/* roulang page: index */
:root {
      --primary: #FF3E1A;
      --primary-dark: #E63512;
      --deep-blue: #0B1E3A;
      --deep-blue-light: #132B4F;
      --accent: #00E5A0;
      --white: #FFFFFF;
      --gray-50: #F4F7FC;
      --gray-100: #EDF1F7;
      --gray-200: #DCE2EB;
      --gray-600: #5A6B7F;
      --gray-800: #1E293B;
      --gray-900: #0F172A;
      --radius-lg: 16px;
      --radius-xl: 24px;
      --radius-full: 30px;
      --shadow-sm: 0 4px 20px rgba(0, 0, 0, 0.04);
      --shadow-md: 0 8px 28px rgba(0, 0, 0, 0.06);
      --shadow-lg: 0 12px 32px rgba(0, 0, 0, 0.08);
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --spacing-xs: 8px;
      --spacing-sm: 16px;
      --spacing-md: 24px;
      --spacing-lg: 40px;
      --spacing-xl: 64px;
      --spacing-2xl: 100px;
      --container-max: 1280px;
      --nav-height: 72px;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--white);
      color: var(--gray-800);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

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

    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.25s;
    }

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

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

    /* 导航系统 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background: rgba(255,255,255,0.96);
      backdrop-filter: blur(8px);
      border-bottom: 1px solid var(--gray-100);
      z-index: 999;
      display: flex;
      align-items: center;
      transition: box-shadow 0.3s;
    }
    .header.scrolled {
      box-shadow: 0 4px 20px rgba(0,0,0,0.04);
    }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-weight: 700;
      font-size: 24px;
      color: var(--deep-blue);
      letter-spacing: -0.5px;
    }
    .logo span {
      color: var(--primary);
    }
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 28px;
      list-style: none;
    }
    .nav-menu a {
      font-size: 15px;
      font-weight: 500;
      color: var(--gray-800);
      padding: 8px 0;
      border-bottom: 2px solid transparent;
      transition: color 0.2s, border-color 0.2s;
    }
    .nav-menu a:hover,
    .nav-menu a.active {
      color: var(--primary);
      border-bottom-color: var(--primary);
    }
    .btn-nav {
      background: var(--primary);
      color: white;
      border: none;
      padding: 10px 22px;
      border-radius: var(--radius-full);
      font-weight: 600;
      font-size: 14px;
      cursor: pointer;
      transition: background 0.25s, transform 0.2s;
      margin-left: 12px;
    }
    .btn-nav:hover {
      background: var(--primary-dark);
      transform: scale(1.02);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
      cursor: pointer;
      padding: 8px;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--deep-blue);
      border-radius: 2px;
      transition: 0.2s;
    }
    .mobile-drawer {
      display: none;
      position: fixed;
      top: 0;
      right: 0;
      width: 75%;
      max-width: 320px;
      height: 100vh;
      background: var(--deep-blue);
      z-index: 1000;
      padding: 32px 24px;
      flex-direction: column;
      gap: 32px;
      transform: translateX(100%);
      transition: transform 0.35s ease;
    }
    .mobile-drawer.open {
      transform: translateX(0);
    }
    .mobile-drawer a {
      color: white;
      font-size: 18px;
      font-weight: 500;
      border-bottom: 1px solid rgba(255,255,255,0.2);
      padding-bottom: 12px;
    }
    .drawer-close {
      align-self: flex-end;
      background: none;
      border: none;
      color: white;
      font-size: 28px;
      cursor: pointer;
    }

    /* 区块通用 */
    section {
      padding: var(--spacing-2xl) 0;
    }
    .section-header {
      text-align: center;
      max-width: 720px;
      margin: 0 auto 48px;
    }
    .section-header h2 {
      font-size: 36px;
      font-weight: 700;
      color: var(--deep-blue);
      margin-bottom: 12px;
    }
    .section-header p {
      color: var(--gray-600);
      font-size: 18px;
    }

    /* 按钮系统 */
    .btn-primary {
      background: var(--primary);
      color: white;
      border: none;
      padding: 14px 32px;
      border-radius: var(--radius-full);
      font-weight: 600;
      font-size: 16px;
      cursor: pointer;
      transition: background 0.25s, transform 0.2s, box-shadow 0.2s;
      display: inline-block;
      text-align: center;
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      transform: scale(1.02);
      box-shadow: 0 8px 18px rgba(255,62,26,0.25);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--deep-blue);
      color: var(--deep-blue);
      padding: 12px 30px;
      border-radius: var(--radius-full);
      font-weight: 600;
      font-size: 16px;
      cursor: pointer;
      transition: all 0.25s;
      display: inline-block;
    }
    .btn-outline:hover {
      background: var(--deep-blue);
      color: white;
      transform: scale(1.02);
    }

