/* roulang page: index */
:root {
            --primary-grad: linear-gradient(135deg, #0D9488 0%, #059669 100%);
            --dark-deep: #022C22;
        }
        html {
            scroll-behavior: smooth;
            font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
        }
        .btn-gradient {
            background: var(--primary-grad);
            transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
        }
        .btn-gradient:hover {
            opacity: 0.95;
            box-shadow: 0 10px 25px -5px rgba(5, 150, 105, 0.4);
            transform: translateY(-1px);
        }
        .accordion-content {
            transition: max-height 0.35s ease-out, opacity 0.25s ease;
            max-height: 0;
            overflow: hidden;
            opacity: 0;
        }
        .accordion-content.active {
            max-height: 240px;
            opacity: 1;
        }