:root {
            --brand: #0066ff;
            --brand-deep: #0044cc;
            --brand-glow: #3399ff;
            --accent: #ff6b35;
            --surface-0: #ffffff;
            --surface-1: #f7f9fc;
            --surface-2: #eef3f9;
            --text-strong: #0a0f1a;
            --text-body: #2a3344;
            --text-muted: #5e6b80;
            --border: #dde4ef;
            --border-light: #eaf0f7;
            --shadow-sm: 0 2px 8px rgba(0,0,0,0.04);
            --shadow-md: 0 8px 28px rgba(0,0,0,0.07);
            --shadow-lg: 0 20px 48px rgba(0,0,0,0.10);
            --radius-sm: 12px;
            --radius: 18px;
            --radius-lg: 26px;
            --radius-xl: 36px;
            --transition: 0.28s cubic-bezier(0.4, 0, 0.2, 1);
            --font-stack: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Roboto, Helvetica, Arial, sans-serif;
        }
        * { margin: 0; padding: 0; box-sizing: border-box; }
        html { scroll-behavior: smooth; }
        body {
            font-family: var(--font-stack);
            background: var(--surface-0);
            color: var(--text-body);
            line-height: 1.65;
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
            overflow-x: hidden;
        }
        a { color: inherit; text-decoration: none; transition: var(--transition); }
        .container { max-width: 1240px; margin: 0 auto; padding: 0 28px; }

        /* 导航栏（与首页统一） */
        .header {
            position: sticky; top: 0; z-index: 120;
            background: rgba(255,255,255,0.88);
            backdrop-filter: saturate(180%) blur(18px);
            -webkit-backdrop-filter: saturate(180%) blur(18px);
            border-bottom: 1px solid var(--border-light);
            padding: 14px 0; transition: var(--transition);
        }
        .header-inner {
            display: flex; align-items: center; justify-content: space-between;
            gap: 16px; flex-wrap: wrap;
        }
        .logo-group { display: flex; align-items: center; gap: 10px; flex-shrink: 0; }
        .logo-icon { width: 38px; height: 38px; flex-shrink: 0; }
        .logo-text {
            font-weight: 750; font-size: 24px; letter-spacing: -0.4px;
            color: var(--text-strong); white-space: nowrap;
        }
        .logo-text .accent-dot { color: var(--brand); }
        .logo-badge {
            font-size: 11px; font-weight: 600; background: var(--brand);
            color: #fff; padding: 3px 10px; border-radius: 30px;
            letter-spacing: 0.3px; white-space: nowrap;
        }
        .nav { display: flex; align-items: center; gap: 26px; flex-wrap: wrap; }
        .nav a {
            font-size: 15px; font-weight: 530; color: var(--text-body);
            position: relative; padding: 6px 0; white-space: nowrap;
        }
        .nav a:hover { color: var(--brand); }
        .nav a.active { color: var(--brand); font-weight: 650; }
        .nav a.active::after {
            content: ''; position: absolute; left: 0; bottom: -2px;
            width: 100%; height: 2.5px; background: var(--brand); border-radius: 4px;
        }
        .nav-pill {
            background: var(--brand); color: #fff !important; font-size: 13px;
            padding: 7px 16px !important; border-radius: 40px; font-weight: 600;
            letter-spacing: 0.2px;
        }
        .nav-pill:hover {
            background: var(--brand-deep) !important; color: #fff !important;
            transform: translateY(-1px); box-shadow: 0 6px 18px rgba(0,102,255,0.28);
        }
        .mobile-toggle {
            display: none; flex-direction: column; gap: 5px; background: none;
            border: none; cursor: pointer; padding: 6px; z-index: 130;
        }
        .mobile-toggle span {
            display: block; width: 26px; height: 2.5px;
            background: var(--text-strong); border-radius: 4px; transition: 0.25s;
        }

        /* 页面头部 */
        .page-hero {
            padding: 50px 0 36px;
            background: linear-gradient(165deg, #f4f8ff 0%, #ffffff 30%, #f9fbff 100%);
            border-bottom: 1px solid var(--border-light);
            text-align: center;
        }
        .page-hero h1 {
            font-size: 42px; font-weight: 800; letter-spacing: -0.025em;
            color: var(--text-strong); margin-bottom: 10px;
        }
        .page-hero .subhead {
            font-size: 17px; color: var(--text-muted); max-width: 650px;
            margin: 0 auto 18px; line-height: 1.6;
        }
        .hero-stats {
            display: flex; flex-wrap: wrap; justify-content: center;
            gap: 24px; font-size: 14px; color: var(--text-muted);
        }
        .hero-stats .stat-item {
            background: #fff; padding: 10px 20px; border-radius: 40px;
            box-shadow: var(--shadow-sm); border: 1px solid var(--border-light);
            display: flex; align-items: center; gap: 8px;
        }
        .stat-num {
            font-weight: 750; font-size: 18px; color: var(--brand);
        }

