* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
  }
  
  body {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background: linear-gradient(135deg, #89fffd, #ef32d9);
    font-family: 'Arial', sans-serif;
  }
  
  .calculator {
    background-color: #1e1e2f;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    padding: 20px;
    max-width: 400px;
    width: 100%;
  }
  
  #display {
    width: 100%;
    height: 70px;
    margin-bottom: 20px;
    font-size: 36px;
    padding: 15px;
    text-align: right;
    border: none;
    border-radius: 10px;
    background-color: #282c34;
    color: #f2f2f2;
    box-shadow: inset 0 4px 8px rgba(0, 0, 0, 0.3);
  }
  
  .buttons {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 15px;
  }
  
  button {
    font-size: 24px;
    padding: 20px;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
    color: black;
  }
  
  .number-btn {
    background-color: #3a3d49;
  }
  
  .function-btn {
    background-color: #f78166;
  }
  
  .equal-btn {
    background-color: #4caf50;
    grid-column: span 2;
  }
  
  .wide-btn {
    grid-column: span 2;
  }
  
  button:hover {
    transform: scale(1.05);
  }
  
  button:active {
    transform: scale(1);
    box-shadow: inset 0 3px 5px rgba(0, 0, 0, 0.2);
  }
  
  button.function-btn:hover {
    background-color: #e8644e;
  }
  
  button.equal-btn:hover {
    background-color: #45a043;
  }
  
  button.number-btn:hover {
    background-color: #2c2f36;
  }