/* roulang page: index */
:root {
      --primary: #0A1F3F;
      --accent: #F04E23;
      --bg: #F8FAFC;
      --card-bg: #FFFFFF;
      --light-gray: #F1F5F9;
      --text-main: #1E293B;
      --text-secondary: #64748B;
      --white: #FFFFFF;
      --border-light: rgba(10, 31, 63, 0.08);
      --shadow-sm: 0 1px 3px rgba(10, 31, 63, 0.06), 0 4px 12px rgba(10, 31, 63, 0.04);
      --shadow-hover: 0 8px 24px rgba(10, 31, 63, 0.10);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 6px;
    }

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

    body {
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      background-color: var(--bg);
      color: var(--text-main);
      line-height: 1.75;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      padding-bottom: 56px; /* 为移动端底部导航留出空间 */
    }

    @media (min-width: 768px) {
      body {
        padding-bottom: 0;
      }
    }

    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }

    h1, h2, h3, h4 {
      font-weight: 700;
      line-height: 1.2;
      color: var(--primary);
    }

    h1 {
      font-size: 2.25rem;
      letter-spacing: -0.02em;
      font-weight: 800;
    }

    @media (min-width: 768px) {
      h1 {
        font-size: 3rem;
      }
    }
    @media (min-width: 1024px) {
      h1 {
        font-size: 3.5rem;
      }
    }

    h2 {
      font-size: 1.75rem;
      font-weight: 700;
      margin-bottom: 1.5rem;
      display: inline-block;
      position: relative;
      padding-bottom: 0.5rem;
    }
    h2::after {
      content: '';
      position: absolute;
      left: 0;
      bottom: 0;
      width: 40px;
      height: 3px;
      background-color: var(--accent);
      border-radius: 2px;
    }
    @media (min-width: 768px) {
      h2 {
        font-size: 2.25rem;
      }
    }

    .section-padding {
      padding-top: 5rem;
      padding-bottom: 5rem;
    }
    @media (min-width: 768px) {
      .section-padding {
        padding-top: 7rem;
        padding-bottom: 7rem;
      }
    }

    /* 导航栏 */
    .desktop-nav {
      display: none;
    }
    @media (min-width: 768px) {
      .desktop-nav {
        display: flex;
        position: sticky;
        top: 0;
        z-index: 50;
        height: 72px;
        background-color: var(--primary);
        color: white;
        align-items: center;
        border-bottom: 1px solid rgba(255,255,255,0.15);
      }
      .nav-link {
        font-weight: 500;
        margin-left: 2.5rem;
        transition: color 0.2s;
        position: relative;
      }
      .nav-link::after {
        content: '';
        position: absolute;
        bottom: -4px;
        left: 50%;
        transform: translateX(-50%);
        width: 0;
        height: 2px;
        background: var(--accent);
        transition: width 0.3s ease;
      }
      .nav-link:hover::after,
      .nav-link.active::after {
        width: 100%;
      }
      .nav-link.active {
        color: var(--accent);
      }
    }

    /* 移动底部导航 */
    .mobile-bottom-nav {
      display: flex;
      position: fixed;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 56px;
      background: var(--primary);
      border-top: 1px solid rgba(255,255,255,0.2);
      z-index: 50;
      justify-content: space-around;
      align-items: center;
      backdrop-filter: blur(4px);
    }
    @media (min-width: 768px) {
      .mobile-bottom-nav {
        display: none;
      }
    }
    .tab-item {
      display: flex;
      flex-direction: column;
      align-items: center;
      color: rgba(255,255,255,0.7);
      font-size: 0.625rem;
      transition: color 0.2s;
      font-weight: 500;
    }
    .tab-item i {
      font-size: 1.3rem;
      margin-bottom: 2px;
    }
    .tab-item.active {
      color: var(--accent);
    }

    /* 卡片 */
    .card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-sm);
      transition: transform 0.3s ease, box-shadow 0.3s ease;
      padding: 2rem;
    }
    .card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }

    .btn-primary {
      background: var(--accent);
      color: white;
      font-weight: 600;
      padding: 0.875rem 2rem;
      border-radius: var(--radius-btn);
      display: inline-block;
      transition: background 0.2s, transform 0.1s;
      border: none;
      cursor: pointer;
      text-align: center;
      min-height: 44px;
    }
    .btn-primary:hover {
      background: #D43D1A;
      transform: scale(1.02);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      font-weight: 600;
      padding: 0.875rem 2rem;
      border-radius: var(--radius-btn);
      transition: all 0.2s;
      min-height: 44px;
      display: inline-block;
      text-align: center;
    }
    .btn-outline:hover {
      background: rgba(10,31,63,0.05);
      border-color: var(--accent);
      color: var(--accent);
    }

    input, textarea {
      border-radius: var(--radius-input);
      border: 1px solid #e2e8f0;
      padding: 0.75rem 1rem;
      width: 100%;
      transition: border 0.2s;
      background: white;
    }
    input:focus, textarea:focus {
      outline: none;
      border-color: var(--accent);
      box-shadow: 0 0 0 3px rgba(240,78,35,0.1);
    }

    .accent-text {
      color: var(--accent);
    }
    .bg-primary {
      background-color: var(--primary);
    }
    .text-primary {
      color: var(--primary);
    }