        /* 创意版块：搜索与分类 */
        .toolbar-section {
            padding: 32px 0 8px;
            background: var(--surface-0);
        }
        .toolbar {
            display: flex; align-items: center; justify-content: space-between;
            gap: 20px; flex-wrap: wrap;
            background: #fff; border-radius: 60px;
            padding: 10px 18px; border: 1px solid var(--border-light);
            box-shadow: var(--shadow-sm);
        }
        .search-box {
            flex: 1; min-width: 200px; position: relative;
        }
        .search-box input {
            width: 100%; border: none; outline: none;
            font-size: 15px; padding: 12px 20px 12px 40px;
            background: var(--surface-1); border-radius: 40px;
            color: var(--text-strong);
        }
        .search-box .search-icon {
            position: absolute; left: 16px; top: 50%;
            transform: translateY(-50%); font-size: 18px;
            color: var(--text-muted); pointer-events: none;
        }
        .filter-tags {
            display: flex; flex-wrap: wrap; gap: 10px;
        }
        .filter-tag {
            padding: 8px 18px; border-radius: 30px;
            font-size: 13px; font-weight: 600; cursor: pointer;
            background: var(--surface-1); color: var(--text-body);
            border: 1px solid transparent; transition: var(--transition);
            white-space: nowrap;
        }
        .filter-tag.active, .filter-tag:hover {
            background: #e8f0ff; color: var(--brand);
            border-color: var(--brand);
        }

        /* 问题列表 */
        .faq-section {
            padding: 32px 0 64px;
            background: var(--surface-1);
        }
        .faq-grid {
            display: grid; grid-template-columns: repeat(auto-fill, minmax(480px, 1fr));
            gap: 20px;
        }
        .faq-item {
            background: #fff; border-radius: var(--radius-lg);
            border: 1px solid var(--border-light);
            padding: 22px 24px; transition: var(--transition);
            box-shadow: var(--shadow-sm);
            position: relative;
        }
        .faq-item:hover {
            border-color: #c0d4f0; box-shadow: var(--shadow-md);
        }
        .faq-item .hot-badge {
            position: absolute; top: -10px; right: -6px;
            background: #ff6b35; color: #fff; font-size: 10px;
            font-weight: 700; padding: 3px 10px; border-radius: 30px;
            letter-spacing: 0.3px;
        }
        .faq-question {
            font-size: 16px; font-weight: 680; color: var(--text-strong);
            margin-bottom: 10px; cursor: pointer;
            display: flex; align-items: center; gap: 8px;
        }
        .faq-question .q-icon {
            color: var(--brand); font-size: 20px; flex-shrink: 0;
        }
        .faq-answer {
            font-size: 14px; color: var(--text-muted);
            line-height: 1.7; display: none;
            border-top: 1px solid var(--border-light);
            padding-top: 12px; margin-top: 8px;
        }
        .faq-item.open .faq-answer { display: block; }
        .faq-item.open .faq-question { color: var(--brand); }

        /* 创意版块：帮助数据 */
        .help-metrics {
            background: #fff; border-radius: var(--radius-xl);
            border: 1px solid var(--border-light); padding: 30px 28px;
            margin-bottom: 32px; display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 20px; box-shadow: var(--shadow-sm);
        }
        .help-metric {
            text-align: center;
        }
        .help-metric .num {
            font-size: 32px; font-weight: 800; color: var(--brand);
            letter-spacing: -0.02em;
        }
        .help-metric p { font-size: 13px; color: var(--text-muted); }

        /* Footer（统一） */
        .footer {
            background: #0a0f1a; color: #b0c0d8; padding: 44px 0 28px;
            border-top: 1px solid #1a2333;
        }
        .footer-grid {
            display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
            gap: 30px; margin-bottom: 28px;
        }
        .footer-col h5 {
            color: #ffffff; font-size: 15px; font-weight: 640;
            margin-bottom: 10px; letter-spacing: 0.2px;
        }
        .footer-col ul { list-style: none; padding: 0; }
        .footer-col ul li {
            font-size: 13px; line-height: 2; color: #8899b4;
        }
        .footer-col a { color: #8899b4; }
        .footer-col a:hover { color: #ffffff; }
        .footer-bottom {
            border-top: 1px solid #1a2333; padding-top: 18px;
            display: flex; flex-wrap: wrap; justify-content: space-between;
            gap: 12px; font-size: 12px; color: #6a7d94;
        }
        .footer-bottom .meta-row { display: flex; flex-wrap: wrap; gap: 16px; }

        /* 响应式 */
        @media (max-width: 1024px) {
            .faq-grid { grid-template-columns: 1fr; }
        }
        @media (max-width: 768px) {
            .nav {
                display: none; width: 100%; flex-direction: column;
                align-items: flex-start; gap: 12px; padding: 14px 0 6px;
                border-top: 1px solid var(--border-light); margin-top: 8px;
            }
            .nav.open { display: flex; }
            .mobile-toggle { display: flex; }
            .page-hero h1 { font-size: 30px; }
            .toolbar { flex-direction: column; align-items: stretch; }
            .help-metrics { grid-template-columns: 1fr 1fr; }
        }
        @media (max-width: 480px) {
            .container { padding: 0 14px; }
            .page-hero h1 { font-size: 26px; }
            .faq-item { padding: 18px 16px; }
            .footer-grid { grid-template-columns: 1fr 1fr; }
            .footer-bottom { flex-direction: column; gap: 6px; }
            .logo-text { font-size: 20px; }
            .help-metrics { grid-template-columns: 1fr; }
        }