/* roulang page: index */
:root {
            --primary: #C25E3E;
            --primary-dark: #A64C2E;
            --slate-base: #1E252B;
            --slate-deep: #181D20;
            --text-main: #2C3338;
            --text-muted: #667085;
            --bg-light: #F9F9F7;
            --border-soft: rgba(30, 37, 43, 0.08);
            --shadow-subtle: 0 4px 20px -2px rgba(30, 37, 43, 0.05);
            --shadow-hover: 0 12px 30px -4px rgba(194, 94, 62, 0.12);
        }
        html {
            scroll-behavior: smooth;
        }
        body {
            background-color: var(--bg-light);
            color: var(--text-main);
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            line-height: 1.6;
        }
        .custom-card {
            background: #ffffff;
            border: 1px solid var(--border-soft);
            box-shadow: var(--shadow-subtle);
            transition: all 0.25s ease;
        }
        .custom-card:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-hover);
            border-color: rgba(194, 94, 62, 0.2);
        }
        .accordion-content {
            transition: max-height 0.3s ease-out, opacity 0.3s ease;
            max-height: 0;
            overflow: hidden;
            opacity: 0;
        }
        .accordion-content.active {
            max-height: 400px;
            opacity: 1;
        }
        .tab-btn.active {
            background-color: var(--primary);
            color: #ffffff;
        }