body, html {
    margin: 0;
    padding: 0;
    font-family: Arial, sans-serif;
    height: 100%;
    display: flex;
  }
  
  /* Container */
  .container {
    display: flex;
    height: 105vh;
  }
  
  /* Navbar Styles */
  .navbar {
    width: 250px;
    background-color: #1f2937; /* Tailwind's gray-800 */
    color: white;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
  }
  
  .navbar-header {
    padding: 16px;
    font-size: 28px;
    font-weight: bold;
    border-bottom: 2px solid #374151; /* Tailwind's gray-700 */
    display: flex;
    justify-content: center;
  }
  
  .navbar-menu {
    list-style: none;
    padding: 0;
    margin: 0;
    flex-grow: 1;
  }
  
  .menu-item {
    padding: 16px;
    transition: background-color 0.3s;
  }
  
  .menu-item a {
    text-decoration: none; /* Remove underline */
    color: inherit; /* Inherit color from parent */
    display: block; /* Make the entire item clickable */
  }
  
  .menu-item:hover {
    background-color: aqua; /* Tailwind's gray-700 */
    transition: 0.7s;
  }
  
  .menu-item a:hover {
    color: #d1d5db; /* Tailwind's gray-300 */
  }
  
  .navbar-footer {
    padding: 16px;
    border-top: 1px solid #374151; /* Tailwind's gray-700 */
    text-align: center;
  }
  
    /* Main Content Styles */
    .main-content {
      flex-grow: 1;
      padding: 32px;
    }
  
    .main-content h1 {
      font-size: 28px;
      font-weight: bold;
    }
  
    .main-content p {
      margin-top: 16px;
      font-size: 16px;
      line-height: 1.5;
    }
  
    form {
      background: linear-gradient(250deg, #78A3D4, #000);
      padding: 30px;
      border-radius: 8px;
      box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
      width: 1604px; /* ปรับให้ฟอร์มกว้างขึ้น */
      box-sizing: border-box;
  }
  
  h2 {
      text-align: center;
      color: #fff;
      margin-bottom: 30px;
  }
  
  label {
      font-size: 16px;
      color: #fff;
      margin-bottom: 10px;
      display: block;
  }
  
  select, textarea {
      width: 100%;
      padding: 12px;
      margin-bottom: 20px;
      border: 1px solid #ddd;
      border-radius: 4px;
      font-size: 16px;
      box-sizing: border-box;
  }
  
  textarea {
      resize: vertical;
      height: 120px; /* ขยายพื้นที่ textarea */
  }
  
  button {
      width: 100%;
      padding: 14px;
      background: linear-gradient(135deg, #fff, #000);
      color: white;
      border: none;
      border-radius: 4px;
      font-size: 18px;
      cursor: pointer;
      transition: 0.7s ease;
  }
  
  button:hover {
      background: linear-gradient(135deg, #000, #fff);
  }
  
  select:focus, textarea:focus {
      border-color: #007bff;
      outline: none;
  }

#phone {
  width: 100%;
  padding: 12px;
  font-size: 16px;
  border: 1px solid #ddd;
  border-radius: 4px;
  background-color: #f9f9f9;
  box-sizing: border-box;
  transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

#phone:focus {
  border-color: #007bff;
  background-color: #e6f0ff;
  outline: none;
  box-shadow: 0 0 5px rgba(0, 123, 255, 0.5);
}