:root {
            --primary: #0d9488;
            --primary-deep: #0f766e;
            --primary-light: #ccfbf1;
            --accent: #0369a1;
            --accent-light: #e0f2fe;
            --gold: #f59e0b;
            --gold-light: #fef3c7;
            --bg: #f6f8f9;
            --surface: #ffffff;
            --text: #1e293b;
            --text-secondary: #475569;
            --text-muted: #64748b;
            --border: #e2e8f0;
            --border-light: #f1f5f9;
            --radius-xl: 20px;
            --radius-lg: 14px;
            --radius-md: 10px;
            --radius-sm: 8px;
            --shadow-sm: 0 1px 3px rgba(15,23,42,0.04);
            --shadow-md: 0 6px 24px rgba(15,23,42,0.06);
            --shadow-lg: 0 16px 48px rgba(15,23,42,0.08);
            --transition: 0.22s cubic-bezier(0.4,0,0.2,1);
            --font-mono: "SF Mono","Fira Code","Cascadia Code",monospace;
        }
        * { box-sizing: border-box; margin: 0; padding: 0; }
        html { scroll-behavior: smooth; scroll-padding-top: 80px; }
        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", sans-serif;
            background: var(--bg); color: var(--text); line-height: 1.72; padding-top: 68px;
            background-image: radial-gradient(ellipse at 75% 15%, rgba(13,148,136,0.04) 0%, transparent 55%),
            radial-gradient(ellipse at 20% 80%, rgba(3,105,161,0.03) 0%, transparent 50%),
            radial-gradient(ellipse at 50% 50%, rgba(245,158,11,0.02) 0%, transparent 60%);
            background-attachment: fixed;
            -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale;
        }
        a { color: var(--primary); text-decoration: none; transition: color var(--transition); }
        a:hover { color: var(--primary-deep); }

        /* 导航栏 — 与首页完全一致 */
        .nav-bar-wrap {
            position: fixed; top: 0; left: 0; right: 0; height: 68px;
            background: rgba(255,255,255,0.82); backdrop-filter: blur(16px) saturate(130%);
            -webkit-backdrop-filter: blur(16px) saturate(130%);
            border-bottom: 1px solid rgba(226,232,240,0.7); z-index: 1000; box-shadow: var(--shadow-sm);
        }
        .nav-bar { max-width: 1240px; height: 100%; margin: 0 auto; padding: 0 1.5rem; display: flex; align-items: center; justify-content: space-between; }
        .nav-brand { display: flex; align-items: center; gap: 10px; font-weight: 750; font-size: 1.2rem; color: var(--text); }
        .nav-brand img { width: 34px; height: 34px; object-fit: contain; border-radius: 8px; }
        .nav-brand span { background: linear-gradient(135deg, #0d9488 0%, #0369a1 100%); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
        .nav-links { display: flex; list-style: none; gap: 1.5rem; align-items: center; }
        .nav-links a { color: var(--text-secondary); font-weight: 520; font-size: 0.92rem; padding: 0.4rem 0; border-bottom: 2px solid transparent; transition: border-color var(--transition), color var(--transition); white-space: nowrap; }
        .nav-links a.active, .nav-links a:hover { border-bottom-color: var(--primary); color: var(--primary); }
        .nav-gh-btn { display: inline-flex; align-items: center; gap: 6px; background: #1e293b; color: #fff !important; padding: 0.4rem 1rem !important; border-radius: 50px !important; border-bottom: none !important; font-size: 0.84rem !important; font-weight: 600 !important; }
        .nav-gh-btn:hover { background: #0f172a !important; color: #fff !important; transform: translateY(-1px); border-bottom: none !important; }

        /* 主容器 */
        .main-container { max-width: 1240px; margin: 0 auto; padding: 2rem 1.5rem 3rem; }

        /* Hero */
        .faq-hero {
            text-align: center; padding: 2rem 1.5rem 1.8rem; background: var(--surface);
            border: 1px solid var(--border); border-radius: var(--radius-xl); box-shadow: var(--shadow-md);
            margin-bottom: 2rem;
        }
        .faq-hero h1 { font-size: 2rem; font-weight: 800; color: #0c3d3a; margin-bottom: 0.5rem; }
        .faq-hero .sub { font-size: 1.1rem; color: var(--text-muted); margin-bottom: 1rem; }

