calc.css

body {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: #efeff2;
    background: url(https://media.istockphoto.com/id/1305511217/photo/maths.jpg?s=612x612&w=is&k=20&c=FUQiPzVtHw5BSVth9AHlDO1F2b_myKYicNFRUIEuzec=);

    background-size: cover;
}

.Calculator {
    width: 300px;
    height: 500px;
    box-shadow: 5px 5px 40px rgba(0, 0, 0, .3);
    background-color: #3d4141;
    overflow: hidden;
    border-radius: 20px;
}

form input {
    width: 100%;
    height: 150px;
    border: none;
    border-radius: 20px;
    font-size: 45px;

    color: whitesmoke;
    background: black;
    text-align: right;
    pointer-events: none;
}

.Buttons {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    padding: 20px;
}

button {
    flex: 0 0 22%;
    margin: 5px 0;
    border: 2px solid black;
    width: 60px;
    height: 50px;
    font-size: 30px;
    font-weight: 700;
    border-radius: 5px;

}

button:hover {
    cursor: pointer;
    border: 2px solid limegreen;
    box-shadow: 2px 2px blueviolet;
    transform: translate(0, -5px);
}

button:active {
    border: 2px solid red;
    box-shadow: 2px 2px maroon;
    transform: translate(0, 7px);
}

.operators {
    background: rgb(61, 173, 164);
    color: alicebluer;
    border-radius: 100px;
}

.operands {
    background-color: aquamarine;
    color: crimson;
    border-radius: 20px;
}

.operands_equal {
    background-color: rgb(161, 212, 84);
    color: rgb(43, 39, 39);
    border-radius: 80px;
}

.operands_clear {
    background-color: red;
    border-radius: 40px;
}