/* Reset */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
  }
  html, body {
    height: 100%;
  }
  body {
    font-family: Arial, sans-serif;
    background-color: #f4f4f4;
    display: flex;
    flex-direction: column;
  }
  
  /* Header & Footer */
  header, footer {
    background-color: #333;
    color: #fff;
    padding: 20px;
    text-align: center;
  }
  
  /* Header Container */
  .header-container {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
  }
  
  /* Hamburger Button (top left) */
  .menu-btn {
    background: none;
    border: none;
    color: #fff;
    font-size: 2rem;
    cursor: pointer;
    position: absolute;
    left: 20px;
    top: 50%;
    transform: translateY(-50%);
    z-index: 101;
  }
  
  /* Curtain Menu (slides in from left) */
  .curtain-menu {
    position: fixed;
    top: 0;
    left: 0;
    width: 300px;
    height: 100%;
    background: rgba(0, 0, 0, 0.9);
    transform: translateX(-100%);
    transition: transform 0.5s ease;
    z-index: 100;
  }
  .curtain-menu.open {
    transform: translateX(0);
  }
  .curtain-menu ul {
    list-style: none;
    padding: 50px 20px;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: 20px;
    text-align: center;
  }
  .curtain-menu ul li a {
    color: #fff;
    font-size: 1.5rem;
    text-decoration: none;
  }
  
  /* Header Title */
  header h1 {
    font-size: 2rem;
  }
  
  /* Footer */
  footer p {
    margin: 0;
    text-align: center;
  }
  
  /* Main Content Area */
  main {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
    padding: 20px;
    width: 100%;
  }
  
  /* Hide content-section by default unless visible class is present */
  .content-section {
    display: none;
    width: 90%;
    margin-bottom: 20px;
  }
  .content-section.visible {
    display: block;
    animation: fadeIn 0.5s ease;
  }
  @keyframes fadeIn {
    from { opacity: 0; }
    to   { opacity: 1; }
  }
  
  /* Grid for 6 columns per row */
  .cards-grid {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: 20px;
    margin-top: 20px;
  }
  
  /* Reagent Card Style */
  .reagent-card {
    background: #fff;
    border-radius: 8px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
    padding: 15px;
    text-align: center;
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
  }
  .reagent-card h3 {
    font-size: 1.2rem;
    margin-bottom: 5px;
  }
  .reagent-card p {
    margin: 5px 0;
    font-size: 0.9rem;
  }
  .reagent-img {
    width: 100%;
    height: 150px;
    object-fit: cover;
    border-radius: 4px;
    margin-bottom: 10px;
  }
  .edit-btn {
    background-color: #ffc107;
    color: #333;
    border: none;
    padding: 5px 10px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: background-color 0.3s ease;
    margin-top: auto; /* push edit button to bottom */
  }
  .edit-btn:hover {
    background-color: #e0a800;
  }
  
  /* Floating Action Button (FAB) */
  .fab {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background-color: #007bff;
    color: #fff;
    border: none;
    border-radius: 50%;
    width: 60px;
    height: 60px;
    font-size: 2rem;
    cursor: pointer;
    box-shadow: 0 4px 8px rgba(0,0,0,0.3);
    z-index: 200;
    transition: background-color 0.3s ease;
  }
  .fab:hover {
    background-color: #0056b3;
  }
  
  /* Modal Overlay */
  .modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 150;
  }
  
  /* Modal Window */
  .modal {
    background: #fff;
    width: 90%;
    max-width: 500px;
    padding: 20px;
    border-radius: 8px;
    position: relative;
    box-shadow: 0 4px 8px rgba(0,0,0,0.2);
  }
  
  /* Modal Close Button */
  .modal-close {
    position: absolute;
    top: 10px;
    right: 15px;
    font-size: 1.5rem;
    cursor: pointer;
  }
  
  /* Form Group */
  .form-group {
    margin-bottom: 15px;
  }
  .form-group label {
    display: block;
    font-weight: bold;
    margin-bottom: 5px;
  }
  .form-group input,
  .form-group select {
    width: 100%;
    padding: 8px;
    border: 1px solid #ccc;
    border-radius: 4px;
  }
  
  /* Submit Button */
  .submit-btn {
    background-color: #28a745;
    color: #fff;
    border: none;
    padding: 10px 15px;
    font-size: 1rem;
    border-radius: 4px;
    cursor: pointer;
    width: 100%;
    transition: background-color 0.3s ease;
    margin-top: 10px;
  }
  .submit-btn:hover {
    background-color: #218838;
  }
  
  /* Delete Button for Edit Modal */
  .delete-btn {
    background-color: #dc3545;
    color: #fff;
    border: none;
    padding: 10px 15px;
    font-size: 1rem;
    border-radius: 4px;
    cursor: pointer;
    width: 100%;
    margin-top: 10px;
    transition: background-color 0.3s ease;
  }
  .delete-btn:hover {
    background-color: #c82333;
  }
  
  /* Reagent Card Style with on-hover effects */
  .reagent-card {
    background: #fff;
    border-radius: 8px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
    padding: 15px;
    text-align: center;
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    transition: transform 0.3s ease, box-shadow 0.3s ease, filter 0.3s ease;
  }
  
  .reagent-card:hover {
    transform: scale(1.05);
    box-shadow: 0 8px 16px rgba(0,0,0,0.4);
    filter: brightness(1.05);
  }