/* roulang page: index */
:root {
      --primary-dark: #0A0F1D;
      --accent-cyan: #00F0FF;
      --accent-red: #FF3A3A;
      --bg-light: #F5F6FA;
      --card-white: #FFFFFF;
      --card-dark: #141B2D;
      --text-main: #1E2A3A;
      --text-muted: #5A6A7E;
      --border-light: #E0E4EA;
      --shadow-sm: 0 4px 20px rgba(0,0,0,0.08);
      --shadow-cyan: 0 8px 30px rgba(0,240,255,0.15);
      --radius-md: 12px;
      --radius-btn: 8px;
      --space-sec: 5rem;
      --max-width: 1280px;
      --nav-height: 64px;
    }

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

    body {
      font-family: system-ui, 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      background-color: var(--bg-light);
      color: var(--text-main);
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
    }

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

    a {
      text-decoration: none;
      color: inherit;
    }

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

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

    /* 导航 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background: rgba(10,15,29,0.85);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      z-index: 1000;
      display: flex;
      align-items: center;
      border-bottom: 1px solid rgba(255,255,255,0.05);
    }

    .header-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }

    .logo {
      font-size: 1.5rem;
      font-weight: 900;
      color: #ffffff;
      letter-spacing: 1px;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo i {
      color: var(--accent-cyan);
      font-size: 1.8rem;
      display: inline-block;
      line-height: 1;
    }

    .nav-links {
      display: flex;
      gap: 2rem;
      align-items: center;
    }
    .nav-links a {
      color: #ddd;
      font-weight: 500;
      font-size: 0.95rem;
      position: relative;
      transition: color 0.2s;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--accent-cyan);
    }
    .nav-links a.active::after {
      content: '';
      position: absolute;
      bottom: -6px;
      left: 0;
      width: 100%;
      height: 2px;
      background: var(--accent-cyan);
    }

    .hamburger {
      display: none;
      font-size: 1.6rem;
      color: white;
      cursor: pointer;
      background: none;
      border: none;
    }

    /* Hero */
    #hero {
      min-height: 100vh;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      position: relative;
      display: flex;
      align-items: center;
      justify-content: center;
      text-align: center;
      color: white;
    }
    #hero::before {
      content: '';
      position: absolute;
      inset: 0;
      background: linear-gradient(to bottom, rgba(10,15,29,0.4) 0%, rgba(10,15,29,0.85) 100%);
    }
    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 800px;
      padding: 0 24px;
    }
    .hero-content h1 {
      font-size: 4rem;
      font-weight: 900;
      letter-spacing: 2px;
      margin-bottom: 1rem;
      line-height: 1.2;
      text-shadow: 0 2px 10px rgba(0,0,0,0.6);
    }
    .hero-content .highlight {
      color: var(--accent-cyan);
    }
    .hero-sub {
      font-size: 1.4rem;
      font-weight: 400;
      margin-bottom: 2.5rem;
      opacity: 0.9;
    }
    .btn-group {
      display: flex;
      gap: 1.2rem;
      justify-content: center;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--accent-cyan);
      color: #0A0F1D;
      font-weight: 700;
      padding: 0.9rem 2.4rem;
      border-radius: var(--radius-btn);
      border: none;
      cursor: pointer;
      transition: filter 0.2s, transform 0.2s;
      font-size: 1rem;
      display: inline-flex;
      align-items: center;
      gap: 6px;
    }
    .btn-primary:hover {
      filter: brightness(1.2);
      transform: translateY(-2px);
    }
    .btn-ghost {
      background: transparent;
      border: 1.5px solid var(--accent-cyan);
      color: var(--accent-cyan);
      font-weight: 600;
      padding: 0.9rem 2.4rem;
      border-radius: var(--radius-btn);
      cursor: pointer;
      transition: all 0.25s;
      font-size: 1rem;
    }
    .btn-ghost:hover {
      background: rgba(0,240,255,0.1);
      border-color: #fff;
      color: #fff;
    }

    /* 通用板块 */
    section {
      padding: var(--space-sec) 0;
    }
    .section-title {
      font-size: 2.5rem;
      font-weight: 800;
      text-align: center;
      margin-bottom: 3rem;
      color: var(--primary-dark);
    }
    .section-title span {
      color: var(--accent-cyan);
    }

    /* 指标看板 */
    #metrics {
      background: var(--bg-light);
    }
    .metrics-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }
    .metric-card {
      background: var(--card-white);
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-sm);
      padding: 2rem 1.5rem;
      text-align: center;
      transition: 0.2s;
    }
    .metric-number {
      font-size: 3rem;
      font-weight: 800;
      color: var(--accent-cyan);
      line-height: 1.2;
    }
    .metric-label {
      color: var(--text-muted);
      font-weight: 500;
      margin-top: 0.5rem;
    }

    /* 服务矩阵 */
    #services {
      background: white;
    }
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 30px;
    }
    .service-card {
      background: var(--card-white);
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-sm);
      overflow: hidden;
      transition: transform 0.3s, box-shadow 0.3s;
      cursor: default;
    }
    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-cyan);
    }
    .service-img {
      height: 210px;
      overflow: hidden;
    }
    .service-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.3s;
    }
    .service-card:hover .service-img img {
      transform: scale(1.04);
    }
    .service-text {
      padding: 1.5rem;
    }
    .service-text h3 {
      font-size: 1.4rem;
      font-weight: 700;
      margin-bottom: 0.4rem;
      display: flex;
      align-items: center;
      justify-content: space-between;
    }
    .service-text i {
      color: var(--accent-cyan);
      font-size: 1.2rem;
    }
    .service-desc {
      color: var(--text-muted);
      font-size: 0.95rem;
    }

