/* roulang page: index */
:root {
      --primary: #D4453B;
      --primary-hover: #C03E35;
      --secondary: #1B1C1E;
      --accent: #F2A900;
      --bg: #FAFAF9;
      --card-bg: #FFFFFF;
      --card-border: #EBEBEB;
      --text-main: #1B1C1E;
      --text-secondary: #5C5D60;
      --text-weak: #8E8F92;
      --white: #FFFFFF;
      --shadow-sm: 0 1px 3px rgba(0,0,0,0.04), 0 1px 2px rgba(0,0,0,0.06);
      --shadow-md: 0 10px 25px rgba(0,0,0,0.08), 0 4px 10px rgba(0,0,0,0.04);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 6px;
      --transition: 0.3s cubic-bezier(0.25, 0.8, 0.25, 1.2);
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: 'Inter', 'PingFang SC', 'Microsoft YaHei', -apple-system, BlinkMacSystemFont, sans-serif;
      background-color: var(--bg);
      color: var(--text-main);
      line-height: 1.75;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }
    /* 导航栏 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      transition: background 0.3s, box-shadow 0.3s;
      background: transparent;
    }
    .header.scrolled {
      background: rgba(255,255,255,0.95);
      backdrop-filter: blur(12px);
      box-shadow: 0 1px 8px rgba(0,0,0,0.05);
    }
    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }
    .logo {
      font-size: 1.6rem;
      font-weight: 700;
      letter-spacing: -0.02em;
      color: var(--white);
      transition: color 0.3s;
    }
    .header.scrolled .logo {
      color: var(--secondary);
    }
    .nav-links {
      display: flex;
      gap: 2.5rem;
      align-items: center;
    }
    .nav-links a {
      font-weight: 500;
      font-size: 0.95rem;
      transition: color 0.2s;
      color: var(--white);
    }
    .header.scrolled .nav-links a {
      color: var(--text-secondary);
    }
    .nav-links a:hover {
      color: var(--accent);
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: background 0.25s, transform 0.25s, box-shadow 0.25s;
      display: inline-block;
      text-align: center;
    }
    .btn-primary:hover {
      background: var(--primary-hover);
      transform: translateY(-2px);
      box-shadow: var(--shadow-md);
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: all 0.25s;
    }
    .btn-outline:hover {
      background: var(--primary);
      color: white;
      transform: translateY(-2px);
    }
    .btn-ghost {
      background: transparent;
      border: 1.5px solid white;
      color: white;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: all 0.25s;
    }
    .btn-ghost:hover {
      background: white;
      color: var(--primary);
      transform: translateY(-2px);
    }
    .burger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
    }
    .burger span {
      width: 24px;
      height: 2px;
      background: white;
      transition: 0.3s;
    }
    .header.scrolled .burger span {
      background: var(--secondary);
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: rgba(0,0,0,0.9);
      backdrop-filter: blur(8px);
      flex-direction: column;
      justify-content: center;
      align-items: center;
      gap: 2rem;
      z-index: 999;
    }
    .mobile-menu a {
      color: white;
      font-size: 1.5rem;
      font-weight: 600;
    }
    /* Hero */
    .hero {
      background: var(--secondary);
      min-height: 90vh;
      display: flex;
      align-items: center;
      padding-top: 80px;
      position: relative;
      overflow: hidden;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 4%;
      width: 100%;
    }
    .hero-left {
      flex: 0 0 48%;
      color: white;
    }
    .hero-right {
      flex: 0 0 48%;
      position: relative;
      animation: float 4s ease-in-out infinite;
      border-radius: 24px;
      overflow: hidden;
      box-shadow: 0 20px 35px rgba(0,0,0,0.3);
    }
    @keyframes float {
      0% { transform: translateY(-6px); }
      50% { transform: translateY(6px); }
      100% { transform: translateY(-6px); }
    }
    .hero-right img {
      width: 100%;
      height: auto;
      display: block;
    }
    .hero-left h1 {
      font-size: 3rem;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 1.5rem;
      letter-spacing: -0.02em;
    }
    .hero-left .sub {
      font-size: 1rem;
      color: rgba(255,255,255,0.7);
      margin-bottom: 2rem;
    }
    .hero-actions {
      display: flex;
      gap: 1rem;
      flex-wrap: wrap;
      align-items: center;
    }
    .hero-note {
      margin-top: 1.2rem;
