/* roulang page: index */
:root {
      --primary: #7B2FF7;
      --primary-glow: rgba(123, 47, 247, 0.5);
      --secondary: #FFB800;
      --bg-dark: #0B0C10;
      --bg-card: #1F2025;
      --bg-light: #F4F4F7;
      --text-white: #FFFFFF;
      --text-dark: #1A1A1A;
      --text-gray: #9CA3AF;
      --border-radius-card: 16px;
      --border-radius-btn: 8px;
      --border-radius-input: 6px;
      --shadow-card: 0 4px 20px rgba(123, 47, 247, 0.15);
      --shadow-card-hover: 0 12px 32px rgba(123, 47, 247, 0.35);
      --transition: all 0.3s ease;
      --font-sans: 'Inter', 'PingFang SC', 'Microsoft YaHei', system-ui, -apple-system, sans-serif;
      --container-max: 1280px;
    }

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

    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }

    body {
      font-family: var(--font-sans);
      line-height: 1.6;
      background-color: var(--bg-dark);
      color: var(--text-white);
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }

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

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

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

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

    /* 导航栏 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background-color: var(--bg-dark);
      border-bottom: 2px solid transparent;
      background-image: linear-gradient(var(--bg-dark), var(--bg-dark)), linear-gradient(90deg, var(--primary), var(--secondary));
      background-origin: border-box;
      background-clip: padding-box, border-box;
      z-index: 1000;
      backdrop-filter: blur(8px);
    }

    .nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
    }

    .logo {
      font-size: 1.8rem;
      font-weight: 700;
      background: linear-gradient(135deg, var(--primary), var(--secondary));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      letter-spacing: 1px;
      display: flex;
      align-items: center;
      gap: 0.5rem;
    }

    .logo-icon {
      font-size: 2rem;
      filter: drop-shadow(0 0 8px var(--primary-glow));
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 2rem;
      list-style: none;
    }

    .nav-links a {
      color: var(--text-white);
      font-weight: 500;
      font-size: 0.95rem;
      position: relative;
      padding: 0.25rem 0;
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      box-shadow: 0 0 8px var(--primary-glow);
      transition: width 0.3s ease;
    }

    .nav-links a:hover {
      color: var(--secondary);
    }

    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }

    .nav-cta {
      background: linear-gradient(135deg, var(--primary), var(--secondary));
      color: white !important;
      padding: 0.6rem 1.8rem !important;
      border-radius: var(--border-radius-btn);
      font-weight: 600;
      box-shadow: 0 4px 12px rgba(123,47,247,0.4);
    }

    .nav-cta:hover {
      filter: brightness(1.15);
      box-shadow: 0 8px 20px rgba(123,47,247,0.6);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: transparent;
      border: none;
      cursor: pointer;
    }

    .hamburger span {
      width: 25px;
      height: 3px;
      background: white;
      border-radius: 3px;
      transition: var(--transition);
    }

    @media (max-width: 768px) {
      .nav-links {
        position: fixed;
        top: 72px;
        left: 0;
        width: 100%;
        background: rgba(11, 12, 16, 0.95);
        backdrop-filter: blur(12px);
        flex-direction: column;
        padding: 2rem;
        gap: 1.5rem;
        transform: translateY(-150%);
        transition: transform 0.4s ease;
        border-bottom: 2px solid var(--primary);
      }
      .nav-links.active {
        transform: translateY(0);
      }
      .hamburger {
        display: flex;
      }
      .nav-cta {
        width: 100%;
        text-align: center;
      }
    }

    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background-color: var(--bg-dark);
      background-image: radial-gradient(circle at 30% 40%, rgba(123,47,247,0.15) 0%, transparent 40%);
      position: relative;
      overflow: hidden;
    }

    .hero::before {
      content: "";
      position: absolute;
      width: 100%;
      height: 100%;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      opacity: 0.25;
      filter: brightness(0.7);
    }

    .hero-content {
      position: relative;
      z-index: 2;
      max-width: 800px;
      margin-top: 2rem;
    }

    .hero h1 {
      font-size: 3.2rem;
      font-weight: 700;
      background: linear-gradient(135deg, var(--primary), var(--secondary));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      margin-bottom: 1.5rem;
      line-height: 1.3;
      text-shadow: 0 0 20px rgba(123,47,247,0.3);
    }

    .hero p {
      font-size: 1.2rem;
      color: var(--text-gray);
      max-width: 600px;
      margin-bottom: 2.5rem;
    }

    .hero-buttons {
      display: flex;
      gap: 1.2rem;
      flex-wrap: wrap;
    }

    .btn-primary {
      background: linear-gradient(135deg, var(--primary), var(--secondary));
      color: white;
      padding: 0.9rem 2.4rem;
      border-radius: var(--border-radius-btn);
      font-weight: 600;
      border: none;
      cursor: pointer;
      box-shadow: 0 8px 24px rgba(123,47,247,0.35);
      transition: var(--transition);
    }

    .btn-primary:hover {
      filter: brightness(1.2);
      box-shadow: 0 12px 28px rgba(123,47,247,0.5);
      transform: translateY(-2px);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: white;
      padding: 0.9rem 2.4rem;
      border-radius: var(--border-radius-btn);
      font-weight: 600;
      transition: var(--transition);
    }

    .btn-outline:hover {
      background: rgba(123,47,247,0.2);
      border-color: var(--secondary);
      color: var(--secondary);
    }

    .scroll-indicator {
      position: absolute;
      bottom: 2rem;
      left: 50%;
      transform: translateX(-50%);
      animation: bounce 2s infinite;
      color: var(--primary);
      font-size: 1.8rem;
    }

    @keyframes bounce {
      0%, 100% { transform: translateX(-50%) translateY(0); }
      50% { transform: translateX(-50%) translateY(10px); }
    }

    @media (max-width: 768px) {
      .hero h1 { font-size: 2.2rem; }
      .hero p { font-size: 1rem; }
    }

    /* 通用板块 */
    section {
      padding: 90px 0;
    }

    .section-title {
      font-size: 2.2rem;
      font-weight: 700;
      text-align: center;
      margin-bottom: 1rem;
      color: white;
    }

    .section-sub {
      text-align: center;
      color: var(--text-gray);
      margin-bottom: 3rem;
    }

    /* 服务卡片 */
    #services {
      background-color: var(--bg-dark);
    }

    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .service-card {
      background: var(--bg-card);
      border-radius: var(--border-radius-card);
      padding: 2rem;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
    }

    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-card-hover);
    }

    .service-icon {
      font-size: 2.5rem;
      color: var(--primary);
      margin-bottom: 1.2rem;
    }

    .service-card h3 {
      font-size: 1.5rem;
      margin-bottom: 0.8rem;
    }

    .service-desc {
      color: var(--text-gray);
      margin-bottom: 1.2rem;
    }

    .tags {
      display: flex;
      flex-wrap: wrap;
      gap: 0.5rem;
    }

    .tag {
      background: rgba(123,47,247,0.2);
      color: #d4bfff;
      padding: 0.25rem 0.9rem;
      border-radius: 20px;
      font-size: 0.8rem;
    }

    @media (max-width: 1024px) {
      .services-grid { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 768px) {
      .services-grid { grid-template-columns: 1fr; }
    }

    /* 数据优势 */
    #advantages {
      background-color: var(--bg-light);
      color: var(--text-dark);
    }

    .stats-grid {
      display: flex;
      justify-content: space-around;
      flex-wrap: wrap;
      gap: 2rem;
    }

    .stat-item {
      text-align: center;
    }

    .stat-number {
      font-family: 'Inter', sans-serif;
      font-size: 3rem;
      font-weight: 700;
      color: var(--secondary);
    }

    .stat-label {
      color: #4B5563;
      font-weight: 500;
    }

    /* 案例 */
    #cases {
      background: var(--bg-dark);
    }

    .cases-grid {
      display: grid;
      grid-template-columns: repeat(2,1fr);
      gap: 24px;
    }

    .case-card {
      position: relative;
      border-radius: var(--border-radius-card);
      overflow: hidden;
      background: var(--bg-card);
    }

    .case-img {
      width: 100%;
      height: 240px;
      object-fit: cover;
    }

    .case-info {
      padding: 1.5rem;
    }

    .case-tag {
      color: var(--secondary);
      font-weight: 600;
      font-size: 0.9rem;
    }

    @media (max-width: 768px) {
      .cases-grid { grid-template-columns: 1fr; }
    }

    /* 解决方案交替 */
    .solution-row {
      display: flex;
      align-items: center;
      gap: 3rem;
      margin-bottom: 4rem;
    }

    .solution-row.reverse {
      flex-direction: row-reverse;
    }

    .solution-img {
      flex: 1;
      border-radius: var(--border-radius-card);
      overflow: hidden;
    }

    .solution-text {
      flex: 1;
    }

    @media (max-width: 768px) {
      .solution-row, .solution-row.reverse {
        flex-direction: column;
      }
    }

    /* FAQ */
    .faq-item {
      background: var(--bg-card);
      border-radius: 12px;
      margin-bottom: 1rem;
      overflow: hidden;
    }

    .faq-question {
      padding: 1.2rem 1.8rem;
      font-weight: 700;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      background: transparent;
      border: none;
      color: white;
      width: 100%;
      text-align: left;
    }

    .faq-answer {
      padding: 0 1.8rem 1.2rem;
      color: var(--text-gray);
      display: none;
    }

    .faq-item.active .faq-answer {
      display: block;
    }

    /* CTA */
    #contact {
      background: var(--bg-dark);
      background-image: radial-gradient(circle at 20% 80%, rgba(123,47,247,0.2), transparent);
    }

    .contact-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 3rem;
    }

    .contact-form input, .contact-form textarea {
      width: 100%;
      background: var(--bg-card);
      border: 1px solid var(--primary);
      border-radius: var(--border-radius-input);
      padding: 0.9rem;
      color: white;
      margin-bottom: 1rem;
    }

    .contact-form button {
      width: 100%;
    }

    @media (max-width: 768px) {
      .contact-grid { grid-template-columns: 1fr; }
    }

    footer {
      background: var(--bg-dark);
      border-top: 2px solid var(--primary);
      padding: 3rem 0;
    }