body{
    background-color: #d0d0d0;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    font-family: 'Segoe UI', sans-serif;

}

.calculadora{
    background-color: #333;
    padding: 20px;
    border-radius: 20px;
    box-shadow: 0 10px 25px rgba(0,0,0,5);
    width: 320px; 
}
 
.visor{
    background-color: black;
    color:#0f0;
    font-size: 36px;
    text-align: right;
    padding: 20px;
    border-radius: 10px;
    margin-bottom: 20px;
    box-shadow: inset 0 0 8px #0f0;
    height: 60px;
    overflow-x: auto;
}

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

button{
    padding: 20px;
  font-size: 20px;
  border: none;
  border-radius: 10px;
  background-color: #555;
  color: white;
  cursor: pointer;
  transition: 0.2s;
}

button::hover{
background-color: #777;
}

button.igual {
  background-color: #009688;
  grid-row: span 2;
}

button.igual:hover {
  background-color: #00796b;
}

button.zero {
  grid-column: span 2;
}