/* roulang page: index */
:root {
      --primary-deep: #0B1A2F;
      --accent-cyan: #00C2E0;
      --accent-gold: #C8963E;
      --cloud-white: #F4F7FC;
      --dark-teal: #1E3A4A;
      --text-light: #CCD6E0;
      --text-dark: #2E3B4E;
      --footer-bg: #070E18;
      --footer-text: #8899AA;
      --glass-bg: rgba(255, 255, 255, 0.03);
      --glass-border: rgba(255, 255, 255, 0.08);
      --card-radius: 16px;
      --btn-radius: 8px;
      --shadow-card: 0 8px 32px rgba(0, 0, 0, 0.2);
      --shadow-hover: 0 12px 40px rgba(0, 194, 224, 0.15);
      --font-stack: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      --font-number: "Inter", "PingFang SC", "Microsoft YaHei", sans-serif;
      --section-gap: 100px;
      --container-max: 1200px;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-stack);
      background-color: var(--primary-deep);
      color: var(--text-light);
      line-height: 1.7;
      font-size: 16px;
      margin: 0;
      overflow-x: hidden;
    }

    a {
      text-decoration: none;
      color: var(--accent-cyan);
      transition: color 0.2s, background 0.2s;
    }

    a:hover {
      color: #33d4f0;
    }

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

    button, .btn {
      font-family: var(--font-stack);
      transition: all 0.3s ease;
    }

    h1, h2, h3, h4, h5, h6 {
      color: #ffffff;
      line-height: 1.3;
    }

    .container-custom {
      max-width: var(--container-max);
      margin: 0 auto;
      padding-left: 20px;
      padding-right: 20px;
    }

    /* 导航栏 */
    .navbar-custom {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1050;
      background: rgba(11, 26, 47, 0.88);
      backdrop-filter: blur(20px);
      transition: background 0.25s, box-shadow 0.25s;
      border-bottom: 1px solid transparent;
    }

    .navbar-scrolled {
      background: rgba(11, 26, 47, 0.96);
      border-bottom: 1px solid rgba(0, 194, 224, 0.2);
    }

    .navbar-brand-custom {
      font-weight: 700;
      font-size: 1.4rem;
      color: #ffffff;
      display: flex;
      align-items: center;
      gap: 10px;
    }
    .navbar-brand-custom i {
      color: var(--accent-cyan);
      font-size: 1.8rem;
    }
    .brand-sub {
      font-size: 0.8rem;
      color: var(--accent-cyan);
      letter-spacing: 1px;
      margin-left: 5px;
      font-weight: 400;
    }

    .nav-link-custom {
      color: #B0C4D8;
      font-weight: 500;
      margin: 0 10px;
      padding: 8px 12px;
      position: relative;
      transition: color 0.2s;
    }
    .nav-link-custom:hover,
    .nav-link-custom.active {
      color: var(--accent-cyan);
    }
    .nav-link-custom::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 50%;
      transform: translateX(-50%);
      width: 0;
      height: 2px;
      background: var(--accent-cyan);
      transition: width 0.25s;
    }
    .nav-link-custom:hover::after,
    .nav-link-custom.active::after {
      width: 70%;
    }

    .search-icon {
      color: #B0C4D8;
      font-size: 1.2rem;
      cursor: pointer;
      transition: color 0.2s;
    }
    .search-icon:hover {
      color: var(--accent-cyan);
    }

    .navbar-toggler {
      border: none;
      color: #ffffff;
    }

    /* Hero */
    .hero-section {
      padding-top: 140px;
      padding-bottom: 100px;
      background: linear-gradient(135deg, #0B1A2F 0%, #05101E 100%);
      position: relative;
      overflow: hidden;
    }

    .hero-particles {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: radial-gradient(circle at 30% 40%, rgba(0,194,224,0.12) 0%, transparent 50%);
      pointer-events: none;
    }

    .hero-title {
      font-size: 3.5rem;
      font-weight: 700;
      color: #ffffff;
      margin-bottom: 1.5rem;
    }

    .hero-sub {
      font-size: 1.25rem;
      color: #CCD6E0;
      margin-bottom: 2.5rem;
      max-width: 520px;
    }

