:root {
            --primary: #1a6dff;
            --primary-hover: #0e56d0;
            --primary-light: #f0f5ff;
            --text-main: #1f2329;
            --text-sub: #8a8e99;
            --border: #e5e6eb;
            --bg-page: #f5f5f6;
            --bg-card: #fff;
            --danger: #ff4d4f;
            --success: #00b42a;
        }

        /* 顶部通知栏 */
        .notice-bar {
            background: #1a6dff;
            color: #fff;
            font-size: 12px;
            text-align: center;
            padding: 6px 16px;
        }
        .notice-bar-inner a { color: #fff; text-decoration: underline; }

        * { margin: 0; padding: 0; box-sizing: border-box; }
        body { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif; background: var(--bg-page); color: var(--text-main); line-height: 1.5; }
        a { text-decoration: none; color: inherit; }
        button { cursor: pointer; border: none; font-family: inherit; }
        input, select { font-family: inherit; }

        /* ========== Header ========== */
        .header { background: #fff; box-shadow: 0 1px 2px rgba(0,0,0,0.05); position: sticky; top: 0; z-index: 100; }
        .header-top { background: #f7f8fa; border-bottom: 1px solid var(--border); font-size: 12px; }
        .header-top-inner { max-width: 1200px; margin: 0 auto; padding: 6px 16px; display: flex; justify-content: space-between; color: var(--text-sub); }
        .header-top a { color: var(--text-sub); margin-left: 16px; transition: color 0.2s; }
        .header-top a:hover { color: var(--text-main); }
        .header-main { max-width: 1200px; margin: 0 auto; padding: 0 16px; display: flex; align-items: center; height: 56px; gap: 20px; flex-wrap: nowrap; }
        .logo { font-size: 20px; font-weight: 700; color: var(--primary); white-space: nowrap; flex-shrink: 0; }
        .main-nav { display: flex; gap: 28px; flex: 1; }
        .main-nav a { font-size: 14px; color: #4e5969; transition: color 0.2s; position: relative; padding: 4px 0; }
        .main-nav a:hover { color: var(--text-main); }
        .main-nav a.active { color: var(--primary); font-weight: 500; }
        .main-nav a.active::after { content: ''; position: absolute; bottom: -14px; left: 0; right: 0; height: 2px; background: var(--primary); border-radius: 1px; }
        .header-actions { display: flex; gap: 16px; align-items: center; }
        .btn-login { padding: 6px 16px; border: 1px solid var(--border); border-radius: 4px; font-size: 13px; color: #4e5969; transition: all 0.2s; }
        .btn-login:hover { border-color: var(--primary); color: var(--primary); }
        .btn-register { padding: 6px 16px; background: var(--primary); color: #fff; border-radius: 4px; font-size: 13px; transition: background 0.2s; }
        .btn-register:hover { background: var(--primary-hover); }
        .btn-avatar {
            width: 34px; height: 34px; background: #1a6dff; color: #fff !important;
            border-radius: 50%; display: flex; align-items: center; justify-content: center;
            font-weight: 600; font-size: 14px; transition: background 0.2s;
            box-shadow: 0 2px 6px rgba(26,109,255,0.3);
        }
        .btn-avatar:hover { background: var(--primary-hover); }
        .mobile-menu-btn { display: none; width: 32px; height: 32px; align-items: center; justify-content: center; border-radius: 4px; margin-left: auto; }
        .mobile-menu-btn:hover { background: #f7f8fa; }
        .mobile-menu-btn svg { width: 20px; height: 20px; color: #4e5969; }

        /* ========== Layout ========== */
        .container { max-width: 1200px; margin: 0 auto; padding: 24px 16px 40px; }
        .product-layout { display: grid; grid-template-columns: 1fr 320px; gap: 20px; align-items: start; }
        .main-content { min-width: 0; }
        
        /* ========== Section Cards ========== */
        .section-card { background: var(--bg-card); border-radius: 8px; padding: 20px; margin-bottom: 16px; border: 1px solid var(--border); }
        .section-title { font-size: 16px; font-weight: 600; color: var(--text-main); margin-bottom: 16px; display: flex; align-items: center; gap: 8px; padding-bottom: 12px; border-bottom: 1px solid #f2f3f5; }
        .section-title svg { width: 20px; height: 20px; color: var(--primary); }

