/* roulang page: index */
:root {
      --primary-dark: #0F5132;
      --primary-glow: #10B981;
      --accent-orange: #F97316;
      --dark-canvas: #0B0F19;
      --light-canvas: #F8FAFC;
      --border-subtle: #E2E8F0;
      --text-main: #1E293B;
      --text-muted: #64748B;
      --font-stack: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    }

    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    body {
      font-family: var(--font-stack);
      background-color: var(--light-canvas);
      color: var(--text-main);
      line-height: 1.7;
      overflow-x: hidden;
      -webkit-font-smoothing: antialiased;
    }

    html {
      scroll-behavior: smooth;
    }

    /* 容器基准 */
    .site-container {
      width: 100%;
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 1.25rem;
      padding-right: 1.25rem;
    }

    /* 首屏堆叠卡片 3D 视觉 */
    .hero-stack-wrap {
      perspective: 1000px;
    }

    .hero-card-side-left {
      transform: rotate(-3deg) translateY(12px) scale(0.95);
      transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
    }
    .hero-card-side-right {
      transform: rotate(3deg) translateY(12px) scale(0.95);
      transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
    }
    .hero-card-main {
      transform: translateZ(30px);
      transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
    }
    .hero-stack-wrap:hover .hero-card-side-left {
      transform: rotate(-5deg) translateX(-18px) translateY(8px) scale(0.98);
    }
    .hero-stack-wrap:hover .hero-card-side-right {
      transform: rotate(5deg) translateX(18px) translateY(8px) scale(0.98);
    }

    /* 交互微动效 */
    .card-hover-lift {
      transition: transform 0.28s ease, box-shadow 0.28s ease;
    }
    .card-hover-lift:hover {
      transform: translateY(-6px);
      box-shadow: 0 20px 25px -5px rgba(15, 81, 50, 0.1), 0 8px 10px -6px rgba(15, 81, 50, 0.08);
    }

    /* FAQ 手风琴展开与收起 */
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s cubic-bezier(0, 1, 0, 1);
    }
    .faq-item.active .faq-answer {
      max-height: 500px;
      transition: max-height 0.45s ease-in-out;
    }
    .faq-item.active .faq-icon {
      transform: rotate(180deg);
    }

    /* 移动端菜单抽屉 */
    #mobileMenu {
      transition: transform 0.3s ease-in-out, opacity 0.3s ease-in-out;
    }
    #mobileMenu.hidden-menu {
      transform: translateY(-100%);
      opacity: 0;
      pointer-events: none;
    }
    #mobileMenu.visible-menu {
      transform: translateY(0);
      opacity: 1;
      pointer-events: auto;
    }

    /* 按钮与表单焦点 */
    input:focus, select:focus, textarea:focus {
      outline: 2px solid var(--primary-glow);
      outline-offset: 1px;
    }