* {
    margin: 0;
    padding: 0;
    font-family: 'Poppins', sans-serif;
    box-sizing: border-box;
}

.container {
    width: 100%;
    height: 100vh;
    background: #e3f9ff;
    display: flex;
    align-items: center;
    justify-content: center;
}

.calculator {
    background: #3a4452;
    padding: 20px;
    border-radius: 10px;
}

.calculator div {
    display: flex;
    justify-content: center;
}

.calculator input {
    border: 0;
    outline: 0;
    width: 60px;
    height: 60px;
    border-radius: 10px;
    box-shadow: -8px -8px 15px rgba(255, 255, 255, 0.1),
                5px 5px 15px rgba(0, 0, 0, 0.2);
    background: transparent;
    color: #fff;
    font-size: 20px;
    cursor: pointer;
    margin: 10px;
}

#display {
    width: 100%;
    height: 80px;
    border: none;
    margin-bottom: 20px;
    border-radius: 10px;
    text-align: right;
    padding: 10px;
    font-size: 30px;
    background: #222;
    color: #fff;
    box-shadow: inset -5px -5px 10px rgba(255,255,255,0.1),
                inset 5px 5px 10px rgba(0,0,0,0.3);
}
form .display{
    display: flex;
    justify-content: center;
    margin: 20px 0;
}
form .display input{
    text-align: right;
    flex: 1;
    font-size: 45px;
    box-shadow: none;
}
form input.equal{
    width: 140px;
}
form input.operator{
    color: rgb(0, 255, 247);
}