*, *::before, *::after {
      box-sizing: border-box;
    }

    body {
      font-family: 'Roboto', sans-serif;
      background: #f5f7fa;
      margin: 0;
      padding: 40px 20px;
      color: #333;
      min-height: 100vh;
      display: flex;
      flex-direction: column;
      align-items: center;
      line-height: 1;
    }

    header {
      width: 100%;
      max-width: 900px;
      text-align: center;
      margin-bottom: 40px;
    }

    header h1 {
      margin: 0;
      font-weight: 700;
      font-size: 2.8rem;
      color: #2c3e50;
      line-height: 1;
    }
    header h2 {
      margin: 0;
      font-weight: 400;
      font-size: 2.1rem;
      color: #2c3e50;
      line-height: 1;
    }
    header h3 {
      margin: 0;
      font-weight: 150;
      font-size: 2.1rem;
      color: #2c3e50;
      line-height: 1;
    }
    
    header p {
      margin-top: 10px;
      font-weight: 400;
      font-size: 1.25rem;
      color: #7f8c8d;
    }

    section {
      width: 100%;
      max-width: 900px;
      margin-bottom: 50px;
    }

    section h2 {
      color: #2980b9;
      font-weight: 600;
      font-size: 1.1rem;
      margin-bottom: 20px;
      border-bottom: 2px solid #2980b9;
      padding-bottom: 5px;
    }

    section h3 {
      color: #2980b9;
      font-weight: 100;
      font-size: 1.1rem;
      margin-bottom: 20px;
      border-bottom: 2px solid #2980b9;
      padding-bottom: 5px;
    }

    .grid-container {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
      gap: 25px;
    }

    a.button {
      display: inline-block;
      background: #2980b9;
      color: #fff;
      text-decoration: none;
      padding: 18px 15px;
      border-radius: 8px;
      font-size: 1.1rem;
      font-weight: 600;
      text-align: center;
      box-shadow: 0 6px 12px rgba(41, 128, 185, 0.3);
      transition: background 0.3s ease, box-shadow 0.3s ease, transform 0.2s ease;
      user-select: none;
      cursor: pointer;
    }

    a.button:hover,
    a.button:focus {
      background: #1c5985;
      box-shadow: 0 8px 16px rgba(28, 89, 133, 0.6);
      outline: none;
      transform: translateY(-2px);
    }

    a.button:active {
      background: #154466;
      box-shadow: 0 4px 8px rgba(21, 68, 102, 0.8);
      transform: translateY(0);
    }

    footer {
      margin-top: auto;
      text-align: center;
      font-size: 0.9rem;
      color: #95a5a6;
      padding: 15px 10px;
      width: 100%;
      max-width: 900px;
    }

    @media (max-width: 400px) {
      a.button {
        font-size: 1rem;
        padding: 14px 10px;
      }
    }