:root {
            --bg-deep: #080d16;
            --bg-card: #111827;
            --bg-card-hover: #161e2d;
            --bg-surface: #0f1726;
            --text-primary: #e8ecf2;
            --text-secondary: #b0bdd0;
            --text-muted: #6f7d94;
            --accent-cyan: #00d4aa;
            --accent-blue: #3b82f6;
            --accent-purple: #8b5cf6;
            --accent-amber: #f59e0b;
            --accent-rose: #f43f5e;
            --border-subtle: #1e293b;
            --border-glow: #1e3a5f;
            --glow-cyan: rgba(0, 212, 170, 0.15);
            --glow-blue: rgba(59, 130, 246, 0.12);
            --radius-sm: 10px;
            --radius-md: 18px;
            --radius-lg: 28px;
            --radius-xl: 36px;
            --transition-fast: 0.18s ease;
            --transition-smooth: 0.28s cubic-bezier(0.4, 0, 0.2, 1);
            --font-mono: 'SF Mono', 'Cascadia Code', 'Consolas', 'Menlo', monospace;
        }

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

        html {
            scroll-behavior: smooth;
            -webkit-font-smoothing: antialiased;
        }

        body {
            font-family: system-ui, -apple-system, 'Segoe UI', 'Helvetica Neue', Helvetica, 'Noto Sans SC', sans-serif;
            background-color: var(--bg-deep);
            color: var(--text-primary);
            line-height: 1.6;
            letter-spacing: 0.01em;
            overflow-x: hidden;
        }

        body::before {
            content: '';
            position: fixed;
            top: -30vh;
            left: -20vw;
            width: 70vw;
            height: 70vh;
            background: radial-gradient(ellipse at center, rgba(0, 180, 140, 0.06) 0%, transparent 70%);
            pointer-events: none;
            z-index: 0;
        }
        body::after {
            content: '';
            position: fixed;
            bottom: -20vh;
            right: -15vw;
            width: 60vw;
            height: 60vh;
            background: radial-gradient(ellipse at center, rgba(100, 80, 240, 0.05) 0%, transparent 70%);
            pointer-events: none;
            z-index: 0;
        }

        .container {
            max-width: 1240px;
            margin: 0 auto;
            padding: 0 24px;
            position: relative;
            z-index: 1;
        }

        /* ========== HEADER (与首页完全一致) ========== */
        .site-header {
            position: sticky;
            top: 0;
            z-index: 100;
            background: rgba(8, 13, 22, 0.82);
            backdrop-filter: blur(18px) saturate(140%);
            -webkit-backdrop-filter: blur(18px) saturate(140%);
            border-bottom: 1px solid var(--border-subtle);
            transition: var(--transition-smooth);
        }

        .header-inner {
            display: flex;
            align-items: center;
            justify-content: space-between;
            flex-wrap: wrap;
            padding: 14px 0;
            gap: 16px;
        }

        .logo-area {
            display: flex;
            align-items: center;
            gap: 10px;
            text-decoration: none;
        }
        .logo-icon {
            width: 42px;
            height: 42px;
            background: linear-gradient(135deg, #00c49a, #0ea5e9);
            border-radius: 12px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 21px;
            font-weight: 800;
            color: #fff;
            box-shadow: 0 0 22px rgba(0, 200, 160, 0.25);
        }
        .logo-text {
            font-size: 1.45rem;
            font-weight: 700;
            letter-spacing: -0.3px;
            background: linear-gradient(135deg, #e8ecf2, #a0c4f0);
            background-clip: text;
            -webkit-background-clip: text;
            color: transparent;
        }
        .logo-sub {
            font-size: 0.7rem;
            color: var(--text-muted);
            display: block;
            letter-spacing: 0.04em;
            font-weight: 400;
            margin-top: -2px;
        }