        /* ========== Product Header & Carousel ========== */
        .product-header { position: relative; }
        .carousel-container { position: relative; overflow: hidden; border-radius: 8px 8px 0 0; background: #f7f8fa; }
        .carousel-track { display: flex; transition: transform 0.3s ease; }
        .carousel-slide { min-width: 100%; position: relative; cursor: zoom-in; }
        .carousel-slide img { width: 100%; height: 320px; object-fit: cover; display: block; }
        .carousel-btn { position: absolute; top: 50%; transform: translateY(-50%); width: 36px; height: 36px; background: rgba(255,255,255,0.9); border-radius: 50%; display: flex; align-items: center; justify-content: center; cursor: pointer; transition: all 0.2s; z-index: 2; box-shadow: 0 2px 6px rgba(0,0,0,0.15); }
        .carousel-btn:hover { background: #fff; transform: translateY(-50%) scale(1.1); }
        .carousel-btn svg { width: 18px; height: 18px; color: #333; }
        .carousel-prev { left: 12px; }
        .carousel-next { right: 12px; }
        .carousel-dots { position: absolute; bottom: 12px; left: 50%; transform: translateX(-50%); display: flex; gap: 6px; z-index: 2; }
        .carousel-dot { width: 8px; height: 8px; border-radius: 50%; background: rgba(255,255,255,0.5); cursor: pointer; transition: all 0.2s; }
        .carousel-dot.active { background: #fff; width: 20px; border-radius: 4px; }
        .carousel-counter { position: absolute; bottom: 12px; right: 12px; background: rgba(0,0,0,0.6); color: #fff; font-size: 12px; padding: 4px 10px; border-radius: 12px; z-index: 2; }
        .zoom-hint { position: absolute; top: 12px; right: 12px; background: rgba(0,0,0,0.6); color: #fff; font-size: 11px; padding: 4px 8px; border-radius: 4px; z-index: 2; display: flex; align-items: center; gap: 4px; }
        .zoom-hint svg { width: 14px; height: 14px; }

        .product-header-content { padding: 20px; }
        .product-info h1 { font-size: 20px; font-weight: 600; margin-bottom: 6px; }
        .product-info p { font-size: 13px; color: var(--text-sub); line-height: 1.5; }

        /* ========== Image Lightbox ========== */
        .lightbox { display: none; position: fixed; top: 0; left: 0; right: 0; bottom: 0; background: rgba(0,0,0,0.95); z-index: 1000; align-items: center; justify-content: center; }
        .lightbox.active { display: flex; }
        .lightbox-close { position: absolute; top: 16px; right: 16px; width: 40px; height: 40px; background: rgba(255,255,255,0.1); border-radius: 50%; display: flex; align-items: center; justify-content: center; cursor: pointer; transition: all 0.2s; z-index: 1001; }
        .lightbox-close:hover { background: rgba(255,255,255,0.2); }
        .lightbox-close svg { width: 20px; height: 20px; color: #fff; }
        .lightbox-img { max-width: 90vw; max-height: 90vh; object-fit: contain; transition: transform 0.2s; cursor: grab; }
        .lightbox-img:active { cursor: grabbing; }
        .lightbox-btn { position: absolute; top: 50%; transform: translateY(-50%); width: 48px; height: 48px; background: rgba(255,255,255,0.1); border-radius: 50%; display: flex; align-items: center; justify-content: center; cursor: pointer; transition: all 0.2s; z-index: 1001; }
        .lightbox-btn:hover { background: rgba(255,255,255,0.2); }
        .lightbox-btn svg { width: 24px; height: 24px; color: #fff; }
        .lightbox-prev { left: 16px; }
        .lightbox-next { right: 16px; }
        .lightbox-counter { position: absolute; bottom: 16px; left: 50%; transform: translateX(-50%); color: rgba(255,255,255,0.7); font-size: 14px; z-index: 1001; }
        .lightbox-zoom-controls { position: absolute; bottom: 16px; right: 16px; display: flex; gap: 8px; z-index: 1001; }
        .lightbox-zoom-btn { width: 36px; height: 36px; background: rgba(255,255,255,0.1); border-radius: 8px; display: flex; align-items: center; justify-content: center; cursor: pointer; transition: all 0.2s; }
        .lightbox-zoom-btn:hover { background: rgba(255,255,255,0.2); }
        .lightbox-zoom-btn svg { width: 18px; height: 18px; color: #fff; }

