* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

.container {
    height: 100vh;
    width: 100vw;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, aquamarine, blue);
}


.calculator {
    max-width: 48vmin;
    width: 100%;
    display: flex;
    align-items: center;
    flex-direction: column;
    justify-content: center;
    border: 2px solid black;
    border-radius: 10px;
    /* flex-wrap: wrap; */
    background-color: blue;
    padding: 15px 9px;
}

.box {
    height: 4rem;
    width: 4rem;
    border-radius: 5px;
    border: 2px solid black;
    margin: 0.5rem;
    font-size: 25px;
    box-shadow: 5px 5px 10px darkblue;
}

.expression {
    height: 4rem;
    width: 90%;
    margin: 10px;
    border-radius: 5px;
    border: 2px solid black;
    font-size: 48px;
    line-height: 4rem;
    letter-spacing: 2px;
    background-color: #fff;
    text-align: end;
    box-shadow: 5px 5px 10px darkblue;
}

#equal {
    width: 9rem;
    font-size: 30px;
    background-color: orange;
}


.operator {
    background-color: rgb(128, 128, 128);
    font-size: 30px;
}

#delete {
    color: red;
}

.box:hover {
    background-color: rgb(255, 255, 255 , 0.9)
}
.operator:hover {
    background-color: rgb(128, 128, 128, 0.9);
}
#equal:hover {
    background-color: rgb(255, 165, 0, 0.9)
}
.row {
    display: flex;
    justify-content: center;
    width: 100%;
}

@media (max-width: 1000px) {
    .calculator {
        max-width: 48vmin;
    }
}
@media (max-width: 780px) {
    .calculator {
        max-width: 58vmin;
    }
}
@media (max-width: 500px) {
    .calculator {
        max-width: 86vmin;
    }
}
@media (max-width: 400px) {
    .calculator {
        max-width: 95vmin;
    }
}