/* roulang page: index */
:root {
      --primary: #E43D2A;
      --primary-dark: #C52716;
      --secondary: #1A1A2E;
      --accent: #F5A623;
      --bg: #F9F9FB;
      --white: #FFFFFF;
      --card-bg: #FFFFFF;
      --text-main: #1A1A2E;
      --text-body: #333333;
      --text-muted: #666666;
      --text-light: #CCCCCC;
      --border-light: #E5E5EA;
      --gradient-brand: linear-gradient(135deg, #E43D2A 0%, #F5A623 100%);
      --shadow-card: 0 8px 28px rgba(0, 0, 0, 0.04);
      --shadow-hover: 0 16px 36px rgba(0, 0, 0, 0.08);
      --radius-xl: 20px;
      --radius-lg: 16px;
      --radius-md: 10px;
      --radius-sm: 8px;
      --font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", sans-serif;
      --transition: 0.25s ease;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: var(--font-family);
      background: var(--bg);
      color: var(--text-body);
      line-height: 1.75;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    /* 导航 */
    .nav {
      position: sticky;
      top: 0;
      z-index: 50;
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(12px);
      height: 72px;
      display: flex;
      align-items: center;
      border-bottom: 1px solid rgba(0,0,0,0.02);
      box-shadow: 0 4px 12px rgba(0,0,0,0.02);
    }
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      font-size: 1.8rem;
      font-weight: 700;
      color: var(--secondary);
      display: flex;
      align-items: center;
      gap: 8px;
      letter-spacing: -0.3px;
    }
    .logo-icon {
      width: 32px;
      height: 32px;
      background: var(--gradient-brand);
      border-radius: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-weight: 700;
      font-size: 18px;
    }
    .nav-menu {
      display: flex;
      gap: 2rem;
      align-items: center;
    }
    .nav-link {
      font-size: 1rem;
      font-weight: 500;
      color: var(--secondary);
      transition: color 0.2s;
      position: relative;
      padding: 4px 0;
    }
    .nav-link::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.25s ease;
    }
    .nav-link:hover {
      color: var(--primary);
    }
    .nav-link:hover::after {
      width: 100%;
    }
    .burger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
    }
    .burger span {
      width: 24px;
      height: 2.5px;
      background: var(--secondary);
      border-radius: 4px;
      transition: 0.2s;
      display: block;
    }
    /* 移动端菜单 */
    .mobile-menu {
      position: fixed;
      top: 72px;
      left: 0;
      width: 100%;
      background: rgba(255,255,255,0.98);
      backdrop-filter: blur(20px);
      flex-direction: column;
      padding: 2rem;
      box-shadow: 0 20px 30px rgba(0,0,0,0.05);
      display: none;
      z-index: 40;
    }
    .mobile-menu.active {
      display: flex;
    }
    .mobile-link {
      padding: 1rem 0;
      font-size: 1.2rem;
      font-weight: 600;
      border-bottom: 1px solid #eee;
      color: var(--secondary);
    }
    /* Hero */
    .hero {
      padding: 3rem 0 4rem;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1.1fr 0.9fr;
      gap: 3rem;
      align-items: center;
    }
    .hero-left h1 {
      font-size: 3.5rem;
      font-weight: 700;
      line-height: 1.25;
      color: var(--secondary);
      letter-spacing: -0.8px;
    }
    .hero-highlight {
      background: var(--gradient-brand);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }
    .hero-sub {
      font-size: 1.2rem;
      color: var(--text-muted);
      margin: 1.5rem 0 2rem;
      max-width: 90%;
    }
    .btn-group {
      display: flex;
      flex-wrap: wrap;
      gap: 1rem;
      align-items: center;
    }
    .btn-primary {
      background: var(--gradient-brand);
      color: white;
      border: none;
      padding: 0.9rem 2.4rem;
      border-radius: 8px;
      font-weight: 600;
      font-size: 1rem;
      cursor: pointer;
      transition: all 0.25s;
      box-shadow: 0 6px 16px rgba(228,61,42,0.3);
      display: inline-block;
    }
    .btn-primary:hover {
      transform: translateY(-2px);
      box-shadow: 0 10px 24px rgba(228,61,42,0.4);
    }
    .btn-outline {
      border: 2px solid var(--primary);
      color: var(--primary);
      background: transparent;
      padding: 0.85rem 2.2rem;
      border-radius: 8px;
      font-weight: 600;
      transition: 0.2s;
    }
    .btn-outline:hover {
      background: var(--primary);
      color: white;
    }
    .stats {
      display: flex;
      gap: 2.5rem;
      margin-top: 2.8rem;
      flex-wrap: wrap;
    }
    .stat-item h3 {
      font-size: 2.4rem;
      font-weight: 800;
      color: var(--accent);
    }
    .hero-right img {
      border-radius: 24px;
      box-shadow: var(--shadow-hover);
    }
    /* section */
    section {
      padding: 5rem 0;
    }
    .section-title {
      font-size: 2.2rem;
      font-weight: 700;
      color: var(--secondary);
      margin-bottom: 1rem;
    }
    .section-sub {
      color: var(--text-muted);
      margin-bottom: 3rem;
      font-size: 1.1rem;
    }
    /* 优势网格 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 1.8rem;
    }
    .value-card {
      background: var(--card-bg);
      padding: 2rem 1.5rem;
      border-radius: 18px;
      box-shadow: var(--shadow-card);
      transition: all 0.3s;
      border-left: 4px solid transparent;
      border-image: linear-gradient(135deg, #E43D2A, #F5A623) 1;
      border-left-style: solid;
    }
    .value-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
    }
    .icon-circle {
      width: 48px;
      height: 48px;
      background: rgba(228,61,42,0.08);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 1.2rem;
      color: var(--primary);
    }
    /* 案例瀑布流 */
    .masonry {
      columns: 3;
      column-gap: 1.5rem;
      margin-top: 1.5rem;
    }
    .case-card {
      break-inside: avoid;
      background: white;
      border-radius: 18px;
      margin-bottom: 1.5rem;
      box-shadow: var(--shadow-card);
      transition: 0.3s;
      overflow: hidden;
    }
    .case-card:hover {
      transform: translateY(-5px);
      box-shadow: var(--shadow-hover);
    }
    .case-img {
      width: 100%;
      transition: transform 0.4s;
    }
    .case-card:hover .case-img {
      transform: scale(1.03);
    }
    .case-content {
      padding: 1.3rem;
    }
    .tag {
      background: #F0F0F5;
      color: var(--primary);
      padding: 0.2rem 0.8rem;
      border-radius: 20px;
      font-size: 0.8rem;
      font-weight: 600;
    }
    /* 对比 */
    .compare-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 2rem;
    }
    .plan-card {
      background: white;
      border-radius: 20px;
      padding: 2rem;
      box-shadow: var(--shadow-card);
      position: relative;
    }
    .featured {
      border-left: 5px solid var(--primary);
    }
    .badge {
      background: var(--accent);
      color: #1A1A2E;
      padding: 0.25rem 1.2rem;
      border-radius: 50px;
      font-weight: 700;
      font-size: 0.8rem;
      position: absolute;
      top: -12px;
      right: 20px;
    }
    /* FAQ */
    .faq-item {
      background: white;
      border-radius: 12px;
      margin-bottom: 1rem;
      padding: 0.8rem 1.5rem;
      box-shadow: 0 2px 10px rgba(0,0,0,0.02);
    }
    .faq-question {
      font-weight: 600;
      font-size: 1.2rem;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      padding: 0.8rem 0;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: 0.3s;
      color: #555;
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      padding-bottom: 15px;
    }
    /* CTA */
    .cta-section {
      background: var(--gradient-brand);
      border-radius: 28px;
      padding: 3rem 2rem;
      color: white;
    }
    .form-row {
      display: flex;
      gap: 2rem;
      flex-wrap: wrap;
    }
    .form-input {
      width: 100%;
      padding: 0.9rem;
      border-radius: 10px;
      border: none;
      margin-bottom: 1rem;
    }
    /* Footer */
    .footer {
      background: var(--secondary);
      color: #ccc;
      padding: 3rem 0 1.5rem;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 2rem;
    }
    @media (max-width: 768px) {
      .nav-menu { display: none; }
      .burger { display: flex; }
      .hero-grid { grid-template-columns: 1fr; }
      .grid-3 { grid-template-columns: 1fr; }
      .masonry { columns: 1; }
      .compare-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; }
      h1 { font-size: 2.4rem !important; }
    }