail h1 { font-size: 17px; }
        .case-summary h2, .case-detail h2 { font-size: 16px; }
        .case-summary h3, .case-detail h3 { font-size: 15px; }
        .case-summary p, .case-detail p { margin: 0 0 10px; }
        .case-summary ul, .case-summary ol, .case-detail ul, .case-detail ol { margin: 0 0 10px 20px; padding: 0; }
        .case-summary li, .case-detail li { margin: 4px 0; padding-left: 2px; }
        .case-summary strong, .case-detail strong { color: #2c2c2c; font-weight: 700; }
        .case-summary em, .case-detail em { color: #555; font-style: normal; font-weight: 600; }
        .case-summary code, .case-detail code { padding: 2px 6px; border-radius: 6px; background: #1e293b; color: #e2e8f0; font-family: Consolas, Monaco, monospace; font-size: 0.9em; }
        .case-summary mark, .case-detail mark { color: #2c2c2c; font-weight: 700; background: #fff3a3; text-decoration: underline; text-decoration-color: #eab308; text-decoration-thickness: 1.4px; }
        .case-summary .keyword-ring, .case-detail .keyword-ring {
            padding: 0 7px; border: 1.5px solid #94a3b8; border-radius: 999px;
            color: #2c2c2c; font-weight: 700; line-height: 1.55; background: rgba(248, 250, 252, 0.78);
            box-decoration-break: clone; -webkit-box-decoration-break: clone;
        }
        .case-summary .article-tip, .case-detail .article-tip {
            display: grid; grid-template-columns: 26px 1fr; gap: 10px; align-items: start;
            margin: 12px 0; padding: 10px 12px; border-radius: 10px; border-left: 3px solid var(--tip-accent);
            background: var(--tip-bg); color: #666;
        }
        .case-summary .article-tip::before, .case-detail .article-tip::before {
            content: var(--tip-label); width: 26px; height: 26px; border-radius: 50%;
            display: grid; place-items: center; background: var(--tip-icon-bg); color: var(--tip-accent);
            font-size: 11px; font-weight: 900; line-height: 1; transform: translateY(2px);
        }
        .case-summary .article-tip p, .case-detail .article-tip p { margin: 0; }
        .case-summary .article-tip.life, .case-detail .article-tip.life { --tip-label: "例"; --tip-bg: #fff7ed; --tip-icon-bg: #ffedd5; --tip-accent: #f97316; }
        .case-summary .article-tip.core, .case-detail .article-tip.core { --tip-label: "核"; --tip-bg: #eef2ff; --tip-icon-bg: #e0e7ff; --tip-accent: #4f46e5; }
        .case-summary .article-tip.warning, .case-detail .article-tip.warning { --tip-label: "!"; --tip-bg: #fff1f2; --tip-icon-bg: #ffe4e6; --tip-accent: #e11d48; }
        .case-summary .article-tip.memory, .case-detail .article-tip.memory { --tip-label: "记"; --tip-bg: #f0fdf4; --tip-icon-bg: #dcfce7; --tip-accent: #16a34a; }
        .case-summary .article-tip.observe, .case-detail .article-tip.observe { --tip-label: "观"; --tip-bg: #f0f9ff; --tip-icon-bg: #e0f2fe; --tip-accent: #0284c7; }
        .case-summary .article-tip.study, .case-summary .article-tip.note,
        .case-detail .article-tip.study, .case-detail .article-tip.note { --tip-label: "知"; --tip-bg: #f8fafc; --tip-icon-bg: #e2e8f0; --tip-accent: #475569; }
        .case-detail {
            margin-top: 12px;
            color: #666;
            font-size: 14px;
            line-height: 1.72;
        }
        .case-detail.collapsed {
            display: -webkit-box;
            -webkit-box-orient: vertical;
            -webkit-line-clamp: 5;
            overflow: hidden;
        }
        .case-detail-toggle {
            width: fit-content;
            margin-top: 10px;
            padding: 0;
            border: none;
            background: transparent;
            color: var(--primary);
            font-size: 13px;
            font-weight: 800;
            cursor: pointer;
        }
        .case-meta { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 16px; align-items: center; border-top: 1px dashed rgba(30,35,54,0.1); padding-top: 16px; }
        .case-meta > span:first-child { font-size: 12px; color: var(--text-dim); }
        .case-mode-text { font-size: 12px; padding: 6px 10px; border-radius: 999px; }

        /* ==== 定价方案区块 ==== */