        .nav-links {
            display: flex;
            gap: 26px;
            align-items: center;
            flex-wrap: wrap;
        }
        .nav-links a {
            text-decoration: none;
            font-weight: 500;
            color: var(--text-secondary);
            transition: color var(--transition-fast);
            font-size: 0.95rem;
            position: relative;
            padding: 4px 0;
        }
        .nav-links a::after {
            content: '';
            position: absolute;
            bottom: -2px;
            left: 0;
            width: 0;
            height: 2px;
            background: var(--accent-cyan);
            border-radius: 2px;
            transition: width var(--transition-smooth);
        }
        .nav-links a:hover,
        .nav-links a.active {
            color: #fff;
        }
        .nav-links a:hover::after,
        .nav-links a.active::after {
            width: 100%;
        }
        .btn-nav-dl {
            border: 1px solid var(--accent-cyan);
            padding: 7px 18px;
            border-radius: 40px;
            color: var(--accent-cyan) !important;
            font-weight: 600;
            transition: all var(--transition-smooth);
            font-size: 0.9rem;
        }
        .btn-nav-dl:hover {
            background: var(--accent-cyan);
            color: #080d16 !important;
            box-shadow: 0 0 20px var(--glow-cyan);
        }
        .btn-nav-dl::after {
            display: none !important;
        }

        /* ========== 页面标题区 ========== */
        .page-hero {
            padding: 56px 0 32px;
            text-align: center;
        }
        .page-badge {
            display: inline-flex;
            align-items: center;
            gap: 6px;
            background: rgba(0, 212, 170, 0.08);
            border: 1px solid rgba(0, 212, 170, 0.2);
            color: #00d4aa;
            font-size: 0.8rem;
            padding: 4px 14px;
            border-radius: 32px;
            margin-bottom: 18px;
            font-weight: 500;
            letter-spacing: 0.04em;
        }
        .page-hero h1 {
            font-size: clamp(2rem, 4vw, 2.8rem);
            font-weight: 800;
            letter-spacing: -0.02em;
            margin-bottom: 14px;
            color: #f0f4f8;
        }
        .page-hero .highlight {
            background: linear-gradient(125deg, #00d4aa, #3b82f6);
            background-clip: text;
            -webkit-background-clip: text;
            color: transparent;
        }
        .page-hero .sub-desc {
            font-size: 1.05rem;
            color: var(--text-secondary);
            max-width: 700px;
            margin: 0 auto 28px;
            line-height: 1.6;
        }

        /* ========== 下载卡片区 ========== */
        .download-cards {
            padding: 32px 0 48px;
        }
        .dl-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 24px;
            max-width: 860px;
            margin: 0 auto;
        }
        .dl-card {
            background: var(--bg-card);
            border-radius: var(--radius-lg);
            padding: 32px 24px;
            border: 1px solid var(--border-subtle);
            text-align: center;
            transition: all var(--transition-smooth);
            position: relative;
            overflow: hidden;
        }
        .dl-card::before {
            content: '';
            position: absolute;
            top: -20px;
            right: -20px;
            width: 80px;
            height: 80px;
            border-radius: 50%;
            opacity: 0.06;
            pointer-events: none;
            transition: opacity var(--transition-smooth);
        }
        .dl-card:hover::before {
            opacity: 0.14;
        }
        .dl-card.standard::before {
            background: #3b82f6;
        }
        .dl-card.speed::before {
            background: #00d4aa;
        }
        .dl-card:hover {
            border-color: var(--border-glow);
            transform: translateY(-3px);
            box-shadow: 0 18px 36px -14px rgba(0,0,0,0.5);
        }
        .dl-card .dl-icon {
            font-size: 2.8rem;
            margin-bottom: 14px;
        }
        .dl-card h2 {
            font-size: 1.5rem;
            font-weight: 700;
            margin-bottom: 6px;
            color: #f0f4f8;
        }
        .dl-card .dl-tag {
            font-size: 0.72rem;
            padding: 4px 10px;
            border-radius: 20px;
            font-weight: 600;
            letter-spacing: 0.03em;
            background: rgba(255,255,255,0.04);
            color: var(--text-muted);
            border: 1px solid var(--border-subtle);
            display: inline-block;
            margin-bottom: 16px;
        }
        .dl-card .dl-info {
            font-size: 0.88rem;
            color: var(--text-secondary);
            margin-bottom: 18px;
            line-height: 1.5;
        }
        .btn-dl {
            display: inline-flex;
            align-items: center;
            gap: 6px;
            padding: 12px 28px;
            border-radius: 40px;
            font-weight: 700;
            font-size: 0.95rem;
            text-decoration: none;
            transition: all var(--transition-smooth);
            border: none;
            cursor: pointer;
            letter-spacing: 0.02em;
        }
        .btn-dl.standard-btn {
            background: var(--accent-blue);
            color: #fff;
            box-shadow: 0 4px 20px rgba(59,130,246,0.3);
        }
        .btn-dl.standard-btn:hover {
            box-shadow: 0 8px 32px rgba(59,130,246,0.5);
            transform: translateY(-1px);
        }
        .btn-dl.speed-btn {
            background: linear-gradient(135deg, #00c49a, #0ea5e9);
            color: #080d16;
            box-shadow: 0 4px 20px rgba(0,200,160,0.3);
        }
        .btn-dl.speed-btn:hover {
            box-shadow: 0 8px 32px rgba(0,200,160,0.5);
            transform: translateY(-1px);
        }

