/* General styles */
    body {
      font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
      margin: 0;
      padding: 20px;
      background-color: #f0f2f5;
      display: flex;
      justify-content: center;
    }
    
    .container {
      max-width: 1000px;
      width: 100%;
      background-color: #f1f1f1;
      border-radius: 8px;
      box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
      padding: 20px;
    }
    
    h1, h2 {
      color: #333;
      margin-top: 0;
    }
    
    /* Controls section */
    .controls {
      display: flex;
      flex-wrap: wrap;
      gap: 16px;
      margin-bottom: 24px;
      justify-content: center;
    }
    
    .control-group {
      display: flex;
      flex-direction: column;
    }
    
    .control-group label {
      font-weight: 500;
      margin-bottom: 4px;
    }
    
    select, input {
      padding: 8px;
      border: 1px solid #ccc;
      border-radius: 4px;
      width: 200px;
    }
    
    input[type="range"] {
      width: 200px;
    }
    
    /* Buttons */
    .buttons {
      display: flex;
      gap: 8px;
      margin-bottom: 24px;
      flex-wrap: wrap;
    }
    
    button {
      padding: 8px 16px;
      border: none;
      border-radius: 4px;
      cursor: pointer;
      font-weight: 500;
      transition: background-color 0.2s;
    }
    
    button:disabled {
      opacity: 0.5;
      cursor: not-allowed;
    }
    
    .btn-start {
      background-color: #4CAF50;
      color: white;
    }
    
    .btn-start:hover:not(:disabled) {
      background-color: #45a049;
    }
    
    .btn-stop {
      background-color: #f44336;
      color: white;
    }
    
    .btn-stop:hover:not(:disabled) {
      background-color: #d32f2f;
    }
    
    .btn-reset {
      background-color: #808080;
      color: white;
    }
    
    .btn-reset:hover {
      background-color: #707070;
    }
    
    .btn-add {
      background-color: #2196F3;
      color: white;
    }
    
    .btn-add:hover:not(:disabled) {
      background-color: #0b7dda;
    }
    
    /* Main display area */
    .display-area {
      display: flex;
      flex-direction: column;
      gap: 24px;
    }
    
    @media (min-width: 768px) {
      .display-area {
        flex-direction: row;
      }
    }
    
    .flask-container, .graph-container {
      flex: 1;
      background-color: white;
      padding: 16px;
      border-radius: 4px;
      box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
    }
    
    /* Flask visualization */
    .flask-visualization {
      position: relative;
      height: 256px;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    
    .flask {
      position: relative;
    }
    
    .flask-body {
      width: 160px;
      height: 160px;
      border: 2px solid #888;
      border-top: 0;
      border-radius: 0 0 80px 80px;
      overflow: hidden;
      position: relative;
    }
    
    .flask-solution {
      position: absolute;
      bottom: 0;
      width: 100%;
      height: 75%;
      border-radius: 0 0 80px 80px;
      transition: background-color 0.5s;
    }
    
    .flask-neck {
      width: 64px;
      height: 48px;
      background-color: white;
      border: 2px solid #888;
      border-bottom: 0;
      margin: 0 auto;
    }
    
    .burette-tip {
      position: absolute;
      top: 0;
      left: 50%;
      transform: translateX(-50%) translateY(-100%);
    }
    
    .burette-stem {
      width: 8px;
      height: 48px;
      background-color: #bbb;
      margin: 0 auto;
    }
    
    .burette-end {
      width: 16px;
      height: 16px;
      background-color: #bbb;
      margin: -4px auto 0;
      border-radius: 0 0 8px 8px;
    }
    
    .drop {
      width: 8px;
      height: 8px;
      background-color: #4dabf7;
      border-radius: 50%;
      margin: 0 auto;
      animation: drop 1s infinite;
    }
    
    @keyframes drop {
      0% {
        transform: translateY(0);
        opacity: 1;
      }
      100% {
        transform: translateY(20px);
        opacity: 0;
      }
    }
    
    .flask-info {
      margin-top: 16px;
    }
    
    .flask-info p {
      margin: 8px 0;
    }
    
    .equivalence-point {
      color: #2e7d32;
      font-weight: bold;
      margin-top: 8px;
    }
    
    /* Graph */
    .graph-container svg {
      border: 1px solid #ddd;
    }
    
    /* Instructions */
    .instructions {
      width: 100%;
      margin-top: 24px;
      background-color: white;
      padding: 16px;
      border-radius: 4px;
      box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
    }
    
    .instructions ul {
      padding-left: 20px;
    }
    
    .instructions li {
      margin-bottom: 4px;
    }
    
    .chem-info {
      margin-top: 16px;
      font-size: 0.9em;
      color: #666;
    }