        .pricing { min-height: 100vh; display: flex; flex-direction: column; justify-content: center; padding: 84px 0 40px; }
        .pricing .section-container { width: 100%; max-width: none; padding: 0 48px; box-sizing: border-box; }
        .pricing-grid { display: flex; justify-content: center; align-items: flex-end; gap: 12px; width: 100%; margin: 0 auto; }
        .pricing-card {
            --pricing-card-flex: 1;
            --pricing-card-height: 326px;
            --pricing-amount-size: 62px;
            position: relative; border-radius: 24px; padding: 42px 26px 24px;
            width: auto; min-height: var(--pricing-card-height);
            flex: var(--pricing-card-flex) 1 0;
            min-width: 0;
            background: rgba(255, 255, 255, 0.94); backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px);
            border: 1px solid rgba(30, 35, 54, 0.06); box-shadow: 0 18px 50px rgba(11, 16, 32, 0.06);
            display: flex; flex-direction: column; align-items: center; justify-content: space-between;
            overflow: visible; cursor: pointer;
            transition: min-height 0.36s ease, transform 0.36s ease, box-shadow 0.36s ease, background 0.36s ease, border-color 0.36s ease;
        }
        .pricing-card.step-0 { --pricing-card-flex: 0.82; --pricing-card-height: 306px; --pricing-amount-size: 52px; }
        .pricing-card.step-1 { --pricing-card-flex: 0.96; --pricing-card-height: 324px; --pricing-amount-size: 58px; }
        .pricing-card.step-2 { --pricing-card-flex: 1.08; --pricing-card-height: 342px; --pricing-amount-size: 60px; }
        .pricing-card.step-4 { --pricing-card-flex: 1.08; --pricing-card-height: 358px; --pricing-amount-size: 64px; }
        .pricing-card:hover { transform: translateY(-8px); box-shadow: 0 28px 70px rgba(11, 16, 32, 0.12); background: #fff; }

        .pricing-card.popular {
            --pricing-card-flex: 1.38;
            --pricing-card-height: 394px;
            --pricing-amount-size: 82px;
            border: 2px solid transparent;
            background:
                linear-gradient(150deg, rgba(255, 255, 255, 0.98), rgba(237, 243, 255, 0.98)) padding-box,
                linear-gradient(135deg, var(--primary), var(--blue)) border-box;
            box-shadow: 0 30px 82px rgba(47, 83, 234, 0.2);
        }
        .pricing-card.custom {
            --pricing-card-flex: 1.28;
            --pricing-card-height: 394px;
            --pricing-amount-size: 74px;
            color: #fff;
            background: linear-gradient(150deg, #1b2a44 0%, #2346d8 48%, #0f9f8f 100%);
            border: 1px solid rgba(255, 255, 255, 0.92);
            box-shadow: 0 24px 70px rgba(47, 83, 234, 0.24);
        }
        .pricing-card.custom::before {
            content: "";
            position: absolute;
            inset: 0;
            border-radius: inherit;
            background:
                radial-gradient(circle at 18% 12%, rgba(255, 255, 255, 0.26), transparent 28%),
                linear-gradient(135deg, rgba(255, 255, 255, 0.16), transparent 44%);
            pointer-events: none;
        }
        .pricing-card.custom .popular-badge {
            z-index: 2;
            background: linear-gradient(135deg, #ffffff, #dff7ff);
            color: #1737b3;
            box-shadow: 0 10px 24px rgba(11, 16, 32, 0.16);
        }
        .pricing-card.custom:hover { background: linear-gradient(150deg, #1b2a44 0%, #2f53ea 48%, #0fb7a5 100%); box-shadow: 0 30px 80px rgba(47, 83, 234, 0.32); }
        .pricing-card.custom .pricing-content,
        .pricing-card.custom .pricing-btn { position: relative; z-index: 1; }
        .popular-badge {
            position: absolute; top: 0; left: 50%; transform: translate(-50%, -50%);
            background: linear-gradient(135deg, var(--primary), var(--blue)); color: #fff;
            padding: 5px 14px; border-radius: 999px; font-size: 12px; font-weight: 800; letter-spacing: 0;
            box-shadow: 0 4px 12px rgba(47, 83, 234, 0.2);
            white-space: nowrap;
        }

        .pricing-content {
            flex: 1;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            width: 90%;
            min-width: 0;
