/* roulang page: index */
:root {
      --primary: #0A1929;
      --accent-cyan: #00D2FF;
      --accent-red: #FF4655;
      --bg-light: #F4F6F9;
      --card-bg: #FFFFFF;
      --text-main: #1A1A2E;
      --text-muted: #5A6070;
      --text-white: #FFFFFF;
      --border-light: #D1D5DB;
      --radius-card: 12px;
      --radius-btn: 8px;
      --shadow-card: 0 4px 20px rgba(10, 25, 41, 0.06);
      --shadow-hover: 0 8px 30px rgba(10, 25, 41, 0.12);
      --transition: 0.3s ease;
    }

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

    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      background-color: var(--bg-light);
      color: var(--text-main);
      line-height: 1.7;
      font-weight: 400;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

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

    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }

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

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: #FFFFFF;
      box-shadow: 0 1px 0 rgba(0,0,0,0.04);
      z-index: 1000;
      height: 72px;
      display: flex;
      align-items: center;
    }

    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }

    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-weight: 700;
      font-size: 22px;
      color: var(--primary);
      letter-spacing: 0.5px;
    }

    .logo-icon {
      width: 32px;
      height: 32px;
      background: var(--accent-red);
      border-radius: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-weight: 800;
      font-size: 18px;
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }

    .nav-links a {
      font-weight: 500;
      color: var(--text-main);
      padding: 8px 0;
      position: relative;
    }

    .nav-links a:hover,
    .nav-links a.active {
      color: var(--accent-cyan);
    }

    .nav-links a.active::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--accent-cyan);
    }

    .nav-cta {
      background: var(--accent-red);
      color: white !important;
      padding: 12px 24px !important;
      border-radius: var(--radius-btn);
      font-weight: 600;
      margin-left: 16px;
    }
    .nav-cta:hover {
      background: #E03A48;
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--primary);
      border-radius: 2px;
      transition: 0.3s;
    }

    /* Hero */
    .hero {
      padding: 140px 0 100px;
      background: linear-gradient(180deg, #F4F6F9 0%, #FFFFFF 100%);
    }

    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
      align-items: center;
    }

    .hero-content h1 {
      font-size: 48px;
      font-weight: 800;
      line-height: 1.2;
      letter-spacing: -0.5px;
      color: var(--primary);
      margin-bottom: 20px;
    }
    .hero-content .subtitle {
      font-size: 18px;
      color: var(--text-muted);
      margin-bottom: 32px;
      max-width: 90%;
    }
    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--accent-red);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      display: inline-block;
      transition: var(--transition);
      border: none;
      cursor: pointer;
    }
    .btn-primary:hover {
      background: #E03A48;
      box-shadow: 0 8px 18px rgba(255,70,85,0.3);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--accent-cyan);
      color: var(--accent-cyan);
      padding: 12px 30px;
      border-radius: var(--radius-btn);
      font-weight: 600;
    }
    .btn-outline:hover {
      background: rgba(0,210,255,0.1);
    }
    .hero-image {
      position: relative;
      border-radius: 16px;
      overflow: hidden;
      box-shadow: var(--shadow-card);
      background: #e0e7ef;
    }
    .hero-image img {
      width: 100%;
      height: auto;
      object-fit: cover;
    }
    .speed-lines {
      position: absolute;
      top: 0; left: 0; width: 100%; height: 100%;
      background: repeating-linear-gradient(45deg, transparent, transparent 2px, rgba(0,210,255,0.08) 3px);
      pointer-events: none;
    }

    /* 通用板块 */
    section {
      padding: 90px 0;
    }

    .section-title {
      font-size: 36px;
      font-weight: 700;
      margin-bottom: 16px;
      color: var(--primary);
      letter-spacing: -0.3px;
    }
    .section-sub {
      color: var(--text-muted);
      margin-bottom: 48px;
    }