        /* ========== Billing Cycles ========== */
        .billing-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px; }
        .billing-card { position: relative; border: 1px solid var(--border); border-radius: 8px; padding: 12px 8px; cursor: pointer; transition: all 0.2s; text-align: center; background: #fff; }
        .billing-card:hover { border-color: var(--primary); transform: translateY(-2px); box-shadow: 0 4px 10px rgba(26,109,255,0.1); }
        .billing-card.active { border-color: var(--primary); background: var(--primary-light); }
        .billing-card.popular::before { content: '推荐'; position: absolute; top: -8px; left: 50%; transform: translateX(-50%); background: #ff7d00; color: #fff; font-size: 10px; padding: 2px 8px; border-radius: 10px; }
        .billing-label { font-size: 13px; font-weight: 500; margin-bottom: 4px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
        .billing-price { font-size: 15px; font-weight: 600; color: var(--danger); }
        .billing-discount { font-size: 11px; color: var(--primary); margin-top: 2px; }

        /* ========== Meta Config (Free) ========== */
        .meta-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }
        .meta-item { display: flex; flex-direction: column; gap: 6px; }
        .meta-label { font-size: 13px; font-weight: 500; color: var(--text-main); }
        .meta-label .req { color: var(--danger); margin-left: 2px; }
        .meta-input, .meta-select { width: 100%; padding: 8px 12px; border: 1px solid var(--border); border-radius: 6px; font-size: 13px; transition: border-color 0.2s; background: #fff; }
        .meta-input:focus, .meta-select:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 2px rgba(26,109,255,0.1); }
        .meta-radio-group { display: flex; flex-wrap: wrap; gap: 8px; }
        .meta-radio-label { display: flex; align-items: center; gap: 6px; padding: 6px 12px; border: 1px solid var(--border); border-radius: 6px; cursor: pointer; transition: all 0.2s; font-size: 13px; }
        .meta-radio-label:hover { border-color: var(--primary); }
        .meta-radio-label.active { border-color: var(--primary); background: var(--primary-light); color: var(--primary); }
        .meta-radio-label input { display: none; }
        .meta-checkbox-group { display: flex; flex-wrap: wrap; gap: 8px; }
        .meta-checkbox-label { display: flex; align-items: center; gap: 6px; padding: 6px 12px; border: 1px solid var(--border); border-radius: 6px; cursor: pointer; transition: all 0.2s; font-size: 13px; }
        .meta-checkbox-label:hover { border-color: var(--primary); }
        .meta-checkbox-label.active { border-color: var(--primary); background: var(--primary-light); color: var(--primary); }
        .meta-checkbox-label input { display: none; }

        /* ========== Addons (Paid) ========== */
        .addon-item { border: 1px solid var(--border); border-radius: 8px; padding: 16px; margin-bottom: 12px; background: #fff; }
        .addon-item:last-child { margin-bottom: 0; }
        .addon-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 10px; }
        .addon-name { font-size: 14px; font-weight: 500; }
        .addon-price-tag { font-size: 12px; color: var(--text-sub); }
        
        .qty-control { display: flex; align-items: center; gap: 0; }
        .qty-btn { width: 32px; height: 32px; border: 1px solid var(--border); background: #fff; display: flex; align-items: center; justify-content: center; font-size: 16px; color: var(--text-main); transition: all 0.2s; }
        .qty-btn:first-child { border-radius: 6px 0 0 6px; }
        .qty-btn:last-child { border-radius: 0 6px 6px 0; }
        .qty-btn:hover { background: #f7f8fa; }
        .qty-input { width: 60px; height: 32px; border: 1px solid var(--border); border-left: none; border-right: none; text-align: center; font-size: 14px; font-weight: 500; -moz-appearance: textfield; }
        .qty-input::-webkit-outer-spin-button, .qty-input::-webkit-inner-spin-button { -webkit-appearance: none; margin: 0; }
        .qty-unit { margin-left: 8px; font-size: 13px; color: var(--text-sub); }

        .addon-options { display: grid; grid-template-columns: repeat(auto-fill, minmax(140px, 1fr)); gap: 10px; }
        .addon-option { border: 1px solid var(--border); border-radius: 6px; padding: 10px; cursor: pointer; transition: all 0.2s; position: relative; }
        .addon-option:hover { border-color: var(--primary); }
        .addon-option.active { border-color: var(--primary); background: var(--primary-light); }
        .addon-option-label { font-size: 13px; font-weight: 500; margin-bottom: 2px; }
        .addon-option-price { font-size: 12px; color: var(--danger); }
        .addon-option input { display: none; }

        /* ========== Product Intro ========== */
        .intro-specs { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; margin-bottom: 20px; }
        .spec-row { display: flex; justify-content: space-between; padding: 8px 0; border-bottom: 1px solid #f2f3f5; font-size: 13px; }
        .spec-row:last-child { border-bottom: none; }
        .spec-label { color: var(--text-sub); }
        .spec-value { font-weight: 500; }
        .intro-features { display: grid; grid-template-columns: repeat(2, 1fr); gap: 10px; }
        .feature-item { display: flex; align-items: center; gap: 8px; font-size: 13px; color: #4e5969; }
        .feature-check { width: 16px; height: 16px; background: var(--primary-light); color: var(--primary); border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 10px; flex-shrink: 0; }

