/* roulang page: index */
:root {
            --primary: #0F1923;
            --accent: #FF4655;
            --cyan: #00E5FF;
            --bg-light: #F5F7FA;
            --surface: #FFFFFF;
            --border-color: #E2E8F0;
        }
        * { box-sizing: border-box; scroll-behavior: smooth; }
        body {
            font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            background-color: var(--bg-light);
            color: #3A434D;
            line-height: 1.75;
            letter-spacing: 0.02em;
            margin: 0;
            padding: 0;
            overflow-x: hidden;
        }
        .hero-diagonal {
            clip-path: polygon(0 0, 100% 0, 100% 92%, 0 100%);
        }
        @media (max-width: 768px) {
            .hero-diagonal {
                clip-path: none;
            }
        }
        .btn-hover-effect {
            transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
        }
        .btn-hover-effect:hover {
            transform: translateY(-2px);
            filter: brightness(0.92);
            box-shadow: 0 10px 18px -4px rgba(255, 70, 85, 0.4);
        }
        .btn-hover-effect:active {
            transform: translateY(0);
            box-shadow: 0 2px 6px -2px rgba(255, 70, 85, 0.4);
        }
        .faq-content {
            display: grid;
            grid-template-rows: 0fr;
            transition: grid-template-rows 0.3s ease-out;
        }
        .faq-item.active .faq-content {
            grid-template-rows: 1fr;
        }
        .faq-item.active .faq-arrow {
            transform: rotate(180deg);
        }