    /* 结果对比 */
    #results {
      background: #F0F2F7;
    }
    .compare-row {
      display: flex;
      align-items: center;
      gap: 30px;
    }
    .compare-card {
      flex: 1;
      background: #EDEFF4;
      border-radius: var(--radius-md);
      padding: 2.5rem 2rem;
      text-align: center;
      color: #5A6A7E;
      box-shadow: var(--shadow-sm);
      border: 1px solid #d0d5dd;
    }
    .compare-card.highlight-card {
      background: var(--card-dark);
      border: 1.5px solid var(--accent-cyan);
      color: white;
      box-shadow: 0 12px 30px rgba(0,240,255,0.2);
    }
    .vs-badge {
      background: var(--accent-red);
      color: white;
      width: 60px;
      height: 60px;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 900;
      font-size: 1.4rem;
      flex-shrink: 0;
      transition: transform 0.3s;
      box-shadow: 0 4px 12px rgba(255,58,58,0.4);
    }
    .vs-badge:hover {
      transform: rotate(-10deg) scale(1.1);
    }
    .compare-label {
      font-weight: 700;
      font-size: 1.3rem;
      margin-bottom: 1rem;
    }
    .compare-data {
      font-size: 2.4rem;
      font-weight: 800;
      margin: 0.8rem 0;
    }
    .highlight-card .compare-data {
      color: var(--accent-cyan);
    }

    /* FAQ */
    #faq {
      background: white;
    }
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      margin-bottom: 0;
    }
    .faq-question {
      width: 100%;
      background: none;
      border: none;
      text-align: left;
      font-size: 1.1rem;
      font-weight: 700;
      padding: 1.2rem 0;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      color: var(--primary-dark);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.3s;
      color: var(--text-muted);
      padding: 0 16px;
      background: #F9FBFF;
      border-radius: 6px;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 16px;
    }
    .faq-item.active .faq-question i {
      color: var(--accent-cyan);
      transform: rotate(180deg);
    }

    /* CTA 联系 */
    #contact {
      background: linear-gradient(135deg, #0A0F1D 0%, #1A1F30 100%);
      color: white;
      position: relative;
      overflow: hidden;
    }
    #contact::after {
      content: '';
      position: absolute;
      top: -30%;
      right: -10%;
      width: 350px;
      height: 350px;
      background: radial-gradient(circle, rgba(0,240,255,0.15) 0%, transparent 70%);
      border-radius: 50%;
    }
    .contact-content {
      position: relative;
      z-index: 2;
      text-align: center;
    }
    .contact-form {
      max-width: 500px;
      margin: 2rem auto 0;
      display: flex;
      flex-direction: column;
      gap: 1.2rem;
    }
    .contact-form input,
    .contact-form textarea {
      padding: 0.9rem 1.2rem;
      border-radius: var(--radius-btn);
      border: 1px solid #3A3F50;
      background: white;
      color: #111;
      font-size: 1rem;
      outline: none;
      transition: 0.2s;
    }
    .contact-form input:focus,
    .contact-form textarea:focus {
      border-color: var(--accent-cyan);
      box-shadow: 0 0 0 3px rgba(0,240,255,0.25);
    }
    .submit-btn {
      background: var(--accent-cyan);
      color: #0A0F1D;
      font-weight: 700;
      padding: 1rem;
      border: none;
      border-radius: var(--radius-btn);
      font-size: 1.1rem;
      cursor: pointer;
      transition: 0.2s;
    }
    .submit-btn:hover {
      filter: brightness(1.15);
    }

    /* Footer */
    .site-footer {
      background: #0A0B10;
      color: #aaa;
      padding: 2.5rem 0 1.8rem;
      font-size: 0.9rem;
    }
    .footer-grid {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 20px;
    }
    .footer-logo {
      font-weight: 800;
      font-size: 1.3rem;
      color: white;
    }
    .footer-links a {
      margin-left: 2rem;
      color: #ccc;
      transition: color 0.2s;
    }
    .footer-links a:hover {
      color: var(--accent-cyan);
    }
    .copyright {
      margin-top: 1.5rem;
      text-align: center;
      color: #666;
    }

    /* 响应式 */
    @media (max-width: 1024px) {
      .services-grid { grid-template-columns: repeat(2, 1fr); }
      .metrics-grid { grid-template-columns: repeat(2, 1fr); }
      .hero-content h1 { font-size: 3.2rem; }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: block; }
      .nav-links.mobile-open {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: var(--nav-height);
        left: 0;
        width: 100%;
        background: rgba(10,15,29,0.96);
        padding: 1.5rem;
        gap: 1.5rem;
      }
      .services-grid { grid-template-columns: 1fr; }
      .metrics-grid { grid-template-columns: 1fr 1fr; }
      .compare-row { flex-direction: column; }
      .hero-content h1 { font-size: 2.4rem; }
      .section-title { font-size: 2rem; }
    }
    @media (max-width: 520px) {
      .metrics-grid { grid-template-columns: 1fr; }
      .btn-group { flex-direction: column; align-items: center; }
    }