/* roulang page: index */
:root {
            --brand-primary: #00D084;
            --brand-hover: #00E599;
            --brand-deep: #0A996F;
            --bg-obsidian: #0A0D10;
            --bg-card: #141A22;
            --text-main: #FFFFFF;
            --text-sub: #94A3B8;
            --border-dark: rgba(255, 255, 255, 0.08);
            --radius-card: 16px;
            --radius-btn: 10px;
        }

        body {
            background-color: var(--bg-obsidian);
            color: #E2E8F0;
            font-family: 'Inter', -apple-system, BlinkMacSystemFont, "PingFang SC", "Noto Sans SC", sans-serif;
            overflow-x: hidden;
            -webkit-font-smoothing: antialiased;
        }

        .border-subtle {
            border: 1px solid var(--border-dark);
        }

        .border-mint-glow:hover {
            border-color: rgba(0, 208, 132, 0.4);
            box-shadow: 0 0 20px rgba(0, 208, 132, 0.12);
        }

        .custom-glass {
            background: rgba(15, 19, 24, 0.75);
            backdrop-filter: blur(16px);
            -webkit-backdrop-filter: blur(16px);
        }

        .hero-mesh {
            background: radial-gradient(circle at 50% 20%, rgba(0, 208, 132, 0.15) 0%, rgba(10, 13, 16, 0.8) 65%, #0A0D10 100%);
        }

        /* 呼吸指示灯 */
        .pulse-dot {
            box-shadow: 0 0 0 0 rgba(0, 208, 132, 0.7);
            animation: pulse-green 2s infinite cubic-bezier(0.66, 0, 0, 1);
        }

        @keyframes pulse-green {
            to {
                box-shadow: 0 0 0 10px rgba(0, 208, 132, 0);
            }
        }

        /* 手风琴折叠平滑过渡 */
        .faq-content {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.35s ease-out, opacity 0.3s ease-out;
            opacity: 0;
        }

        .faq-item.active .faq-content {
            max-height: 280px;
            opacity: 1;
        }

        .faq-item.active .faq-icon {
            transform: rotate(180deg);
        }

        /* 卡片悬浮过渡 */
        .card-lift {
            transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1), border-color 0.3s ease, box-shadow 0.3s ease;
        }
        .card-lift:hover {
            transform: translateY(-4px);
        }