styles.css

body {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100vh;
    margin: 0;
    background-color: #f5f5f5; /* Light gray background color */
  }
  
  .calculator {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 8px;
    max-width: 400px;
    margin: 20px;
    background-color: #579fda; /* Blue background color */
    border: 10px solid #1b4c84; /* Thick border color */
    border-radius: 8px; /* Rounded corners */
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1); /* Shadow for a lifted effect */
  }
  
  .display {
    grid-column: span 4;
    background-color: #65abf1; /* Darker blue for display background */
    padding: 15px;
    text-align: right;
    font-size: 1.5em;
    color: #090808; /* White text */
    border-top-left-radius: 8px;
    border-top-right-radius: 8px;
  }
  
  button {
    padding: 15px;
    font-size: 1.2em;
    background-color: #4caf50; /* Green buttons */
    color: #100c0c; /* White text */
    border: none;
    border-radius: 4px;
    cursor: pointer;
  }
  
  .equals {
    grid-column: span 2;
    background-color: #ff9800; /* Orange equals button */
  }
  
  .zero {
    grid-column: span 2;
  }
  
  .filler {
    grid-column: span 4;
    opacity: 0;
    cursor: default;
  }