        /* 问题分类快速导航 */
        .category-nav {
            display: flex; flex-wrap: wrap; gap: 0.7rem; justify-content: center; margin-bottom: 2rem;
        }
        .cat-chip {
            padding: 0.4rem 1.2rem; border-radius: 50px; background: var(--surface);
            border: 1px solid var(--border); font-size: 0.85rem; font-weight: 520;
            color: var(--text-secondary); cursor: pointer; transition: all var(--transition);
            white-space: nowrap;
        }
        .cat-chip:hover, .cat-chip.active { background: var(--primary-light); color: var(--primary); border-color: var(--primary); }

        /* FAQ 列表 */
        .faq-section { margin-bottom: 2rem; }
        .faq-section h2 { font-size: 1.4rem; margin-bottom: 1.2rem; color: #0c3d3a; display: flex; align-items: center; gap: 8px; border-bottom: 2px solid var(--border-light); padding-bottom: 0.5rem; }
        .faq-list { display: flex; flex-direction: column; gap: 0.8rem; }
        .faq-item {
            background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-lg);
            overflow: hidden; transition: box-shadow var(--transition);
        }
        .faq-item:hover { box-shadow: var(--shadow-md); }
        .faq-question {
            width: 100%; background: none; border: none; text-align: left; padding: 1.2rem 1.5rem;
            font-size: 1rem; font-weight: 620; color: var(--text); cursor: pointer;
            display: flex; justify-content: space-between; align-items: center; transition: color var(--transition);
            background: #fcfdfd;
        }
        .faq-question:hover { color: var(--primary); }
        .faq-icon { font-size: 1.4rem; line-height: 1; transition: transform 0.3s; color: var(--text-muted); }
        .faq-question.active .faq-icon { transform: rotate(45deg); color: var(--primary); }
        .faq-answer {
            max-height: 0; overflow: hidden; transition: max-height 0.4s ease, padding 0.3s ease;
            background: #ffffff; padding: 0 1.5rem;
        }
        .faq-answer.open { max-height: 500px; padding-bottom: 1.3rem; }
        .faq-answer p { font-size: 0.92rem; color: var(--text-secondary); line-height: 1.7; }
        .faq-answer .solution-box {
            background: #f8fafc; border-left: 3px solid var(--primary); border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
            padding: 0.8rem 1rem; margin: 0.8rem 0; font-size: 0.88rem;
        }
        .inline-code { background: #f1f5f9; color: #c2410c; padding: 0.15rem 0.4rem; border-radius: 4px; font-family: var(--font-mono); font-size: 0.88em; }

        /* 诊断工具卡片 */
        .diag-card {
            background: var(--surface); border-radius: var(--radius-lg); padding: 1.8rem;
            border: 1px solid var(--border); margin-top: 2rem;
            display: flex; flex-wrap: wrap; gap: 1.5rem; align-items: center;
        }
        .diag-icon { font-size: 3rem; }
        .diag-content { flex: 1; }
        .diag-content h3 { margin-bottom: 0.5rem; }
        .btn-outline {
            display: inline-block; padding: 0.55rem 1.4rem; border-radius: 50px; border: 2px solid var(--primary);
            color: var(--primary); font-weight: 600; transition: all 0.25s; margin-top: 0.8rem;
        }
        .btn-outline:hover { background: rgba(13,148,136,0.05); color: var(--primary-deep); }

        /* 页脚 — 与首页完全一致 */
        footer { margin-top: 3rem; background: #0f172a; color: #94a3b8; padding: 2.8rem 1.5rem 1.8rem; font-size: 0.87rem; }
        .footer-grid { max-width: 1140px; margin: 0 auto; display: grid; grid-template-columns: repeat(3, 1fr); gap: 2rem; margin-bottom: 2rem; }
        .footer-col h4 { color: #e2e8f0; font-size: 0.95rem; margin-bottom: 0.8rem; font-weight: 600; }
        .footer-col ul { list-style: none; }
        .footer-col ul li { margin-bottom: 0.5rem; }
        .footer-col ul li a { color: #94a3b8; font-size: 0.84rem; }
        .footer-col ul li a:hover { color: #ffffff; }
        .footer-bottom { max-width: 1140px; margin: 0 auto; padding-top: 1.4rem; border-top: 1px solid rgba(148,163,184,0.13); text-align: center; font-size: 0.8rem; color: #64748b; }

        @media (max-width: 768px) {
            .nav-links { gap: 0.6rem; }
        }