    /* Hero */
    .hero {
      background: linear-gradient(135deg, #0B1E3A 0%, #132B4F 100%);
      padding: calc(var(--nav-height) + 60px) 0 80px;
      position: relative;
      overflow: hidden;
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 5fr 7fr;
      gap: 48px;
      align-items: center;
    }
    .hero-left h1 {
      font-size: 48px;
      font-weight: 700;
      line-height: 1.2;
      color: white;
      margin-bottom: 24px;
    }
    .hero-left p {
      font-size: 18px;
      color: rgba(255,255,255,0.8);
      margin-bottom: 32px;
      line-height: 1.7;
    }
    .hero-buttons {
      display: flex;
      flex-wrap: wrap;
      gap: 16px;
    }
    .hero-right {
      background: rgba(255,255,255,0.06);
      border-radius: var(--radius-lg);
      overflow: hidden;
      backdrop-filter: blur(4px);
      position: relative;
      min-height: 360px;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    .hero-img {
      width: 100%;
      height: auto;
      object-fit: cover;
      border-radius: var(--radius-lg);
    }
    .data-badge-hero {
      position: absolute;
      bottom: 24px;
      left: 24px;
      background: rgba(0,0,0,0.65);
      backdrop-filter: blur(12px);
      padding: 12px 20px;
      border-radius: 40px;
      color: white;
      display: flex;
      gap: 32px;
    }

    /* 数据亮点 */
    .data-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      background: var(--gray-50);
      border-radius: var(--radius-lg);
      padding: 40px 32px;
    }
    .data-badge {
      background: rgba(255,62,26,0.07);
      border-radius: 40px;
      padding: 20px 24px;
      text-align: center;
      transition: 0.3s;
    }
    .data-badge:hover {
      background: rgba(255,62,26,0.12);
      transform: translateY(-2px);
    }
    .data-number {
      font-size: 40px;
      font-weight: 800;
      color: var(--primary);
    }
    .data-label {
      color: var(--gray-600);
      font-size: 15px;
      margin-top: 6px;
    }

    /* 核心业务矩阵 */
    .services-grid {
      display: grid;
      grid-template-columns: 8fr 4fr;
      gap: 24px;
    }
    .service-card {
      background: white;
      border-radius: var(--radius-lg);
      padding: 32px;
      box-shadow: var(--shadow-sm);
      transition: transform 0.3s, box-shadow 0.3s;
    }
    .service-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-lg);
    }
    .service-card h3 {
      font-size: 20px;
      font-weight: 600;
      margin: 16px 0 8px;
    }
    .stack-cards {
      display: flex;
      flex-direction: column;
      gap: 24px;
    }

    /* 生态系统 */
    .eco-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .eco-card {
      background: white;
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: 0.3s;
    }
    .eco-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-lg);
    }
    .eco-img {
      height: 200px;
      background-size: cover;
      background-position: center;
    }

    /* 合作伙伴 */
    .partner-wall {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 32px;
      background: var(--gray-50);
      border-radius: var(--radius-lg);
      padding: 48px;
    }
    .partner-logo {
      filter: grayscale(1);
      opacity: 0.7;
      transition: 0.3s;
      font-weight: 700;
      font-size: 20px;
      color: var(--gray-600);
    }
    .partner-logo:hover {
      filter: grayscale(0);
      opacity: 1;
      color: var(--primary);
    }

    /* 技术平台 */
    .tech-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }
    .tech-badges {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
      margin-top: 24px;
    }

    /* 案例 */
    .cases-masonry {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
      align-items: start;
    }
    .case-card {
      background: white;
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: 0.3s;
    }
    .case-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-lg);
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid var(--gray-200);
      padding: 20px 0;
    }
    .faq-question {
      display: flex;
      align-items: center;
      gap: 16px;
      font-weight: 600;
      cursor: pointer;
    }
    .faq-answer {
      padding-left: 48px;
      color: var(--gray-600);
      display: none;
      margin-top: 12px;
    }
    .faq-item.open .faq-answer {
      display: block;
    }

    /* CTA */
    .cta-section {
      background: var(--deep-blue);
      color: white;
      padding: 80px 0;
    }
    .cta-card {
      background: white;
      border-radius: var(--radius-lg);
      padding: 48px;
      color: var(--gray-800);
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
    }

    /* Footer */
    .footer {
      background: var(--gray-900);
      color: #ccc;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }

    @media (max-width: 1024px) {
      .hero-grid { grid-template-columns: 1fr; }
      .services-grid { grid-template-columns: 1fr; }
      .eco-grid { grid-template-columns: 1fr 1fr; }
      .cases-masonry { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }
    @media (max-width: 768px) {
      .nav-menu { display: none; }
      .hamburger { display: flex; }
      .mobile-drawer { display: flex; }
      .eco-grid { grid-template-columns: 1fr; }
      .data-grid { grid-template-columns: 1fr 1fr; }
      .cta-card { grid-template-columns: 1fr; }
      .hero-left h1 { font-size: 36px; }
      .section-header h2 { font-size: 30px; }
      .tech-row { grid-template-columns: 1fr; }
    }