/* roulang page: index */
/* ===== 设计变量与全局重置 ===== */
    :root {
      --primary: #0A0E27;
      --primary-soft: #1A1F3A;
      --accent: #00F0FF;
      --accent-glow: rgba(0, 240, 255, 0.2);
      --secondary-accent: #FF3366;
      --bg: #F8FAFC;
      --surface: #FFFFFF;
      --text-main: #1E293B;
      --text-muted: #64748B;
      --text-placeholder: #94A3B8;
      --border-light: #E2E8F0;
      --shadow-card: 0 10px 25px -5px rgba(0,0,0,0.03), 0 8px 10px -6px rgba(0,0,0,0.02);
      --shadow-card-hover: 0 20px 35px -10px rgba(0,240,255,0.12), 0 10px 15px -6px rgba(0,0,0,0.06);
      --shadow-btn: 0 4px 14px 0 rgba(0,240,255,0.25);
      --transition-base: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
      --font-mono: 'DIN Alternate', 'Roboto Mono', 'Courier New', monospace;
      --radius-card: 14px;
      --radius-btn: 10px;
    }
    
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    
    html {
      scroll-behavior: smooth;
      background-color: var(--bg);
    }
    
    body {
      font-family: 'Inter', 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      color: var(--text-main);
      background: var(--bg);
      line-height: 1.7;
      font-weight: 400;
      letter-spacing: 0.01em;
      -webkit-font-smoothing: antialiased;
    }
    
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    
    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s;
    }
    
    /* 容器与栅格 */
    .container {
      max-width: 1350px;
      margin: 0 auto;
      padding: 0 32px;
      width: 100%;
    }
    
    @media (max-width: 768px) {
      .container {
        padding: 0 20px;
      }
    }
    
    /* 按钮全局 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 1rem;
      letter-spacing: 0.02em;
      cursor: pointer;
      border: none;
      background: transparent;
      transition: all var(--transition-base);
      text-align: center;
      white-space: nowrap;
      line-height: 1.2;
    }
    
    .btn-primary {
      background: var(--accent);
      color: var(--primary);
      box-shadow: var(--shadow-btn);
    }
    
    .btn-primary:hover {
      background: #00e0f0;
      box-shadow: 0 8px 22px rgba(0,240,255,0.45);
      transform: translateY(-2px);
      color: var(--primary);
    }
    
    .btn-outline {
      border: 1.5px solid var(--primary-soft);
      color: var(--primary);
      background: transparent;
      backdrop-filter: blur(4px);
    }
    
    .btn-outline:hover {
      background: var(--primary);
      color: white;
      border-color: var(--primary);
      transform: translateY(-2px);
    }
    
    .btn-accent {
      background: var(--secondary-accent);
      color: white;
      box-shadow: 0 8px 18px rgba(255,51,102,0.3);
    }
    
    .btn-accent:hover {
      background: #ff1a55;
      box-shadow: 0 12px 24px rgba(255,51,102,0.5);
      transform: scale(1.03);
    }
    
    /* 板块标题 */
    .section-title {
      font-size: 2.5rem;
      font-weight: 800;
      letter-spacing: -0.02em;
      color: var(--primary);
      margin-bottom: 1rem;
      line-height: 1.2;
    }
    .section-subtitle {
      font-size: 1.2rem;
      color: var(--text-muted);
      margin-bottom: 3.5rem;
      max-width: 700px;
    }
    @media (max-width: 640px) {
      .section-title {
        font-size: 2rem;
      }
    }
    
    /* 导航栏 */
    .navbar {
      position: sticky;
      top: 0;
      background: rgba(255,255,255,0.88);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(0,0,0,0.02);
      z-index: 50;
      padding: 1rem 0;
      transition: box-shadow 0.2s;
      box-shadow: 0 8px 20px rgba(0,0,0,0.02);
    }
    
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
    }
    
    .logo {
      display: flex;
      align-items: center;
    }
    .logo-text {
      font-size: 1.7rem;
      font-weight: 800;
      letter-spacing: -0.03em;
      background: linear-gradient(135deg, var(--primary) 45%, #0f172a 80%);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      margin-left: 4px;
      line-height: 1.2;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 2.5rem;
    }
    .nav-links a {
      font-weight: 500;
      color: var(--text-main);
      font-size: 1rem;
      position: relative;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -6px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent);
      transition: width 0.25s;
    }
    .nav-links a:hover {
      color: var(--accent);
    }
    .nav-links a:hover::after {
      width: 100%;
    }
    .mobile-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 1.8rem;
      color: var(--primary);
    }
    
