/* roulang page: index */
/* ===== CSS 变量与基础 Reset ===== */
    :root {
      --primary: #F04E23;
      --primary-hover: #D13E1A;
      --dark-bg: #1E1E1E;
      --warm-sand: #F5EDE3;
      --white: #FFFFFF;
      --text-main: #2C2C2C;
      --text-light: #B0B0B0;
      --success: #0F9B4E;
      --border-light: #E0E0E0;
      --border-input: #D0D0D0;
      
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --shadow-card: 0 4px 20px rgba(0,0,0,0.08);
      --shadow-card-hover: 0 12px 32px rgba(0,0,0,0.15);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-input: 6px;
      --transition: 0.25s ease;
      
      --section-gap: 100px;
      --card-gap: 24px;
    }
    
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    
    html {
      scroll-behavior: smooth;
    }
    
    body {
      font-family: var(--font-sans);
      font-size: 16px;
      font-weight: 400;
      line-height: 1.7;
      color: var(--text-main);
      background-color: var(--white);
      -webkit-font-smoothing: antialiased;
    }
    
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    
    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition);
    }
    
    button, input, textarea {
      font-family: inherit;
      font-size: inherit;
    }
    
    .container {
      width: 90%;
      max-width: 1200px;
      margin: 0 auto;
    }
    
    /* ===== 排版 ===== */
    h1 {
      font-size: 48px;
      font-weight: 700;
      letter-spacing: -0.5px;
      line-height: 1.2;
    }
    
    h2 {
      font-size: 36px;
      font-weight: 600;
      line-height: 1.3;
    }
    
    h3 {
      font-size: 22px;
      font-weight: 600;
      line-height: 1.4;
    }
    
    .section-title {
      margin-bottom: 16px;
      color: var(--dark-bg);
    }
    
    .section-subtitle {
      font-size: 18px;
      color: var(--text-main);
      opacity: 0.8;
      margin-bottom: 48px;
      max-width: 600px;
    }
    
    /* ===== 按钮系统 ===== */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 14px 32px;
      font-size: 16px;
      font-weight: 600;
      letter-spacing: 1px;
      border-radius: var(--radius-btn);
      transition: all var(--transition);
      cursor: pointer;
      border: none;
      background: transparent;
      white-space: nowrap;
    }
    
    .btn-primary {
      background-color: var(--primary);
      color: var(--white);
      border: 2px solid var(--primary);
    }
    
    .btn-primary:hover {
      background-color: var(--primary-hover);
      border-color: var(--primary-hover);
      transform: scale(1.03);
      box-shadow: 0 8px 18px rgba(240,78,35,0.3);
    }
    
    .btn-outline {
      background: transparent;
      color: var(--primary);
      border: 2px solid var(--primary);
    }
    
    .btn-outline:hover {
      background-color: var(--primary);
      color: var(--white);
      transform: scale(1.03);
    }
    
    .btn-large {
      padding: 18px 40px;
      font-size: 18px;
    }
    
    /* ===== 导航栏 ===== */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background-color: var(--dark-bg);
      z-index: 1000;
      display: flex;
      align-items: center;
      box-shadow: 0 2px 10px rgba(0,0,0,0.2);
    }
    
    .header-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 90%;
      max-width: 1200px;
      margin: 0 auto;
    }
    
    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 24px;
      font-weight: 700;
      color: var(--white);
      letter-spacing: 1px;
    }
    
    .logo-icon {
      display: inline-block;
      width: 28px;
      height: 28px;
      background: var(--primary);
      clip-path: polygon(50% 0%, 100% 38%, 82% 100%, 18% 100%, 0% 38%);
      transform: rotate(90deg);
      margin-right: 4px;
    }
    
    .nav-menu {
      display: flex;
      list-style: none;
      gap: 32px;
    }
    
    .nav-menu a {
      color: var(--white);
      font-weight: 500;
      padding: 8px 0;
      position: relative;
      transition: color var(--transition);
    }
    
    .nav-menu a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 3px;
      background: var(--primary);
      transition: width var(--transition);
    }
    
    .nav-menu a:hover {
      color: var(--primary);
    }
    
    .nav-menu a:hover::after {
      width: 100%;
    }
    
    .hamburger {
      display: none;
      font-size: 24px;
      color: var(--white);
      cursor: pointer;
      background: none;
      border: none;
    }
    
    /* 移动端导航 */
    @media (max-width: 768px) {
      .hamburger {
        display: block;
      }
      .nav-menu {
        position: fixed;
        top: 72px;
        left: 0;
        width: 100%;
        height: calc(100vh - 72px);
        background: var(--dark-bg);
        flex-direction: column;
        justify-content: center;
        align-items: center;
        gap: 40px;
        transform: translateX(100%);
        transition: transform 0.3s ease;
      }
      .nav-menu.active {
        transform: translateX(0);
      }
      .nav-menu a {
        font-size: 24px;
      }
    }
    
    /* ===== Hero 首屏 ===== */
    .hero {
      height: 100vh;
      min-height: 600px;
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      position: relative;
      display: flex;
      align-items: center;
      margin-top: 0;
    }
    
    .hero-overlay {
      position: absolute;
      inset: 0;
      background: linear-gradient(90deg, rgba(30,30,30,0.75) 0%, rgba(30,30,30,0.4) 100%);
      z-index: 1;
    }
    
    .hero-content {
      position: relative;
      z-index: 2;
      width: 90%;
      max-width: 1200px;
      margin: 0 auto;
      color: var(--white);
    }
    
    .hero h1 {
      color: var(--white);
      margin-bottom: 20px;
      max-width: 700px;
    }
    
    .hero-subtitle {
      font-size: 18px;
      color: rgba(245, 237, 227, 0.9);
      margin-bottom: 40px;
      max-width: 500px;
    }
    
    .hero-buttons {
      display: flex;
      gap: 20px;
      flex-wrap: wrap;
    }
    
    .scroll-indicator {
      position: absolute;
      bottom: 30px;
      right: 40px;
      z-index: 2;
      color: var(--white);
      font-size: 32px;
      animation: bounce 2s infinite;
      opacity: 0.8;
    }
    
    @keyframes bounce {
      0%, 20%, 50%, 80%, 100% { transform: translateY(0); }
      40% { transform: translateY(-10px); }
      60% { transform: translateY(-5px); }
    }
    
    /* ===== 区块通用 ===== */
    section {
      padding: var(--section-gap) 0;
    }
    
    .bg-warm {
      background-color: var(--warm-sand);
    }
    
    /* ===== 核心优势 (非对称网格) ===== */
    .advantages-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: var(--card-gap);
      margin-top: 20px;
    }
    
    .advantage-card {
      background: var(--white);
      padding: 32px 24px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      transition: all var(--transition);
    }
    
    .advantage-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-card-hover);
    }
    
    .advantage-card.wide {
      grid-column: span 2;
      display: flex;
      align-items: center;
      gap: 30px;
    }
    
    .advantage-icon {
      font-size: 36px;
      color: var(--primary);
      margin-bottom: 16px;
    }
    
    .advantage-card h3 {
      margin-bottom: 8px;
    }
    
    @media (max-width: 768px) {
      .advantages-grid {
        grid-template-columns: 1fr;
      }
      .advantage-card.wide {
        grid-column: span 1;
        flex-direction: column;
      }
    }
    
    /* ===== 服务项目卡片 ===== */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: var(--card-gap);
    }
    
    .service-card {
      background: var(--white);
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      overflow: hidden;
      transition: all var(--transition);
    }
    
    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-card-hover);
    }
    
    .service-card img {
      height: 200px;
      width: 100%;
      object-fit: cover;
    }
    
    .service-card-body {
      padding: 24px;
    }
    
    .service-card h3 {
      margin-bottom: 8px;
    }
    
    .service-link {
      color: var(--primary);
      font-weight: 600;
      margin-top: 12px;
      display: inline-block;
    }
    
    @media (max-width: 1024px) and (min-width: 769px) {
      .services-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }
    
    @media (max-width: 768px) {
      .services-grid {
        grid-template-columns: 1fr 1fr;
      }
    }
    
    /* ===== 数据计数器 ===== */
    .stats-container {
      display: flex;
      justify-content: space-around;
      flex-wrap: wrap;
      gap: 30px;
      text-align: center;
    }
    
    .stat-item {
      flex: 1;
      min-width: 150px;
    }
    
    .stat-number {
      font-size: 48px;
      font-weight: 700;
      color: var(--success);
      display: block;
    }
    
    .stat-label {
      color: var(--text-main);
      margin-top: 8px;
    }
    
    /* ===== 经典案例 (左右交替) ===== */
    .case-row {
      display: flex;
      align-items: center;
      gap: 40px;
      margin-bottom: 60px;
    }
    
    .case-row.reverse {
      flex-direction: row-reverse;
    }
    
    .case-img, .case-text {
      flex: 1;
    }
    
    .case-img img {
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
    }
    
    @media (max-width: 768px) {
      .case-row, .case-row.reverse {
        flex-direction: column;
      }
    }
    
    /* ===== 流程时间轴 ===== */
    .process-steps {
      display: flex;
      justify-content: space-between;
      position: relative;
      margin-top: 40px;
    }
    
    .process-steps::before {
      content: '';
      position: absolute;
      top: 35px;
      left: 0;
      width: 100%;
      height: 3px;
      background: var(--border-light);
      z-index: 0;
    }
    
    .step {
      flex: 1;
      text-align: center;
      position: relative;
      z-index: 1;
    }
    
    .step-number {
      width: 70px;
      height: 70px;
      background: var(--white);
      border: 3px solid var(--primary);
      color: var(--primary);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 28px;
      font-weight: 700;
      margin: 0 auto 16px;
      transition: 0.3s;
    }
    
    .step:hover .step-number {
      background: var(--primary);
      color: white;
    }
    
    @media (max-width: 768px) {
      .process-steps {
        flex-direction: column;
        gap: 30px;
      }
      .process-steps::before {
        display: none;
      }
    }
    
    /* ===== FAQ 手风琴 ===== */
    .faq-item {
      background: var(--white);
      border-bottom: 1px solid var(--border-light);
    }
    
    .faq-question {
      padding: 20px 16px;
      font-weight: 600;
      font-size: 18px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      background: none;
      border: none;
      width: 100%;
      text-align: left;
      color: var(--dark-bg);
    }
    
    .faq-icon {
      color: var(--primary);
      font-size: 20px;
      transition: transform 0.3s;
    }
    
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      background: var(--warm-sand);
      padding: 0 16px;
    }
    
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 16px;
    }
    
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }
    
    /* ===== CTA 区域 ===== */
    .cta-block {
      background: var(--dark-bg);
      text-align: center;
      padding: 80px 0;
    }
    
    .cta-block h2 {
      color: var(--white);
      margin-bottom: 16px;
    }
    
    /* ===== 联系表单 ===== */
    .contact-form {
      display: flex;
      flex-direction: column;
      gap: 20px;
      max-width: 500px;
      margin: 30px auto 0;
    }
    
    .contact-form input, .contact-form textarea {
      padding: 14px 16px;
      border: 1px solid var(--border-input);
      border-radius: var(--radius-input);
      background: var(--white);
      transition: border 0.2s;
    }
    
    .contact-form input:focus, .contact-form textarea:focus {
      outline: none;
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(240,78,35,0.1);
    }
    
    /* ===== 页脚 ===== */
    .site-footer {
      background: var(--dark-bg);
      color: var(--text-light);
      padding: 60px 0 30px;
    }
    
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 40px;
    }
    
    .footer-logo {
      font-size: 22px;
      font-weight: 700;
      color: white;
      margin-bottom: 12px;
    }
    
    .copyright {
      text-align: center;
      margin-top: 40px;
      font-size: 14px;
      opacity: 0.7;
    }
    
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
      :root {
        --section-gap: 60px;
      }
      h1 { font-size: 36px; }
      h2 { font-size: 28px; }
    }