/* roulang page: index */
:root {
      --primary-orange: #FF7A2E;
      --bg-deep-purple: #0B0A1A;
      --accent-cyan: #00E5CC;
      --glass-bg: rgba(25, 20, 45, 0.7);
      --glass-border: rgba(0, 229, 204, 0.25);
      --glow-shadow: 0 8px 32px rgba(0, 229, 204, 0.08);
      --card-radius: 16px;
      --btn-radius: 12px;
      --input-radius: 10px;
      --transition-fast: 0.2s ease;
      --transition-smooth: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    }

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

    body {
      font-family: 'Noto Sans SC', sans-serif;
      background-color: var(--bg-deep-purple);
      color: #e2e8f0;
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }

    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }
    @media (min-width: 1024px) {
      .container {
        padding-left: 2rem;
        padding-right: 2rem;
      }
    }

    /* 玻璃拟态卡片 */
    .glass-card {
      background: var(--glass-bg);
      backdrop-filter: blur(14px);
      -webkit-backdrop-filter: blur(14px);
      border: 1px solid var(--glass-border);
      border-radius: var(--card-radius);
      box-shadow: var(--glow-shadow);
      transition: border-color var(--transition-smooth), box-shadow var(--transition-smooth), transform var(--transition-smooth);
    }
    .glass-card:hover {
      border-color: var(--accent-cyan);
      box-shadow: 0 12px 40px rgba(0, 229, 204, 0.2);
      transform: translateY(-4px);
    }

    /* 按钮基础 */
    .btn-primary {
      background-color: var(--primary-orange);
      color: white;
      border-radius: var(--btn-radius);
      padding: 0.9rem 2rem;
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 0.5rem;
      transition: all var(--transition-smooth);
      box-shadow: 0 4px 14px rgba(255, 122, 46, 0.35);
      border: none;
      cursor: pointer;
      letter-spacing: 0.02em;
    }
    .btn-primary:hover {
      box-shadow: 0 8px 28px rgba(255, 122, 46, 0.55);
      transform: translateY(-2px);
    }
    .btn-primary:active {
      transform: translateY(1px);
      box-shadow: 0 2px 8px rgba(255, 122, 46, 0.4);
    }
    .btn-primary:focus-visible {
      outline: 2px solid var(--accent-cyan);
      outline-offset: 3px;
    }

    .btn-ghost {
      background: transparent;
      border: 1px solid rgba(205, 210, 220, 0.5);
      color: #e2e8f0;
      border-radius: var(--btn-radius);
      padding: 0.9rem 2rem;
      font-weight: 500;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 0.5rem;
      transition: all var(--transition-smooth);
      backdrop-filter: blur(4px);
    }
    .btn-ghost:hover {
      border-color: var(--accent-cyan);
      background: rgba(0, 229, 204, 0.1);
      color: white;
      transform: translateY(-1px);
    }

    /* 导航固定 */
    .navbar {
      position: sticky;
      top: 0;
      z-index: 50;
      background: rgba(11, 10, 26, 0.82);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(0, 229, 204, 0.15);
    }

    /* 汉堡菜单动画 */
    .mobile-menu {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
    }
    .mobile-menu.open {
      max-height: 350px;
    }

    /* 哈希链节点动画 */
    .hash-node {
      display: inline-block;
      width: 8px;
      height: 8px;
      background: var(--primary-orange);
      border-radius: 50%;
      margin: 0 4px;
      animation: pulse-glow 2s infinite;
    }
    @keyframes pulse-glow {
      0% { box-shadow: 0 0 6px var(--primary-orange); }
      50% { box-shadow: 0 0 18px var(--primary-orange), 0 0 28px var(--accent-cyan); }
      100% { box-shadow: 0 0 6px var(--primary-orange); }
    }

    /* 背景暗纹点阵 */
    .dot-pattern {
      background-image: radial-gradient(rgba(0, 229, 204, 0.08) 1px, transparent 1px);
      background-size: 40px 40px;
    }

    /* 瀑布流案例 */
    .masonry {
      column-count: 1;
      column-gap: 1.5rem;
    }
    @media (min-width: 768px) {
      .masonry { column-count: 2; }
    }
    @media (min-width: 1024px) {
      .masonry { column-count: 3; }
    }
    .masonry-item {
      break-inside: avoid;
      margin-bottom: 1.5rem;
      display: inline-block;
      width: 100%;
    }

    /* FAQ手风琴 */
    details.faq-item {
      background: rgba(25, 20, 45, 0.5);
      border: 1px solid rgba(255, 255, 255, 0.06);
      border-radius: 12px;
      padding: 1rem 1.5rem;
      transition: background 0.2s, border-color 0.2s;
    }
    details.faq-item[open] {
      background: rgba(25, 20, 45, 0.75);
      border-color: var(--accent-cyan);
    }
    summary {
      list-style: none;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: space-between;
      font-weight: 500;
    }
    summary::-webkit-details-marker { display: none; }
    .faq-icon {
      color: var(--primary-orange);
      font-weight: bold;
      margin-right: 0.75rem;
    }

    footer a:hover {
      color: var(--accent-cyan);
    }
    .footer-divider {
      border-top: 1px solid rgba(255,255,255,0.08);
    }