/* roulang page: index */
:root {
      --deep-midnight: #0A0E27;
      --card-bg: #111633;
      --card-inner: #141A35;
      --orange-prime: #FF4D2E;
      --orange-hover: #FF6B4A;
      --energy-gold: #F5A623;
      --cyber-cyan: #00E5FF;
      --text-body: #B0B8D1;
      --text-light: #E0E4F0;
      --border-dim: rgba(0, 229, 255, 0.15);
      --border-glow: rgba(0, 229, 255, 0.35);
      --shadow-cyan: 0 0 20px rgba(0, 229, 255, 0.08);
      --shadow-card: 0 10px 25px -8px rgba(0,0,0,0.6);
      --radius-lg: 12px;
      --radius-md: 8px;
      --radius-btn: 6px;
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', 'Inter', sans-serif;
      --font-mono: 'Rajdhani', 'Orbitron', 'Inter', sans-serif;
      --transition-base: all 0.25s ease;
      --container-max: 1200px;
      --backdrop-blur: blur(12px);
    }
    * {
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--deep-midnight);
      color: var(--text-body);
      line-height: 1.7;
      margin: 0;
      overflow-x: hidden;
    }
    h1, h2, h3, h4, .nav-brand, .stat-number, .btn {
      font-family: var(--font-sans);
      letter-spacing: -0.5px;
    }
    h1, h2 {
      font-weight: 800;
    }
    .stat-number, .mono-text {
      font-family: var(--font-mono);
      font-weight: 700;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      color: var(--cyber-cyan);
      text-decoration: none;
      transition: var(--transition-base);
    }
    a:hover {
      color: var(--orange-prime);
    }
    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding-left: 1.5rem;
      padding-right: 1.5rem;
    }
    /* 导航卡片化面板 */
    .navbar {
      background: rgba(13, 18, 48, 0.8);
      backdrop-filter: var(--backdrop-blur);
      border-bottom: 1px solid rgba(0, 229, 255, 0.25);
      padding: 0.75rem 0;
      position: fixed;
      top: 0;
      width: 100%;
      z-index: 1030;
    }
    .navbar .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
    }
    .nav-brand {
      font-family: 'Orbitron', sans-serif;
      font-weight: 800;
      font-size: 1.8rem;
      color: #fff;
      display: flex;
      align-items: center;
      gap: 0.25rem;
    }
    .nav-brand span {
      color: var(--orange-prime);
      margin-right: 0.2rem;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 0.75rem;
      flex-wrap: wrap;
    }
    .nav-item {
      background: rgba(20, 26, 53, 0.6);
      border: 1px solid var(--border-dim);
      border-radius: var(--radius-md);
      padding: 0.5rem 1.1rem;
      color: var(--text-light);
      font-weight: 600;
      font-size: 0.95rem;
      transition: var(--transition-base);
      backdrop-filter: blur(4px);
    }
    .nav-item:hover {
      background: rgba(0, 229, 255, 0.08);
      border-color: var(--cyber-cyan);
      color: #fff;
    }
    .btn-nav-cta {
      background: var(--orange-prime);
      border: none;
      color: white;
      font-weight: 700;
      padding: 0.6rem 1.6rem;
      border-radius: var(--radius-btn);
      margin-left: 0.5rem;
      transition: var(--transition-base);
      text-decoration: none;
      display: inline-block;
    }
    .btn-nav-cta:hover {
      background: var(--orange-hover);
      box-shadow: 0 0 15px rgba(255,77,46,0.5);
      color: white;
    }
    /* 移动端汉堡菜单 */
    .navbar-toggler {
      background: transparent;
      border: 1px solid var(--cyber-cyan);
      color: var(--cyber-cyan);
      padding: 0.4rem 0.7rem;
      border-radius: var(--radius-md);
      font-size: 1.4rem;
    }
    .offcanvas {
      background: #0D1230;
      color: var(--text-body);
    }
    .offcanvas-header {
      border-bottom: 1px solid var(--border-dim);
    }
    .offcanvas .nav-item {