    /* 亮点网格 */
    .highlights-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .highlight-card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 32px 28px;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
      position: relative;
    }
    .highlight-card:nth-child(2) {
      margin-top: -20px;
    }
    .highlight-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .icon-circle {
      width: 56px;
      height: 56px;
      background: rgba(0,210,255,0.1);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 24px;
      color: var(--accent-cyan);
      font-size: 28px;
    }
    .highlight-card h3 {
      font-size: 22px;
      font-weight: 600;
      margin-bottom: 12px;
    }

    /* 案例瀑布流 */
    .cases-masonry {
      columns: 3;
      column-gap: 24px;
    }
    .case-card {
      break-inside: avoid;
      background: var(--card-bg);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      margin-bottom: 24px;
      transition: var(--transition);
    }
    .case-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .case-img {
      width: 100%;
      height: auto;
      object-fit: cover;
    }
    .case-body {
      padding: 20px;
    }
    .tag {
      background: rgba(0,210,255,0.08);
      color: var(--accent-cyan);
      font-size: 13px;
      padding: 4px 10px;
      border-radius: 20px;
      font-weight: 500;
      display: inline-block;
      margin-bottom: 10px;
    }
    .case-body h3 {
      font-size: 20px;
      margin-bottom: 8px;
    }

    /* 对比区 */
    .compare-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 32px;
    }
    .compare-card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 36px;
      box-shadow: var(--shadow-card);
    }
    .compare-card.right {
      border: 2px solid var(--accent-cyan);
    }
    .compare-list {
      list-style: none;
      margin-top: 24px;
    }
    .compare-list li {
      margin-bottom: 14px;
      display: flex;
      align-items: center;
      gap: 10px;
    }
    .icon-check {
      color: #10B981;
    }
    .icon-minus {
      color: #9CA3AF;
    }

    /* FAQ */
    .faq-item {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      margin-bottom: 12px;
      box-shadow: 0 2px 8px rgba(0,0,0,0.02);
    }
    .faq-question {
      padding: 20px 24px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      background: transparent;
      border: none;
      width: 100%;
      text-align: left;
      font-size: 18px;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      padding: 0 24px;
      color: var(--text-muted);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-bottom: 20px;
    }

    /* CTA 横幅 */
    .cta-banner {
      background: var(--primary);
      padding: 80px 0;
      text-align: center;
      color: white;
      position: relative;
      overflow: hidden;
    }
    .cta-banner::before {
      content: '';
      position: absolute;
      top:0;left:0;width:100%;height:100%;
      background: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 200 200"><path d="M20 20 L40 10 L60 30" stroke="%2300D2FF" fill="none" stroke-width="0.5" opacity="0.15"/></svg>');
    }
    .cta-banner h2 {
      font-size: 40px;
      margin-bottom: 16px;
      position: relative;
    }
    .btn-large {
      background: var(--accent-red);
      padding: 16px 48px;
      font-size: 18px;
      margin-top: 24px;
    }

    /* 表单 */
    .contact-wrapper {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
    }
    .form-group input, .form-group textarea {
      width: 100%;
      padding: 14px;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-btn);
      font-family: inherit;
      margin-bottom: 20px;
      transition: 0.2s;
    }
    .form-group input:focus {
      border-color: var(--accent-cyan);
      box-shadow: 0 0 0 3px rgba(0,210,255,0.1);
      outline: none;
    }

    footer {
      background: var(--primary);
      color: #B0B8C1;
      padding: 60px 0 20px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }
    footer a:hover {
      color: var(--accent-cyan);
    }

    @media (max-width: 1024px) {
      .hero-grid { grid-template-columns: 1fr; }
      .highlights-grid { grid-template-columns: 1fr 1fr; }
      .cases-masonry { columns: 2; }
      .compare-grid { grid-template-columns: 1fr; }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; flex-direction: column; position: absolute; top:72px; left:0; background: white; width:100%; padding:20px; }
      .nav-links.active { display: flex; }
      .hamburger { display: flex; }
      .highlights-grid { grid-template-columns: 1fr; }
      .cases-masonry { columns: 1; }
      .contact-wrapper { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }