/* roulang page: index */
:root {
      --primary-deep: #0A0E17;
      --accent-red: #E63916;
      --accent-glow: #F4A261;
      --bg-card: #141A24;
      --bg-card-hover: #1E2532;
      --text-primary: #F0F2F5;
      --text-secondary: #B0B8C1;
      --text-muted: #6B7380;
      --border-subtle: rgba(255,255,255,0.06);
      --border-glow: rgba(244,162,97,0.35);
      --shadow-card: 0 12px 28px rgba(0,0,0,0.6);
      --shadow-hover: 0 20px 40px rgba(0,0,0,0.8);
      --radius-md: 12px;
      --radius-sm: 8px;
      --font-sans: 'Inter', 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --font-mono: 'JetBrains Mono', 'Roboto Mono', 'SF Mono', monospace;
      --transition-smooth: all 0.25s cubic-bezier(0.2, 0.0, 0, 1.0);
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
      background-color: var(--primary-deep);
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--primary-deep);
      color: var(--text-primary);
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition-smooth);
    }
    button, .btn {
      cursor: pointer;
      font-family: var(--font-sans);
      border: none;
      background: none;
      transition: var(--transition-smooth);
    }
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
      width: 100%;
    }
    /* 导航栏 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 50;
      background: rgba(10, 14, 23, 0.8);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid transparent;
      background-image: linear-gradient(rgba(10,14,23,0.8), rgba(10,14,23,0.8)), linear-gradient(90deg, var(--accent-glow), var(--accent-red));
      background-origin: border-box;
      background-clip: padding-box, border-box;
      padding: 0 16px;
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      max-width: 1280px;
      margin: 0 auto;
      height: 72px;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-weight: 800;
      font-size: 1.8rem;
      letter-spacing: -0.5px;
      color: white;
      position: relative;
    }
    .logo-icon {
      font-size: 2rem;
      filter: drop-shadow(0 0 6px var(--accent-red));
      margin-right: 2px;
    }
    .logo-text {
      background: linear-gradient(to right, #fff, #e0e0e0);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-link {
      font-weight: 500;
      font-size: 1rem;
      color: var(--text-secondary);
      position: relative;
      padding: 6px 0;
    }
    .nav-link::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0%;
      height: 2px;
      background: var(--accent-red);
      transition: width 0.2s ease;
    }
    .nav-link:hover {
      color: white;
    }
    .nav-link:hover::after {
      width: 100%;
    }
    .btn-primary {
      background: var(--accent-red);
      color: white;
      font-weight: 600;
      padding: 10px 24px;
      border-radius: var(--radius-sm);
      letter-spacing: 0.3px;
      box-shadow: 0 4px 14px rgba(230,57,22,0.4);
      display: inline-flex;
      align-items: center;
      justify-content: center;
    }
    .btn-primary:hover {
      background: #C42D0F;
      box-shadow: 0 0 22px rgba(244,162,97,0.5);
      transform: translateY(-1px);
    }
    .btn-outline {
      background: transparent;
      border: 1px solid var(--accent-red);
      color: var(--accent-red);
      font-weight: 600;
      padding: 10px 24px;
      border-radius: var(--radius-sm);
    }
    .btn-outline:hover {
      background: var(--accent-red);
      color: white;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: transparent;
      border: none;
    }
    .hamburger span {
      width: 26px;
      height: 2px;
      background: white;
      border-radius: 2px;
      transition: 0.2s;
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 72px;
      left: 0;
      width: 100%;
      background: #0b111c;
      backdrop-filter: blur(16px);
      padding: 24px;
      flex-direction: column;
      gap: 20px;
      border-bottom: 1px solid var(--accent-red);
      z-index: 49;
    }
    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background-image: radial-gradient(circle at 20% 30%, rgba(20,26,36,0.7) 0%, #0A0E17 90%), url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      position: relative;
      padding-top: 80px;
    }
    .hero-content {
      max-width: 800px;
      margin: 0 auto;
      text-align: center;
      position: relative;
      z-index: 2;
    }
    .hero h1 {
      font-size: clamp(3rem, 8vw, 4.8rem);
      font-weight: 900;
      letter-spacing: -0.02em;
      line-height: 1.1;
      margin-bottom: 24px;
      color: white;
    }
    .highlight {
