body {
      font-family: Arial, sans-serif;
      font-size: 18px;
      background-color: #f4f4f4;
      display: flex;
      /*canh lề trai-phải*/
      justify-content: center;
      /*canh lề trên-dưới*/
      align-items: center;
      min-height: 100vh;
      margin: 0;
      padding: 20px;
      box-sizing: border-box;
    }

    .container {
      background-color: #fff;
      padding: 25px 20px;
      border-radius: 8px;
      box-shadow: 0 0 15px rgba(0,0,0,0.1);
      width: 100%;
      max-width: 80vw;
    }
    .highlight {
      color: red;
      font-style: italic;
    }
    h1 {
      text-align: center;
      color: #333;
      margin-bottom: 20px;
    }

    .form-group {
      margin-bottom: 15px;
    }

    .form-group label {
      display: block;
      margin-bottom: 5px;
      color: #555;
      font-weight: bold;
    }
	.form-group input[type="password"],
    .form-group input[type="text"],
    .form-group input[type="email"]{
      width: 100%;
      padding: 10px;
      border: 1px solid #ddd;
      border-radius: 4px;
      box-sizing: border-box;
    }
    .form-group select {
      display: inline-block;
      width: 100%;
      max-width: 500px;
      height: 40px;               /* fix chiều cao */
      padding: 8px 12px;
      font-size: 14px;
      border: 1px solid #ccc;
      border-radius: 4px;
      background-color: #fff;

      /* giữ mũi tên mặc định */
      appearance: auto;
      -webkit-appearance: auto;
      -moz-appearance: auto;

      /* bỏ mấy cái gây lỗi */
      white-space: normal;
      text-overflow: initial;
      overflow: visible;
    }

    .form-group input[type="file"] {
      width: 100%;
      line-height: 60px;         /* căn text theo chiều cao */
      padding: 0 10px;           /* padding ngang thôi, bỏ padding dọc */
      border: 1px solid #ddd;
      border-radius: 4px;
      box-sizing: border-box;
      appearance: none;          /* bỏ style mặc định của browser */
      -webkit-appearance: none;  /* Safari, Chrome */
      -moz-appearance: none;     /* Firefox */
    }

    .form-group input[type="file"] {
      padding: 3px;
    }

    .form-group input:focus,
    .form-group select:focus {
      outline: none;
      border-color: #007bff;
      box-shadow: 0 0 0 0.2rem rgba(0,123,255,.25);
    }

    .btn-submit {
      background-color: #007bff;
      color: white;
      padding: 10px 15px;
      border: none;
      border-radius: 8px;
      cursor: pointer;
      font-size: 16px;
      width: 200px;
      transition: background-color 0.3s ease;
    }

    .btn-submit:hover {
      background-color: #0056b3;
    }

    .profile-preview {
      max-width: 150px;
      max-height: 150px;
      border: 1px solid #ddd;
      margin-top: 5px;
      border-radius: 4px;
    }

    .messages .error,
    .messages .success {
      padding: 10px;
      border-radius: 4px;
      margin-bottom: 15px;
    }

    .messages .error {
      background-color: #f8d7da;
      color: #721c24;
      border: 1px solid #f5c6cb;
    }

    .messages .success {
      background-color: #d4edda;
      color: #155724;
      border: 1px solid #c3e6cb;
    }

    .messages .success a {
      color: #0f5132;
      font-weight: bold;
      text-decoration: underline;
    }
  
  @media screen and (max-width: 480px) {
      .container {
        padding: 20px 15px;
      }

      .form-group input,
      .form-group select {
        font-size: 16px;
      }

      .btn-submit {
        font-size: 18px;
      }
    }
.image-container {
  width: 100%;
  max-width: 500px;
  margin: auto;
}

.frame {
  width: 400px;
  height: 300px;
  border: 2px dashed #ccc;
  overflow: hidden;
  position: relative;
  margin-top: 10px;
  background-color: #f9f9f9;
}

.frame img {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%) scale(1);
  transition: transform 0.2s ease;
  cursor: grab;
}