/* Base styles */
 * {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
  }
  
  body {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background-color: #f0f0f0;
    font-family: Arial, sans-serif;
  }
  
  /* Calculator styles */
  .calculator {
    background-color: #333;
    padding: 20px;
    border-radius: 20px;
    box-shadow: 0px 10px 20px rgba(0, 0, 0, 0.5);
  }
  
  /* Display styles */
  .display {
    color: #333;
    background-color: #9BD5C0;
    margin-bottom: 10px;
    padding: 20px;
    border-radius: 10px;
    display: flex;
    justify-content: space-between;
    align-items: center;
  }
  
  #display {
    border: none;
    background-color: transparent;
    font-size: 2em;
    width: 100%;
    text-align: right;
  }
  
  /* Button grid */
  .buttons {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
  }
  
  /* Button styles */
  .button {
    background-color: #666;
    color: white;
    border: none;
    border-radius: 10px;
    margin: 5px;
    padding: 15px 0;
    flex-basis: calc(25% - 10px);
    font-size: 1.5em;
    transition: background-color 0.3s ease;
    cursor: pointer;
  }
  
  .button:active {
    background-color: #555;
  }
  
  /* Modifier buttons */
  #clear-display {
    background-color: #ff6666; /* Red color for clear button */
  }
  
  #add, #subtract, #multiply, #divide, #equals {
    background-color: #4d4d4d; /* Darker color for operation buttons */
  }
  
  /* Handling the equals button separately if needed */
  #equals {
    background-color: #337ab7; /* Different color for the equals button */
  }
  
  /* Adjust the width of the zero button to be double */
  .button[id="0"] {
    flex-basis: calc(50% - 10px);
  }
  
  /* Adjust the width of the operator buttons to be full */
  .button[id="divide"] {
    flex-basis: 100%;
  }
  
  /* Hover effect */
  .button:hover {
    background-color: #7e7e7e;
  }