            transform-origin: center;
            transition: transform 0.3s ease;
        }
        .pricing-title {
            margin-bottom: 8px;
            color: var(--text);
            font-size: 16px;
            font-weight: 850;
            line-height: 1.28;
            text-align: center;
            white-space: nowrap;
        }
        .pricing-amount-row {
            display: inline-flex;
            align-items: flex-end;
            justify-content: center;
            gap: 3px;
            width: 80%;
            max-width: 100%;
        }
        .pricing-amount {
            color: var(--text);
            font-family: var(--font-serif);
            font-size: var(--pricing-amount-size);
            font-weight: 950;
            line-height: 1;
            letter-spacing: 0;
            font-variant-numeric: tabular-nums;
            transition: color 0.3s ease;
        }
        .pricing-unit {
            margin-bottom: 0.16em;
            color: #999;
            font-family: var(--font-sans);
            font-size: 12px;
            font-weight: 750;
            line-height: 1;
            letter-spacing: 0;
        }
        .pricing-pay {
            margin-top: 10px;
            color: var(--primary);
            font-size: 15px;
            font-weight: 900;
            line-height: 1;
            text-align: center;
        }
        .pricing-card.custom .pricing-pay { color: rgba(255, 255, 255, 0.86); }
        .pricing-discount {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: 7px;
            margin-top: 8px;
            color: #9aa1af;
            font-size: 12px;
            font-weight: 850;
            line-height: 1;
            white-space: nowrap;
        }
        .pricing-original-pay {
            color: #9aa1af;
            text-decoration: line-through;
            font-weight: 800;
        }
        .pricing-discount-badge {
            padding: 5px 9px;
            border-radius: 999px;
            background: linear-gradient(135deg, #ff5a66, #ff8a3d);
            color: #fff;
            border: 0;
            box-shadow: 0 8px 18px rgba(255, 90, 102, 0.24);
        }
        .pricing-card.custom .pricing-discount,
        .pricing-card.custom .pricing-original-pay,
        .pricing-card.custom .pricing-discount { color: rgba(255, 255, 255, 0.74); }
        .pricing-card.custom .pricing-discount-badge { background: rgba(255, 255, 255, 0.94); color: #1737b3; box-shadow: 0 8px 18px rgba(0, 0, 0, 0.12); }
        .pricing-scene {
            display: grid;
            gap: 6px;
            margin-top: 16px;
            color: #999;
            font-family: var(--font-sans);
            font-size: 12px;
            font-weight: 750;
            line-height: 1.25;
            text-align: center;
            width: 100%;
        }
        .pricing-scene-line {
            display: block;
        }
        .pricing-scene-line:first-child {
            color: #8a91a3;
            font-weight: 800;
        }
        .pricing-scene-line:last-child {
            color: #5f6678;
            font-weight: 700;
        }
        .pricing-card.popular .pricing-title { font-size: 18px; }
        .pricing-card.popular .pricing-scene,
        .pricing-card.popular .pricing-unit { font-size: 12px; }
        .pricing-card.custom .pricing-title { color: rgba(255, 255, 255, 0.86); }
        .pricing-card.custom .pricing-amount { color: #fff; }
        .pricing-card.custom .pricing-unit,
        .pricing-card.custom .pricing-scene { color: rgba(255, 255, 255, 0.7); }
        .pricing-card.custom .pricing-scene-line:first-child { color: rgba(255, 255, 255, 0.82); }
        .pricing-card.custom .pricing-scene-line:last-child { color: rgba(255, 255, 255, 0.66); }
        .pricing-card:hover .pricing-content { transform: scale(1.03); }

        .pricing-btn { width: auto; min-width: 96px; padding: 12px 18px; font-size: 14px; font-weight: 800; border-radius: 12px; transition: all 0.3s ease; cursor: pointer; white-space: nowrap; }
        .pricing-card.popular .pricing-btn { width: 100%; }
        .pricing-btn.outline { background: #fff; border: 1px solid rgba(30, 35, 54, 0.15); color: var(--text-muted); }
        .pricing-btn.outline:hover { background: rgba(30, 35, 54, 0.05); color: var(--text); }
        .pricing-btn.primary { background: #eef3ff; color: #3152c7; border: 1px solid rgba(47, 83, 234, 0.12); box-shadow: none; }
        .pricing-card.step-2 .pricing-btn.primary { background: #dfe8ff; color: #2b4bd0; box-shadow: 0 6px 16px rgba(47, 83, 234, 0.12); }
        .pricing-card.step-3 .pricing-btn.primary { background: #5c78f2; color: #fff; border: none; box-shadow: 0 8px 20px rgba(47, 83, 234, 0.2); }
        .pricing-card.step-4 .pricing-btn.primary { background: #3152d9; color: #fff; border: none; box-shadow: 0 10px 24px rgba(47, 83, 234, 0.24); }
        .pricing-btn.primary:hover { filter: brightness(0.97); transform: translateY(-2px); box-shadow: 0 12px 28px rgba(47, 83, 234, 0.24); }
        .pricing-btn.custom { background: #fff; color: #1737b3; border: none; box-shadow: 0 12px 30px rgba(0, 0, 0, 0.16); }
        .pricing-btn.custom:hover { transform: translateY(-2px); box-shadow: 0 16px 36px rgba(0, 0, 0, 0.22); filter: brightness(1.02); }
        .pricing-redeem-link {
            display: inline-flex;
            justify-content: center;
            color: rgba(47, 119, 210, 0.62);
            font-size: 12px;
            font-weight: 700;
            text-decoration: none;
        }
        .pricing-redeem-link:hover { color: rgba(47, 119, 210, 0.9); }
        .pricing-redeem-row {
            display: flex;
            justify-content: center;
            margin: -18px 0 24px;
        }
        .payment-loading {
            position: fixed;
            inset: 0;
            z-index: 1190;
            display: none;
            place-items: center;
            background: rgba(11, 16, 32, 0.58);
            backdrop-filter: blur(4px);
        }
        .payment-loading.active { display: grid; }
        .payment-loading-card {
            width: min(300px, calc(100vw - 48px));
            padding: 26px;
            border-radius: 22px;
            background: rgba(255, 255, 255, 0.96);
            text-align: center;
            box-shadow: 0 28px 80px rgba(11, 16, 32, 0.28);
        }
        .payment-loading-spinner {
            width: 42px;
            height: 42px;
            margin: 0 auto 14px;
            border-radius: 999px;
            border: 4px solid rgba(47, 83, 234, 0.14);
            border-top-color: var(--primary);
            animation: payment-spin 0.8s linear infinite;
        }
        .payment-loading-title { color: var(--text); font-size: 16px; font-weight: 850; }
        .payment-loading-text { margin-top: 6px; color: var(--text-muted); font-size: 13px; line-height: 1.5; }
        @keyframes payment-spin { to { transform: rotate(360deg); } }
        .payment-modal {
            position: fixed;
            inset: 0;
            z-index: 1200;
            display: none;
            align-items: center;
            justify-content: center;
            padding: 24px;
            background: rgba(11, 16, 32, 0.42);
            backdrop-filter: blur(3px);
        }
        .payment-modal.active { display: flex; }
        .payment-panel {
            width: min(760px, 100%);
            padding: 0;
            border-radius: 22px;
            background: rgba(255, 255, 255, 0.96);
            border: 1px solid rgba(255, 255, 255, 0.86);
            overflow: hidden;
            box-shadow: 0 28px 80px rgba(11, 16, 32, 0.22);
        }
        .payment-head {
            display: flex;
            align-items: flex-start;
            justify-content: space-between;
            gap: 16px;
            padding: 22px 24px 0;
            margin-bottom: 0;
        }
        .payment-title { color: var(--text); font-size: 18px; font-weight: 850; }
        .payment-subtitle { margin-top: 4px; color: var(--text-muted); font-size: 13px; line-height: 1.5; }
        .payment-close {
            width: 32px;
            height: 32px;
            border: 0;
            border-radius: 999px;
            background: rgba(30, 35, 54, 0.08);
            color: var(--text-muted);
            font-size: 20px;
            cursor: pointer;
        }
        .payment-body {
            display: grid;
            grid-template-columns: minmax(0, 1fr) 292px;
            gap: 22px;
            padding: 22px 24px 24px;
        }
        .payment-product {
            min-height: 250px;
            padding: 22px;
            border-radius: 18px;
            background: linear-gradient(145deg, rgba(47, 83, 234, 0.1), rgba(15, 183, 165, 0.08));
            border: 1px solid rgba(47, 83, 234, 0.12);
        }
        .payment-product-label { color: var(--primary); font-size: 12px; font-weight: 850; }
        .payment-product-name { margin-top: 12px; color: var(--text); font-size: 26px; font-weight: 900; line-height: 1.2; }
        .payment-product-price { margin-top: 12px; color: var(--text); font-size: 34px; font-weight: 950; }
        .payment-product-price span { color: var(--text-muted); font-size: 14px; font-weight: 750; }
        .payment-product-meta {
            display: grid;
            gap: 9px;
            margin-top: 18px;
            color: var(--text-muted);
            font-size: 13px;
            font-weight: 700;
            line-height: 1.55;
        }
        .payment-qr-box {
            min-height: 240px;
            display: grid;
            place-items: center;
            padding: 14px;
            border-radius: 18px;
            background: #fff;
            border: 1px solid rgba(30, 35, 54, 0.08);
        }
        .payment-qr-box img { width: 220px; height: 220px; object-fit: contain; }
        .payment-link-fallback {
            display: grid;
            gap: 10px;
            color: var(--text-muted);
            font-size: 13px;
            line-height: 1.6;
            text-align: center;
        }
        .payment-link-fallback img { justify-self: center; }
        .payment-qr-divider {
            color: var(--text-muted);
            font-size: 12px;
            font-weight: 700;
        }
        .payment-copy-btn {
            min-height: 38px;
            border: none;
            border-radius: 12px;
            font-weight: 800;
            cursor: pointer;
        }
        .payment-copy-btn { background: rgba(47, 83, 234, 0.1); color: var(--primary); }
        .payment-status {
            margin-top: 12px;
            color: var(--text-muted);
            font-size: 13px;
            font-weight: 700;
            text-align: center;
        }
        .payment-confirm-actions {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 10px;
            margin-top: 16px;
        }
        .payment-confirm-actions button {
            min-height: 40px;
            border: 0;
            border-radius: 12px;
            font-weight: 850;
            cursor: pointer;
        }
        .payment-confirm-primary { background: var(--primary); color: #fff; }
        .payment-confirm-secondary { background: rgba(30, 35, 54, 0.08); color: var(--text-muted); }
        .redeem-panel { width: min(430px, 100%); }
        .redeem-body {
            display: grid;
            gap: 14px;
            padding: 22px 24px 24px;
        }
        .redeem-input {
            width: 100%;
            height: 48px;
            border: 1px solid rgba(30, 35, 54, 0.12);
            border-radius: 14px;
            padding: 0 14px;
            color: var(--text);
            background: #fff;
            font-size: 15px;
            font-weight: 850;
            letter-spacing: 0.08em;
            text-transform: uppercase;
            outline: none;
        }
        .redeem-input:focus { border-color: rgba(47, 83, 234, 0.5); box-shadow: 0 0 0 4px rgba(47, 83, 234, 0.08); }
        .redeem-submit {
            height: 44px;
            border: 0;
            border-radius: 14px;
            background: var(--primary);
            color: #fff;
            font-size: 14px;
            font-weight: 900;
            cursor: pointer;
        }
        .redeem-submit:disabled { opacity: 0.58; cursor: not-allowed; }
        .redeem-status {
            min-height: 20px;
            color: var(--text-muted);
            font-size: 13px;
            font-weight: 700;
            line-height: 1.5;
        }
        .contact-panel { width: min(430px, 100%); }
        .contact-body {
            display: grid;
