body{
    display: flex;
    flex-direction: column;
    align-items: center;
    
}
.calc-borda{
    border: 20px solid black;
    padding: 20px;
}
#display{
    width: 400px;
    height: 40px;
    background-color: black;
    margin: 4px;
    padding-left: 10px;
    color: white;
    font-size: 18px;
    font-family: Verdana, Geneva, Tahoma, sans-serif;
}

.calculadora {
    border: 1px solid #ccc;
    border-radius: 5px;
    width: 400px;
}

button {
height: 60px;
background-color: #fff;
border-radius: 3px;
border: 1px solid #c4c4c4;
background-color: transparent;
font-size: 2rem;
color: #333;
background-image: linear-gradient(to bottom,transparent,transparent 50%,rgba(0,0,0,.04));
box-shadow: inset 0 0 0 1px rgba(255,255,255,.05), inset 0 1px 0 0 rgba(255,255,255,.45), inset 0 -1px 0 0 rgba(255,255,255,.15), 0 1px 0 0 rgba(255,255,255,.15);
text-shadow: 0 1px rgba(255,255,255,.4);
}

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

.operador {
color: #91999e;
}

.igual {
    background-color: #2e86c0;
    border-color: #337cac;
    color: #fff;
}

.igual:hover {
    background-color:#4e9ed4;
}

.teclas-calculadora {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr 1fr;
}