/* roulang page: index */
:root {
      --primary: #FF6B00;
      --primary-deep: #E55D00;
      --secondary-dark: #1A1A2E;
      --secondary-deep: #16213E;
      --accent-red: #E94560;
      --bg-light: #F8F9FA;
      --text-main: #1E1E2F;
      --text-muted: #5A5A72;
      --border-light: rgba(0,0,0,0.06);
      --shadow-card: 0 4px 20px rgba(0,0,0,0.08);
      --shadow-hover: 0 8px 30px rgba(0,0,0,0.15);
      --radius-lg: 16px;
      --radius-btn: 50px;
      --font-sans: -apple-system, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --font-mono: "Inter", "Roboto", "SF Mono", monospace;
    }

    * {
      box-sizing: border-box;
    }

    body {
      margin: 0;
      font-family: var(--font-sans);
      background-color: #FFFFFF;
      color: var(--text-main);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      display: flex;
      min-height: 100vh;
      flex-direction: row;
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s;
    }

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

    button, input, textarea {
      font-family: inherit;
    }

    /* 左侧竖向导航桌面 */
    .side-nav {
      width: 240px;
      background: linear-gradient(180deg, var(--secondary-dark) 0%, var(--secondary-deep) 100%);
      color: white;
      display: flex;
      flex-direction: column;
      align-items: center;
      padding: 2.5rem 1.25rem;
      position: fixed;
      top: 0;
      left: 0;
      height: 100vh;
      z-index: 50;
      box-shadow: 4px 0 20px rgba(0,0,0,0.2);
    }

    .nav-brand {
      display: flex;
      flex-direction: column;
      align-items: center;
      margin-bottom: 3rem;
    }

    .nav-logo-icon {
      font-size: 2.8rem;
      color: var(--primary);
      filter: drop-shadow(0 4px 6px rgba(255,107,0,0.4));
      margin-bottom: 0.5rem;
    }

    .nav-logo-text {
      font-size: 1.5rem;
      font-weight: 700;
      letter-spacing: 1px;
      color: white;
    }

    .nav-links {
      display: flex;
      flex-direction: column;
      width: 100%;
      gap: 0.5rem;
      flex: 1;
    }

    .nav-link {
      display: flex;
      align-items: center;
      padding: 0.8rem 1.25rem;
      border-radius: 12px;
      color: rgba(255,255,255,0.8);
      font-weight: 500;
      font-size: 1rem;
      transition: all 0.2s ease;
      position: relative;
    }

    .nav-link:hover {
      background: rgba(255,255,255,0.08);
      color: var(--primary);
    }

    .nav-link.active {
      background: rgba(255,107,0,0.12);
      color: var(--primary);
      border-left: 4px solid var(--primary);
      padding-left: calc(1.25rem - 4px);
    }

    /* 主内容区 */
    .main-content {
      margin-left: 240px;
      flex: 1;
      width: calc(100% - 240px);
      max-width: 100%;
    }

    /* 移动端顶部导航 */
    .mobile-header {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: var(--secondary-dark);
      padding: 1rem 1.5rem;
      justify-content: space-between;
      align-items: center;
      z-index: 55;
      box-shadow: 0 4px 15px rgba(0,0,0,0.3);
    }

    .hamburger {
      font-size: 1.8rem;
      color: white;
      background: none;
      border: none;
      cursor: pointer;
    }

    .mobile-menu {
      display: none;
      position: fixed;
      top: 70px;
      left: 0;
      width: 100%;
      background: A#1A1A2E;
      backdrop-filter: blur(15px);
      flex-direction: column;
      padding: 1.5rem;
      gap: 0.8rem;
      z-index: 60;
    }

    .mobile-menu a {
      color: white;
      padding: 0.8rem 1rem;
      border-radius: 12px;
      font-weight: 500;
    }

    /* 组件样式 */
    .btn-primary {
      background: var(--primary);
      color: white;
      border-radius: var(--radius-btn);
      padding: 0.9rem 2.2rem;
      font-weight: 600;
      transition: all 0.25s;
      border: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      box-shadow: 0 4px 12px rgba(255,107,0,0.3);
    }

    .btn-primary:hover {
      background: var(--primary-deep);
      box-shadow: 0 0 22px rgba(255,107,0,0.6);
      transform: translateY(-2px);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--accent-red);
      color: var(--accent-red);
      border-radius: var(--radius-btn);
      padding: 0.9rem 2.2rem;
      font-weight: 600;
      transition: all 0.25s;
    }

    .btn-outline:hover {
      background: var(--accent-red);
      color: white;
    }

    .section-padding {
      padding: 6rem 2.5rem;
    }

    @media (max-width: 1024px) {
      .section-padding {
        padding: 4rem 2rem;
      }
    }

    .card-service {
      background: white;
      border-radius: var(--radius-lg);
      padding: 2.5rem;
      box-shadow: var(--shadow-card);
      transition: all 0.3s ease;
      height: 100%;
    }

    .card-service:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }

    .stat-badge {
      background: rgba(255,255,255,0.06);
      backdrop-filter: blur(8px);
      border-radius: 20px;
      padding: 2rem 1.5rem;
      text-align: center;
      border: 1px solid rgba(255,255,255,0.15);
    }

    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 1.5rem 0;
      cursor: pointer;
    }

    .footer-link:hover {
      color: var(--primary);
    }

    @media (max-width: 768px) {
      body {
        flex-direction: column;
      }
      .side-nav {
        display: none;
      }
      .mobile-header {
        display: flex;
      }
      .main-content {
        margin-left: 0;
        width: 100%;
        padding-top: 70px;
      }
      .mobile-menu.open {
        display: flex;
      }
    }