      display: block;
      margin: 0.5rem 0;
      background: transparent;
      border: none;
      font-size: 1.2rem;
    }
    /* Hero */
    .hero-section {
      padding: 160px 0 100px;
      background: radial-gradient(circle at 30% 40%, rgba(255,77,46,0.12) 0%, rgba(0,14,39,0) 60%), 
                  radial-gradient(circle at 80% 20%, rgba(0,229,255,0.08) 0%, transparent 50%);
      position: relative;
    }
    .hero-title {
      font-size: 3.2rem;
      font-weight: 800;
      color: #fff;
      line-height: 1.2;
    }
    .hero-highlight {
      background: linear-gradient(135deg, var(--cyber-cyan), var(--orange-prime));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    .btn-primary-custom {
      background: var(--orange-prime);
      border: none;
      color: white;
      font-weight: 700;
      padding: 0.8rem 2rem;
      border-radius: var(--radius-btn);
      transition: var(--transition-base);
    }
    .btn-primary-custom:hover {
      background: var(--orange-hover);
      box-shadow: 0 0 18px rgba(255,77,46,0.7);
    }
    .btn-outline-cyan {
      border: 1px solid var(--cyber-cyan);
      color: var(--cyber-cyan);
      background: transparent;
      font-weight: 600;
      padding: 0.8rem 2rem;
      border-radius: var(--radius-btn);
      transition: var(--transition-base);
    }
    .btn-outline-cyan:hover {
      background: rgba(0,229,255,0.08);
      color: #fff;
    }
    .section-padding {
      padding: 100px 0;
    }
    .section-title {
      font-size: 2.4rem;
      font-weight: 800;
      color: #fff;
      margin-bottom: 1rem;
      position: relative;
      display: inline-block;
    }
    .section-title::after {
      content: '';
      position: absolute;
      left: 0;
      bottom: -8px;
      width: 70px;
      height: 4px;
      background: var(--orange-prime);
    }
    .card-custom {
      background: var(--card-inner);
      border: 1px solid var(--border-dim);
      border-radius: var(--radius-lg);
      padding: 2rem;
      transition: var(--transition-base);
      box-shadow: var(--shadow-cyan);
      height: 100%;
    }
    .card-custom:hover {
      transform: translateY(-5px);
      border-color: var(--cyber-cyan);
      box-shadow: 0 0 25px rgba(0,229,255,0.2);
    }
    .service-icon {
      width: 50px;
      height: 50px;
      display: flex;
      align-items: center;
      justify-content: center;
      border: 1px solid var(--cyber-cyan);
      border-radius: var(--radius-md);
      margin-bottom: 1.5rem;
      color: var(--cyber-cyan);
      font-size: 1.8rem;
    }
    .stat-number {
      font-size: 3rem;
      color: var(--cyber-cyan);
      text-shadow: 0 0 12px rgba(0,229,255,0.5);
    }
    .stat-label {
      color: var(--text-body);
      font-weight: 600;
    }
    .case-img {
      aspect-ratio: 16/9;
      background: #1a1f3a;
      border-radius: var(--radius-md);
      overflow: hidden;
      position: relative;
    }
    .case-img img {
      object-fit: cover;
      width: 100%;
      height: 100%;
    }
    .faq-accordion .accordion-button {
      background: var(--card-inner);
      color: #fff;
      font-weight: 700;
      border-left: 4px solid var(--cyber-cyan);
      border-radius: 0 !important;
    }
    .faq-accordion .accordion-button:not(.collapsed) {
      background: #1a2040;
      border-left-color: var(--orange-prime);
    }
    .footer-dark {
      background: #060b1f;
      border-top: 1px solid rgba(0,229,255,0.2);
    }
    @media (max-width: 768px) {
      .hero-title {
        font-size: 2.5rem;
      }
      .navbar .nav-links {
        display: none;
      }
      .section-title {
        font-size: 2rem;
      }
    }