/* roulang page: index */
:root {
            --color-primary: #0F2B48;
            --color-primary-dark: #0B1A2A;
            --color-accent: #00B686;
            --color-accent-hover: #009E74;
            --color-bg: #F8FAFC;
            --color-text: #1E293B;
            --color-text-muted: #64748B;
            --color-border: #E2E8F0;
            --radius-card: 12px;
            --shadow-subtle: 0 4px 20px -2px rgba(15, 43, 72, 0.06);
            --shadow-hover: 0 12px 28px -4px rgba(15, 43, 72, 0.12);
        }

        html {
            scroll-behavior: smooth;
        }

        body {
            background-color: var(--color-bg);
            color: var(--color-text);
            font-family: system-ui, -apple-system, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            line-height: 1.75;
        }

        .hero-banner-bg {
            background-image: linear-gradient(135deg, rgba(11, 26, 42, 0.94) 0%, rgba(15, 43, 72, 0.88) 100%), url('/assets/images/aed284a70ad576e8.jpg');
            background-size: cover;
            background-position: center;
        }

        .dark-section-bg {
            background-image: linear-gradient(135deg, rgba(11, 26, 42, 0.97) 0%, rgba(15, 43, 72, 0.95) 100%), url('/assets/images/1e2f0badc9095d16.jpg');
            background-size: cover;
            background-position: center;
        }

        .card-custom {
            background: #FFFFFF;
            border: 1px solid var(--color-border);
            border-radius: var(--radius-card);
            box-shadow: var(--shadow-subtle);
            transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.3s cubic-bezier(0.16, 1, 0.3, 1);
        }

        .card-custom:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-hover);
        }

        .btn-accent {
            background-color: var(--color-accent);
            color: #FFFFFF;
            font-weight: 600;
            transition: all 0.25s ease;
        }

        .btn-accent:hover {
            background-color: var(--color-accent-hover);
            transform: translateY(-1px);
            box-shadow: 0 8px 16px -2px rgba(0, 182, 134, 0.35);
        }

        .faq-item[open] summary svg {
            transform: rotate(180deg);
        }
        
        .sticky-nav {
            backdrop-filter: blur(12px);
            -webkit-backdrop-filter: blur(12px);
        }

        .badge-tag {
            font-size: 0.75rem;
            letter-spacing: 0.08em;
            text-transform: uppercase;
        }