/* roulang page: index */
:root {
      --primary-deep: #0A0E27;
      --primary-deep-soft: #141832;
      --accent-cyan: #00F0FF;
      --accent-magenta: #FF2D78;
      --bg-light: #F4F6F9;
      --text-dark: #1A1A2E;
      --text-muted: #5C6B8A;
      --white: #FFFFFF;
      --border-light: rgba(0, 240, 255, 0.15);
      --border-hover: rgba(0, 240, 255, 0.6);
      --shadow-card: 0 4px 20px rgba(10, 14, 39, 0.06);
      --shadow-hover: 0 12px 32px rgba(0, 240, 255, 0.12);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 6px;
      --font-title: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --font-body: 'PingFang SC', 'Microsoft YaHei', 'Inter', 'SF Mono', sans-serif;
      --transition-smooth: all 0.25s ease;
    }

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

    html {
      scroll-behavior: smooth;
    }

    body {
      font-family: var(--font-body);
      background-color: var(--bg-light);
      color: var(--text-dark);
      line-height: 1.8;
      font-size: 16px;
      overflow-x: hidden;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }

    h1, h2, h3, h4 {
      font-family: var(--font-title);
      font-weight: 700;
      letter-spacing: -0.5px;
    }

    h1 {
      font-size: 48px;
      line-height: 1.2;
      color: var(--white);
    }

    h2 {
      font-size: 36px;
      margin-bottom: 1rem;
      color: var(--primary-deep);
    }

    h3 {
      font-size: 24px;
      color: var(--primary-deep);
    }

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

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

    button, .btn {
      cursor: pointer;
      font-family: var(--font-body);
      font-weight: 600;
      transition: var(--transition-smooth);
      border: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
    }

    /* 导航 */
    header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(10, 14, 39, 0.82);
      backdrop-filter: blur(12px);
      z-index: 1000;
      border-bottom: 1px solid rgba(0, 240, 255, 0.1);
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 16px 24px;
      max-width: 1280px;
      margin: 0 auto;
    }

    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 1.7rem;
      font-weight: 800;
      color: var(--white);
      letter-spacing: 1px;
    }
    .logo i {
      color: var(--accent-cyan);
      font-size: 2rem;
    }
    .logo span {
      background: linear-gradient(to right, #fff, #e0f2fe);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-links a {
      color: #ccd6f0;
      font-weight: 500;
      position: relative;
      padding: 8px 0;
      transition: color 0.2s;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 3px;
      background: var(--accent-cyan);
      transition: width 0.3s;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--accent-cyan);
    }
    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }
    .nav-cta {
      background: var(--accent-magenta);
      color: white;
      padding: 10px 22px;
      border-radius: 30px;
      font-weight: 600;
      box-shadow: 0 4px 12px rgba(255, 45, 120, 0.4);
    }
    .nav-cta:hover {
      background: #ff4d8c;
      transform: translateY(-1px);
    }
    .hamburger {
      display: none;
      font-size: 1.8rem;
      color: white;
      cursor: pointer;
    }
    @media (max-width: 768px) {
      .nav-links {
        position: fixed;
        top: 70px;
        left: 0;
        width: 100%;
        background: rgba(10, 14, 39, 0.96);
        backdrop-filter: blur(16px);
        flex-direction: column;
        gap: 20px;
        padding: 32px 24px;
        transform: translateY(-120%);
        transition: transform 0.35s ease;
        align-items: flex-start;
      }
      .nav-links.active-mob {
        transform: translateY(0);
      }
      .hamburger {
        display: block;
      }
      .nav-cta {
        align-self: flex-start;
      }
    }

    /* Hero */
    .hero {
      background: radial-gradient(circle at 20% 20%, #141832, #0A0E27);
      padding: 140px 0 100px;
      position: relative;
      overflow: hidden;
    }
    .hero .container {
      display: flex;
      align-items: center;
      gap: 48px;
    }
    .hero-left {
      flex: 1;
    }
    .hero-left h1 {
      margin-bottom: 18px;
    }
    .hero-sub {
      font-size: 18px;
      color: #b0c4de;
      margin-bottom: 32px;
      max-width: 480px;
    }
    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--accent-cyan);
      color: #0A0E27;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 700;
      box-shadow: 0 6px 18px rgba(0,240,255,0.3);
    }
    .btn-primary:hover {
      background: #33f5ff;
      box-shadow: 0 8px 24px rgba(0,240,255,0.5);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--accent-cyan);
      color: var(--accent-cyan);
      padding: 14px 32px;
      border-radius: var(--radius-btn);
    }
    .btn-outline:hover {
      background: rgba(0,240,255,0.08);
    }
    .hero-right {
      flex: 1;
      position: relative;
    }
    .hero-img {
      width: 100%;
      border-radius: 20px;
      box-shadow: 0 20px 40px rgba(0,240,255,0.15);
      border: 1px solid rgba(0,240,255,0.2);
    }
    @media (max-width: 768px) {
      .hero .container {
        flex-direction: column;
      }
      h1 {
        font-size: 36px;
      }
    }

