/* roulang page: index */
:root {
      --color-brand: #0E7490;
      --color-brand-dark: #155E75;
      --color-accent: #10B981;
      --color-accent-hover: #059669;
      --color-bg-base: #F8FAFC;
      --color-text-main: #0F172A;
      --color-text-body: #334155;
      --color-text-muted: #64748B;
      --color-border: #E2E8F0;
      --color-dark-surface: #0F172A;
    }

    * {
      box-sizing: border-box;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }

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

    .font-mono-num {
      font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
    }

    /* 容器控制 */
    .app-container {
      width: 100%;
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 1.25rem;
      padding-right: 1.25rem;
    }
    @media (min-width: 768px) {
      .app-container {
        padding-left: 2rem;
        padding-right: 2rem;
      }
    }

    /* 按钮基础与交互微动效 */
    .btn-primary {
      background-color: var(--color-brand);
      color: #ffffff;
      transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    }
    .btn-primary:hover {
      background-color: var(--color-brand-dark);
      transform: translateY(-2px);
      box-shadow: 0 10px 15px -3px rgba(14, 116, 144, 0.25);
    }
    .btn-primary:active {
      transform: scale(0.98);
    }

    .btn-accent {
      background-color: var(--color-accent);
      color: #ffffff;
      transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    }
    .btn-accent:hover {
      background-color: var(--color-accent-hover);
      transform: translateY(-2px);
      box-shadow: 0 10px 15px -3px rgba(16, 185, 129, 0.3);
    }
    .btn-accent:active {
      transform: scale(0.98);
    }

    /* 卡片悬浮 */
    .hover-card {
      transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1), box-shadow 0.3s cubic-bezier(0.4, 0, 0.2, 1), border-color 0.3s ease;
    }
    .hover-card:hover {
      transform: translateY(-4px);
      box-shadow: 0 14px 28px -6px rgba(15, 23, 42, 0.08);
      border-color: #CBD5E1;
    }

    /* 手风琴折叠平滑过渡 */
    .accordion-content {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s cubic-bezier(0.4, 0, 0.2, 1), opacity 0.3s ease;
      opacity: 0;
    }
    .accordion-item.active .accordion-content {
      max-height: 400px;
      opacity: 1;
    }
    .accordion-item.active .accordion-icon {
      transform: rotate(180deg);
    }

    /* 移动端菜单抽屉 */
    #mobileMenuDrawer {
      transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1), opacity 0.3s ease;
    }
    #mobileMenuDrawer.hidden-menu {
      transform: translateY(-100%);
      opacity: 0;
      pointer-events: none;
    }