        /* ========== 使用流程 ========== */
        .steps-section {
            padding: 48px 0 56px;
        }
        .section-label {
            text-align: center;
            font-size: 0.8rem;
            text-transform: uppercase;
            letter-spacing: 0.12em;
            color: var(--accent-cyan);
            margin-bottom: 8px;
            font-weight: 600;
        }
        .section-title {
            text-align: center;
            font-size: clamp(1.6rem, 3vw, 2.2rem);
            font-weight: 700;
            margin-bottom: 10px;
            letter-spacing: -0.02em;
            color: #f0f4f8;
        }
        .section-desc {
            text-align: center;
            color: var(--text-secondary);
            max-width: 680px;
            margin: 0 auto 40px auto;
            font-size: 1rem;
            line-height: 1.6;
        }
        .steps-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 16px;
            max-width: 1000px;
            margin: 0 auto;
        }
        .step-item {
            background: var(--bg-card);
            border-radius: var(--radius-md);
            padding: 22px 16px;
            text-align: center;
            border: 1px solid var(--border-subtle);
            transition: var(--transition-smooth);
        }
        .step-item:hover {
            border-color: var(--border-glow);
            box-shadow: 0 8px 24px -8px rgba(0,0,0,0.4);
        }
        .step-num {
            font-family: var(--font-mono);
            font-size: 2rem;
            font-weight: 900;
            color: var(--accent-cyan);
            opacity: 0.8;
            margin-bottom: 6px;
        }
        .step-item h4 {
            font-weight: 600;
            color: #f0f4f8;
            margin-bottom: 4px;
        }
        .step-item p {
            font-size: 0.82rem;
            color: var(--text-muted);
            line-height: 1.4;
        }

        /* ========== 三种模式 ========== */
        .modes-section {
            padding: 40px 0 64px;
        }
        .modes-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 24px;
            margin-top: 32px;
        }
        .mode-card {
            background: var(--bg-card);
            border-radius: var(--radius-lg);
            padding: 28px 20px;
            border: 1px solid var(--border-subtle);
            transition: all var(--transition-smooth);
            text-align: center;
            position: relative;
        }
        .mode-card:hover {
            border-color: var(--border-glow);
            transform: translateY(-3px);
            box-shadow: 0 14px 32px -10px rgba(0,0,0,0.5);
        }
        .mode-emoji {
            font-size: 2.8rem;
            margin-bottom: 12px;
        }
        .mode-card h3 {
            font-size: 1.2rem;
            font-weight: 700;
            color: #f0f4f8;
            margin-bottom: 6px;
        }
        .mode-card .mode-badge {
            font-size: 0.7rem;
            padding: 3px 10px;
            border-radius: 16px;
            background: rgba(255,255,255,0.04);
            color: var(--text-muted);
            border: 1px solid var(--border-subtle);
            display: inline-block;
            margin-bottom: 12px;
        }
        .mode-card p {
            font-size: 0.85rem;
            color: var(--text-secondary);
            line-height: 1.5;
            margin-bottom: 16px;
        }
        .mode-link {
            font-weight: 600;
            color: var(--accent-cyan);
            text-decoration: none;
            font-size: 0.85rem;
            display: inline-flex;
            align-items: center;
            gap: 4px;
        }