        /* ========== Order Sidebar ========== */
        .order-sidebar { position: sticky; top: 72px; }
        .order-card { background: var(--bg-card); border-radius: 8px; padding: 20px; border: 1px solid var(--border); }
        .order-title { font-size: 15px; font-weight: 600; margin-bottom: 16px; padding-bottom: 12px; border-bottom: 1px solid #f2f3f5; }
        .order-summary-row { display: flex; justify-content: space-between; padding: 6px 0; font-size: 13px; }
        .order-label { color: var(--text-sub); }
        .order-value { font-weight: 500; }
        .order-divider { height: 1px; background: #f2f3f5; margin: 8px 0; }
        .order-total { display: flex; justify-content: space-between; align-items: baseline; padding: 12px 0; }
        .order-total-label { font-size: 14px; font-weight: 500; }
        .order-total-price { font-size: 24px; font-weight: 600; color: var(--danger); }
        .order-total-unit { font-size: 13px; color: var(--text-sub); font-weight: 400; }
        .btn-buy { width: 100%; padding: 12px; background: var(--primary); color: #fff; border-radius: 6px; font-size: 15px; font-weight: 500; transition: background 0.2s; }
        .btn-buy:hover { background: var(--primary-hover); }
        .order-note { margin-top: 12px; font-size: 12px; color: var(--text-sub); text-align: center; }

        /* ========== Mobile Bottom Bar ========== */
        .mobile-buy-bar { display: none; position: fixed; bottom: 0; left: 0; right: 0; background: #fff; padding: 12px 16px; box-shadow: 0 -2px 8px rgba(0,0,0,0.08); z-index: 99; }
        .mobile-buy-inner { display: flex; align-items: center; gap: 12px; }
        .mobile-buy-price { flex: 1; }
        .mobile-buy-price .label { font-size: 12px; color: var(--text-sub); }
        .mobile-buy-price .price { font-size: 20px; font-weight: 600; color: var(--danger); }
        .mobile-buy-btn { padding: 12px 32px; background: var(--primary); color: #fff; border-radius: 6px; font-size: 14px; font-weight: 500; }

        /* ========== Footer ========== */
        .footer { background: #fff; border-top: 1px solid var(--border); padding: 32px 16px; text-align: center; font-size: 13px; color: var(--text-sub); margin-top: 40px; }

        /* 移动端导航 */
        .mobile-nav-overlay { display: none; position: fixed; top: 0; left: 0; right: 0; bottom: 0; background: rgba(0,0,0,0.5); z-index: 200; opacity: 0; transition: opacity 0.3s; }
        .mobile-nav-overlay.active { display: block; opacity: 1; }
        .mobile-nav-panel { position: fixed; top: 0; right: -280px; width: 280px; height: 100%; background: #fff; z-index: 201; transition: right 0.3s ease; overflow-y: auto; }
        .mobile-nav-overlay.active .mobile-nav-panel { right: 0; }
        .mobile-nav-header { padding: 16px; border-bottom: 1px solid #e8eaed; display: flex; justify-content: space-between; align-items: center; }
        .mobile-nav-header span { font-size: 16px; font-weight: 600; color: var(--text-main); }
        .mobile-nav-close { width: 32px; height: 32px; display: flex; align-items: center; justify-content: center; cursor: pointer; border-radius: 4px; }
        .mobile-nav-close:hover { background: #f7f8fa; }
        .mobile-nav-close svg { width: 18px; height: 18px; color: #8a8e99; }
        .mobile-nav-list { padding: 8px 0; }
        .mobile-nav-list a { display: block; padding: 14px 16px; font-size: 15px; color: var(--text-main); border-bottom: 1px solid #f2f3f5; transition: background 0.15s; }
        .mobile-nav-list a:hover, .mobile-nav-list a.active { background: #f0f5ff; color: var(--primary); }
        .mobile-nav-actions { padding: 16px; display: flex; gap: 12px; }
        .mobile-nav-actions a { flex: 1; text-align: center; padding: 10px; border-radius: 6px; font-size: 14px; }
        .mobile-nav-actions .btn-login-m { border: 1px solid var(--border); color: #4e5969; }
        .mobile-nav-actions .btn-register-m { background: var(--primary); color: #fff; }
        .mobile-nav-actions .btn-cs-m { background: #f7f8fa; color: #4e5969; text-align: center; }

