/* roulang page: index */
:root {
      --primary: #0A1A2F;
      --primary-deep: #05101E;
      --accent: #00C2FF;
      --accent-light: rgba(0, 194, 255, 0.18);
      --highlight: #FF6B35;
      --success: #00D68F;
      --warning: #FF3B30;
      --gray-bg: #F4F7FB;
      --white: #FFFFFF;
      --text: #333333;
      --text-light: #666666;
      --text-footer: #A0B0C0;
      --border-light: #E0E6ED;
      --border-card: rgba(255,255,255,0.1);
      --glass-bg: rgba(255,255,255,0.06);
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-lg: 16px;
      --shadow-card: 0 8px 32px rgba(0,0,0,0.08);
      --shadow-hover: 0 12px 40px rgba(0,194,255,0.15);
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --transition: 0.25s ease;
      --container: 1280px;
    }

    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-sans);
      font-size: 16px;
      line-height: 1.7;
      color: var(--text);
      background-color: var(--white);
      -webkit-font-smoothing: antialiased;
    }

    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition);
    }

    button, input, textarea {
      font-family: inherit;
    }

    .container {
      width: 100%;
      max-width: var(--container);
      margin: 0 auto;
      padding: 0 24px;
    }

    /* 导航 */
    #header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 100;
      background: rgba(10, 26, 47, 0.85);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border-bottom: 1px solid rgba(0, 194, 255, 0.25);
      transition: background 0.3s ease, padding 0.3s ease;
    }
    #header.scrolled {
      background: rgba(5, 16, 30, 0.95);
      box-shadow: 0 4px 20px rgba(0,0,0,0.3);
    }
    .nav-bar {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
      padding: 0 24px;
      max-width: var(--container);
      margin: 0 auto;
    }
    .logo {
      font-size: 1.8rem;
      font-weight: 700;
      color: white;
      display: flex;
      align-items: center;
      gap: 8px;
      letter-spacing: 1px;
    }
    .logo-icon {
      font-size: 2rem;
      color: var(--accent);
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-links a {
      color: white;
      font-weight: 500;
      font-size: 1rem;
      position: relative;
      padding: 4px 0;
      transition: color var(--transition);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent);
      transition: width var(--transition);
    }
    .nav-links a:hover {
      color: var(--accent);
    }
    .nav-links a:hover::after {
      width: 100%;
    }
    .btn-nav {
      background: var(--accent);
      color: #0A1A2F !important;
      font-weight: 700;
      padding: 8px 20px;
      border-radius: 30px;
      transition: all var(--transition);
      border: none;
      cursor: pointer;
      white-space: nowrap;
    }
    .btn-nav:hover {
      background: #33d4ff;
      box-shadow: 0 0 18px rgba(0,194,255,0.7);
      color: #05101E !important;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
    }
    .hamburger span {
      width: 28px;
      height: 3px;
      background: white;
      border-radius: 3px;
      transition: 0.3s;
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 72px;
      left: 0;
      width: 100%;
      background: rgba(5,16,30,0.98);
      backdrop-filter: blur(24px);
      flex-direction: column;
      padding: 32px 24px;
      gap: 24px;
      z-index: 99;
      border-bottom: 1px solid var(--accent);
    }
    .mobile-menu a {
      color: white;
      font-size: 1.3rem;
      font-weight: 500;
    }
    .mobile-menu .btn-nav {
      display: inline-block;
      width: fit-content;
    }

