* {
    padding: 0;
    margin: 0;
    box-sizing: border-box;
    font-family: 'Poppins', sans-serif;
}
body {
    background-color: powderblue;
}
.container {
    width: 100%;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}
.calc {
    background-color: #354253;
    padding: 20px;
    border-radius: 10px;
    border: 3px solid #66a19b;
}
form .display {
    display: flex;
    justify-content: flex-end;
    margin: 10px 0;
}
form .display input {
    border: none;
    outline: none;
    width: 60px;
    height: 60px;
    border-radius: 10px;
    font-size: 20px;
    color: #fff;
    margin: 10px;
    cursor: pointer;
    background: transparent;
    text-align: right;
    flex: 1;
}
.calc form .num button {
    border: none;
    outline: none;
    width: 60px;
    height: 60px;
    border-radius: 50%;
    background: transparent;
    box-shadow: -8px -8px 15px rgba(255, 255, 255, 0.1), 5px 5px 15px rgba(0, 0, 0, 0.2);
    font-size: 20px;
    color: #fff;
    margin: 10px;
    cursor: pointer;
}
form .num button.equal {
    background-color: #fb7c14;
    box-shadow: none;
}
form .num button.operator {
    color: aqua;
}
form .num button:hover:not(.equal) {
    color: aqua;
}
form .num button:active {
    background-color: black;
    transform: translate(2px, 2px);
}