body{
    margin: 0;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background-color: black;
}
h1{
    color: white;
    font-family: 'Gill Sans', 'Gill Sans MT', Calibri, 'Trebuchet MS', sans-serif;
    font-size: 50px;
}
operator-btn{
    background-color: #393838;
}
button{
    width: 100px;
    height: 100px;
    border-radius: 10px;
    border: none;
    background-color: #343434;
    color: rgb(255, 255, 255);
    font-size: 3rem;
    font-weight: bold;
    cursor: pointer;
}
#btn{
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
    padding: 25px;
}
#calculator{
    font-family: Arial, sans-serif;
    background-color: hsl(0, 0%, 15%);
    border-radius: 15px;
    max-width: 500px;
    overflow: hidden;
}
#display{
    width: 100%;
    padding: 20px;
    font-size: 5rem;
    text-align:left;
    border: none;
    background-color: #2f2f2f;
    color: white;
}

button:hover{
    background-color: #393838;
    transform:translateY(-3px);
    transition-property:transform,background-color,color;
    transition-duration: .4s;
    transition-timing-function:ease ;
    transition-delay: 0s ;
    background-color: rgb(28, 28, 28)
}
.Equal:active{
    background-color: green;
}

.clear:active{
    background-color: red;
}