/* roulang page: index */
:root {
      --deep-space: #1A1F36;
      --star-silver: #4B6A99;
      --cyber-green: #00C9A7;
      --cyber-green-hover: #00B394;
      --bg-light: #F8FAFC;
      --white: #FFFFFF;
      --text-dark: #1E293B;
      --text-gray: #64748B;
      --border-light: #E2E8F0;
      --border-hover: #4B6A99;
      --shadow-sm: 0 4px 20px rgba(26, 31, 54, 0.06);
      --shadow-lg: 0 12px 32px rgba(26, 31, 54, 0.12);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 6px;
      --gutter: 1.5rem;
      --transition: all 0.25s ease;
    }

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

    body {
      font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      background-color: var(--bg-light);
      color: var(--text-dark);
      line-height: 1.75;
      font-size: 1rem;
      -webkit-font-smoothing: antialiased;
    }

    .english-number, .data-number {
      font-family: "Inter", "SF Pro Display", system-ui, -apple-system, sans-serif;
    }

    h1, h2, h3, h4 {
      font-weight: 700;
      letter-spacing: -0.2px;
    }

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

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

    .container-custom {
      width: 100%;
      max-width: 1200px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 20px;
      padding-right: 20px;
    }

    /* 按钮覆盖 Bootstrap */
    .btn-primary-custom {
      background-color: var(--cyber-green);
      border: none;
      color: var(--white);
      font-weight: 600;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      transition: var(--transition);
      display: inline-block;
      font-size: 1rem;
      letter-spacing: 0.3px;
      box-shadow: 0 4px 12px rgba(0, 201, 167, 0.25);
    }
    .btn-primary-custom:hover {
      background-color: var(--cyber-green-hover);
      color: var(--white);
      box-shadow: 0 8px 20px rgba(0, 201, 167, 0.4);
      transform: translateY(-2px);
    }

    .btn-outline-custom {
      background: transparent;
      border: 2px solid var(--star-silver);
      color: var(--star-silver);
      font-weight: 600;
      padding: 12px 28px;
      border-radius: var(--radius-btn);
      transition: var(--transition);
      display: inline-block;
      font-size: 1rem;
    }
    .btn-outline-custom:hover {
      background-color: var(--star-silver);
      color: var(--white);
      border-color: var(--star-silver);
      transform: translateY(-2px);
    }

    /* 导航栏 */
    #nav {
      background-color: var(--deep-space);
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      box-shadow: 0 4px 20px rgba(0,0,0,0.15);
    }
    .navbar {
      padding: 0.8rem 0;
    }
    .navbar-brand {
      font-size: 1.5rem;
      font-weight: 700;
      color: white !important;
      letter-spacing: 0.5px;
    }
    .navbar-toggler {
      border: none;
      color: white;
    }
    .navbar-toggler-icon {
      background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='rgba(255, 255, 255, 0.8)' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e");
    }
    .nav-link {
      color: rgba(255,255,255,0.8) !important;
      font-weight: 500;
      margin: 0 0.5rem;
      transition: var(--transition);
    }
    .nav-link:hover, .nav-link.active {
      color: var(--cyber-green) !important;
    }
    .navbar-nav .btn-primary-custom {
      margin-left: 1rem;
      padding: 10px 22px;
      font-size: 0.95rem;
    }
    @media (max-width: 991px) {
      .navbar-nav .btn-primary-custom {
        margin: 0.5rem 0 0 0;
        width: fit-content;
      }
    }

    /* 板块间距 */
    section {
      padding: 100px 0;
      scroll-margin-top: 70px;
    }
    @media (max-width: 768px) {
      section {
        padding: 70px 0;
      }
    }

    /* Hero */
    #hero {
      background-color: var(--bg-light);
      padding-top: 140px;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 3rem;
    }
    .hero-left {
      flex: 0 0 55%;
    }
    .hero-right {
      flex: 0 0 45%;
      position: relative;
    }
    .hero-right img {
      border-radius: 16px;
      box-shadow: var(--shadow-lg);
      width: 100%;
      height: auto;
      object-fit: cover;
      aspect-ratio: 4/3;
    }
    .hero-right::after {
      content: "";
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: linear-gradient(135deg, rgba(26,31,54,0.25) 0%, rgba(26,31,54,0.05) 70%);
      border-radius: 16px;
      pointer-events: none;
    }
    h1 {
      font-size: 2.75rem;
      font-weight: 700;
      color: var(--deep-space);
      line-height: 1.25;
      margin-bottom: 1.5rem;
    }
    .hero-sub {
      font-size: 1.125rem;
      color: var(--text-gray);
      margin-bottom: 2rem;
      max-width: 90%;
    }
    @media (max-width: 991px) {
      .hero-grid {
        flex-direction: column;
      }
      .hero-left, .hero-right {
        flex: 0 0 100%;
      }
      h1 {
        font-size: 2.2rem;
      }
    }