            gap: 18px;
            justify-items: center;
            padding: 22px 24px 26px;
        }
        .contact-qr {
            width: 220px;
            height: 220px;
            object-fit: contain;
            padding: 10px;
            border-radius: 18px;
            background: #fff;
            border: 1px solid rgba(30, 35, 54, 0.08);
        }
        .contact-email {
            width: 100%;
            display: grid;
            gap: 6px;
            padding: 14px;
            border-radius: 14px;
            background: rgba(47, 83, 234, 0.08);
            color: var(--text-muted);
            font-size: 13px;
            font-weight: 800;
            text-align: center;
        }
        .contact-email a {
            color: var(--primary);
            font-size: 15px;
            word-break: break-all;
            text-decoration: none;
        }
        /* ==== 常见问题区块 ==== */
        .faq { min-height: 100vh; display: flex; flex-direction: column; justify-content: center; padding: 40px 0; }
        .faq-list { max-width: 800px; margin: 0 auto; display: flex; flex-direction: column; gap: 16px; }
        .faq-item { background: rgba(255, 255, 255, 0.4); border: 1px solid rgba(255, 255, 255, 0.6); border-radius: 18px; overflow: hidden; transition: background 0.3s ease, box-shadow 0.3s ease; }
        .faq-item.active { background: rgba(255, 255, 255, 0.85); box-shadow: var(--shadow-soft); border-color: rgba(47, 83, 234, 0.1); }
        .faq-question { width: 100%; display: flex; justify-content: space-between; align-items: center; padding: 24px; text-align: left; background: none; border: none; cursor: pointer; font-size: 16px; font-weight: 700; color: var(--text); transition: color 0.3s ease; }
        .faq-icon { color: var(--text-dim); transition: transform 0.4s cubic-bezier(0.2, 0.8, 0.2, 1); }
        .faq-item.active .faq-icon { transform: rotate(180deg); color: var(--primary); }
        .faq-answer { display: grid; grid-template-rows: 0fr; transition: grid-template-rows 0.4s cubic-bezier(0.2, 0.8, 0.2, 1); }
        .faq-answer-inner { min-height: 0; overflow: hidden; padding: 0 24px; color: var(--text-muted); font-size: 14px; line-height: 1.7; opacity: 0; transition: opacity 0.4s ease; }
        .faq-item.active .faq-answer { grid-template-rows: 1fr; }
        .faq-item.active .faq-answer-inner { padding-bottom: 24px; opacity: 1; }

        /* About Us Layout */
        .about { padding: 40px 0 84px; }
        .about-wrapper { display: flex; flex-direction: row; align-items: center; justify-content: space-between; gap: 60px; padding: 40px 0; }
        .about-copy { flex: 1.5; display: flex; flex-direction: column; justify-content: center; align-items: flex-start; }
        .about-copy .section-title { text-align: left; margin-bottom: 20px; font-weight: 500; font-size: clamp(28px, 2.5vw, 42px); letter-spacing: 0.02em; }
        .about-copy .section-desc { text-align: left; margin-bottom: 0; max-width: 580px; }
        .about-contact { flex: 1; display: flex; flex-direction: column; justify-content: center; align-items: flex-end; gap: 16px; color: var(--text-muted); font-size: 14px; font-weight: 700; }
        .wechat-qr { width: 168px; height: 168px; border-radius: 18px; border: 1px solid rgba(255, 255, 255, 0.8); background: rgba(255, 255, 255, 0.5); padding: 8px; box-shadow: var(--shadow-soft); backdrop-filter: blur(10px); }

        /* Footer */
        .footer { padding: 32px 0 46px; border-top: 1px solid rgba(255,255,255,0.06); }
        .footer-bottom { width: 100%; display: flex; justify-content: center; }
        .footer-links-row { display: flex; flex-wrap: wrap; gap: 16px; align-items: center; justify-content: center; color: var(--text-dim); font-size: 13px; font-weight: 500; }
        .footer-links-row a { transition: color 0.3s ease; }
        .footer-links-row a:hover { color: var(--text); }
        .divider { color: rgba(30,35,54,0.15); user-select: none; }

        .fade-in { opacity: 0; transform: translateY(28px); transition: opacity 0.7s ease, transform 0.7s ease; }
        .fade-in.visible { opacity: 1; transform: translateY(0); }

        /* 视频模态框 */
        .modal-overlay {
