* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
  }
  
  body {
    
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background-color: cadetblue;
    background-position: 50%;
    font-family: Arial, sans-serif;
  }
  
  .calculadora {
    width: 300px;
    padding: 20px;
    background: #272121;
    border-radius: 10px;
    display: grid;
    gap: 10px;
  }
  

  .resultado {
    background: #47aa55;
    color: rgb(0, 0, 0);
    font-size: 28px;
    text-align: right;
    padding: 10px;
    border-radius: 5px;
    min-height: 50px;
    display: flex;
    align-items: center;
    justify-content: flex-end;
    overflow-x: auto;
  }
  

  .linha {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
  }
  

  button {
    padding: 15px;
    font-size: 18px;
    border-radius: 5px;
    border: none;
    background: #444;
    color: #fff;
    cursor: pointer;
    transition: background 0.2s, transform 0.1s;


  }
  
  button:hover {
    background: #666;
  }
  
  button:active {
    transform: scale(0.95);
  }
  

  button.operador {
    background: #ff9500;
  }
  
  button.operador:hover {
    background: #e08600;
  }
  

  button.reset {
    background: #f44336;
  }
  
  button.reset:hover {
    background: #d7372a;
  }
  

  button.voltar {
    background: #2196f3;
  }
  
  button.voltar:hover {
    background: #1e88e5;
  }