:root {
      --primary-color: rgb(255, 149, 0);
      --primary-hover: rgb(230, 135, 0);
      --bg-color: #f7f9fa;
      --card-bg: #ffffff;
      --text-main: #2c3e50;
      --text-muted: #7f8c8d;
      --border-color: #ebedf0;
      --max-width: 1200px;
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
      background-color: var(--bg-color);
      color: var(--text-main);
      line-height: 1.6;
    }
    a {
      color: inherit;
      text-decoration: none;
      transition: color 0.3s;
    }
    a:hover {
      color: var(--primary-color);
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 20px;
    }
    
    
    .header {
      background-color: #fff;
      border-bottom: 1px solid var(--border-color);
      position: sticky;
      top: 0;
      z-index: 1000;
      box-shadow: 0 2px 8px rgba(0,0,0,0.05);
    }
    .header-inner {
      display: flex;
      justify-content: space-between;
      align-items: center;
      height: 70px;
    }
    .logo {
      display: inline-flex;
      align-items: center;
      gap: 12px;
    }
    .logo img {
      display: block;
      height: 40px;
      width: auto;
      max-width: 160px;
      object-fit: contain;
    }
    .logo span {
      display: inline-block;
      font-size: 20px;
      font-weight: 800;
      color: #111;
    }
    .nav-list {
      display: flex;
      gap: 24px;
      list-style: none;
      align-items: center;
    }
    .nav-list a {
      font-weight: 500;
      font-size: 15px;
      padding: 8px 4px;
    }
    .menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 24px;
      cursor: pointer;
    }

    
    .drawer-overlay {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: rgba(0,0,0,0.5);
      z-index: 9998;
      opacity: 0;
      visibility: hidden;
      transition: all 0.3s ease;
    }
    .drawer-overlay.active {
      opacity: 1;
      visibility: visible;
    }
    .drawer {
      position: fixed;
      top: 0;
      left: -280px;
      width: 280px;
      height: 100%;
      background: #fff;
      z-index: 9999;
      box-shadow: 4px 0 12px rgba(0,0,0,0.15);
      transition: all 0.3s ease;
      display: flex;
      flex-direction: column;
      padding: 20px;
    }
    .drawer.active {
      left: 0;
    }
    .drawer-header {
      display: flex;
      justify-content: space-between;
      align-items: center;
      margin-bottom: 30px;
      border-bottom: 1px solid var(--border-color);
      padding-bottom: 15px;
    }
    .drawer-close {
      background: none;
      border: none;
      font-size: 24px;
      cursor: pointer;
    }
    .drawer-nav {
      display: flex;
      flex-direction: column;
      gap: 20px;
    }

    
    .download-hero {
      background: linear-gradient(135deg, #1a1a1a 0%, #2c3e50 100%);
      color: #fff;
      padding: 80px 0;
      text-align: center;
    }
    .download-hero h1 {
      font-size: 36px;
      font-weight: 800;
      margin-bottom: 15px;
    }
    .download-hero p {
      font-size: 16px;
      color: #ccc;
      max-width: 600px;
      margin: 0 auto 30px;
    }
    .download-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      margin: 60px 0;
    }
    .download-card {
      background: #fff;
      border-radius: 12px;
      padding: 40px;
      border: 1px solid var(--border-color);
      box-shadow: 0 4px 15px rgba(0,0,0,0.02);
      text-align: center;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 20px;
    }
    .download-card h2 {
      font-size: 22px;
      font-weight: 800;
    }
    .download-card p {
      color: var(--text-muted);
      font-size: 14px;
    }
    .download-btn {
      background: var(--primary-color);
      color: #fff;
      padding: 12px 40px;
      border-radius: 30px;
      font-weight: 700;
      transition: background 0.3s;
      width: 100%;
      max-width: 200px;
    }
    .download-btn:hover {
      background: var(--primary-hover);
      color: #fff;
    }

    
    .steps-section {
      margin-bottom: 60px;
    }
    .steps-title {
      font-size: 24px;
      font-weight: 800;
      text-align: center;
      margin-bottom: 40px;
    }
    .steps-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 30px;
    }
    .step-item {
      text-align: center;
      background: #fff;
      padding: 30px;
      border-radius: 12px;
      border: 1px solid var(--border-color);
    }
    .step-number {
      width: 40px;
      height: 40px;
      background: var(--primary-color);
      color: #fff;
      border-radius: 50%;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
      font-size: 18px;
      margin-bottom: 20px;
    }
    .step-item h3 {
      font-size: 16px;
      font-weight: 700;
      margin-bottom: 10px;
    }
    .step-item p {
      font-size: 14px;
      color: var(--text-muted);
    }

    
    .footer {
      background-color: #1a1a1a;
      color: #999;
      padding: 50px 0 20px;
      font-size: 14px;
    }
    .footer-top {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 40px;
      border-bottom: 1px solid #2d2d2d;
      padding-bottom: 40px;
    }
    .footer-col {
      display: flex;
      flex-direction: column;
      gap: 15px;
    }
    .footer-col h4 {
      color: #fff;
      font-size: 16px;
      font-weight: 700;
    }
    .footer-col ul {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }
    .footer-col ul a {
      color: #999;
    }
    .footer-col ul a:hover {
      color: #fff;
    }
    .footer-about .logo {
      margin-bottom: 15px;
    }
    .footer-about .logo span {
      color: #fff;
    }
    .footer-contact p {
      margin-bottom: 8px;
    }

    
    .friend-links {
      padding: 20px 0;
      border-bottom: 1px solid #2d2d2d;
    }
    .friend-title {
      font-weight: 700;
      color: #fff;
      margin-bottom: 12px;
      font-size: 14px;
    }
    .friend-content {
      display: flex;
      flex-wrap: wrap;
      gap: 15px;
    }
    .friend-content a {
      color: #888;
      font-size: 13px;
    }
    .friend-content a:hover {
      color: var(--primary-color);
    }

    .footer-bottom {
      padding-top: 20px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 15px;
      font-size: 13px;
    }

    @media (max-width: 992px) {
      .nav-list {
        display: none;
      }
      .menu-toggle {
        display: block;
      }
      .footer-top {
        grid-template-columns: 1fr 1fr;
      }
    }
    @media (max-width: 768px) {
      .download-grid, .steps-grid {
        grid-template-columns: 1fr;
      }
    }