/* roulang page: index */
:root {
      --deep-blue: #0B1A2E;
      --warm-gold: #D4A853;
      --bg-warm: #F5F3EE;
      --text-primary: #1A1A1A;
      --text-secondary: #5A5A5A;
      --card-bg: #FFFFFF;
      --shadow-sm: 0 2px 12px rgba(11,26,46,0.06);
      --shadow-gold: 0 0 16px rgba(212,168,83,0.4);
      --radius-lg: 12px;
      --radius-sm: 8px;
      --border-light: rgba(11,26,46,0.08);
      --dark-green: #1F4B3E;
      --dark-red: #8B3A3A;
    }

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

    body {
      font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', sans-serif;
      background-color: var(--bg-warm);
      color: var(--text-primary);
      line-height: 1.7;
      font-size: 16px;
      display: flex;
      min-height: 100vh;
      -webkit-font-smoothing: antialiased;
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease, background 0.25s ease;
    }

    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

    button, .btn {
      cursor: pointer;
      font-family: inherit;
      border: none;
      background: none;
    }

    h1, h2, h3 {
      font-weight: 600;
      line-height: 1.3;
    }

    h1 { font-size: 48px; font-weight: 700; line-height: 1.2; }
    h2 { font-size: 36px; }
    h3 { font-size: 22px; }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 左侧导航桌面 */
    .side-nav {
      position: fixed;
      left: 0;
      top: 0;
      width: 220px;
      height: 100vh;
      background-color: var(--deep-blue);
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      padding: 32px 0 24px;
      z-index: 100;
      box-shadow: 2px 0 20px rgba(0,0,0,0.15);
    }

    .nav-logo {
      padding: 0 24px 32px;
      border-bottom: 1px solid rgba(255,255,255,0.1);
      margin-bottom: 16px;
    }

    .nav-logo .brand {
      font-size: 22px;
      font-weight: 700;
      color: #FFFFFF;
      letter-spacing: 1px;
      line-height: 1.3;
    }

    .nav-logo .domain {
      font-size: 12px;
      color: rgba(245,243,238,0.6);
      display: block;
      margin-top: 4px;
    }

    .nav-links {
      flex: 1;
      display: flex;
      flex-direction: column;
      padding: 0 12px;
    }

    .nav-link {
      color: rgba(245,243,238,0.85);
      padding: 14px 20px;
      margin: 4px 0;
      border-radius: 6px;
      font-size: 15px;
      font-weight: 500;
      letter-spacing: 0.5px;
      position: relative;
      transition: all 0.2s ease;
    }

    .nav-link:hover {
      color: var(--warm-gold);
      background: rgba(212,168,83,0.08);
    }

    .nav-link.active {
      color: var(--warm-gold);
      background: rgba(212,168,83,0.12);
    }

    .nav-link.active::before {
      content: '';
      position: absolute;
      left: 0;
      top: 50%;
      transform: translateY(-50%);
      width: 3px;
      height: 20px;
      background: var(--warm-gold);
      border-radius: 0 3px 3px 0;
    }

    .nav-footer {
      padding: 20px 24px 0;
      font-size: 12px;
      color: rgba(245,243,238,0.5);
    }

    /* 移动端顶部导航 */
    .mobile-header {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 64px;
      background: var(--deep-blue);
      align-items: center;
      justify-content: space-between;
      padding: 0 20px;
      z-index: 110;
      box-shadow: 0 2px 12px rgba(0,0,0,0.2);
    }

    .mobile-logo {
      font-size: 20px;
      font-weight: 700;
      color: #fff;
    }

    .hamburger {
      font-size: 26px;
      color: var(--warm-gold);
      background: none;
      border: none;
    }

    .mobile-menu {
      display: none;
      position: fixed;
      top: 64px;
      left: 0;
      width: 100%;
      background: var(--deep-blue);
      flex-direction: column;
      padding: 20px;
      z-index: 105;
    }

    .mobile-menu a {
      color: #f5f3ee;
      padding: 14px 0;
      border-bottom: 1px solid rgba(255,255,255,0.08);
      font-size: 17px;
    }

    /* 主内容区 */
    .main-content {
      margin-left: 220px;
      width: calc(100% - 220px);
      background: var(--bg-warm);
    }

    section {
      padding: 80px 0;
    }

    .btn-primary {
      background: var(--warm-gold);
      color: var(--deep-blue);
      font-weight: 600;
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      display: inline-block;
      transition: all 0.25s ease;
      box-shadow: 0 4px 12px rgba(212,168,83,0.25);
      font-size: 16px;
      letter-spacing: 0.5px;
      border: none;
    }

    .btn-primary:hover {
      background: #b8923a;
      box-shadow: var(--shadow-gold);
      transform: translateY(-1px);
    }

    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--warm-gold);
      color: var(--warm-gold);
      font-weight: 600;
      padding: 12px 30px;
      border-radius: var(--radius-sm);
      transition: 0.25s;
      font-size: 16px;
    }

    .btn-outline:hover {
      background: rgba(212,168,83,0.1);
    }

    .card {
      background: var(--card-bg);
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-sm);
      transition: transform 0.25s ease, box-shadow 0.25s ease;
    }

    .card:hover {
      transform: translateY(-4px);
      box-shadow: 0 12px 28px rgba(11,26,46,0.08);
    }

    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }

    .text-gold { color: var(--warm-gold); }
    .bg-dark { background: var(--deep-blue); color: #F5F3EE; }

    @media (max-width: 1024px) {
      .side-nav { display: none; }
      .mobile-header { display: flex; }
      .main-content { margin-left: 0; width: 100%; }
      .grid-3, .grid-4 { grid-template-columns: repeat(2, 1fr); }
      h1 { font-size: 36px; }
      h2 { font-size: 28px; }
    }

    @media (max-width: 768px) {
      .grid-3, .grid-4 { grid-template-columns: 1fr; }
      section { padding: 56px 0; }
      h1 { font-size: 30px; }
    }