body {
    background-color: darkslategray;
}

#main-text {
    height: 35px;
    width: 300px;
    margin-bottom: 2px;
    margin-top: 10px;
}

.main-conatiner {
    padding-left: 450px;
    padding-top: 20px;
}

.child-container {
    padding: 10px;
    border: 2px solid blue;
    height: 352px;
    width: 310px;
}

h1 {
    color: white;
    margin: 0;
    padding: 0;
}

hr {
    padding: 0;
    margin-top: -17px;
    margin-bottom: 5px;
}

.btn-number {
    height: 35px;
    width: 70px;
    margin: 2px;
    font-weight: bold;
}

#equal-to {
    width: 150px;

}

span {
    margin-left: 220px;
    color: rgb(253, 252, 252);
    font-weight: bold;

}

input {
    font-weight: bold;
    text-align: right;
    border-radius: 5px;
    font-size: 20px;
}

button {
    border-radius: 5px;
}