/* roulang page: index */
:root {
            --color-steel-bg: #0F172A;
            --color-surface-light: #FFFFFF;
            --color-surface-subtle: #F8FAFC;
            --color-brand-blue: #1E3A8A;
            --color-pulse-green: #0D9488;
            --color-accent-amber: #F59E0B;
            --border-radius-base: 8px;
        }
        * {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
            -webkit-tap-highlight-color: transparent;
        }
        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            background-color: #F8FAFC;
            color: #1E293B;
            line-height: 1.65;
            text-rendering: optimizeLegibility;
            overflow-x: hidden;
        }
        .metal-card {
            border: 1px solid rgba(226, 232, 240, 0.9);
            box-shadow: 0 4px 6px -1px rgba(15, 23, 42, 0.05), 0 2px 4px -2px rgba(15, 23, 42, 0.05);
            transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
        }
        .metal-card:hover {
            transform: translateY(-4px);
            box-shadow: 0 12px 24px -6px rgba(15, 23, 42, 0.12), 0 4px 8px -4px rgba(15, 23, 42, 0.06);
            border-color: #CBD5E1;
        }
        .dark-metal-card {
            background: linear-gradient(180deg, #1E293B 0%, #0F172A 100%);
            border: 1px solid rgba(51, 65, 85, 0.8);
            box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.3);
            transition: all 0.3s ease;
        }
        .dark-metal-card:hover {
            border-color: #0D9488;
            box-shadow: 0 14px 28px -4px rgba(13, 148, 136, 0.15);
        }
        .glow-pulse {
            position: relative;
        }
        .glow-pulse::after {
            content: '';
            position: absolute;
            top: 0; left: 0; right: 0; bottom: 0;
            border-radius: inherit;
            box-shadow: 0 0 15px rgba(16, 185, 129, 0.4);
            opacity: 0;
            transition: opacity 0.3s ease;
        }
        .glow-pulse:hover::after {
            opacity: 1;
        }
        .faq-content {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.35s ease-out, padding 0.3s ease;
        }
        .faq-item.active .faq-content {
            max-height: 240px;
        }
        .faq-item.active .faq-chevron {
            transform: rotate(180deg);
        }
        .faq-item.active {
            background-color: #ECFDF5;
            border-color: #A7F3D0;
        }