/* roulang page: index */
/* ----- CSS Variables & Reset ----- */
    :root {
      --primary: #7C3AED;
      --primary-glow: rgba(124, 58, 237, 0.7);
      --accent-cyan: #00F0FF;
      --accent-orange: #FF6B35;
      --bg-deep: #0F0F1A;
      --bg-section: #1A1A2E;
      --bg-section-alt: #16162A;
      --bg-card: rgba(255, 255, 255, 0.03);
      --border-card: rgba(255, 255, 255, 0.06);
      --text-primary: #F0EDF5;
      --text-secondary: rgba(240, 237, 245, 0.7);
      --text-tertiary: rgba(240, 237, 245, 0.45);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 6px;
      --font-heading: 'Orbitron', 'PingFang SC', 'Microsoft YaHei', sans-serif;
      --font-body: 'Inter', 'PingFang SC', 'Microsoft YaHei', sans-serif;
      --shadow-glow: 0 0 20px rgba(124, 58, 237, 0.08);
      --transition: 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-deep);
      color: var(--text-primary);
      line-height: 1.75;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }
    
    img {
      max-width: 100%;
      display: block;
    }
    
    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }
    
    button, input {
      font-family: inherit;
    }
    
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }
    
    /* ----- 导航 (Header) ----- */
    #header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: rgba(15, 15, 26, 0.85);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      border-bottom: 1px solid transparent;
      background-image: linear-gradient(rgba(15,15,26,0.85), rgba(15,15,26,0.85)), 
                        linear-gradient(to right, var(--accent-cyan), var(--primary));
      background-origin: border-box;
      background-clip: padding-box, border-box;
      transition: background 0.3s, box-shadow 0.3s;
    }
    
    #header.scrolled {
      background: rgba(15, 15, 26, 0.95);
      box-shadow: 0 4px 20px rgba(0,0,0,0.5);
    }
    
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 72px;
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }
    
    .logo {
      font-family: var(--font-heading);
      font-weight: 700;
      font-size: 1.8rem;
      letter-spacing: 1px;
      background: linear-gradient(to right, var(--accent-cyan), var(--primary));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      display: inline-block;
    }
    
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 2rem;
    }
    
    .nav-link {
      font-weight: 500;
      color: var(--text-secondary);
      position: relative;
      padding: 4px 0;
      font-size: 0.95rem;
    }
    
    .nav-link::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent-cyan);
      transition: width 0.3s;
    }
    
    .nav-link:hover,
    .nav-link.active {
      color: var(--text-primary);
    }
    
    .nav-link:hover::after,
    .nav-link.active::after {
      width: 100%;
    }
    
    .nav-cta {
      background: var(--accent-orange);
      color: white;
      padding: 10px 22px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 0.9rem;
      transition: all 0.25s;
      box-shadow: 0 0 12px rgba(255,107,53,0.3);
    }
    
    .nav-cta:hover {
      background: #FF8255;
      box-shadow: 0 0 18px rgba(255,107,53,0.6);
      color: white;
    }
    
    .hamburger {
      display: none;
      flex-direction: column;
      cursor: pointer;
      gap: 5px;
    }
    
    .hamburger span {
      width: 28px;
      height: 2.5px;
      background: var(--text-primary);
      transition: 0.3s;
    }
    
    /* 移动端导航 */
    @media (max-width: 768px) {
      .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 75%;
        max-width: 320px;
        height: 100vh;
        background: #0A0A14;
        flex-direction: column;
        justify-content: center;
        gap: 2.5rem;
        transition: right 0.4s ease;
        box-shadow: -10px 0 30px rgba(0,0,0,0.6);
        z-index: 999;
      }
      .nav-menu.active {
        right: 0;
      }
      .hamburger {
        display: flex;
        z-index: 1001;
      }
      .nav-cta {
        width: fit-content;
      }
    }
    
    /* ----- Hero 首屏 ----- */
    #hero {
      padding: 160px 0 100px;
      background: radial-gradient(circle at 20% 30%, rgba(124,58,237,0.15) 0%, transparent 50%),
                  url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      background-blend-mode: overlay;
      position: relative;
      overflow: hidden;
    }
    
    #hero::before {
      content: '';
      position: absolute;
      inset: 0;
      background: repeating-linear-gradient(0deg, rgba(0,240,255,0.02) 0px, rgba(0,240,255,0.02) 1px, transparent 1px, transparent 40px);
      pointer-events: none;
    }
    
    .hero-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 3rem;
      align-items: center;
    }
    
    .hero-content h1 {
      font-family: var(--font-heading);
      font-size: clamp(42px, 5vw, 68px);
      font-weight: 800;
      line-height: 1.15;
      margin-bottom: 1.5rem;
      background: linear-gradient(to right, #fff, var(--accent-cyan));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      letter-spacing: -0.02em;
    }
    
    .hero-sub {
      font-size: 1.2rem;
      color: var(--text-secondary);
      margin-bottom: 2.5rem;
      max-width: 90%;
    }
    
    .hero-buttons {
      display: flex;
      gap: 1.2rem;
      flex-wrap: wrap;
    }
    
    .btn-primary {
      background: var(--accent-orange);
      color: white;
      padding: 14px 34px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 1rem;
      box-shadow: 0 0 20px rgba(255,107,53,0.4);
      transition: all 0.3s;
      border: none;
      cursor: pointer;
      display: inline-block;
    }
    
    .btn-primary:hover {
      background: #FF8255;
      box-shadow: 0 0 28px rgba(255,107,53,0.7);
      transform: translateY(-2px);
    }
    
