style.css

* {
    margin: 0;
    padding: 0;
}

body {
    background-color: rgb(37, 40, 82);
    color: azure;
    font-family: 'Courier New', Courier, monospace;
    font-size: 30px;
}

input {
    font-family: 'Courier New', Courier, monospace;
    font-size: 30px;
    margin: 0;
    padding: 0;
}

.mainDiv {
    display: flex;
    align-items: flex-start;
    justify-content: center;
    margin: 100px 0;
}

.box {
    margin: 30px;
}

.lable {
    margin: 15px 0;
}

.numberOfPeople {
    display: flex;
    flex-direction: row;
    align-items: center;
    justify-content: start;
    margin: 0 50px;
}

.currencySign {
    border: 1px solid lightblue;
    border-right: 0;
    padding: 12px 0;
    background-color: rgb(31, 34, 68);
}

.currencyInput {
    display: flex;
    align-items: center;
    justify-content: center;
}

input[type=number] {
    padding: 12px 10px;
    margin: 8px 0;
    background-color: rgb(31, 34, 68);
    border: 1px solid lightblue;
    border-left: 0;
    color: aliceblue;
}

input[type=number]:focus {
    outline: none;
}

input::-webkit-outer-spin-button,
input::-webkit-inner-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

button {
    background-color: whitesmoke;
    width: 60px;
    height: 60px;
    border: none;
    border-radius: 50%;
    color: rgb(46, 51, 98);
    font-size: 30px;
    margin: 0 20px;
    transition-duration: 0.1s;
    box-shadow: 0 8px 16px 0 rgba(0, 0, 0, 0.2), 0 6px 20px 0 rgba(0, 0, 0, 0.19);
}

button:hover {
    color: aliceblue;
    background-color: rgb(31, 34, 68);
    border: 1px solid white;
    box-shadow: 0 12px 16px 0 rgba(0, 0, 0, 0.24), 0 17px 50px 0 rgba(0, 0, 0, 0.19);
    cursor: pointer;
}

button:active {
    color: aliceblue;
    background-color: rgb(59, 65, 121);
    border: 1px solid white;
}