* {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    body {
      font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Helvetica, sans-serif;
      background-color: #ffffff;
      color: #111111;
      line-height: 1.5;
      scroll-behavior: smooth;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }

    .header {
      background-color: #ffffff;
      border-bottom: 1px solid #e5e7eb;
      position: sticky;
      top: 0;
      z-index: 50;
    }

    .nav {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      padding: 18px 0;
    }

    .logo {
      font-size: 1.8rem;
      font-weight: 700;
      letter-spacing: -0.02em;
      background: linear-gradient(135deg, #25D366, #128C7E);
      -webkit-background-clip: text;
      background-clip: text;
      color: transparent;
      text-decoration: none;
    }

    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
      list-style: none;
    }

    .nav-links a {
      text-decoration: none;
      font-weight: 500;
      color: #1f2937;
      transition: color 0.2s;
      font-size: 1rem;
    }

    .nav-links a:hover {
      color: #25D366;
    }

    .nav-links .active {
      color: #128C7E;
      font-weight: 600;
    }

    .page-header {
      background: linear-gradient(145deg, #f0fdf4, #ffffff);
      padding: 64px 0 48px;
      text-align: center;
    }

    .page-header h1 {
      font-size: 2.8rem;
      font-weight: 800;
      background: linear-gradient(135deg, #075e54, #128C7E);
      -webkit-background-clip: text;
      background-clip: text;
      color: transparent;
      margin-bottom: 16px;
    }

    .page-header p {
      font-size: 1.2rem;
      color: #374151;
      max-width: 680px;
      margin: 0 auto;
    }

    .guide-nav {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 12px;
      margin: 32px 0 48px;
    }

    .guide-nav a {
      background: #f3f4f6;
      padding: 10px 24px;
      border-radius: 60px;
      text-decoration: none;
      font-weight: 500;
      color: #1f2937;
      transition: all 0.2s;
    }

    .guide-nav a:hover {
      background: #25D366;
      color: white;
    }

    .tutorial-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
      gap: 40px;
      margin: 48px 0 80px;
    }

    .tutorial-card {
      background: #ffffff;
      border-radius: 32px;
      box-shadow: 0 8px 24px rgba(0, 0, 0, 0.04);
      border: 1px solid #eef2f0;
      overflow: hidden;
      transition: transform 0.2s, box-shadow 0.2s;
    }

    .tutorial-card:hover {
      transform: translateY(-4px);
      box-shadow: 0 20px 30px -12px rgba(0, 0, 0, 0.1);
    }

    .card-img {
      background: #cbf0da;
      padding: 32px;
      text-align: center;
      font-size: 3rem;
    }

    .card-content {
      padding: 28px 24px 32px;
    }

    .card-content h3 {
      font-size: 1.5rem;
      font-weight: 700;
      margin-bottom: 12px;
    }

    .card-content p {
      color: #4b5563;
      margin-bottom: 20px;
    }

    .step-list {
      list-style: none;
      margin: 16px 0;
    }

    .step-list li {
      margin-bottom: 12px;
      display: flex;
      align-items: flex-start;
      gap: 12px;
    }

    .step-num {
      background: #25D36620;
      color: #075e54;
      font-weight: bold;
      width: 24px;
      height: 24px;
      border-radius: 30px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      font-size: 0.8rem;
    }

    .btn-guide {
      margin-top: 12px;
      display: inline-flex;
      align-items: center;
      gap: 8px;
      color: #128C7E;
      font-weight: 600;
      text-decoration: none;
    }

    .tip-box {
      background: #fefce8;
      border-left: 4px solid #facf5a;
      padding: 20px 24px;
      border-radius: 24px;
      margin: 48px 0;
    }

    .faq-mini {
      background: #f9fafb;
      border-radius: 40px;
      padding: 48px 32px;
      margin-bottom: 64px;
    }

    .faq-mini h2 {
      text-align: center;
      margin-bottom: 32px;
      font-size: 1.8rem;
    }

    .accordion-item {
      background: white;
      border-radius: 20px;
      margin-bottom: 16px;
      padding: 8px 24px;
      border: 1px solid #e2e8f0;
    }

    .accordion-question {
      font-weight: 600;
      padding: 16px 0;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }

    .accordion-answer {
      padding-bottom: 20px;
      color: #4a5568;
      border-top: 1px solid #edf2f7;
      display: none;
    }

    .accordion-answer.show {
      display: block;
    }

    .footer {
      border-top: 1px solid #eaeef3;
      padding: 48px 0 32px;
      background: #fafcff;
    }

    .footer-grid {
      display: flex;
      flex-wrap: wrap;
      justify-content: space-between;
      gap: 32px;
      margin-bottom: 40px;
    }

    .footer-col {
      min-width: 140px;
    }

    .footer-col h4 {
      font-weight: 600;
      margin-bottom: 18px;
      color: #111827;
    }

    .footer-col ul {
      list-style: none;
    }

    .footer-col li {
      margin-bottom: 12px;
    }

    .footer-col a {
      text-decoration: none;
      color: #4b5563;
      font-size: 0.9rem;
    }

    .footer-col a:hover {
      color: #128C7E;
    }

    .copyright {
      text-align: center;
      padding-top: 28px;
      border-top: 1px solid #e5e7eb;
      font-size: 0.8rem;
      color: #6c757d;
    }

    @media (max-width: 768px) {
      .nav {
        flex-direction: column;
        gap: 16px;
      }
      .nav-links {
        flex-wrap: wrap;
        justify-content: center;
        gap: 20px;
      }
      .page-header h1 {
        font-size: 2rem;
      }
      .tutorial-grid {
        grid-template-columns: 1fr;
      }
    }