    @media (max-width: 1024px) {
      .nav-links {
        gap: 1.8rem;
      }
    }
    @media (max-width: 768px) {
      .nav-links {
        position: fixed;
        top: 0;
        right: -100%;
        width: 72%;
        max-width: 300px;
        height: 100vh;
        background: rgba(255,255,255,0.98);
        backdrop-filter: blur(18px);
        flex-direction: column;
        padding: 90px 30px 30px;
        gap: 2rem;
        transition: right 0.35s ease;
        box-shadow: -8px 0 28px rgba(0,0,0,0.07);
      }
      .nav-links.active {
        right: 0;
      }
      .mobile-toggle {
        display: block;
        z-index: 60;
      }
    }
    
    /* Hero 区域 */
    .hero {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      align-items: center;
      min-height: 85vh;
      padding: 40px 0;
      position: relative;
    }
    .hero-content h1 {
      font-size: 3.8rem;
      font-weight: 800;
      line-height: 1.15;
      letter-spacing: -0.02em;
      color: var(--primary);
    }
    .hero-highlight {
      color: var(--accent);
    }
    .hero-desc {
      font-size: 1.3rem;
      color: var(--text-muted);
      margin: 1.8rem 0 2.5rem;
      max-width: 550px;
    }
    .hero-actions {
      display: flex;
      gap: 1.2rem;
      flex-wrap: wrap;
    }
    .hero-visual {
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      min-height: 380px;
      border-radius: 32px;
      background-blend-mode: overlay;
      background-color: rgba(10,14,39,0.15);
      box-shadow: 0 30px 50px -25px rgba(0,240,255,0.3);
    }
    @media (max-width: 900px) {
      .hero {
        grid-template-columns: 1fr;
        text-align: center;
        min-height: auto;
      }
      .hero-visual {
        min-height: 280px;
        order: -1;
      }
      .hero-content h1 {
        font-size: 2.7rem;
      }
    }
    
    /* 数据带 */
    .data-strip {
      display: flex;
      flex-wrap: wrap;
      justify-content: space-around;
      gap: 2rem;
      background: var(--surface);
      margin: 3rem 0;
      padding: 2.8rem 1.5rem;
      border-radius: 0;
      box-shadow: var(--shadow-card);
    }
    .data-item {
      text-align: center;
      font-family: var(--font-mono);
    }
    .data-number {
      font-size: 2.8rem;
      font-weight: 800;
      color: var(--accent);
      display: block;
    }
    .data-label {
      color: var(--text-muted);
      font-weight: 500;
      font-family: 'Inter', sans-serif;
    }
    
    /* 服务卡片网格 2x3 */
    .service-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
      margin-top: 2rem;
    }
    .service-card {
      background: var(--surface);
      padding: 2.8rem 1.8rem;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      transition: all var(--transition-base);
      text-align: center;
    }
    .service-card:hover {
      transform: translateY(-12px);
      box-shadow: var(--shadow-card-hover);
    }
    .service-icon {
      font-size: 2.6rem;
      color: var(--accent);
      margin-bottom: 1.6rem;
    }
    @media (max-width: 900px) {
      .service-grid {
        grid-template-columns: repeat(2,1fr);
      }
    }
    @media (max-width: 550px) {
      .service-grid {
        grid-template-columns: 1fr;
      }
    }
    
    /* 冠军案例 三列不同高 */
    .case-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .case-card {
      background: var(--surface);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      overflow: hidden;
      transition: 0.3s;
    }
    .case-img {
      height: 200px;
      background-size: cover;
      transition: 0.4s;
      position: relative;
    }
    .case-card:hover .case-img {
      transform: scale(1.04);
      filter: brightness(1.08);
    }
    .case-body {
      padding: 1.6rem;
    }
    @media (max-width: 768px) {
      .case-grid {
        grid-template-columns: 1fr;
      }
    }
    
    /* 流程 */
    .flow-steps {
      display: flex;
      justify-content: space-between;
      position: relative;
    }
    .flow-step {
      flex:1;
      text-align: center;
      position: relative;
    }
    .flow-num {
      font-size: 2rem;
      font-weight: 800;
      color: var(--accent);
    }
    @media (max-width: 700px) {
      .flow-steps {
        flex-direction: column;
        gap: 2rem;
      }
    }
    
    /* FAQ */
    .faq-items {
      max-width: 860px;
      margin:0 auto;
    }
    .faq-card {
      background: var(--surface);
      border-radius: 14px;
      margin-bottom: 16px;
      box-shadow: 0 2px 12px rgba(0,0,0,0.02);
    }
    .faq-question {
      padding: 1.6rem 2rem;
      font-weight: 700;
      display: flex;
      justify-content: space-between;
    }
    
    /* 全局 CTA */
    .global-cta {
      background: radial-gradient(circle at center, #131b3a 0%, #0A0E27 95%);
      padding: 5rem 2rem;
      text-align: center;
    }
    
    footer {
      background: var(--surface);
      padding: 3.5rem 0 2rem;
      color: var(--text-muted);
    }