/* roulang page: index */
:root {
      --color-black: #1A1A1A;
      --color-orange: #FF4F1E;
      --color-orange-dark: #E0441A;
      --color-gray: #6B7280;
      --color-light-gray: #F3F4F6;
      --color-bg: #FAFAFA;
      --color-white: #FFFFFF;
      --color-border: #E5E7EB;
      --color-text: #4B5563;
      --color-footer-bg: #111111;
      --color-footer-text: #9CA3AF;
      
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --font-number: "Inter", "SF Pro Display", sans-serif;
      
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-lg: 16px;
      --radius-pill: 20px;
      
      --shadow-sm: 0 2px 8px rgba(0,0,0,0.04);
      --shadow-md: 0 12px 24px rgba(0,0,0,0.08);
      --shadow-orange: 0 4px 14px rgba(255,79,30,0.35);
      
      --max-width: 1280px;
      --section-gap: 120px;
    }
    
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    
    html {
      scroll-behavior: smooth;
    }
    
    body {
      font-family: var(--font-sans);
      font-size: 16px;
      line-height: 1.7;
      color: var(--color-text);
      background-color: var(--color-bg);
      -webkit-font-smoothing: antialiased;
    }
    
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    
    /* 导航系统 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      background: var(--color-white);
      border-bottom: 1px solid var(--color-border);
      box-shadow: 0 1px 4px rgba(0,0,0,0.02);
      z-index: 1000;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      max-width: var(--max-width);
      padding: 0 24px;
    }
    
    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 24px;
      font-weight: 700;
      color: var(--color-black);
      text-decoration: none;
      letter-spacing: -0.5px;
    }
    
    .logo-icon {
      display: flex;
      align-items: center;
      justify-content: center;
      width: 32px;
      height: 32px;
      position: relative;
    }
    
    .logo-icon svg {
      width: 28px;
      height: 28px;
      stroke: var(--color-orange);
      fill: none;
      stroke-width: 2.5;
    }
    
    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }
    
    .nav-link {
      font-size: 15px;
      font-weight: 500;
      color: var(--color-text);
      text-decoration: none;
      position: relative;
      padding: 8px 0;
      transition: color 0.2s ease;
    }
    
    .nav-link::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--color-orange);
      transition: width 0.25s ease;
    }
    
    .nav-link:hover,
    .nav-link.active {
      color: var(--color-orange);
    }
    
    .nav-link:hover::after,
    .nav-link.active::after {
      width: 100%;
    }
    
    .btn-primary {
      background: var(--color-orange);
      color: white;
      font-weight: 600;
      padding: 12px 28px;
      border-radius: var(--radius-sm);
      text-decoration: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      border: none;
      cursor: pointer;
      font-size: 15px;
      transition: background 0.2s ease, box-shadow 0.2s ease;
      white-space: nowrap;
    }
    
    .btn-primary:hover {
      background: var(--color-orange-dark);
      box-shadow: var(--shadow-orange);
    }
    
    .btn-outline {
      background: transparent;
      border: 2px solid var(--color-orange);
      color: var(--color-orange);
      font-weight: 600;
      padding: 10px 28px;
      border-radius: var(--radius-sm);
      text-decoration: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      cursor: pointer;
      font-size: 15px;
      transition: background 0.2s ease, color 0.2s ease;
      white-space: nowrap;
    }
    
    .btn-outline:hover {
      background: rgba(255,79,30,0.1);
      color: var(--color-orange);
    }
    
    .hamburger {
      display: none;
      background: none;
      border: none;
      font-size: 28px;
      color: var(--color-black);
      cursor: pointer;
      width: 48px;
      height: 48px;
      align-items: center;
      justify-content: center;
      border-radius: 8px;
      transition: background 0.2s;
    }
    
    .hamburger:hover {
      background: #f5f5f5;
    }
    
    /* 移动端导航 */
    @media (max-width: 768px) {
      .nav-menu {
        position: fixed;
        top: 72px;
        left: 0;
        width: 100%;
        height: calc(100vh - 72px);
        background: white;
        flex-direction: column;
        justify-content: center;
        gap: 32px;
        transform: translateX(100%);
        transition: transform 0.35s ease;
        z-index: 999;
        box-shadow: 0 10px 20px rgba(0,0,0,0.05);
      }
      
      .nav-menu.active {
        transform: translateX(0);
      }
      
      .nav-link {
        font-size: 22px;
        font-weight: 600;
      }
      
      .hamburger {
        display: flex;
      }
      
      .desktop-cta {
        display: none;
      }
      
      .mobile-cta {
        display: block;
        margin-top: 24px;
      }
    }
    
    @media (min-width: 769px) {
      .mobile-cta {
        display: none;
      }
    }
    
    /* 通用板块样式 */
    section {
      padding: var(--section-gap) 0;
    }
    
    .section-title {
      font-size: 40px;
      font-weight: 700;
      line-height: 1.25;
      color: var(--color-black);
      margin-bottom: 16px;
      letter-spacing: -0.02em;
    }
    
    .section-subtitle {
      font-size: 18px;
      color: var(--color-gray);
      max-width: 600px;
      margin-bottom: 48px;
    }
    
    /* Hero */
    .hero {
      height: 100vh;
      min-height: 700px;
      background: linear-gradient(rgba(0,0,0,0.55), rgba(0,0,0,0.4)), url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      display: flex;
      align-items: center;
      justify-content: flex-start;
      color: white;
      position: relative;
      margin-top: 72px;
    }
    
    .hero-content {
      max-width: 700px;
      animation: fadeUp 0.9s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    }
    
    .hero h1 {
      font-size: 56px;
      font-weight: 800;
      line-height: 1.15;
      letter-spacing: -0.02em;
      margin-bottom: 24px;
      color: white;
    }
    
    .hero p {
      font-size: 18px;
      color: rgba(255,255,255,0.85);
      margin-bottom: 40px;
      max-width: 500px;
    }
    
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    
    .scroll-indicator {
      position: absolute;
      bottom: 30px;
      left: 50%;
      transform: translateX(-50%);
      color: white;
      font-size: 24px;
      animation: bounce 2s infinite;
      opacity: 0.8;
    }
    
    @keyframes bounce {
      0%, 20%, 50%, 80%, 100% { transform: translateX(-50%) translateY(0); }
      40% { transform: translateX(-50%) translateY(-10px); }
      60% { transform: translateX(-50%) translateY(-4px); }
    }
    
    @keyframes fadeUp {
      from { opacity: 0; transform: translateY(30px); }
      to { opacity: 1; transform: translateY(0); }
    }
    
    /* 核心优势 非对称布局 */
    .advantages-grid {
      display: grid;
      grid-template-columns: 5fr 7fr;
      gap: 24px;
      align-items: start;
    }
    
    .advantage-card {
      background: white;
      border-radius: var(--radius-md);
      padding: 32px;
      transition: all 0.3s ease;
      border: 1px solid var(--color-border);
      display: flex;
      flex-direction: column;
      height: fit-content;
    }
    
    .advantage-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }
    
    .advantage-large {
      background: white;
      border-radius: var(--radius-md);
      overflow: hidden;
      border: 1px solid var(--color-border);
      transition: 0.3s;
    }
    
    .advantage-large:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }
    
    .advantage-large img {
      width: 100%;
      height: 240px;
      object-fit: cover;
      display: block;
    }
    
    .advantage-large .card-text {
      padding: 28px;
    }
    
    .advantage-icon {
      font-size: 28px;
      color: var(--color-orange);
      margin-bottom: 16px;
    }
    
    .advantage-card h3, .advantage-large h3 {
      font-size: 24px;
      font-weight: 600;
      margin-bottom: 12px;
      color: var(--color-black);
    }
    
    /* 产品体系 */
    .product-row {
      display: flex;
      gap: 32px;
      align-items: center;
      padding: 32px 0;
      border-bottom: 1px solid var(--color-border);
    }
    
    .product-row:last-child {
      border-bottom: none;
    }
    
    .product-text {
      flex: 1;
    }
    
    .product-text h3 {
      font-size: 28px;
      font-weight: 600;
      margin-bottom: 12px;
    }
    
    .product-tags {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      margin-top: 16px;
    }
    