    .btn-primary-custom {
      background: var(--accent-cyan);
      color: #0B1A2F;
      font-weight: 600;
      padding: 12px 32px;
      border-radius: var(--btn-radius);
      border: none;
      box-shadow: 0 4px 12px rgba(0,194,224,0.3);
    }
    .btn-primary-custom:hover {
      background: #00d4f0;
      color: #0B1A2F;
      box-shadow: 0 0 18px rgba(0,194,224,0.6);
      transform: translateY(-2px);
    }

    .btn-outline-custom {
      background: transparent;
      color: var(--accent-cyan);
      border: 1px solid var(--accent-cyan);
      font-weight: 600;
      padding: 12px 32px;
      border-radius: var(--btn-radius);
    }
    .btn-outline-custom:hover {
      background: rgba(0,194,224,0.1);
      color: var(--accent-cyan);
      box-shadow: 0 0 15px rgba(0,194,224,0.5);
      transform: translateY(-2px);
    }

    .hero-visual {
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      min-height: 350px;
      border-radius: 24px;
      background-blend-mode: overlay;
      position: relative;
      opacity: 0.9;
    }

    /* 通用区块 */
    .section-block {
      padding: var(--section-gap) 0;
    }

    .section-title {
      font-weight: 600;
      font-size: 2rem;
      margin-bottom: 0.75rem;
      color: #ffffff;
      position: relative;
    }
    .underline-cyan {
      width: 50px;
      height: 4px;
      background: var(--accent-cyan);
      margin: 10px 0 25px;
    }

    /* 玻璃卡片 */
    .glass-card {
      background: var(--glass-bg);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border: 1px solid var(--glass-border);
      border-radius: var(--card-radius);
      box-shadow: var(--shadow-card);
      transition: all 0.3s ease;
    }
    .glass-card:hover {
      box-shadow: var(--shadow-hover);
      border-color: rgba(255,255,255,0.15);
      transform: translateY(-4px);
    }

    /* 服务卡片 */
    .service-img {
      height: 160px;
      object-fit: cover;
      border-radius: var(--card-radius) var(--card-radius) 0 0;
    }

    /* 数据带 */
    .data-strip {
      background: rgba(30, 58, 74, 0.7);
      backdrop-filter: blur(4px);
      padding: 50px 0;
    }
    .data-number {
      font-size: 3rem;
      font-weight: 700;
      color: var(--accent-gold);
      font-family: var(--font-number);
    }
    .data-label {
      color: #B0C4D8;
      letter-spacing: 2px;
      font-size: 0.9rem;
    }

    /* FAQ 手风琴重绘 */
    .accordion-custom .accordion-item {
      background: transparent;
      border: none;
      border-bottom: 1px solid rgba(255,255,255,0.06);
    }
    .accordion-custom .accordion-button {
      background: transparent;
      color: #ffffff;
      font-weight: 500;
      box-shadow: none;
      padding: 20px 0;
      font-size: 1.1rem;
    }
    .accordion-custom .accordion-button:not(.collapsed) {
      background: transparent;
      color: var(--accent-cyan);
      box-shadow: none;
    }
    .accordion-custom .accordion-button::after {
      display: none;
    }
    .accordion-custom .accordion-button i {
      transition: transform 0.3s;
      color: var(--accent-cyan);
    }
    .accordion-custom .accordion-button:not(.collapsed) i {
      transform: rotate(45deg);
    }
    .accordion-custom .accordion-body {
      background: rgba(255,255,255,0.02);
      color: #CCD6E0;
      padding: 20px 20px 20px 0;
    }

    /* CTA 横幅 */
    .cta-banner {
      background: #0B1A2F;
      border-top: 1px solid rgba(0,194,224,0.2);
    }

    /* 页脚 */
    .footer-custom {
      background: var(--footer-bg);
      color: var(--footer-text);
      padding: 60px 0 20px;
    }
    .footer-link {
      color: #8899AA;
      transition: color 0.2s;
    }
    .footer-link:hover {
      color: var(--accent-cyan);
    }
    .copyright {
      color: #556677;
      font-size: 0.85rem;
    }

    @media (max-width: 992px) {
      .hero-title { font-size: 2.8rem; }
    }
    @media (max-width: 768px) {
      .hero-title { font-size: 2.2rem; }
      .section-block { padding: 60px 0; }
      .data-number { font-size: 2.2rem; }
    }