/* roulang page: index */
:root {
            --brand-primary: #1D4ED8;
            --brand-electric: #2563EB;
            --brand-pulse: #06B6D4;
            --brand-dark: #0B0F19;
            --brand-card-bg: #FFFFFF;
            --brand-border: #E2E8F0;
            --brand-text-main: #0F172A;
            --brand-text-sub: #475569;
            --brand-amber: #F59E0B;
        }

        /* 基础重置与平滑滚动 */
        *, *::before, *::after {
            box-sizing: border-box;
        }

        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            color: var(--brand-text-main);
            background-color: #F8FAFC;
            overflow-x: hidden;
            line-height: 1.6;
        }

        /* 品牌渐变与动效类 */
        .bg-brand-gradient {
            background: linear-gradient(135deg, #1E40AF 0%, #0284C7 50%, #06B6D4 100%);
        }

        .bg-brand-gradient-hover:hover {
            background: linear-gradient(135deg, #1D4ED8 0%, #0369A1 50%, #0891B2 100%);
        }

        .text-brand-gradient {
            background: linear-gradient(135deg, #2563EB 0%, #06B6D4 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }

        .border-brand-gradient {
            border-image: linear-gradient(to bottom, rgba(37, 99, 235, 0.4), rgba(6, 182, 212, 0.1)) 1;
        }

        /* 数据徽章与呼吸点 */
        .data-badge-pulse {
            position: relative;
            display: inline-flex;
            align-items: center;
            gap: 0.375rem;
            padding: 0.25rem 0.75rem;
            border-radius: 9999px;
            font-size: 0.75rem;
            font-weight: 600;
            letter-spacing: 0.025em;
            background: rgba(6, 182, 212, 0.1);
            color: #0284C7;
            border: 1px solid rgba(6, 182, 212, 0.3);
        }

        .pulse-indicator {
            width: 0.5rem;
            height: 0.5rem;
            border-radius: 9999px;
            background-color: #06B6D4;
            box-shadow: 0 0 0 0 rgba(6, 182, 212, 0.7);
            animation: pulse-ring 2s infinite cubic-bezier(0.4, 0, 0.6, 1);
        }

        @keyframes pulse-ring {
            0% {
                transform: scale(0.95);
                box-shadow: 0 0 0 0 rgba(6, 182, 212, 0.7);
            }
            70% {
                transform: scale(1);
                box-shadow: 0 0 0 6px rgba(6, 182, 212, 0);
            }
            100% {
                transform: scale(0.95);
                box-shadow: 0 0 0 0 rgba(6, 182, 212, 0);
            }
        }

        /* 圆角大卡片通用微交互 */
        .tech-card {
            border-radius: 1.5rem;
            background: #FFFFFF;
            border: 1px solid #E2E8F0;
            box-shadow: 0 10px 30px -10px rgba(15, 23, 42, 0.05);
            transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
        }

        .tech-card:hover {
            transform: translateY(-4px);
            box-shadow: 0 20px 35px -12px rgba(37, 99, 235, 0.12);
            border-color: rgba(37, 99, 235, 0.35);
        }

        /* 倒计时环形视觉装饰 */
        .countdown-ring-wrap {
            position: relative;
            width: 140px;
            height: 140px;
        }

        .countdown-svg {
            transform: rotate(-90deg);
        }

        .countdown-circle-bg {
            fill: none;
            stroke: rgba(226, 232, 240, 0.3);
            stroke-width: 8;
        }

        .countdown-circle-active {
            fill: none;
            stroke: url(#cyan-blue-grad);
            stroke-width: 8;
            stroke-linecap: round;
            stroke-dasharray: 377;
            stroke-dashoffset: 75;
            transition: stroke-dashoffset 1s ease-in-out;
        }

        /* 移动端菜单过渡 */
        #mobile-menu {
            transition: max-height 0.35s ease-in-out, opacity 0.3s ease-in-out;
        }
        #mobile-menu.menu-closed {
            max-height: 0;
            opacity: 0;
            overflow: hidden;
            pointer-events: none;
        }
        #mobile-menu.menu-open {
            max-height: 600px;
            opacity: 1;
            pointer-events: auto;
        }

        /* FAQ 手风琴展开样式 */
        .faq-answer {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.35s cubic-bezier(0, 1, 0, 1), padding 0.3s ease;
        }
        .faq-item.active .faq-answer {
            max-height: 500px;
            transition: max-height 0.5s ease-in-out, padding 0.3s ease;
        }
        .faq-item.active .faq-arrow {
            transform: rotate(180deg);
        }