    .tag {
      background: var(--color-light-gray);
      padding: 4px 16px;
      border-radius: var(--radius-pill);
      font-size: 13px;
      font-weight: 500;
      color: var(--color-black);
    }
    
    .product-image {
      flex: 1;
      border-radius: var(--radius-md);
      overflow: hidden;
    }
    
    .product-image img {
      width: 100%;
      height: 260px;
      object-fit: cover;
      transition: transform 0.3s ease;
    }
    
    .product-image img:hover {
      transform: scale(1.03);
    }
    
    /* 场景方案 交替布局 */
    .scene-block {
      display: flex;
      gap: 48px;
      align-items: center;
      margin-bottom: 80px;
    }
    
    .scene-block.reverse {
      flex-direction: row-reverse;
    }
    
    .scene-img {
      flex: 1;
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }
    
    .scene-img img {
      width: 100%;
      height: 340px;
      object-fit: cover;
    }
    
    .scene-desc {
      flex: 1;
    }
    
    .scene-desc h3 {
      font-size: 28px;
      margin-bottom: 16px;
    }
    
    .feature-list {
      list-style: none;
      margin-top: 20px;
    }
    
    .feature-list li {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 12px;
      color: var(--color-text);
    }
    
    .feature-list li::before {
      content: "●";
      color: var(--color-orange);
      font-size: 14px;
    }
    
    /* 案例实力 */
    .brand-wall {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      margin-bottom: 48px;
    }
    
    .brand-placeholder {
      background: #f0f0f0;
      height: 80px;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: var(--radius-sm);
      color: #8a8a8a;
      font-weight: 500;
      transition: color 0.2s, background 0.2s;
    }
    
    .brand-placeholder:hover {
      color: var(--color-orange);
      background: #fafafa;
    }
    
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    
    .stat-card {
      background: white;
      padding: 32px;
      border-radius: var(--radius-md);
      text-align: center;
      border: 1px solid var(--color-border);
    }
    
    .stat-number {
      font-size: 48px;
      font-weight: 800;
      color: var(--color-orange);
      font-family: var(--font-number);
    }
    
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    
    .faq-item {
      border-bottom: 1px solid var(--color-border);
      padding: 20px 0;
      cursor: pointer;
    }
    
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      font-size: 18px;
      color: var(--color-black);
    }
    
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      background: #F9FAFB;
      border-radius: 8px;
      margin-top: 12px;
      padding: 0 20px;
    }
    
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 20px;
    }
    
    .faq-item.active .faq-icon {
      transform: rotate(180deg);
    }
    
    /* 底部 CTA */
    .cta-section {
      background: var(--color-black);
      color: white;
    }
    
    .cta-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 48px;
      align-items: center;
    }
    
    .form-group {
      margin-bottom: 20px;
    }
    
    .form-group input, .form-group textarea {
      width: 100%;
      padding: 14px;
      border-radius: var(--radius-sm);
      border: 1px solid #D1D5DB;
      font-family: inherit;
      background: white;
      transition: border 0.2s;
    }
    
    .form-group input:focus, .form-group textarea:focus {
      border-color: var(--color-orange);
      outline: none;
      box-shadow: 0 0 0 3px rgba(255,79,30,0.2);
    }
    
    /* 页脚 */
    .footer {
      background: var(--color-footer-bg);
      color: var(--color-footer-text);
      padding: 60px 0 30px;
    }
    
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }
    
    .copyright {
      margin-top: 40px;
      padding-top: 20px;
      border-top: 1px solid #333;
      text-align: center;
    }
    
    @media (max-width: 1024px) {
      .advantages-grid { grid-template-columns: 1fr; }
      .product-row { flex-direction: column; }
      .scene-block, .scene-block.reverse { flex-direction: column; }
      .cta-grid { grid-template-columns: 1fr; }
      .brand-wall { grid-template-columns: repeat(2,1fr); }
      .stats-grid { grid-template-columns: 1fr; }
    }
    
    @media (max-width: 768px) {
      .section-title { font-size: 28px; }
      .hero h1 { font-size: 36px; }
      .hero { justify-content: center; text-align: center; }
      .hero-content { text-align: center; }
      .hero-buttons { justify-content: center; }
      .footer-grid { grid-template-columns: 1fr; }
    }