      color: var(--accent-red);
      text-shadow: 0 0 18px rgba(230,57,22,0.5);
    }
    .hero-sub {
      font-size: 1.3rem;
      font-weight: 400;
      color: var(--text-secondary);
      margin-bottom: 40px;
      max-width: 600px;
      margin-left: auto;
      margin-right: auto;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      justify-content: center;
      flex-wrap: wrap;
    }
    /* 板块通用 */
    section {
      padding: 100px 0;
    }
    .section-title {
      font-size: 2.5rem;
      font-weight: 700;
      margin-bottom: 16px;
      letter-spacing: -0.5px;
    }
    .section-desc {
      color: var(--text-secondary);
      font-size: 1.15rem;
      margin-bottom: 48px;
      max-width: 700px;
    }
    /* 核心优势 不对称网格 */
    .features-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      margin-top: 24px;
    }
    .feature-card {
      background: var(--bg-card);
      border: 1px solid var(--border-subtle);
      border-radius: var(--radius-md);
      padding: 32px 24px;
      transition: var(--transition-smooth);
      position: relative;
      overflow: hidden;
    }
    .feature-card::before {
      content: '';
      position: absolute;
      left: 0;
      top: 20%;
      height: 60%;
      width: 4px;
      background: var(--accent-red);
      border-radius: 0 4px 4px 0;
    }
    .feature-card:hover {
      background: var(--bg-card-hover);
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
      border-color: var(--border-glow);
    }
    .feature-icon {
      font-size: 2.2rem;
      color: var(--accent-glow);
      margin-bottom: 20px;
    }
    .feature-card h3 {
      font-size: 1.4rem;
      margin-bottom: 12px;
    }
    .grid-span-2 {
      grid-column: span 2;
    }
    /* 场景 */
    .scenario-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 80px;
    }
    .scenario-img {
      flex: 1;
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-card);
    }
    .scenario-text {
      flex: 1;
    }
    .tag {
      background: rgba(230,57,22,0.2);
      color: var(--accent-glow);
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 0.8rem;
      font-weight: 600;
      display: inline-block;
      margin-bottom: 12px;
    }
    /* 案例数据 */
    .stats-grid {
      display: flex;
      justify-content: space-around;
      flex-wrap: wrap;
      gap: 40px;
      margin: 40px 0;
    }
    .stat-number {
      font-family: var(--font-mono);
      font-size: 3.5rem;
      font-weight: 700;
      background: linear-gradient(135deg, var(--accent-glow), var(--accent-red));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
    }
    /* 价格卡 */
    .pricing-grid {
      display: flex;
      gap: 24px;
      justify-content: center;
      flex-wrap: wrap;
    }
    .price-card {
      background: var(--bg-card);
      border: 1px solid var(--border-subtle);
      border-radius: var(--radius-md);
      padding: 40px 28px;
      flex: 1 1 260px;
      max-width: 300px;
      transition: var(--transition-smooth);
    }
    .price-card.featured {
      border-color: var(--accent-red);
      box-shadow: 0 0 28px rgba(230,57,22,0.3);
      transform: scale(1.02);
    }
    .price-amount {
      font-size: 3rem;
      font-weight: 800;
    }
    /* FAQ */
    .faq-item {
      background: #141A24;
      border-radius: var(--radius-sm);
      margin-bottom: 12px;
      padding: 20px 24px;
      cursor: pointer;
      border-left: 3px solid transparent;
      transition: 0.2s;
    }
    .faq-item:hover {
      border-left-color: var(--accent-red);
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      font-weight: 600;
    }
    /* CTA banner */
    .cta-band {
      background: linear-gradient(135deg, #1A1120, #0F1219);
      border-top: 1px solid var(--accent-red);
      border-bottom: 1px solid var(--accent-red);
      text-align: center;
      padding: 80px 0;
    }
    footer {
      background: #06090f;
      padding: 40px 0;
      border-top: 2px solid var(--accent-red);
      color: var(--text-muted);
    }
    @media (max-width: 1024px) {
      .features-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .grid-span-2 {
        grid-column: span 2;
      }
    }
    @media (max-width: 768px) {
      .nav-menu { display: none; }
      .hamburger { display: flex; }
      .mobile-menu.active { display: flex; }
      .features-grid {
        grid-template-columns: 1fr;
      }
      .grid-span-2 {
        grid-column: span 1;
      }
      .scenario-row {
        flex-direction: column;
        gap: 30px;
      }
      section {
        padding: 70px 0;
      }
    }