/* roulang page: index */
:root {
            --color-primary: #0C1E17;
            --color-secondary: #16A34A;
            --color-accent: #EA580C;
            --color-canvas: #F8F9F6;
            --color-border: #E2E8F0;
        }
        
        * {
            box-sizing: border-box;
        }

        html {
            scroll-behavior: smooth;
        }

        body {
            background-color: var(--color-canvas);
            color: #1E293B;
            font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", "Inter", sans-serif;
            line-height: 1.7;
            overflow-x: hidden;
        }

        section {
            scroll-margin-top: 84px;
        }

        .card-shadow {
            box-shadow: 0 4px 20px -2px rgba(12, 30, 23, 0.05);
            transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
        }

        .card-shadow:hover {
            box-shadow: 0 16px 32px -4px rgba(12, 30, 23, 0.1);
            transform: translateY(-4px);
        }

        .stacked-container {
            perspective: 1000px;
        }

        .stacked-card-main {
            transform: translateZ(20px);
            z-index: 20;
        }

        .stacked-card-left {
            transform: rotate(-3deg) translateY(12px) scale(0.96);
            z-index: 10;
        }

        .stacked-card-right {
            transform: rotate(3deg) translateY(12px) scale(0.96);
            z-index: 10;
        }

        .accordion-content {
            transition: max-height 0.3s ease-out, opacity 0.3s ease-out;
            max-height: 0;
            opacity: 0;
            overflow: hidden;
        }

        .accordion-content.active {
            max-height: 280px;
            opacity: 1;
        }

        .rotate-arrow {
            transition: transform 0.3s ease;
        }

        .rotate-arrow.active {
            transform: rotate(180deg);
        }