    /* 板块标题 */
    .section-title {
      font-size: 2rem;
      font-weight: 700;
      color: var(--text-dark);
      margin-bottom: 0.5rem;
      position: relative;
      display: inline-block;
    }
    .section-title::after {
      content: "";
      display: block;
      width: 40px;
      height: 4px;
      background-color: var(--cyber-green);
      margin-top: 8px;
    }

    /* 亮点 */
    .highlight-card {
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 2rem 1.5rem;
      box-shadow: var(--shadow-sm);
      border: 1px solid var(--border-light);
      transition: var(--transition);
      text-align: center;
    }
    .highlight-card:hover {
      box-shadow: var(--shadow-lg);
      transform: translateY(-4px);
      border-color: var(--border-hover);
    }
    .data-number {
      font-size: 2.5rem;
      font-weight: 800;
      color: var(--cyber-green);
      margin-bottom: 0.5rem;
    }

    /* 案例瀑布 */
    .cases-grid {
      column-count: 3;
      column-gap: 1.5rem;
    }
    .case-card {
      break-inside: avoid;
      background: var(--white);
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      border: 1px solid var(--border-light);
      margin-bottom: 1.5rem;
      transition: var(--transition);
    }
    .case-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-lg);
      border-color: var(--border-hover);
    }
    .case-img {
      height: 180px;
      background-color: #E2E8F0;
      object-fit: cover;
      width: 100%;
    }
    .case-body {
      padding: 1.2rem;
    }
    .case-tag {
      display: inline-block;
      background: rgba(0,201,167,0.1);
      color: var(--cyber-green);
      font-size: 0.8rem;
      font-weight: 600;
      padding: 0.2rem 0.8rem;
      border-radius: 20px;
      margin-bottom: 0.6rem;
    }
    @media (max-width: 991px) {
      .cases-grid {
        column-count: 2;
      }
    }
    @media (max-width: 768px) {
      .cases-grid {
        column-count: 1;
      }
    }

    /* 对比 */
    .compare-wrapper {
      display: flex;
      gap: 2rem;
      align-items: stretch;
    }
    .compare-col {
      flex: 1;
      background: var(--white);
      border-radius: var(--radius-card);
      padding: 2rem;
      border: 1px solid var(--border-light);
    }
    .compare-col.right {
      background: var(--deep-space);
      color: white;
      border: 1px solid var(--deep-space);
      position: relative;
    }
    .compare-col.right h3, .compare-col.right li {
      color: white;
    }
    .badge-recommend {
      background: var(--cyber-green);
      color: #1A1F36;
      font-weight: 700;
      padding: 0.2rem 1rem;
      border-radius: 20px;
      font-size: 0.8rem;
      position: absolute;
      top: -12px;
      right: 20px;
    }
    .compare-list {
      list-style: none;
      padding: 0;
      margin-top: 1.5rem;
    }
    .compare-list li {
      padding: 0.7rem 0;
      border-bottom: 1px solid rgba(0,0,0,0.05);
    }
    .right .compare-list li {
      border-bottom: 1px solid rgba(255,255,255,0.15);
    }
    @media (max-width: 768px) {
      .compare-wrapper {
        flex-direction: column;
      }
    }

    /* FAQ 手风琴覆盖 */
    .accordion-item {
      border: 1px solid var(--border-light);
      border-radius: var(--radius-card) !important;
      margin-bottom: 1rem;
      overflow: hidden;
      background: var(--white);
    }
    .accordion-button {
      font-weight: 600;
      font-size: 1.125rem;
      color: var(--text-dark);
      background: var(--white);
      box-shadow: none;
      padding: 1.2rem 1.5rem;
    }
    .accordion-button:not(.collapsed) {
      background-color: #F1F5F9;
      color: var(--deep-space);
      box-shadow: none;
    }
    .accordion-button::before {
      content: "";
      width: 8px;
      height: 8px;
      background: var(--cyber-green);
      border-radius: 50%;
      margin-right: 12px;
      flex-shrink: 0;
    }
    .accordion-button::after {
      display: none;
    }
    .accordion-body {
      background: #F1F5F9;
      padding: 1.5rem;
      color: var(--text-gray);
    }

    /* CTA */
    #contact {
      background: var(--deep-space);
    }
    .cta-form input {
      border-radius: var(--radius-input);
      padding: 12px 16px;
      border: none;
      box-shadow: 0 2px 10px rgba(0,0,0,0.08);
    }

    /* Footer */
    #footer {
      background: var(--deep-space);
      color: #94a3b8;
      padding: 3rem 0 2rem;
      border-top: 2px solid var(--cyber-green);
    }
    .footer-links a {
      color: #94a3b8;
      margin-right: 1.2rem;
    }
    .footer-links a:hover {
      color: var(--cyber-green);
    }