body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            line-height: 1.6;
            color: #333;
            max-width: 1024px;
            margin: 0 auto;
            padding: 4px;
            background-color: #f5f5f5;
        }
        
        .container {
            background-color: white;
            padding: 1em;
            border-radius: 8px;
            box-shadow: 2px 2px 4px rgb(128, 128, 128);
        }
        
        h1 {
            color: #fff;
            margin-top: 0;
            font-size: 1.25em;
            text-align: center;
            background: gray;
            text-transform: uppercase;
        }
        
        h2 {
            color: #2767fd;
            margin-top: 0;
            font-size: 1.2em;
            padding-left: 4%;
        }
        
        .cuestion {
            margin-bottom: 30px;
            padding: 1em;
            border: 1px solid #ddd;
            border-radius: 8px;
            background-color: wheat;
            transition: all 0.3s ease;
        }
        
        .cuestion:hover {
            box-shadow: 4px 4px 4px rgba(0,0,0,0.5);
        }
        
        .enunciado {
            margin-bottom: 15px;
        }
        
        .ce {
            font-size: 0.9em;
            color: #7f8c8d;
            background-color: #ecf0f1;
            padding: 5px 12px;
            border-radius: 4px;
            display: inline-block;
            margin-top: 10px;
        }
        
        .respuesta-usuario {
            width: 96%;
            padding: 1em;
            margin: 15px 0;
            border: 1px inset #f9f9f9;
            border-radius: 4px;
            background-color: white;
            font-family: inherit;
            transition: border-color 0.3s;
        }
        
        .respuesta-usuario:focus {
            outline: none;
            border-color: #3498db;
        }
        
        .respuesta-usuario[placeholder]:empty:before {
            content: attr(placeholder);
            color: #95a5a6;
            font-style: italic;
        }
        
        .btn {
            background-color: #2767fd;
            color: white;
            padding: 10px 20px;
            border: none;
            border-radius: 6px;
            cursor: pointer;
            margin-right: 10px;
            font-size: 0.95em;
            transition: all 0.3s;
            float: right;
        }
        
        .btn:hover {
            background-color: #03ac0d;
            transform: translateY(-1px);
        }
        
        .btn:disabled {
            background-color: #bdc3c7;
            cursor: not-allowed;
            transform: none;
        }
        
        .solucion {
            display: none;
            margin-top: 10px;
            padding: 10px;
            background-color: #e8f4fc;
            border-left: 4px solid #3498db;
            border-radius: 0 8px 8px 0;
        }
        
        ul {
            padding-left: 20px;
        }
        
        li {
            margin-bottom: 8px;
        }
        
        .clean {
            clear: both;
        }
        
        pre {
            background-color: #f0f0f0;
            padding: 1em;
            border-radius: 4px;
            overflow-x: auto;
            font-family: 'Courier New', Courier, monospace;
            line-height: 1.6;
            border-left: 3px solid #3498db;
        }
    .boton-inicio {
  display: inline-block;
  text-align: center;
  text-decoration: none;
  margin: 3em;
  background-color: #ff3030;
  color: white;
  float: right;
  border: none;
  padding: 8px 16px;
  border-radius: 50px;
  font-size: 1em;
  transition: all 0.3s ease;
  box-shadow: 2px 2px 2px rgb(255, 255, 255);
}    
    .boton-inicio:hover {
      background-color: #2980b9;
      transform: translateY(-2px);
      box-shadow: 0 4px 8px rgba(0,0,0,0.2);
    }        
        @media (max-width: 768px) {
            body {
                padding: 10px;
            }
            
            .container {
                padding: 10px;
            }
            
            .cuestion {
                padding: 10px;
            }
        }