/* roulang page: index */
:root {
            --brand-primary: #B89558;
            --brand-dark: #0E1116;
            --brand-charcoal: #12151A;
            --brand-gray: #5A626F;
            --brand-bg: #F8F9FA;
            --border-line: rgba(18, 21, 26, 0.08);
            --border-dark: rgba(255, 255, 255, 0.12);
        }
        
        * {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
        }

        html {
            scroll-behavior: smooth;
            font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
            background-color: var(--brand-bg);
            color: var(--brand-charcoal);
            text-rendering: optimizeLegibility;
            -webkit-font-smoothing: antialiased;
        }

        /* 顶部毛玻璃导航微细节 */
        .glass-nav {
            backdrop-filter: blur(16px);
            -webkit-backdrop-filter: blur(16px);
            background-color: rgba(255, 255, 255, 0.92);
            border-bottom: 1px solid var(--border-line);
        }

        /* 极简卡片与微交互动效 */
        .system-card {
            background: #FFFFFF;
            border: 1px solid var(--border-line);
            transition: all 0.35s cubic-bezier(0.16, 1, 0.3, 1);
        }
        .system-card:hover {
            transform: translateY(-4px);
            box-shadow: 0 20px 35px -10px rgba(18, 21, 26, 0.08);
            border-color: rgba(184, 149, 88, 0.4);
        }

        /* 深色区块高阶卡片 */
        .dark-card {
            background: rgba(255, 255, 255, 0.03);
            border: 1px solid var(--border-dark);
            transition: all 0.35s cubic-bezier(0.16, 1, 0.3, 1);
        }
        .dark-card:hover {
            background: rgba(255, 255, 255, 0.06);
            border-color: rgba(184, 149, 88, 0.6);
            transform: translateY(-4px);
        }

        /* FAQ 手风琴展开动效 */
        .accordion-content {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.35s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.3s ease;
            opacity: 0;
        }
        .accordion-item.active .accordion-content {
            max-height: 380px;
            opacity: 1;
        }
        .accordion-item.active .accordion-icon {
            transform: rotate(45deg);
        }

        /* 单线标签与按钮 */
        .btn-gold {
            background-color: var(--brand-primary);
            color: #FFFFFF;
            transition: all 0.25s ease;
        }
        .btn-gold:hover {
            background-color: var(--brand-goldDeep);
            box-shadow: 0 4px 16px rgba(184, 149, 88, 0.25);
        }