/* Reset CSS */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
  }
  
  body {
    font-family: 'Roboto', sans-serif;
    line-height: 1.6;
    background: linear-gradient(to bottom, #6a11cb, #2575fc); /* Gradient nền chính */
    color: #333;
    padding: 0 1rem;
  }
  
  .container {
    max-width: 900px;
    margin: 2rem auto;
    background: rgba(255, 255, 255, 0.9); /* Nền trắng mờ */
    border-radius: 12px;
    box-shadow: 0 6px 15px rgba(0, 0, 0, 0.1);
    padding: 2rem;
    backdrop-filter: blur(10px); /* Hiệu ứng mờ nền */
  }
  
  h1 {
    text-align: center;
    font-size: 2.5rem;
    color: #2575fc;
    margin-bottom: 1.5rem;
    font-weight: 700;
    position: relative;
  }
  
  h1::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background: #2575fc;
    margin: 0.5rem auto 0;
    border-radius: 2px;
  }
  
  .form-container {
    margin-bottom: 2rem;
  }
  
  .form-group {
    display: flex;
    flex-direction: column;
    margin-bottom: 1.5rem;
  }
  
  .form-group label {
    font-weight: 500;
    margin-bottom: 0.5rem;
    color: #444;
    font-size: 1rem;
  }
  
  .form-group input,
  .form-group textarea,
  .form-group select {
    padding: 0.9rem;
    font-size: 1rem;
    border: 1px solid #ddd;
    border-radius: 8px;
    outline: none;
    transition: all 0.3s ease;
    background-color: #f9f9f9;
  }
  
  .form-group input:focus,
  .form-group textarea:focus,
  .form-group select:focus {
    border-color: #2575fc;
    box-shadow: 0 0 8px rgba(37, 117, 252, 0.3);
    background-color: #ffffff;
  }
  
  .form-group textarea {
    resize: vertical;
    min-height: 120px;
  }
  
  .form-actions {
    display: flex;
    justify-content: flex-end;
    gap: 1rem;
  }
  
  .form-actions button {
    padding: 0.8rem 1.5rem;
    font-size: 1rem;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 500;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
  }
  
  #saveBtn {
    background: linear-gradient(to right, #2575fc, #6a11cb);
    color: #fff;
  }
  
  #saveBtn:hover {
    background: linear-gradient(to right, #1a5fc1, #531bb8);
    transform: translateY(-2px);
    box-shadow: 0 6px 15px rgba(0, 0, 0, 0.2);
  }
  
  .delete-btn {
    background: #ff4d4d;
    color: #fff;
  }
  
  .delete-btn:hover {
    background: #e63939;
    transform: translateY(-2px);
    box-shadow: 0 6px 15px rgba(0, 0, 0, 0.2);
  }
  
  .course-list-container {
    margin-top: 2rem;
    padding: 1.5rem;
    background: rgba(255, 255, 255, 0.9); /* Nền trắng mờ */
    border-radius: 12px;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
    backdrop-filter: blur(10px); /* Hiệu ứng mờ nền */
  }
  
  .course-list-container h2 {
    font-size: 1.8rem;
    margin-bottom: 1rem;
    color: #2575fc;
    text-align: center;
    font-weight: 600;
    position: relative;
  }
  
  .course-list-container h2::after {
    content: '';
    display: block;
    width: 40px;
    height: 3px;
    background: #2575fc;
    margin: 0.5rem auto 0;
    border-radius: 2px;
  }
  
  table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 1rem;
    background-color: rgba(255, 255, 255, 0.9); /* Nền trắng mờ */
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
  }
  
  table th,
  table td {
    border: 1px solid #ddd;
    padding: 1rem;
    text-align: center;
    font-size: 1rem;
  }
  
  table th {
    background-color: #2575fc;
    color: #fff;
    font-weight: 600;
  }
  
  table td {
    word-wrap: break-word;
    max-width: 200px;
    color: #555;
  }
  
  table tbody tr:nth-child(even) {
    background-color: rgba(245, 245, 245, 0.9);
  }
  
  table tbody tr:hover {
    background-color: rgba(240, 240, 240, 0.9);
    transition: background-color 0.3s ease, transform 0.2s ease;
    transform: scale(1.01);
  }
  
  /* Responsive Design */
  @media (max-width: 768px) {
    .form-group {
      flex-direction: column;
    }
  
    .form-actions {
      flex-direction: column;
      gap: 0.5rem;
    }
  
    table {
      display: block;
      overflow-x: auto;
      white-space: nowrap;
    }
  
    table th,
    table td {
      font-size: 0.9rem;
      padding: 0.8rem;
    }
  }