:root {
            --primary: #6C5CE7;
            --primary-hover: #5A4BD1;
            --dark: #0f172a;
            --light: #f8fafc;
            --text: #475569;
            --border: #e2e8f0;
            --radius: 16px;
        }
        *{margin:0;padding:0;box-sizing:border-box;}
        body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;color:var(--text);background:#fff;line-height:1.6;}
        header{border-bottom:1px solid var(--border);position:sticky;top:0;background:rgba(255,255,255,0.85);backdrop-filter:blur(12px);z-index:100;}
        .nav-container{max-width:1200px;margin:0 auto;display:flex;justify-content:space-between;align-items:center;padding:16px 20px;}
        .logo a{display:flex;align-items:center;gap:10px;font-size:22px;font-weight:700;color:var(--primary);text-decoration:none;}
        .logo svg{width:32px;height:32px;fill:var(--primary);}
        .nav-links a{color:var(--text);text-decoration:none;margin-left:25px;font-size:15px;font-weight:500;transition:all 0.2s;padding:6px 12px;border-radius:6px;}
        .nav-links a:hover,.nav-links a.active{color:#fff;background-color:var(--primary);}

        section{padding:80px 20px;}
        .container{max-width:1000px;margin:0 auto;}
        .section-title{font-size:36px;color:var(--dark);font-weight:800;letter-spacing:-0.5px;text-align:center;}
        .section-subtitle{font-size:16px;color:#64748b;text-align:center;max-width:650px;margin:15px auto 50px;}

        /* FAQ 头部 */
        .faq-hero{background:radial-gradient(120% 120% at 50% 0%, rgba(108,92,231,0.05) 0%, rgba(255,255,255,0) 100%);text-align:center;}
        .faq-hero .hero-icon{font-size:60px;margin-bottom:15px;}

        /* 分类筛选标签 */
        .category-tabs{display:flex;justify-content:center;flex-wrap:wrap;gap:12px;margin:0 0 40px;}
        .cat-tab{padding:10px 22px;border-radius:50px;border:1px solid var(--border);background:#fff;color:var(--text);font-weight:500;cursor:pointer;transition:0.2s;font-size:14px;}
        .cat-tab:hover,.cat-tab.active{background:var(--primary);color:#fff;border-color:var(--primary);}

        /* FAQ 列表 */
        .faq-list{display:flex;flex-direction:column;gap:16px;}
        .faq-item{background:#fff;border:1px solid var(--border);border-radius:var(--radius);overflow:hidden;transition:0.25s;}
        .faq-item:hover{border-color:#cbd5e1;box-shadow:0 8px 20px rgba(0,0,0,0.02);}
        .faq-question{padding:22px 28px;display:flex;justify-content:space-between;align-items:center;cursor:pointer;font-weight:600;color:var(--dark);font-size:17px;user-select:none;background:var(--light);}
        .faq-question .arrow{font-size:20px;transition:0.3s;color:var(--primary);}
        .faq-item.open .faq-question .arrow{transform:rotate(180deg);}
        .faq-answer{padding:0 28px;max-height:0;overflow:hidden;transition:max-height 0.4s ease, padding 0.3s ease;color:var(--text);font-size:15px;line-height:1.8;background:#fff;}
        .faq-item.open .faq-answer{padding:20px 28px;max-height:600px;}
        .faq-answer p{margin-bottom:14px;}
        .faq-answer ul{padding-left:20px;margin-bottom:14px;}
        .faq-answer li{margin-bottom:6px;}
        .faq-answer code{background:rgba(108,92,231,0.1);padding:2px 8px;border-radius:4px;font-family:Consolas,monospace;color:var(--primary);font-size:14px;}

        /* 额外帮助卡片 */
        .help-extra{display:grid;grid-template-columns:1fr 1fr;gap:24px;margin-top:60px;}
        .help-card{background:var(--light);border-radius:var(--radius);padding:30px;text-align:center;border:1px solid var(--border);}
        .help-card h3{font-size:20px;color:var(--dark);margin-bottom:12px;}
        .help-card p{font-size:14px;color:#64748b;margin-bottom:20px;}
        .help-btn{display:inline-block;background:var(--primary);color:#fff;padding:10px 22px;border-radius:8px;text-decoration:none;font-weight:600;font-size:14px;transition:0.2s;}
        .help-btn:hover{background:var(--primary-hover);}

        footer{background:var(--dark);color:#94a3b8;padding:70px 20px 40px;font-size:14px;border-top:1px solid #1e293b;}
        .footer-grid{max-width:1200px;margin:0 auto;display:grid;grid-template-columns:2fr repeat(4,1fr);gap:40px;padding-bottom:40px;border-bottom:1px solid #1e293b;}
        .footer-brand h4{color:#fff;font-size:18px;margin-bottom:12px;}
        .footer-column h5{color:#fff;font-size:15px;margin-bottom:16px;font-weight:600;}
        .footer-column ul{list-style:none;}
        .footer-column li{margin-bottom:10px;}
        .footer-column a{color:#94a3b8;text-decoration:none;transition:color 0.2s;}
        .footer-column a:hover{color:#fff;}
        .footer-bottom{max-width:1200px;margin:30px auto 0;display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:15px;}

        @media(max-width:768px){
            .help-extra{grid-template-columns:1fr;}
            .nav-container{flex-direction:column;gap:15px;}
            .nav-links a{margin-left:10px;font-size:14px;}
        }