* {  
  box-sizing: border-box;  
}  

body {  
  font-family: Arial, sans-serif;  
  background-color: #f4f4f4;  
  display: flex;  
  justify-content: center;  
  margin: 0;
  padding: 20px;  
}  

.container {  
  background-color: #ffffff;  
  border-radius: 10px;  
  padding: 30px;  
  box-shadow: 0px 0px 15px rgba(0, 0, 0, 0.1);  
  width: 80%;  
  max-width: 900px;
}  

textarea {  
  width: 100%;  
  height: 200px;  
  border-radius: 5px;  
  padding: 15px;  
  font-size: 16px;  
  border: 1px solid #ddd;  
  resize: none;  
}  

a.button, button {
  display: block;  
  width: 100%;  
  margin: 20px 0;  
  padding: 10px;  
  background-color: #3498db;  
  color: #ffffff;  
  border: none;  
  border-radius: 5px;  
  cursor: pointer;  
  font-size: 18px;  
}  

button:hover {  
  background-color: #2980b9;  
}  

button:disabled {  
  background-color: #b3c2c8;  
  cursor: not-allowed;  
}  

@keyframes spin {  
  0% { transform: rotate(0deg); }  
  100% { transform: rotate(360deg); }  
}  

#spinner {  
  display: none;  
  margin-right: 10px;  
  animation: spin 1s linear infinite;  
}  

#spinner.show {  
  display: inline-block;  
}  

#output-div {  
  display: none;  
  background-color: #f9f9f9;  
  border: 1px solid #ddd;  
  padding: 15px;  
  border-radius: 5px;  
  font-size: 16px;  
}