/* roulang page: index */
/* ----- 设计变量与基础重置 ----- */
    :root {
      --primary: #9D00FF;
      --primary-glow: #b840ff;
      --dark: #0D0D0D;
      --darker: #1A1A1A;
      --energy-orange: #FF4D00;
      --energy-orange-hover: #e64400;
      --cyan: #00E5FF;
      --cyan-glow: rgba(0, 229, 255, 0.5);
      --white: #FFFFFF;
      --gray-light: #F2F2F2;
      --text-light: #CCCCCC;
      --text-muted: #999999;
      --card-bg: rgba(30, 30, 30, 0.85);
      --card-border: rgba(255, 255, 255, 0.08);
      --radius-card: 16px;
      --radius-btn: 8px;
      --radius-input: 8px;
      --shadow-card: 0 12px 28px rgba(0, 0, 0, 0.6);
      --shadow-hover: 0 18px 36px rgba(0, 0, 0, 0.8);
      --transition: 0.25s ease-in-out;
      --font-heading: 'Oswald', 'Montserrat', 'Segoe UI', '思源黑体', 'System-ui', sans-serif;
      --font-body: 'Inter', 'Roboto', 'PingFang SC', 'Microsoft YaHei', '苹方', system-ui, sans-serif;
    }

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

    html {
      scroll-behavior: smooth;
    }

    body {
      font-family: var(--font-body);
      background-color: var(--dark);
      color: var(--text-light);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }

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

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

    a:hover {
      color: var(--energy-orange);
      opacity: 0.9;
    }

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

    input, textarea {
      font-family: var(--font-body);
      outline: none;
      border-radius: var(--radius-input);
      border: 1px solid var(--cyan);
      background: rgba(20, 20, 20, 0.9);
      color: var(--white);
      padding: 14px 18px;
      transition: var(--transition);
      width: 100%;
      font-size: 16px;
    }

    input:focus, textarea:focus {
      border-color: var(--energy-orange);
      box-shadow: 0 0 12px rgba(255, 77, 0, 0.4);
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 24px;
    }

    @media (max-width: 768px) {
      .container {
        padding: 0 20px;
      }
    }

    /* 标题字体全局调整 */
    h1, h2, h3, .heading {
      font-family: var(--font-heading);
      font-weight: 700;
      letter-spacing: 0.5px;
    }

    h1 {
      font-size: clamp(40px, 7vw, 64px);
      line-height: 1.1;
    }

    h2 {
      font-size: clamp(32px, 5vw, 44px);
      margin-bottom: 1rem;
    }

    h3 {
      font-size: 24px;
      font-weight: 600;
    }

    /* ----- 导航与分屏 Hero 联动布局 ----- */
    .hero-wrapper {
      display: flex;
      min-height: 100vh;
      position: relative;
      background-color: var(--dark);
    }

    .nav-side {
      width: 40%;
      background: rgba(13, 13, 13, 0.92);
      backdrop-filter: blur(12px);
      display: flex;
      flex-direction: column;
      justify-content: center;
      padding: 2rem 3rem;
      position: relative;
      z-index: 10;
      border-right: 1px solid rgba(157, 0, 255, 0.25);
    }

    .logo-area {
      margin-bottom: 3rem;
    }

    .logo-text {
      font-family: var(--font-heading);
      font-size: 2.5rem;
      font-weight: 700;
      color: var(--primary);
      text-shadow: 0 0 12px var(--primary-glow);
      letter-spacing: 2px;
      line-height: 1.2;
    }

    .nav-links {
      display: flex;
      flex-direction: column;
      gap: 1.8rem;
      margin-top: 2rem;
    }

    .nav-links a {
      color: var(--text-light);
      font-size: 1.4rem;
      font-weight: 500;
      letter-spacing: 1px;
      padding: 0.3rem 0;
      border-bottom: 2px solid transparent;
      transition: var(--transition);
      width: fit-content;
    }

    .nav-links a:hover {
      color: var(--cyan);
      border-bottom-color: var(--cyan);
      text-shadow: 0 0 8px var(--cyan-glow);
    }

    .hero-visual {
      width: 60%;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      position: relative;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    .hero-overlay {
      position: absolute;
      inset: 0;
      background: linear-gradient(135deg, rgba(157, 0, 255, 0.45) 0%, rgba(13, 13, 13, 0.7) 100%);
    }

    .hero-content {
      position: relative;
      z-index: 5;
      text-align: left;
      padding: 3rem;
      max-width: 600px;
      margin-left: auto;
      margin-right: auto;
    }

    .hero-content h1 {
      color: var(--white);
      text-shadow: 0 0 30px rgba(0, 0, 0, 0.8);
      margin-bottom: 1.2rem;
    }