        /* ========== 商品描述（自定义） ========== */
        .pd-card { background: #fff; border-radius: 8px; padding: 20px; border: 1px solid #e5e6eb; }
        .pd-space-y-4 > * + * { margin-top: 16px; }
        .pd-flex { display: flex; }
        .pd-items-start { align-items: flex-start; }
        .pd-items-center { align-items: center; }
        .pd-gap-2 { gap: 8px; }
        .pd-gap-3 { gap: 12px; }
        .pd-pb-3 { padding-bottom: 12px; }
        .pd-border-b { border-bottom: 1px solid #e5e6eb; }
        .pd-border-gray-100 { border-color: #f2f3f5; }
        .pd-mt-1 { margin-top: 4px; }
        .pd-ml-1 { margin-left: 4px; }
        .pd-leading-relaxed { line-height: 1.625; }
        .pd-grid { display: grid; grid-template-columns: 1fr; gap: 12px; }
        @media (min-width: 768px) {
            .pd-grid-cols-2 { grid-template-columns: 1fr 1fr; }
        }
        .pd-p-3 { padding: 12px; }
        .pd-bg-gray-50 { background: #f7f8fa; }
        .pd-bg-blue-100 { background: #f0f5ff; }
        .pd-bg-green-100 { background: #ecfdf5; }
        .pd-bg-purple-100 { background: #f5f3ff; }
        .pd-bg-orange-100 { background: #fff7ed; }
        .pd-bg-yellow-50 { background: #fffbeb; }
        .pd-rounded-lg { border-radius: 8px; }
        .pd-rounded-full { border-radius: 50%; }
        .pd-w-4 { width: 16px; }
        .pd-w-8 { width: 32px; }
        .pd-h-8 { height: 32px; }
        .pd-text-xs { font-size: 12px; }
        .pd-text-sm { font-size: 13px; }
        .pd-text-gray-400 { color: #9ca3af; }
        .pd-text-gray-600 { color: #6b7280; }
        .pd-text-gray-700 { color: #374151; }
        .pd-text-blue-500 { color: #1a6dff; }
        .pd-text-blue-600 { color: #2563eb; }
        .pd-text-green-500 { color: #10b981; }
        .pd-text-purple-500 { color: #8b5cf6; }
        .pd-text-orange-500 { color: #f97316; }
        .pd-text-yellow-600 { color: #d97706; }
        .pd-text-center { text-align: center; }
        .pd-flex-col { flex-direction: column; }
        .pd-gap-2 { gap: 8px; }
        .pd-font-medium { font-weight: 500; }
        .pd-border { border: 1px solid #e5e6eb; }
        .pd-border-yellow-100 { border-color: #fef3c7; }
        .pd-justify-center { justify-content: center; }
        .pd-flex-shrink-0 { flex-shrink: 0; }
        .pd-inline { display: inline; }
        a.pd-hover\:text-blue-800:hover { color: #1e40af; }
        .pd-inline-flex { display: inline-flex; }

        /* ========== Responsive ========== */
        @media (max-width: 900px) {
            .product-layout { grid-template-columns: 1fr; }
            .order-sidebar { display: none; }
            .mobile-buy-bar { display: block; }
            .billing-grid { grid-template-columns: repeat(4, 1fr); gap: 6px; }
            .billing-card { padding: 8px 4px; }
            .billing-label { font-size: 11px; }
            .billing-price { font-size: 13px; }
            .billing-discount { font-size: 10px; }
            .meta-grid { grid-template-columns: 1fr; }
            .addon-options { grid-template-columns: repeat(2, 1fr); }
            .intro-specs { grid-template-columns: 1fr; }
            .intro-features { grid-template-columns: 1fr; }
            .header-top, .main-nav, .header-actions { display: none; }
            .mobile-menu-btn { display: flex; }
            .header-main { height: 48px; gap: 12px; padding: 0 12px; }
            .logo { font-size: 17px; }
            .container { padding: 12px 12px 80px; }
            .carousel-slide img { height: 200px; }
            .carousel-btn { width: 30px; height: 30px; }
            .carousel-btn svg { width: 14px; height: 14px; }
            .carousel-prev { left: 8px; }
            .carousel-next { right: 8px; }
            .product-header-content { padding: 16px 12px; }
            .section-card { padding: 16px; margin-bottom: 12px; }
            .section-title { font-size: 15px; margin-bottom: 12px; padding-bottom: 10px; }
        }