        /* ========== 问题导向入口 ========== */
        .problem-entrance {
            padding: 40px 0 56px;
            border-top: 1px solid var(--border-subtle);
        }
        .problem-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 20px;
            margin-top: 32px;
        }
        .problem-card {
            background: var(--bg-card);
            border-radius: var(--radius-md);
            padding: 22px 18px;
            border: 1px solid var(--border-subtle);
            text-decoration: none;
            color: inherit;
            transition: all var(--transition-smooth);
            display: flex;
            flex-direction: column;
            gap: 8px;
        }
        .problem-card:hover {
            border-color: var(--border-glow);
            transform: translateY(-2px);
            box-shadow: 0 12px 28px -10px rgba(0,0,0,0.4);
        }
        .problem-card .card-emoji {
            font-size: 2.2rem;
        }
        .problem-card h4 {
            font-weight: 700;
            color: #f0f4f8;
            font-size: 1rem;
        }
        .problem-card p {
            font-size: 0.8rem;
            color: var(--text-muted);
        }
        .card-link {
            font-weight: 600;
            color: var(--accent-cyan);
            font-size: 0.8rem;
            display: inline-flex;
            align-items: center;
            gap: 4px;
            margin-top: auto;
        }
        .problem-card.card-gaming { border-top: 3px solid #f43f5e; }
        .problem-card.card-streaming { border-top: 3px solid #f59e0b; }
        .problem-card.card-office { border-top: 3px solid #3b82f6; }

        /* ========== 内链区 ========== */
        .quick-links {
            padding: 32px 0 48px;
        }
        .ql-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 16px;
            margin-top: 24px;
        }
        .ql-card {
            background: var(--bg-card);
            border-radius: var(--radius-sm);
            padding: 16px;
            border: 1px solid var(--border-subtle);
            text-decoration: none;
            color: #e8ecf2;
            transition: all var(--transition-smooth);
            display: flex;
            align-items: center;
            gap: 10px;
            font-weight: 500;
            font-size: 0.88rem;
        }
        .ql-card:hover {
            border-color: var(--accent-cyan);
            box-shadow: 0 0 16px var(--glow-cyan);
            color: #fff;
        }

        /* ========== FOOTER (与首页一致) ========== */
        .site-footer {
            background: var(--bg-surface);
            border-top: 1px solid var(--border-subtle);
            padding: 48px 0 28px;
            color: var(--text-muted);
            font-size: 0.88rem;
        }
        .footer-links {
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            gap: 32px;
            margin-bottom: 36px;
        }
        .footer-col {
            flex: 1;
            min-width: 140px;
        }
        .footer-col h4 {
            font-weight: 600;
            margin-bottom: 14px;
            color: #e8ecf2;
            font-size: 0.95rem;
        }
        .footer-col a {
            display: block;
            color: var(--text-muted);
            text-decoration: none;
            margin-bottom: 10px;
            font-size: 0.85rem;
            transition: color var(--transition-fast);
        }
        .footer-col a:hover {
            color: var(--accent-cyan);
        }
        .copyright {
            text-align: center;
            font-size: 0.78rem;
            padding-top: 20px;
            border-top: 1px solid var(--border-subtle);
            color: var(--text-muted);
        }
        .copyright a {
            color: var(--accent-cyan);
            text-decoration: none;
        }

        @media (max-width: 768px) {
            .dl-grid { grid-template-columns: 1fr; }
            .steps-grid { grid-template-columns: 1fr 1fr; }
            .modes-grid { grid-template-columns: 1fr; }
            .problem-grid { grid-template-columns: 1fr; }
            .ql-grid { grid-template-columns: 1fr; }
            .header-inner { flex-direction: column; gap: 12px; }
            .nav-links { gap: 16px; justify-content: center; }
        }
        @media (max-width: 480px) {
            .steps-grid { grid-template-columns: 1fr; }
            .page-hero h1 { font-size: 1.8rem; }
        }