    /* Hero */
    #hero {
      height: 100vh;
      min-height: 700px;
      display: flex;
      align-items: center;
      background: linear-gradient(135deg, #0A1A2F 0%, #05101E 100%);
      position: relative;
      overflow: hidden;
    }
    .hero-bg-pattern {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background-image: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100" opacity="0.06"><polygon points="50,0 100,25 100,75 50,100 0,75 0,25" fill="none" stroke="white" stroke-width="0.8"/></svg>');
      background-size: 80px 80px;
      pointer-events: none;
    }
    .hero-glow {
      position: absolute;
      top: 20%;
      left: 5%;
      width: 300px;
      height: 300px;
      background: radial-gradient(circle, rgba(0,194,255,0.25) 0%, transparent 70%);
      filter: blur(60px);
      animation: floatGlow 7s infinite alternate;
    }
    @keyframes floatGlow {
      0% { transform: translate(0,0); opacity: 0.7; }
      100% { transform: translate(50px, -30px); opacity: 0.4; }
    }
    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 700px;
      color: white;
    }
    .hero-content h1 {
      font-size: 3rem;
      font-weight: 700;
      line-height: 1.3;
      margin-bottom: 20px;
    }
    .hero-content .subtitle {
      font-size: 1.2rem;
      color: rgba(255,255,255,0.8);
      margin-bottom: 36px;
    }
    .btn-group {
      display: flex;
      gap: 20px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--accent);
      color: #0A1A2F;
      font-weight: 700;
      padding: 14px 36px;
      border-radius: 8px;
      border: none;
      cursor: pointer;
      transition: 0.2s;
      display: inline-block;
      text-align: center;
    }
    .btn-primary:hover {
      background: #33d4ff;
      box-shadow: 0 0 24px rgba(0,194,255,0.7);
    }
    .btn-outline {
      background: transparent;
      border: 1px solid var(--accent);
      color: var(--accent);
      padding: 14px 36px;
      border-radius: 8px;
      font-weight: 600;
      transition: 0.2s;
    }
    .btn-outline:hover {
      background: rgba(0,194,255,0.1);
    }

    /* 通用板块 */
    section {
      padding: 100px 0;
    }
    .section-title {
      font-size: 2.25rem;
      font-weight: 700;
      margin-bottom: 16px;
      color: var(--primary);
    }
    .section-desc {
      color: var(--text-light);
      margin-bottom: 48px;
    }

    /* 服务 */
    #services {
      background: var(--gray-bg);
    }
    .services-grid {
      display: grid;
      grid-template-columns: repeat(2,1fr);
      gap: 32px;
    }
    .service-card {
      background: rgba(255,255,255,0.7);
      backdrop-filter: blur(12px);
      border: 1px solid rgba(255,255,255,0.5);
      border-radius: var(--radius-lg);
      padding: 32px;
      transition: all 0.25s;
      box-shadow: var(--shadow-card);
    }
    .service-card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }
    .service-icon {
      font-size: 2.5rem;
      color: var(--accent);
      margin-bottom: 20px;
    }
    .service-card h3 {
      font-size: 1.5rem;
      margin-bottom: 12px;
    }

    /* 优势 */
    #advantages {
      background: linear-gradient(180deg, #FFFFFF 0%, #F0F4FA 100%);
    }
    .stats-row {
      display: flex;
      justify-content: space-around;
      text-align: center;
      gap: 32px;
    }
    .stat-item .number {
      font-size: 3rem;
      font-weight: 800;
      color: var(--highlight);
    }

    /* 案例 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 32px;
    }
    .case-card {
      background: white;
      border-radius: var(--radius-md);
      overflow: hidden;
      box-shadow: var(--shadow-card);
      border: 1px solid var(--border-light);
    }
    .case-img {
      height: 200px;
      background-size: cover;
    }

    /* 方案流程 */
    .steps-line {
      display: flex;
      justify-content: space-between;
      position: relative;
    }
    .step {
      text-align: center;
      flex:1;
    }

    /* FAQ */
    .faq-item {
      background: #F4F7FB;
      border-radius: 8px;
      margin-bottom: 12px;
    }
    .faq-question {
      padding: 18px 24px;
      font-weight: 700;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
    }

    /* 联系 */
    #contact .contact-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }
    .glass-form {
      background: rgba(255,255,255,0.8);
      backdrop-filter: blur(16px);
      border-radius: 20px;
      padding: 36px;
      box-shadow: 0 20px 40px rgba(0,0,0,0.08);
    }

    /* 页脚 */
    #footer {
      background: var(--primary-deep);
      color: var(--text-footer);
      padding: 60px 0 20px;
    }

    @media (max-width: 1024px) {
      .cases-grid { grid-template-columns: 1fr 1fr; }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .services-grid, .cases-grid, .stats-row, .steps-line { grid-template-columns: 1fr; flex-direction: column; }
      .hero-content h1 { font-size: 2rem; }
      #contact .contact-grid { grid-template-columns: 1fr; }
    }