            position: fixed; inset: 0; backdrop-filter: blur(2px);
            z-index: 9999; display: flex; align-items: center; justify-content: center;
            opacity: 0; pointer-events: none; transition: opacity 0.3s ease;
        }
        .modal-overlay.active { opacity: 1; pointer-events: auto; }
        .modal-content {
            width: 90%; max-width: 900px; aspect-ratio: 16/9; background: #0c101a; border-radius: 20px;
            position: relative; box-shadow: 0 32px 80px rgba(0,0,0,0.5);
            transform: scale(0.95) translateY(20px); transition: all 0.4s cubic-bezier(0.2, 0.8, 0.2, 1);
            display: flex; flex-direction: column; align-items: center; justify-content: center; border: 1px solid rgba(255,255,255,0.08);
        }
        .modal-overlay.active .modal-content { transform: scale(1) translateY(0); }
        .modal-video-container {
            width: 100%;
            height: 100%;
            display: flex;
            flex-direction: column;
            align-items: stretch;
        }
        .modal-video-frame { width: 100%; height: 100%; border: 0; border-radius: 20px; background: #101a2e; }

        html[data-zda-theme="dark"] body,
        html[data-zda-theme="dark"] .boot-screen { background: var(--bg); }
        html[data-zda-theme="dark"] .navbar { background: rgba(30, 41, 59, 0.86); border-bottom-color: rgba(148, 163, 184, 0.22); }
        html[data-zda-theme="dark"] .navbar.scrolled { background: rgba(30, 41, 59, 0.94); box-shadow: 0 8px 34px rgba(2, 6, 23, 0.3); }
        html[data-zda-theme="dark"] .stage-shell,
        html[data-zda-theme="dark"] .input-dock,
        html[data-zda-theme="dark"] .topic-card,
        html[data-zda-theme="dark"] .flow-card,
        html[data-zda-theme="dark"] .faq-item,
        html[data-zda-theme="dark"] .pricing-card,
        html[data-zda-theme="dark"] .payment-loading-card,
        html[data-zda-theme="dark"] .payment-panel {
            border-color: var(--line);
            background: var(--panel);
            box-shadow: var(--shadow-soft);
        }
        html[data-zda-theme="dark"] .flow-card.active,
        html[data-zda-theme="dark"] .faq-item.active { background: var(--panel-strong); }
        html[data-zda-theme="dark"] .input-row input,
        html[data-zda-theme="dark"] .topic-chip,
        html[data-zda-theme="dark"] .case-tag,
        html[data-zda-theme="dark"] .redeem-input {
            border-color: var(--line);
            background: rgba(15, 23, 42, 0.84);
            color: var(--text);
        }
        html[data-zda-theme="dark"] .input-row input::placeholder { color: rgba(148, 163, 184, 0.72); }
        html[data-zda-theme="dark"] .topic-chip:hover { background: rgba(168, 85, 247, 0.2); }
        html[data-zda-theme="dark"] .highlight { background: linear-gradient(180deg, transparent 45%, rgba(168, 85, 247, 0.22) 46%, rgba(20, 184, 166, 0.15) 100%); }
        html[data-zda-theme="dark"] .theme-label { background: rgba(51, 65, 85, 0.78); }
        html[data-zda-theme="dark"] .case-summary,
        html[data-zda-theme="dark"] .case-summary h1,
        html[data-zda-theme="dark"] .case-summary h2,
        html[data-zda-theme="dark"] .case-summary h3,
        html[data-zda-theme="dark"] .case-summary strong,
        html[data-zda-theme="dark"] .case-summary em,
        html[data-zda-theme="dark"] .case-detail { color: var(--text); }
        html[data-zda-theme="dark"] .case-detail h1,
        html[data-zda-theme="dark"] .case-detail h2,
        html[data-zda-theme="dark"] .case-detail h3,
        html[data-zda-theme="dark"] .case-detail strong { color: var(--text); }
        html[data-zda-theme="dark"] .case-detail em { color: var(--text-muted); }
        html[data-zda-theme="dark"] .case-summary mark,
        html[data-zda-theme="dark"] .case-detail mark { color: var(--text); background: rgba(234, 179, 8, 0.22); text-decoration-color: rgba(250, 204, 21, 0.72); }
        html[data-zda-theme="dark"] .case-summary .keyword-ring,
        html[data-zda-theme="dark"] .case-detail .keyword-ring { color: var(--text); border-color: rgba(148, 163, 184, 0.46); background: rgba(30, 41, 59, 0.62); }
