/* roulang page: index */
:root {
      --primary: #1A1A2E;
      --accent: #E94560;
      --accent-hover: #C73650;
      --vivid: #0F3460;
      --bg: #FAFAFA;
      --dark-bg: #16213E;
      --text: #2C2C2C;
      --text-light: #777;
      --white: #FFFFFF;
      --border: #EEEEEE;
      --success: #2ECC71;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 6px;
      --shadow: 0 2px 16px rgba(26, 26, 46, 0.06);
      --shadow-hover: 0 8px 32px rgba(26, 26, 46, 0.12);
      --font-zh: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", sans-serif;
      --font-en: "Inter", "SF Pro Display", sans-serif;
      --transition: 0.25s ease;
    }
    *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
    html { scroll-behavior: smooth; }
    body {
      font-family: var(--font-zh);
      color: var(--text);
      background: var(--bg);
      line-height: 1.9;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }
    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }
    h1, h2, h3, h4 { font-family: var(--font-zh); color: var(--primary); }
    h1 {
      font-size: 48px;
      font-weight: 800;
      letter-spacing: -0.5px;
      line-height: 1.2;
    }
    h2 {
      font-size: 36px;
      font-weight: 700;
      line-height: 1.3;
      margin-bottom: 16px;
      position: relative;
      display: inline-block;
    }
    h2::after {
      content: '';
      position: absolute;
      left: 0;
      bottom: -8px;
      width: 40px;
      height: 4px;
      background: var(--accent);
      border-radius: 2px;
    }
    h3 {
      font-size: 20px;
      font-weight: 600;
      line-height: 1.4;
      color: var(--primary);
    }
    p { max-width: 680px; }
    .section {
      padding: 80px 0;
    }
    @media (max-width: 1024px) {
      .section { padding: 60px 0; }
      h1 { font-size: 42px; }
      h2 { font-size: 32px; }
    }
    @media (max-width: 768px) {
      .section { padding: 48px 0; }
      h1 { font-size: 36px; }
      h2 { font-size: 28px; }
      h3 { font-size: 18px; }
    }
    @media (max-width: 480px) {
      .container { padding: 0 16px; }
      h1 { font-size: 32px; }
      h2 { font-size: 26px; }
    }

    /* 导航 */
    .nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      padding: 16px 0;
      transition: background 0.3s, box-shadow 0.3s, padding 0.3s;
      background: transparent;
    }
    .nav-scrolled {
      background: var(--white);
      box-shadow: 0 2px 12px rgba(0,0,0,0.05);
      padding: 10px 0;
    }
    .nav .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
    }
    .logo {
      font-family: var(--font-zh);
      font-weight: 800;
      font-size: 24px;
      color: var(--white);
      letter-spacing: 1px;
      transition: color 0.3s;
      text-decoration: none;
      display: flex;
      align-items: baseline;
      gap: 4px;
    }
    .nav-scrolled .logo { color: var(--primary); }
    .logo span {
      font-size: 12px;
      font-weight: 600;
      letter-spacing: 2px;
      color: var(--accent);
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: rgba(255,255,255,0.9);
      text-decoration: none;
      position: relative;
      transition: color 0.2s;
    }
    .nav-scrolled .nav-links a { color: var(--primary); }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -6px;
      left: 0;
      width: 0;
      height: 3px;
      background: var(--accent);
      transition: width 0.25s;
    }
    .nav-links a:hover::after,
    .nav-links a.active::after { width: 100%; }
    .btn-nav {
      background: var(--accent);
      color: white !important;
      padding: 10px 24px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: background 0.2s;
    }
    .btn-nav:hover { background: var(--accent-hover); }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
    }
    .hamburger span {
      width: 25px;
      height: 2.5px;
      background: var(--white);
      transition: 0.3s;
    }
    .nav-scrolled .hamburger span { background: var(--primary); }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .mobile-menu {
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background: var(--primary);
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        gap: 24px;
        transform: translateX(100%);
        transition: transform 0.3s;
        z-index: 999;
      }
      .mobile-menu.open { transform: translateX(0); }
      .mobile-menu a {
        color: white;
        font-size: 20px;
        text-decoration: none;
        font-weight: 500;
      }
      .close-btn {
        position: absolute;
        top: 24px;
        right: 24px;
        background: none;
        border: none;
        color: white;
        font-size: 32px;
        cursor: pointer;
      }
    }

    /* 按钮 */
    .btn-primary {
      background: var(--accent);
      color: white;
      border: none;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      cursor: pointer;
      transition: background 0.2s, transform 0.2s;
      text-decoration: none;
      display: inline-block;
      min-width: 140px;
      text-align: center;
    }
    .btn-primary:hover { background: var(--accent-hover); transform: translateY(-2px); }
    .btn-secondary {
      background: transparent;
      color: var(--primary);
      border: 2px solid var(--primary);
      padding: 12px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: 0.2s;
      text-decoration: none;
      display: inline-block;
      min-width: 140px;
      text-align: center;
    }
    .btn-secondary:hover { background: var(--primary); color: white; }
    .btn-text {
      color: var(--accent);
      text-decoration: none;
      border-bottom: 1px dashed var(--accent);
      font-weight: 500;
      transition: border 0.2s;
    }
    .btn-text:hover { border-bottom-style: solid; }

