/* roulang page: index */
:root {
            --primary: #0B2545;
            --secondary: #134074;
            --accent: #FF6B35;
            --cyber: #00B4D8;
            --deepdark: #05192D;
            --lightbg: #F4F7FA;
        }
        html { scroll-behavior: smooth; }
        body { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif; }
        .gradient-ocean {
            background: linear-gradient(135deg, #0B2545 0%, #134074 50%, #0077B6 100%);
        }
        .gradient-deep {
            background: linear-gradient(180deg, #05192D 0%, #0B2545 100%);
        }
        .text-gradient {
            background: linear-gradient(135deg, #00B4D8 0%, #90E0EF 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }
        .btn-hover-lift {
            transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
        }
        .btn-hover-lift:hover {
            transform: translateY(-2px);
            box-shadow: 0 10px 25px -5px rgba(255, 107, 53, 0.4);
        }
        .btn-cyber-hover:hover {
            transform: translateY(-2px);
            box-shadow: 0 10px 25px -5px rgba(0, 180, 216, 0.4);
        }
        .accordion-content {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.35s ease-out;
        }
        .accordion-item.active .accordion-content {
            max-height: 250px;
        }
        .accordion-item.active .accordion-icon {
            transform: rotate(180deg);
        }