        html[data-zda-theme="dark"] .case-summary .article-tip,
        html[data-zda-theme="dark"] .case-detail .article-tip { color: var(--text-muted); background: rgba(30, 41, 59, 0.72); }
        html[data-zda-theme="dark"] .case-summary .article-tip::before,
        html[data-zda-theme="dark"] .case-detail .article-tip::before { background: rgba(15, 23, 42, 0.82); }
        html[data-zda-theme="dark"] .case-summary blockquote { background: rgba(51, 65, 85, 0.32); }
        html[data-zda-theme="dark"] .pricing-card:hover { background: var(--panel-strong); }
        html[data-zda-theme="dark"] .pricing-card.popular {
            border-color: transparent;
            background:
                linear-gradient(150deg, rgba(30, 41, 59, 0.98), rgba(35, 49, 78, 0.98)) padding-box,
                linear-gradient(135deg, #8da2ff, #5c78f2) border-box;
            box-shadow: 0 30px 82px rgba(92, 120, 242, 0.24);
        }
        html[data-zda-theme="dark"] .pricing-card.custom,
        html[data-zda-theme="dark"] .pricing-card.custom:hover { background: linear-gradient(150deg, #1e293b 0%, #7c3aed 50%, #0f766e 100%); }
        html[data-zda-theme="dark"] .pricing-original-pay { color: rgba(148, 163, 184, 0.78); }
        html[data-zda-theme="dark"] .pricing-discount { color: #fda4af; }
        html[data-zda-theme="dark"] .pricing-discount-badge { background: linear-gradient(135deg, #fb7185, #fb923c); color: #fff; }
        html[data-zda-theme="dark"] .pricing-btn.outline { background: rgba(51, 65, 85, 0.42); border-color: var(--line); color: var(--text-muted); }
        html[data-zda-theme="dark"] .pricing-btn.outline:hover,
        html[data-zda-theme="dark"] .payment-confirm-secondary,
        html[data-zda-theme="dark"] .payment-close { background: rgba(51, 65, 85, 0.42); }
        html[data-zda-theme="dark"] .payment-qr-box { background: #fff; }
        html[data-zda-theme="dark"] .contact-email { background: rgba(51, 65, 85, 0.42); }
        html[data-zda-theme="dark"] .wechat-qr { border-color: var(--line); background: rgba(30, 41, 59, 0.78); }
        html[data-zda-theme="dark"] .divider { color: rgba(148, 163, 184, 0.24); }
        /* ============================================================
           响应式布局区域
        ============================================================ */
        @media (max-width: 1600px) {
            .pricing .section-container { padding: 0 32px; }
            .pricing-grid { gap: 10px; }
            .pricing-card.step-0 { --pricing-card-flex: 0.78; }
            .pricing-card.step-1 { --pricing-card-flex: 0.9; }
            .pricing-card.step-2 { --pricing-card-flex: 1; }
            .pricing-card.step-4 { --pricing-card-flex: 1; }
            .pricing-card.popular { --pricing-card-flex: 1.3; }
            .pricing-card.custom { --pricing-card-flex: 1.18; }
            .pricing-card {
                --pricing-card-height: 304px;
                --pricing-amount-size: 56px;
                padding: 36px 18px 22px;
            }
            .pricing-card.step-0 { --pricing-card-height: 284px; --pricing-amount-size: 46px; }
            .pricing-card.step-1 { --pricing-card-height: 298px; --pricing-amount-size: 52px; }
            .pricing-card.step-2 { --pricing-card-height: 314px; --pricing-amount-size: 54px; }
            .pricing-card.step-4 { --pricing-card-height: 328px; --pricing-amount-size: 58px; }
            .pricing-card.popular { --pricing-card-height: 364px; --pricing-amount-size: 74px; }
            .pricing-card.custom { --pricing-card-height: 364px; --pricing-amount-size: 66px; }
            .pricing-title { font-size: 15px; }
            .pricing-card.popular .pricing-title { font-size: 17px; }
        }

        @media (max-width: 1180px) {
            .topic-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
            .pricing-grid { flex-wrap: wrap; align-items: flex-end; }
            .pricing-card,
            .pricing-card.step-0,
            .pricing-card.step-1,
            .pricing-card.step-2,
            .pricing-card.step-4,
            .pricing-card.popular,
            .pricing-card.custom {
                flex: 1 1 calc(33.333% - 12px);
            }
        }