/* roulang page: index */
:root {
      --primary: #E9405C;
      --primary-hover: #FF5A78;
      --secondary-bg: #1A1D2E;
      --accent: #00E5A0;
      --body-bg: #0F1119;
      --card-bg: #1A1D2E;
      --card-border: rgba(255,255,255,0.05);
      --text-white: #FFFFFF;
      --text-body: #B0B5C6;
      --text-muted: #6B7084;
      --nav-width: 220px;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 6px;
      --shadow-card: 0 4px 24px rgba(0,0,0,0.4);
      --shadow-hover: 0 8px 40px rgba(233,64,92,0.15);
      --transition: all 0.25s ease;
      --font-system: "PingFang SC","Microsoft YaHei","Helvetica Neue",sans-serif;
      --font-mono: "Inter","SF Pro Display",sans-serif;
    }
    * {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      font-family: var(--font-system);
      background-color: var(--body-bg);
      color: var(--text-body);
      line-height: 1.7;
      display: flex;
      min-height: 100vh;
      overflow-x: hidden;
    }
    h1, h2, h3, h4 {
      font-family: var(--font-mono);
      color: var(--text-white);
      margin: 0 0 1rem;
      font-weight: 700;
    }
    a {
      color: var(--text-body);
      text-decoration: none;
      transition: var(--transition);
    }
    a:hover {
      color: var(--primary);
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    button, .button {
      font-family: var(--font-system);
      transition: var(--transition);
      cursor: pointer;
      border: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
    }
    /* 左侧导航 App Shell */
    .app-nav {
      position: fixed;
      left: 0;
      top: 0;
      width: var(--nav-width);
      height: 100vh;
      background-color: #0D0F17;
      border-right: 1px solid rgba(255,255,255,0.06);
      display: flex;
      flex-direction: column;
      z-index: 100;
      padding: 1.5rem 0;
      transition: var(--transition);
    }
    .nav-logo {
      height: 80px;
      display: flex;
      align-items: center;
      padding: 0 1.5rem;
      margin-bottom: 2rem;
    }
    .logo-text {
      font-size: 1.6rem;
      font-weight: 700;
      color: var(--text-white);
      letter-spacing: 1px;
      display: flex;
      align-items: center;
      gap: 10px;
    }
    .logo-icon {
      color: var(--primary);
      font-size: 2rem;
    }
    .nav-menu {
      list-style: none;
      margin: 0;
      padding: 0;
      flex: 1;
    }
    .nav-item {
      margin-bottom: 0.25rem;
    }
    .nav-link {
      display: flex;
      align-items: center;
      padding: 0.8rem 1.5rem;
      color: var(--text-body);
      font-size: 0.95rem;
      border-left: 3px solid transparent;
      transition: var(--transition);
      font-weight: 500;
    }
    .nav-link i {
      width: 24px;
      margin-right: 12px;
      font-size: 1.1rem;
      text-align: center;
    }
    .nav-link:hover {
      background-color: rgba(233,64,92,0.05);
      color: #FFFFFF;
      border-left-color: var(--primary);
    }
    .nav-link.active {
      color: var(--primary);
      background-color: rgba(233,64,92,0.08);
      border-left-color: var(--primary);
    }
    /* 移动端顶部栏 */
    .mobile-header {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 56px;
      background: #0D0F17;
      align-items: center;
      padding: 0 1.2rem;
      z-index: 99;
      border-bottom: 1px solid rgba(255,255,255,0.06);
    }
    .hamburger {
      font-size: 1.6rem;
      color: var(--text-white);
      background: none;
      border: none;
      margin-right: 1rem;
    }
    .mobile-logo {
      font-weight: 700;
      font-size: 1.3rem;
      color: var(--text-white);
    }
    .drawer {
      position: fixed;
      top: 0;
      left: -280px;
      width: 260px;
      height: 100vh;
      background: #0D0F17;
      z-index: 200;
      transition: left 0.3s ease;
      padding: 2rem 1rem;
      border-right: 1px solid rgba(255,255,255,0.06);
    }
    .drawer.open {
      left: 0;
    }
    .drawer .nav-link {
      padding: 0.9rem 1rem;
    }
    .overlay {
      display: none;
      position: fixed;
      inset: 0;
      background: rgba(0,0,0,0.6);
      z-index: 150;
    }
    .overlay.show {
      display: block;
    }
    /* 主内容区 */
    .main-content {
      margin-left: var(--nav-width);
      width: calc(100% - var(--nav-width));
      background: var(--body-bg);
    }
    section {
      padding: 60px 48px;
      max-width: 1200px;
      margin: 0 auto;
    }
    .section-title {
      font-size: 2.2rem;
      margin-bottom: 1.5rem;
      position: relative;
    }
    .section-title::after {
      content: '';
      display: block;
      width: 60px;
      height: 4px;
      background: var(--primary);
      margin-top: 0.5rem;
      border-radius: 2px;
    }
    /* Hero */
    #hero {
      height: 100vh;
      display: flex;
      align-items: center;
      background: linear-gradient(135deg, rgba(15,17,25,0.9) 0%, rgba(26,29,46,0.75) 100%), url('/assets/images/backpic/hero-bg.webp') center/cover no-repeat;
      padding: 0 48px;