    .section {
      padding: 90px 0;
    }
    .section-title {
      text-align: center;
      margin-bottom: 48px;
    }
    .section-title h2 {
      display: inline-block;
      border-bottom: 4px solid var(--accent-cyan);
      padding-bottom: 6px;
    }

    /* 核心优势网格 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 32px;
    }
    .adv-card {
      background: white;
      padding: 32px 24px;
      border-radius: var(--radius-card);
      border: 1px solid var(--border-light);
      box-shadow: var(--shadow-card);
      transition: var(--transition-smooth);
    }
    .adv-card:hover {
      border-color: var(--accent-magenta);
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }
    .adv-icon {
      font-size: 2.4rem;
      color: var(--accent-cyan);
      margin-bottom: 16px;
    }
    @media (max-width: 1024px) {
      .grid-3 { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 640px) {
      .grid-3 { grid-template-columns: 1fr; }
    }

    /* 服务矩阵 左标签右详情 */
    .service-flex {
      display: flex;
      gap: 32px;
    }
    .service-tabs {
      flex: 1;
      display: flex;
      flex-direction: column;
      gap: 8px;
    }
    .tab-btn {
      background: white;
      border: none;
      padding: 16px 20px;
      text-align: left;
      border-left: 4px solid transparent;
      font-weight: 600;
      border-radius: 8px;
      transition: 0.2s;
      background: #fff;
      box-shadow: 0 2px 8px rgba(0,0,0,0.02);
    }
    .tab-btn.active {
      border-left-color: var(--accent-cyan);
      color: var(--accent-cyan);
      background: #f0fcff;
    }
    .service-detail {
      flex: 2;
      background: white;
      padding: 28px;
      border-radius: 16px;
      box-shadow: var(--shadow-card);
      border: 1px solid var(--border-light);
    }
    @media (max-width: 768px) {
      .service-flex { flex-direction: column; }
    }

    /* 案例瀑布 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(2,1fr);
      gap: 28px;
    }
    .case-card {
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      transition: var(--transition-smooth);
      border: 1px solid var(--border-light);
    }
    .case-card:hover {
      transform: translateY(-5px);
      box-shadow: var(--shadow-hover);
    }
    .case-img {
      height: 200px;
      background-size: cover;
      background-position: center;
      transition: transform 0.4s;
    }
    .case-card:hover .case-img {
      transform: scale(1.05);
    }
    .case-info {
      padding: 20px;
    }
    .tag {
      background: var(--accent-magenta);
      color: white;
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 0.8rem;
      font-weight: 600;
      display: inline-block;
      margin-bottom: 8px;
    }
    @media (max-width: 640px) {
      .cases-grid { grid-template-columns: 1fr; }
    }

    /* 对比表 */
    .compare-table {
      overflow-x: auto;
      background: white;
      border-radius: 16px;
      box-shadow: var(--shadow-card);
    }
    table {
      width: 100%;
      border-collapse: collapse;
      min-width: 600px;
    }
    th {
      background: #0A0E27;
      color: white;
      padding: 16px;
    }
    td, th {
      padding: 14px 16px;
      text-align: center;
    }
    .highlight-col {
      border-top: 4px solid var(--accent-magenta);
      background: #fff5f9;
    }

    /* FAQ */
    .faq-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
    }
    .faq-item {
      background: white;
      padding: 18px;
      border-radius: 12px;
      box-shadow: 0 2px 10px rgba(0,0,0,0.03);
      cursor: pointer;
    }
    .faq-q {
      font-weight: 700;
      display: flex;
      align-items: center;
      gap: 10px;
    }
    @media (max-width: 640px) {
      .faq-grid { grid-template-columns: 1fr; }
    }

    /* 联系 */
    .contact-row {
      display: flex;
      gap: 40px;
      background: white;
      border-radius: 20px;
      padding: 40px;
    }
    .contact-form input, .contact-form textarea {
      width: 100%;
      padding: 12px;
      margin-bottom: 16px;
      border: none;
      border-bottom: 2px solid #ddd;
      outline: none;
      transition: 0.2s;
    }
    .contact-form input:focus {
      border-bottom-color: var(--accent-cyan);
    }
    .btn-magenta {
      background: var(--accent-magenta);
      color: white;
      padding: 14px 28px;
      border-radius: 30px;
      font-weight: bold;
      width: 100%;
    }

    footer {
      background: #0A0E27;
      color: #ccc;
      padding: 60px 0 20px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 32px;
    }
    @media (max-width: 768px) {
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }