/* roulang page: index */
:root {
            --primary: #7C3AED;
            --primary-dark: #5B21B6;
            --accent-cyan: #06B6D4;
            --accent-coral: #F43F5E;
            --bg-light-1: #F8FAFC;
            --bg-light-2: #F1F5F9;
            --text-dark: #1E293B;
            --text-muted: #64748B;
            --radius-large: 24px;
            --shadow-brand: 0 10px 25px -5px rgba(124, 58, 237, 0.12);
            --shadow-card-hover: 0 20px 35px -5px rgba(124, 58, 237, 0.22);
        }

        html {
            scroll-behavior: smooth;
        }

        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
            color: var(--text-dark);
            background-color: #FFFFFF;
            overflow-x: hidden;
        }

        /* 统一大圆角卡片与阴影微动效 */
        .brand-card {
            border-radius: var(--radius-large);
            box-shadow: var(--shadow-brand);
            transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
            border: 1px solid rgba(226, 232, 240, 0.8);
        }
        .brand-card:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-card-hover);
            border-color: rgba(124, 58, 237, 0.35);
        }

        /* 渐变文本 */
        .text-gradient {
            background: linear-gradient(135deg, #7C3AED 0%, #06B6D4 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }
        .text-gradient-coral {
            background: linear-gradient(135deg, #F43F5E 0%, #7C3AED 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }

        /* 徽章胶囊 */
        .capsule-badge {
            display: inline-flex;
            align-items: center;
            gap: 6px;
            padding: 4px 14px;
            border-radius: 9999px;
            font-size: 0.825rem;
            font-weight: 600;
        }

        /* 交互按钮 */
        .btn-gradient {
            background: linear-gradient(135deg, #7C3AED 0%, #5B21B6 100%);
            color: #FFFFFF;
            transition: all 0.25s ease;
            box-shadow: 0 4px 14px rgba(124, 58, 237, 0.35);
        }
        .btn-gradient:hover {
            background: linear-gradient(135deg, #6D28D9 0%, #4C1D95 100%);
            transform: translateY(-2px);
            box-shadow: 0 6px 20px rgba(124, 58, 237, 0.45);
        }

        /* 手风琴展开与收起 */
        .accordion-content {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.35s ease-out, opacity 0.3s ease;
            opacity: 0;
        }
        .accordion-item.active .accordion-content {
            max-height: 400px;
            opacity: 1;
        }
        .accordion-item.active .accordion-icon {
            transform: rotate(180deg);
        }