    .btn-outline {
      border: 1.5px solid var(--accent-cyan);
      background: transparent;
      color: var(--accent-cyan);
      padding: 14px 34px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      transition: all 0.3s;
      display: inline-block;
    }
    
    .btn-outline:hover {
      background: rgba(0,240,255,0.1);
      box-shadow: 0 0 18px rgba(0,240,255,0.25);
    }
    
    .hero-visual {
      background: rgba(255,255,255,0.02);
      border-radius: 20px;
      overflow: hidden;
      border: 1px solid rgba(255,255,255,0.05);
      height: 380px;
      display: flex;
      align-items: center;
      justify-content: center;
      position: relative;
    }
    
    .hero-visual img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      opacity: 0.9;
    }
    
    @media (max-width: 992px) {
      .hero-grid {
        grid-template-columns: 1fr;
      }
      .hero-visual {
        height: 300px;
      }
    }
    
    /* ----- 通用板块标题 ----- */
    .section-title {
      font-family: var(--font-heading);
      font-size: clamp(28px, 3.5vw, 44px);
      font-weight: 700;
      margin-bottom: 1rem;
      text-align: center;
    }
    
    .section-sub {
      color: var(--text-secondary);
      text-align: center;
      max-width: 700px;
      margin: 0 auto 3.5rem;
    }
    
    section {
      padding: 90px 0;
    }
    
    /* ----- 核心优势 Features ----- */
    #features {
      background: var(--bg-section);
    }
    
    .features-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 2rem;
    }
    
    .feature-card {
      background: var(--bg-card);
      border: 1px solid var(--border-card);
      border-radius: var(--radius-card);
      padding: 32px 28px;
      transition: all 0.3s;
      box-shadow: var(--shadow-glow);
    }
    
    .feature-card:hover {
      border-color: var(--accent-cyan);
      box-shadow: 0 0 25px rgba(0,240,255,0.15);
      transform: translateY(-6px);
    }
    
    .feature-icon {
      font-size: 2.4rem;
      color: var(--accent-cyan);
      margin-bottom: 1.5rem;
    }
    
    .feature-card h3 {
      font-size: 1.4rem;
      margin-bottom: 0.8rem;
      font-weight: 600;
    }
    
    @media (max-width: 768px) {
      .features-grid {
        grid-template-columns: 1fr;
      }
    }
    
    /* ----- 服务矩阵 Services ----- */
    #services {
      background: var(--bg-section-alt);
    }
    
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 2rem;
    }
    
    .service-card {
      background: var(--bg-card);
      border: 1px solid var(--border-card);
      border-radius: var(--radius-card);
      padding: 28px;
      transition: 0.3s;
    }
    
    .service-card:hover {
      border-color: var(--primary);
      background: rgba(255,255,255,0.05);
    }
    
    .service-card img {
      width: 100%;
      height: 160px;
      object-fit: cover;
      border-radius: 8px;
      margin-bottom: 1.2rem;
    }
    
    .service-card h3 {
      font-size: 1.3rem;
      margin-bottom: 0.5rem;
    }
    
    @media (max-width: 768px) {
      .services-grid {
        grid-template-columns: 1fr;
      }
    }
    
    /* ----- 数据统计 Stats ----- */
    #stats {
      background: var(--bg-deep);
    }
    
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 2rem;
      text-align: center;
    }
    
    .stat-number {
      font-family: var(--font-heading);
      font-size: 3rem;
      font-weight: 700;
      color: var(--accent-cyan);
    }
    
    @media (max-width: 768px) {
      .stats-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    
    /* ----- 案例展示 Cases ----- */
    #cases {
      background: var(--bg-section);
    }
    
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 2rem;
    }
    
    .case-card {
      background: var(--bg-card);
      border-radius: var(--radius-card);
      overflow: hidden;
      border: 1px solid var(--border-card);
      transition: 0.3s;
    }
    
    .case-card:hover {
      border-color: var(--primary);
    }
    
    .case-img {
      height: 180px;
      overflow: hidden;
    }
    
    .case-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: 0.4s;
    }
    
    .case-card:hover .case-img img {
      transform: scale(1.04);
    }
    
    .case-info {
      padding: 20px;
    }
    
    @media (max-width: 768px) {
      .cases-grid {
        grid-template-columns: 1fr;
      }
    }
    
    /* ----- 流程 Process ----- */
    #process {
      background: var(--bg-section-alt);
    }
    
    .process-steps {
      display: flex;
      justify-content: space-between;
      position: relative;
    }
    
    .step {
      text-align: center;
      flex: 1;
    }
    
    .step-num {
      width: 50px;
      height: 50px;
      background: var(--primary);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 1rem;
      font-weight: 700;
      font-size: 1.4rem;
    }
    
    @media (max-width: 768px) {
      .process-steps {
        flex-direction: column;
        gap: 2rem;
      }
    }
    
    /* ----- FAQ 手风琴 ----- */
    #faq {
      background: var(--bg-deep);
    }
    
    .faq-item {
      border-bottom: 1px solid rgba(255,255,255,0.08);
      padding: 18px 0;
    }
    
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      font-size: 1.1rem;
      cursor: pointer;
    }
    
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: var(--text-secondary);
      padding-right: 40px;
    }
    
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-top: 12px;
    }
    
    /* ----- CTA 横幅 ----- */
    #cta {
      background: linear-gradient(135deg, #7C3AED, #1E1B4B);
      padding: 70px 0;
      text-align: center;
    }
    
    /* ----- 页脚 ----- */
    #footer {
      background: #0A0A14;
      padding: 60px 0 30px;
    }
    
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 2rem;
    }
    
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }
    
    .copyright {
      text-align: center;
      margin-top: 40px;
      color: var(--text-tertiary);
      font-size: 0.9rem;
    }