/* roulang page: index */
:root {
      --deep-blue: #0B1A2E;
      --dark-panel: #0F2338;
      --cyan: #00E5FF;
      --orange: #FF6B35;
      --white: #FFFFFF;
      --white-85: rgba(255,255,255,0.85);
      --white-60: rgba(255,255,255,0.6);
      --white-35: rgba(255,255,255,0.35);
      --card-bg: rgba(255,255,255,0.05);
      --card-border: rgba(0,229,255,0.15);
      --shadow-card: 0 8px 32px rgba(0,0,0,0.4);
      --shadow-glow: 0 16px 48px rgba(0,229,255,0.15);
      --radius-sm: 8px;
      --radius-md: 16px;
      --radius-lg: 24px;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", system-ui, -apple-system, sans-serif;
      --font-eng: "Inter", "SF Pro Display", system-ui, sans-serif;
      --navbar-blur: rgba(11,26,46,0.8);
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      background-color: var(--deep-blue);
      color: var(--white-85);
      font-family: var(--font-sans);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      color: inherit;
      text-decoration: none;
    }
    button, input {
      font-family: inherit;
    }
    .container {
      width: 100%;
      max-width: 1200px;
      margin: 0 auto;
      padding-left: 24px;
      padding-right: 24px;
    }
    /* 导航 */
    #header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: var(--navbar-blur);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border-bottom: 1px solid rgba(0,229,255,0.2);
      z-index: 1000;
      transition: background 0.3s;
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 70px;
    }
    .logo {
      font-size: 1.7rem;
      font-weight: 700;
      color: var(--white);
      letter-spacing: -0.02em;
      display: flex;
      align-items: center;
    }
    .logo span {
      color: var(--cyan);
      margin-right: 6px;
    }
    .nav-links {
      display: flex;
      gap: 2rem;
      font-weight: 500;
      color: var(--white-85);
    }
    .nav-links a {
      position: relative;
      padding: 8px 0;
      transition: color 0.2s;
      font-size: 0.95rem;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--cyan);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0%;
      height: 2px;
      background: var(--cyan);
      transition: width 0.25s ease;
    }
    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: transparent;
      border: none;
      cursor: pointer;
      padding: 8px;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--white);
      transition: 0.3s;
    }
    /* Hero */
    #hero {
      padding-top: 110px;
      min-height: 90vh;
      display: flex;
      align-items: center;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      position: relative;
}
    #hero::before {
      content: '';
      position: absolute;
      inset: 0;
      background: linear-gradient(135deg, rgba(11,26,46,0.85) 0%, rgba(11,26,46,0.5) 100%);
      backdrop-filter: blur(2px);
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 2.5rem;
      align-items: center;
      position: relative;
      z-index: 2;
    }
    .hero-title {
      font-size: 3.4rem;
      font-weight: 700;
      line-height: 1.2;
      letter-spacing: -0.02em;
      color: var(--white);
      margin-bottom: 1.2rem;
    }
    .hero-sub {
      font-size: 1.2rem;
      color: var(--white-60);
      margin-bottom: 2rem;
    }
    .btn-group {
      display: flex;
      gap: 1rem;
      flex-wrap: wrap;
    }
    .btn {
      padding: 12px 32px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      font-size: 1rem;
      transition: all 0.2s ease;
      border: none;
      cursor: pointer;
      display: inline-block;
      text-align: center;
    }
    .btn-primary {
      background: var(--orange);
      color: white;
      box-shadow: 0 8px 18px rgba(255,107,53,0.3);
    }
    .btn-primary:hover {
      background: #FF7F50;
      box-shadow: 0 0 22px rgba(255,107,53,0.7);
      transform: scale(1.02);
    }
    .btn-outline {
      background: transparent;
      border: 1px solid var(--cyan);
      color: var(--cyan);
    }
    .btn-outline:hover {
      background: rgba(0,229,255,0.1);
      color: white;
    }
    /* 板块通用 */
    section {
      padding: 5rem 0;
    }
    .section-title {
      font-size: 2.4rem;
      font-weight: 700;
      letter-spacing: -0.02em;
      text-align: center;
      margin-bottom: 0.5rem;
      color: var(--white);
    }
    .section-sub {
      text-align: center;
      color: var(--white-60);
      max-width: 600px;
      margin: 0 auto 2.5rem;
    }
    /* 亮点网格 */
    #highlights {
      background: var(--dark-panel);
      background-image: radial-gradient(circle at 20% 0%, rgba(0,229,255,0.08) 0%, transparent 40%);
    }
    .grid-unequal {
      display: grid;
      grid-template-columns: repeat(12, 1fr);
      gap: 24px;
    }
    .card {
      background: var(--card-bg);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border: 1px solid var(--card-border);
      border-radius: var(--radius-lg);
      padding: 28px;
      box-shadow: var(--shadow-card);
      transition: all 0.25s;
    }
    .card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-glow);
      border-color: rgba(0,229,255,0.35);
    }
    .card-icon {
      font-size: 2rem;
      color: var(--cyan);
      margin-bottom: 20px;
    }
    .card h3 {
      font-size: 1.7rem;
      font-weight: 700;
      color: var(--white);
    }
    .card-desc {
      color: var(--white-60);
      margin: 12px 0 18px;
    }
    .metric {
      font-family: var(--font-eng);
      font-size: 2.3rem;
      font-weight: 700;
      color: var(--cyan);
    }
    .span-4 { grid-column: span 4; }
    .span-6 { grid-column: span 6; }
    .span-8 { grid-column: span 8; }
    /* 案例瀑布流 */
    #cases {
      background: var(--deep-blue);
    }
    .waterfall {
      columns: 2;
      column-gap: 28px;
    }
    .case-card {
      break-inside: avoid;
      margin-bottom: 28px;
      background: var(--card-bg);
      backdrop-filter: blur(16px);
      border: 1px solid var(--card-border);
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--shadow-card);
    }
    .case-img {
      position: relative;
      height: 220px;
      background-size: cover;
      background-position: center;
    }
    .case-tag-group {
      display: flex;
      gap: 8px;
      color: var(--cyan);
    }
    .case-content {
      padding: 20px;
    }
    /* 方案对比 */
    #solutions .compare-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .feature-list li {
      display: flex;
      align-items: center;
      gap: 8px;
    }
    /* faq */
    .faq-item {
      background: rgba(255,255,255,0.03);
      border-radius: var(--radius-md);
      margin-bottom: 16px;
      border-left: 3px solid transparent;
      transition: 0.3s;
    }
    .faq-item.active {
      border-left-color: var(--cyan);
    }
    /* cta横幅 */
    #cta {
      background: var(--deep-blue);
      text-align: center;
      border-top: 1px solid rgba(0,229,255,0.15);
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
      border-bottom: 1px solid rgba(255,255,255,0.1);
      padding-bottom: 2.5rem;
    }
    @media (max-width: 1024px) {
      .hero-grid { grid-template-columns: 1fr; }
      .grid-unequal { grid-template-columns: repeat(2,1fr);}
      .compare-grid { grid-template-columns: 1fr; }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .waterfall { columns: 1; }
      .footer-grid { grid-template-columns: 1fr; }
    }