    /* Hero */
    .hero {
      height: 100vh;
      display: flex;
      align-items: center;
      background: var(--bg);
      position: relative;
      overflow: hidden;
    }
    .hero .container {
      display: flex;
      align-items: center;
      gap: 60px;
    }
    .hero-left { flex: 1; }
    .hero-left h1 { color: var(--primary); margin-bottom: 20px; }
    .hero-left .subtitle {
      font-size: 18px;
      color: var(--text-light);
      margin-bottom: 32px;
      max-width: 500px;
    }
    .hero-buttons { display: flex; gap: 16px; flex-wrap: wrap; }
    .hero-right {
      flex: 1;
      height: 500px;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      border-radius: 24px;
      position: relative;
      overflow: hidden;
      box-shadow: var(--shadow-hover);
    }
    .hero-right::after {
      content: '';
      position: absolute;
      inset: 0;
      background: linear-gradient(135deg, rgba(26,26,46,0.7) 0%, rgba(15,52,96,0.4) 100%);
    }
    @media (max-width: 768px) {
      .hero .container { flex-direction: column; text-align: center; }
      .hero-right { width: 100%; height: 40vh; order: -1; }
      .hero-left h1 { font-size: 36px; }
      .hero-buttons { justify-content: center; }
    }

    /* 卡片 */
    .card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 24px;
      box-shadow: var(--shadow);
      border: 1px solid var(--border);
      transition: var(--transition);
    }
    .card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .grid-2x3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    @media (max-width: 768px) {
      .grid-2x3 { grid-template-columns: 1fr; }
    }
    .icon-circle {
      width: 48px;
      height: 48px;
      background: var(--vivid);
      border-radius: 50%;
      margin-bottom: 16px;
    }

    /* 数据带 */
    .stats {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      text-align: center;
    }
    .stat-number {
      font-size: 56px;
      font-weight: 800;
      color: var(--accent);
      font-family: var(--font-en);
    }
    .stat-label { font-size: 14px; color: var(--text-light); }
    @media (max-width: 768px) {
      .stats { grid-template-columns: 1fr 1fr; }
    }

    /* 案例卡片 */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .case-card {
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow);
    }
    .case-img {
      width: 100%;
      aspect-ratio: 16/9;
      background: #ddd;
      object-fit: cover;
      transition: transform 0.3s;
    }
    .case-card:hover .case-img { transform: scale(1.03); }
    .case-info { padding: 16px; }
    .tag {
      background: var(--accent);
      color: white;
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 12px;
      display: inline-block;
    }

    /* 流程 */
    .steps {
      display: flex;
      justify-content: space-between;
      position: relative;
    }
    .step {
      text-align: center;
      flex: 1;
      position: relative;
    }
    .step-num {
      width: 40px;
      height: 40px;
      background: var(--primary);
      color: white;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 12px;
      font-weight: 700;
    }
    .step::after {
      content: '';
      position: absolute;
      top: 20px;
      left: 60%;
      width: 80%;
      height: 2px;
      border-top: 2px dashed var(--border);
    }
    .step:last-child::after { display: none; }
    @media (max-width: 768px) {
      .steps { flex-direction: column; gap: 32px; }
      .step::after { display: none; }
    }

    /* FAQ */
    .faq-item {
      background: white;
      border-bottom: 1px solid var(--border);
    }
    .faq-question {
      padding: 16px;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      background: white;
    }
    .faq-answer {
      padding: 0 16px 16px;
      display: none;
      background: #FAFAFA;
      font-size: 15px;
    }
    .faq-item.active .faq-answer { display: block; }
    .faq-toggle { font-size: 20px; transition: 0.2s; }

    /* CTA */
    .cta-band {
      background: var(--dark-bg);
      color: white;
      text-align: center;
      padding: 80px 0;
    }
    .cta-band h2 { color: white; }
    .cta-band h2::after { left: 50%; transform: translateX(-50%); }

    /* 页脚 */
    .footer {
      background: var(--primary);
      color: rgba(255,255,255,0.8);
      padding: 60px 0 0;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 32px;
    }
    .footer a { color: rgba(255,255,255,0.7); text-decoration: none; }
    .footer input {
      padding: 12px;
      border-radius: var(--radius-input);
      border: none;
      width: 100%;
    }
    .copyright {
      text-align: center;
      padding: 20px 0;
      font-size: 13px;
      color: rgba(255,255,255,0.5);
    }
    @media (max-width: 768px) {
      .footer-grid { grid-template-columns: 1fr; }
    }