      font-size: 0.9rem;
      color: rgba(255,255,255,0.6);
    }
    .hero-note span {
      color: var(--accent);
      font-weight: 600;
    }
    /* 板块通用 */
    section {
      padding: 100px 0;
    }
    .section-title {
      font-size: 2rem;
      font-weight: 700;
      margin-bottom: 1rem;
      letter-spacing: -0.02em;
    }
    .section-desc {
      color: var(--text-secondary);
      margin-bottom: 3rem;
      max-width: 600px;
    }
    /* 亮点网格 */
    .grid-2x3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
      margin-top: 2rem;
    }
    .grid-card {
      background: var(--card-bg);
      border: 1px solid var(--card-border);
      border-radius: var(--radius-card);
      padding: 2rem;
      transition: all 0.3s;
    }
    .grid-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
      border-color: var(--primary);
    }
    .grid-card .icon {
      font-size: 2.5rem;
      color: var(--primary);
      margin-bottom: 1rem;
    }
    .grid-card h3 {
      font-size: 1.25rem;
      margin-bottom: 0.5rem;
    }
    .grid-card p {
      color: var(--text-secondary);
      font-size: 0.95rem;
    }
    /* 数据带 */
    .data-strip {
      background: var(--secondary);
      padding: 60px 0;
      color: white;
    }
    .data-items {
      display: flex;
      justify-content: space-around;
      text-align: center;
      flex-wrap: wrap;
    }
    .data-item .number {
      font-family: 'Inter', 'DIN', sans-serif;
      font-size: 2.5rem;
      font-weight: 600;
      color: var(--accent);
    }
    .data-item .label {
      color: var(--text-weak);
    }
    /* 案例瀑布 */
    .masonry {
      columns: 3;
      column-gap: 24px;
      margin-top: 2rem;
    }
    .masonry-card {
      break-inside: avoid;
      background: var(--card-bg);
      border-radius: var(--radius-card);
      border: 1px solid var(--card-border);
      margin-bottom: 24px;
      overflow: hidden;
      transition: all 0.3s;
    }
    .masonry-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }
    .masonry-card img {
      width: 100%;
      display: block;
    }
    .masonry-info {
      padding: 1.2rem;
    }
    .masonry-info h3 {
      margin-bottom: 0.3rem;
    }
    .tag {
      background: #f0f0f0;
      padding: 4px 10px;
      border-radius: 20px;
      font-size: 0.75rem;
      color: var(--text-secondary);
      display: inline-block;
    }
    /* 对比表 */
    .compare-table {
      display: flex;
      gap: 1rem;
      margin-top: 2rem;
      overflow-x: auto;
    }
    .compare-col {
      flex: 1;
      background: white;
      border-radius: var(--radius-card);
      padding: 1.5rem;
      border: 1px solid var(--card-border);
    }
    .compare-col.highlight {
      background: #FEF5F4;
      border-color: var(--primary);
    }
    .compare-row {
      display: flex;
      justify-content: space-between;
      padding: 0.8rem 0;
      border-bottom: 1px solid #eee;
    }
    /* FAQ */
    .faq-item {
      background: white;
      border-radius: var(--radius-card);
      margin-bottom: 1rem;
      border-left: 3px solid var(--primary);
      transition: 0.2s;
      overflow: hidden;
    }
    .faq-question {
      padding: 1.2rem;
      font-weight: 600;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.3s;
      padding: 0 1.2rem;
      color: var(--text-secondary);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 0 1.2rem 1.2rem;
    }
    /* CTA横幅 */
    .cta-band {
      background: var(--secondary);
      text-align: center;
      padding: 80px 0;
      color: white;
    }
    /* 页脚 */
    .footer {
      background: var(--secondary);
      color: var(--text-weak);
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 2rem;
    }
    .footer a {
      color: var(--text-weak);
      display: block;
      margin-bottom: 0.5rem;
    }
    .footer a:hover {
      color: white;
    }
    @media (max-width: 1024px) {
      .hero-grid {
        flex-direction: column;
      }
      .hero-left, .hero-right {
        flex: auto;
        width: 100%;
      }
      .grid-2x3 {
        grid-template-columns: repeat(2, 1fr);
      }
      .masonry {
        columns: 2;
      }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .burger { display: flex; }
      .grid-2x3 {
        grid-template-columns: 1fr;
      }
      .masonry {
        columns: 1;
      }
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
      section {
        padding: 70px 0;
      }
    }