    .hero-sub {
      font-size: 1.4rem;
      color: var(--text-light);
      margin-bottom: 2rem;
    }

    .btn-primary {
      background: var(--energy-orange);
      color: white;
      padding: 16px 38px;
      border-radius: var(--radius-btn);
      font-size: 1.2rem;
      font-weight: 700;
      box-shadow: 0 8px 20px rgba(255, 77, 0, 0.5);
      letter-spacing: 1px;
    }

    .btn-primary:hover {
      background: var(--energy-orange-hover);
      box-shadow: 0 12px 28px rgba(255, 77, 0, 0.8);
      transform: translateY(-2px);
    }

    .btn-outline {
      border: 2px solid var(--cyan);
      color: var(--cyan);
      padding: 12px 30px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 1rem;
      margin-left: 16px;
    }

    .btn-outline:hover {
      background: var(--cyan);
      color: var(--dark);
      box-shadow: 0 0 20px var(--cyan-glow);
    }

    /* 移动端导航汉堡 */
    .mobile-nav-toggle {
      display: none;
      background: none;
      border: none;
      color: white;
      font-size: 2rem;
      position: fixed;
      top: 20px;
      right: 20px;
      z-index: 999;
    }

    @media (max-width: 1024px) {
      .hero-wrapper {
        flex-direction: column;
      }
      .nav-side {
        width: 100%;
        flex-direction: row;
        justify-content: space-between;
        align-items: center;
        padding: 1rem 2rem;
        position: fixed;
        top: 0;
        left: 0;
        height: 70px;
        z-index: 50;
        background: rgba(13, 13, 13, 0.95);
      }
      .nav-links {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 70px;
        left: 0;
        width: 100%;
        background: #0D0D0D;
        padding: 2rem;
        gap: 1.5rem;
      }
      .nav-links.active {
        display: flex;
      }
      .mobile-nav-toggle {
        display: block;
      }
      .hero-visual {
        width: 100%;
        min-height: 100vh;
        padding-top: 70px;
      }
      .logo-text {
        font-size: 2rem;
      }
      .hero-content {
        padding: 2rem;
      }
    }

    /* ----- 通用板块样式 ----- */
    section {
      padding: 5rem 0;
    }

    .section-title {
      text-align: center;
      margin-bottom: 3.5rem;
    }

    .section-title h2 {
      color: var(--white);
    }

    .section-title p {
      color: var(--text-muted);
      max-width: 700px;
      margin: 0 auto;
      font-size: 1.2rem;
    }

    /* 卡片网格非对称 */
    .features-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 28px;
      align-items: start;
    }

    .feature-card {
      background: var(--card-bg);
      backdrop-filter: blur(8px);
      border: 1px solid var(--card-border);
      border-radius: var(--radius-card);
      padding: 2.2rem;
      box-shadow: var(--shadow-card);
      transition: var(--transition);
    }

    .feature-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
      border-color: var(--primary);
    }

    .feature-card.large {
      grid-row: span 2;
      display: flex;
      flex-direction: column;
      justify-content: center;
    }

    @media (max-width: 768px) {
      .features-grid {
        grid-template-columns: 1fr;
      }
      .feature-card.large {
        grid-row: span 1;
      }
    }

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

    /* 服务卡片横向滚动 */
    .services-scroll {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding-bottom: 1rem;
      scrollbar-width: thin;
      scrollbar-color: var(--primary) var(--dark);
    }

    .service-card {
      flex: 0 0 280px;
      background: var(--card-bg);
      border-radius: var(--radius-card);
      overflow: hidden;
      border: 1px solid var(--card-border);
    }

    .service-card img {
      width: 100%;
      height: 180px;
      object-fit: cover;
    }

    .service-info {
      padding: 1.5rem;
    }

    /* 数据统计 */
    .stats-grid {
      display: flex;
      justify-content: space-around;
      flex-wrap: wrap;
      gap: 2rem;
      background: #1A1A1A;
      padding: 3rem 2rem;
      border-radius: 24px;
    }

    .stat-number {
      font-size: 3.5rem;
      font-weight: 800;
      color: var(--energy-orange);
    }

    /* FAQ */
    .faq-item {
      border-bottom: 1px solid #333;
      margin-bottom: 1rem;
    }
    .faq-question {
      background: none;
      color: white;
      padding: 1.2rem 0;
      width: 100%;
      text-align: left;
      font-size: 1.3rem;
      font-weight: 600;
      display: flex;
      justify-content: space-between;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: 0.3s;
      color: #bbb;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-bottom: 1rem;
    }

    footer {
      background: #0A0A0A;
      padding: 3rem 0;
      color: #aaa;
    }