      margin: 0;
      max-width: 100%;
    }
    .hero-content {
      max-width: 700px;
    }
    .hero h1 {
      font-size: 3.8rem;
      font-weight: 800;
      line-height: 1.2;
      background: linear-gradient(to right, #FFFFFF 30%, #E9405C 80%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }
    .hero-sub {
      font-size: 1.25rem;
      color: #B0B5C6;
      margin: 1.5rem 0 2rem;
      max-width: 550px;
    }
    .btn-group {
      display: flex;
      gap: 1rem;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 1rem;
      box-shadow: 0 4px 14px rgba(233,64,92,0.4);
    }
    .btn-primary:hover {
      background: var(--primary-hover);
      box-shadow: 0 0 20px rgba(233,64,92,0.6);
      color: white;
    }
    .btn-outline {
      border: 2px solid var(--primary);
      color: var(--primary);
      background: transparent;
      padding: 14px 36px;
      border-radius: var(--radius-btn);
      font-weight: 600;
    }
    .btn-outline:hover {
      background: rgba(233,64,92,0.1);
      border-color: var(--primary-hover);
      color: var(--primary-hover);
    }
    /* 卡片网格 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .card {
      background: var(--card-bg);
      border: 1px solid var(--card-border);
      border-radius: var(--radius-card);
      padding: 28px;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
    }
    .card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .icon-circle {
      width: 56px;
      height: 56px;
      background: rgba(233,64,92,0.1);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--accent);
      font-size: 1.6rem;
      margin-bottom: 1.2rem;
      transition: var(--transition);
    }
    .card:hover .icon-circle {
      background: var(--primary);
      color: white;
    }
    .card h3 {
      font-size: 1.3rem;
      margin-bottom: 0.6rem;
    }
    /* 数据区 */
    .data-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      text-align: center;
    }
    .data-item .number {
      font-size: 2.8rem;
      font-weight: 700;
      background: linear-gradient(135deg, #E9405C, #00E5A0);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }
    .data-label {
      color: var(--text-muted);
      font-size: 0.9rem;
    }
    /* 案例网格 */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .case-card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      overflow: hidden;
      border: 1px solid var(--card-border);
      transition: var(--transition);
    }
    .case-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .case-img {
      aspect-ratio: 16/10;
      background: #2A2D3A;
      position: relative;
      overflow: hidden;
    }
    .case-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    .case-info {
      padding: 20px;
    }
    .tag {
      display: inline-block;
      background: rgba(0,229,160,0.12);
      color: var(--accent);
      font-size: 0.75rem;
      padding: 4px 10px;
      border-radius: 4px;
      margin-top: 8px;
    }
    /* FAQ */
    .faq-list {
      max-width: 800px;
    }
    .faq-item {
      border-bottom: 1px solid rgba(255,255,255,0.06);
    }
    .faq-question {
      width: 100%;
      background: none;
      border: none;
      color: #FFFFFF;
      font-size: 1rem;
      font-weight: 600;
      padding: 1.2rem 0;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
    }
    .faq-icon {
      color: var(--primary);
      font-size: 1.2rem;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-body);
      font-size: 0.9rem;
      padding: 0 0;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-bottom: 1rem;
    }
    /* CTA 区 */
    .cta-block {
      background: #1A1D2E;
      text-align: center;
      padding: 70px 20px;
      border-radius: 0;
    }
    /* 页脚 */
    .footer {
      background: #0D0F17;
      padding: 40px 48px 20px;
      border-top: 1px solid rgba(255,255,255,0.06);
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 30px;
    }
    .copyright {
      margin-top: 2rem;
      padding-top: 1.5rem;
      border-top: 1px solid rgba(255,255,255,0.06);
      color: var(--text-muted);
      font-size: 0.85rem;
    }
    /* 响应式 */
    @media (max-width: 1024px) {
      .app-nav {
        display: none;
      }
      .mobile-header {
        display: flex;
      }
      .main-content {
        margin-left: 0;
        width: 100%;
        padding-top: 56px;
      }
      section {
        padding: 48px 24px;
      }
      .grid-3, .case-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .data-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    @media (max-width: 640px) {
      .grid-3, .case-grid {
        grid-template-columns: 1fr;
      }
      .data-grid {
        grid-template-columns: 1fr;
      }
      .hero h1 {
        font-size: 2.4rem;
      }
      .btn-group {
        flex-direction: column;
        width: 100%;
      }
      .btn-group .btn-primary, .btn-group .btn-outline {
        width: 100%;
      }
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }