/* roulang page: index */
:root {
      --primary: #FF4D00;
      --primary-dark: #E04400;
      --accent: #00E5FF;
      --gray-dark: #1A1A1A;
      --charcoal: #0D0D0D;
      --light-gray: #F5F5F5;
      --mid-gray: #9E9E9E;
      --white: #FFFFFF;
      --border-light: #E0E0E0;
      --shadow-sm: 0 4px 12px rgba(0,0,0,0.08);
      --shadow-hover: 0 8px 24px rgba(0,0,0,0.15);
      --radius-lg: 12px;
      --radius-md: 8px;
      --transition: 0.3s ease;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --font-data: "Inter", "Roboto", sans-serif;
      --max-width: 1200px;
      --nav-height: 72px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--white);
      color: var(--gray-dark);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    h1, h2, h3, h4 {
      font-weight: 600;
      line-height: 1.3;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition);
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      transition: all var(--transition);
      border: none;
      background: none;
    }
    /* 导航 */
    .nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(26, 26, 26, 0.85);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      z-index: 1000;
      height: var(--nav-height);
      display: flex;
      align-items: center;
      border-bottom: 1px solid rgba(255,255,255,0.08);
    }
    .nav .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    .logo {
      font-size: 1.8rem;
      font-weight: 700;
      letter-spacing: -0.5px;
      color: var(--white);
      display: flex;
      align-items: center;
    }
    .logo span {
      color: var(--primary);
    }
    .logo .accent-dot {
      color: var(--accent);
      margin-left: 2px;
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      color: var(--white);
      font-weight: 500;
      font-size: 1rem;
      position: relative;
      padding: 4px 0;
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0%;
      height: 2px;
      background: var(--accent);
      transition: width var(--transition);
    }
    .nav-links a:hover::after {
      width: 100%;
    }
    .btn-primary {
      background: var(--primary);
      color: var(--white);
      font-weight: 700;
      padding: 12px 28px;
      border-radius: var(--radius-md);
      font-size: 1rem;
      display: inline-block;
      box-shadow: 0 4px 10px rgba(255,77,0,0.3);
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      box-shadow: 0 6px 16px rgba(255,77,0,0.45);
      transform: translateY(-1px);
    }
    .btn-secondary {
      background: transparent;
      border: 2px solid var(--accent);
      color: var(--accent);
      font-weight: 700;
      padding: 10px 28px;
      border-radius: var(--radius-md);
      font-size: 1rem;
      display: inline-block;
    }
    .btn-secondary:hover {
      background: rgba(0,229,255,0.1);
      border-color: #33eaff;
      color: #33eaff;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      z-index: 1001;
    }
    .hamburger span {
      width: 26px;
      height: 2.5px;
      background: var(--white);
      border-radius: 2px;
      transition: var(--transition);
    }
    /* 移动端导航 */
    @media (max-width: 768px) {
      .hamburger {
        display: flex;
      }
      .nav-links {
        position: fixed;
        top: 0;
        right: -100%;
        width: 75%;
        max-width: 320px;
        height: 100vh;
        background: var(--charcoal);
        flex-direction: column;
        padding: 100px 32px 40px;
        gap: 28px;
        transition: right 0.4s ease;
        box-shadow: -8px 0 24px rgba(0,0,0,0.5);
        backdrop-filter: blur(10px);
      }
      .nav-links.active {
        right: 0;
      }
      .nav-links a {
        font-size: 1.2rem;
      }
    }
    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background: linear-gradient(135deg, rgba(13,13,13,0.82) 0%, rgba(26,26,26,0.7) 100%), url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      padding-top: var(--nav-height);
      color: var(--white);
      position: relative;
    }
    .hero .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      flex-wrap: wrap;
      gap: 48px;
    }
    .hero-content {
      flex: 1 1 500px;
    }
    .hero h1 {
      font-size: 3.2rem;
      font-weight: 700;
      line-height: 1.2;
      color: var(--white);
      margin-bottom: 1.5rem;
    }
    .hero h1 .highlight {
      color: var(--accent);
    }
    .hero p {
      font-size: 1.2rem;
      color: rgba(255,255,255,0.85);
      margin-bottom: 2rem;
      max-width: 560px;
    }
    .hero-buttons {
      display: flex;
      gap: 20px;
      flex-wrap: wrap;
    }
    .hero-visual {
      flex: 1 1 400px;
      position: relative;
    }
    .hero-visual img {
      border-radius: var(--radius-lg);
      box-shadow: 0 20px 40px rgba(0,0,0,0.6);
      border: 1px solid rgba(255,255,255,0.15);
    }
    @media (max-width: 992px) {
      .hero h1 {
        font-size: 2.5rem;
      }
    }
    @media (max-width: 768px) {
      .hero .container {
        flex-direction: column;
        text-align: center;
      }
      .hero-content {
        flex: unset;
        width: 100%;
      }
      .hero-buttons {
        justify-content: center;
      }
      .hero h1 {
        font-size: 2rem;
      }
    }
    /* 通用板块 */
    section {
      padding: 80px 0;
    }
    .section-title {
      font-size: 2.2rem;
      font-weight: 600;
      margin-bottom: 1rem;
      color: var(--gray-dark);
    }
    .section-sub {
      color: var(--mid-gray);
      margin-bottom: 48px;
      font-size: 1.1rem;
    }
    .bg-light {
      background-color: var(--light-gray);
    }
    .bg-dark {
      background-color: var(--gray-dark);
      color: var(--white);
    }
    /* 优势卡片不对称网格 */
    .features-grid {
      display: grid;
      grid-template-columns: 2fr 1fr;
      gap: 28px;
    }
    .feature-card {
      background: var(--white);
      border-radius: var(--radius-lg);
      padding: 32px;
      box-shadow: var(--shadow-sm);
      transition: all var(--transition);
      border-left: 4px solid var(--primary);
    }
    .feature-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-hover);
      border-left-color: var(--accent);
    }
    .feature-card.large {
      grid-row: span 2;
    }
    .feature-icon {
      font-size: 2.2rem;
      color: var(--primary);
      margin-bottom: 16px;
    }
    .feature-card h3 {
      font-size: 1.5rem;
      margin-bottom: 12px;
    }
    @media (max-width: 768px) {
      .features-grid {
        grid-template-columns: 1fr;
      }
    }
    /* 服务图文交错 */
    .service-row {
      display: flex;
      align-items: center;
      gap: 48px;
      margin-bottom: 64px;
    }
    .service-row.reverse {
      flex-direction: row-reverse;
    }
    .service-img {
      flex: 1 1 45%;
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }
    .service-text {
      flex: 1 1 45%;
    }
    .service-text h3 {
      font-size: 1.8rem;
      margin-bottom: 16px;
    }
    @media (max-width: 768px) {
      .service-row, .service-row.reverse {
        flex-direction: column;
      }
    }
    /* 案例卡片 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 28px;
    }
    .case-card {
      background: var(--charcoal);
      border-radius: var(--radius-lg);
      padding: 28px;
      color: var(--white);
      transition: var(--transition);
      border: 1px solid #2a2a2a;
    }
    .case-card:hover {
      border-color: var(--accent);
      transform: translateY(-4px);
    }
    .case-number {
      font-family: var(--font-data);
      font-size: 2.6rem;
      font-weight: 700;
      color: var(--accent);
    }
    /* 证言 */
    .testimonial-slider {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding-bottom: 12px;
    }
    .testimonial-card {
      min-width: 300px;
      background: var(--white);
      border-radius: var(--radius-lg);
      padding: 28px;
      box-shadow: var(--shadow-sm);
      border-left: 5px solid var(--accent);
      font-style: italic;
    }
    /* FAQ */
    .faq-item {
      border: 1px solid var(--border-light);
      border-radius: var(--radius-md);
      margin-bottom: 12px;
      background: var(--white);
      transition: var(--transition);
    }
    .faq-question {
      width: 100%;
      padding: 18px 24px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      font-size: 1.1rem;
      background: transparent;
      border: none;
      cursor: pointer;
    }
    .faq-answer {
      padding: 0 24px 18px;
      color: var(--mid-gray);
      display: none;
    }
    .faq-item.active {
      border-color: var(--accent);
    }
    .faq-item.active .faq-answer {
      display: block;
    }
    /* CTA */
    .cta-band {
      background: var(--primary);
      color: var(--white);
      text-align: center;
      padding: 72px 24px;
    }
    /* 页脚 */
    .footer {
      background: var(--charcoal);
      color: var(--mid-gray);
      padding: 56px 0 24px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 32px;
      margin-bottom: 32px;
    }
    .footer a:hover {
      color: var(--primary);
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr 1fr;
      }
      section {
        padding: 56px 0;
      }
    }
    .copyright {
      text-align: center;
      font-size: 0.9rem;
      border-top: 1px solid #2a2a2a;
      padding-top: 20px;
    }