/* roulang page: index */
:root {
      --primary-titanium: #1A211F;
      --accent-signal: #C8FF00;
      --bg-warm-white: #F7F5F0;
      --bg-deep-rock: #2A2D2B;
      --text-dark: #1A211F;
      --text-muted: #4A4D4B;
      --border-subtle: #E8E6E1;
      --white: #FFFFFF;
      --shadow-sm: 0 4px 12px rgba(0,0,0,0.04);
      --shadow-md: 0 12px 24px rgba(0,0,0,0.08);
      --radius-md: 12px;
      --radius-sm: 8px;
      --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Inter", sans-serif;
      --transition-base: 0.3s ease-in-out;
      --container-max: 1280px;
      --section-gap: 120px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-warm-white);
      color: var(--text-dark);
      line-height: 1.6;
      overflow-x: hidden;
    }
    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }
    /* 导航 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 100;
      background: rgba(255,255,255,0.02);
      backdrop-filter: blur(10px);
      -webkit-backdrop-filter: blur(10px);
      border-bottom: 1px solid transparent;
      transition: background 0.4s ease, border-color 0.3s ease;
      padding: 16px 0;
    }
    .site-header.scrolled {
      background: var(--bg-deep-rock);
      backdrop-filter: blur(16px);
      border-bottom: 1px solid rgba(255,255,255,0.1);
    }
    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }
    .logo {
      font-weight: 800;
      font-size: 1.8rem;
      letter-spacing: -0.5px;
      color: var(--accent-signal);
      text-decoration: none;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo-icon {
      font-size: 2rem;
      filter: drop-shadow(0 2px 6px rgba(200,255,0,0.4));
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }
    .nav-link {
      color: var(--bg-warm-white);
      text-decoration: none;
      font-weight: 500;
      font-size: 1rem;
      position: relative;
      transition: color 0.3s;
    }
    .nav-link:hover {
      color: var(--accent-signal);
    }
    .header-cta {
      background: var(--accent-signal);
      color: var(--primary-titanium);
      font-weight: 700;
      padding: 12px 24px;
      border-radius: var(--radius-sm);
      text-decoration: none;
      transition: all 0.25s ease;
      box-shadow: 0 4px 10px rgba(200,255,0,0.25);
      letter-spacing: 0.3px;
    }
    .header-cta:hover {
      background: #b0e600;
      box-shadow: 0 6px 18px rgba(200,255,0,0.5);
    }
    .mobile-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 2rem;
      color: var(--accent-signal);
      cursor: pointer;
    }
    @media (max-width: 768px) {
      .nav-menu {
        display: none;
      }
      .mobile-toggle {
        display: block;
      }
      .header-cta.desktop-only {
        display: none;
      }
    }
    .mobile-drawer {
      position: fixed;
      top: 0;
      left: 0;
      width: 80%;
      max-width: 300px;
      height: 100vh;
      background: var(--bg-deep-rock);
      backdrop-filter: blur(20px);
      padding: 48px 24px;
      transform: translateX(-100%);
      transition: transform 0.4s ease;
      z-index: 200;
      display: flex;
      flex-direction: column;
      gap: 32px;
    }
    .mobile-drawer.active {
      transform: translateX(0);
    }
    .mobile-drawer .nav-link {
      font-size: 1.4rem;
      font-weight: 600;
    }
    .drawer-close {
      align-self: flex-end;
      background: none;
      border: none;
      color: white;
      font-size: 2rem;
    }
    /* Hero */
    .hero {
      height: 100vh;
      display: flex;
      align-items: center;
      background: var(--primary-titanium);
      color: white;
      position: relative;
      overflow: hidden;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
      align-items: center;
      width: 100%;
    }
    .hero-title {
      font-size: 56px;
      font-weight: 800;
      letter-spacing: -0.02em;
      line-height: 1.15;
      color: white;
      margin-bottom: 24px;
    }
    .hero-sub {
      font-size: 1.3rem;
      color: rgba(255,255,255,0.8);
      margin-bottom: 40px;
    }
    .hero-badges {
      display: flex;
      gap: 40px;
      margin-top: 48px;
    }
    .badge-number {
      font-family: 'Inter', sans-serif;
      font-size: 2.8rem;
      font-weight: 700;
      color: var(--accent-signal);
    }
    .hero-image {
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      border-radius: 24px;
      height: 500px;
      width: 100%;
      box-shadow: 0 20px 40px rgba(0,0,0,0.5);
      mask-image: linear-gradient(to bottom, black 80%, transparent 100%);
    }
    @media (max-width: 768px) {
      .hero-grid {
        grid-template-columns: 1fr;
        text-align: center;
      }
      .hero-title {
        font-size: 36px;
        line-height: 1.3;
      }
      .hero-image {
        height: 300px;
        order: -1;
      }
      .hero-badges {
        justify-content: center;
      }
    }
    section {
      padding: var(--section-gap) 0;
    }
    .section-title {
      font-size: 40px;
      font-weight: 700;
      margin-bottom: 16px;
      color: var(--primary-titanium);
    }
    .section-sub {
      color: var(--text-muted);
      max-width: 600px;
      margin-bottom: 60px;
    }
    .advantages-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      grid-template-rows: auto auto;
      gap: 24px;
    }
    .adv-card {
      background: white;
      border: 1px solid var(--border-subtle);
      border-radius: var(--radius-md);
      padding: 40px;
      transition: all 0.3s ease;
    }
    .adv-card.wide {
      grid-column: span 2;
    }
    .adv-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-md);
    }
    .adv-icon {
      font-size: 2.8rem;
      margin-bottom: 24px;
    }
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }
    .service-item {
      background: white;
      padding: 36px;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-subtle);
    }
    .scenario-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 80px;
    }
    .scenario-img {
      flex: 1;
      background-size: cover;
      border-radius: 20px;
      height: 320px;
    }
    .case-track {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding: 20px 0;
    }
    .case-card {
      background: rgba(255,255,255,0.08);
      backdrop-filter: blur(12px);
      border-radius: 16px;
      padding: 28px;
      min-width: 260px;
      color: white;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-subtle);
    }
    .faq-question {
      background: none;
      border: none;
      width: 100%;
      text-align: left;
      font-weight: 600;
      font-size: 1.2rem;
      padding: 24px 0;
      display: flex;
      justify-content: space-between;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 40px;
    }
    input, textarea {
      background: transparent;
      border: none;
      border-bottom: 1px solid rgba(255,255,255,0.5);
      padding: 12px 0;
      color: white;
      width: 100%;
    }
    .btn-primary {
      background: var(--accent-signal);
      color: #1A211F;
      font-weight: 700;
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      border: none;
      cursor: pointer;
    }
    @media (max-width: 768px) {
      .advantages-grid, .services-grid, .footer-grid {
        grid-template-columns: 1fr;
      }
      .adv-card.wide { grid-column: span 1; }
      .scenario-row { flex-direction: column; }
    }