style.css

body{
    margin: 0;
    padding: 0;
    overflow-x: hidden;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
}
.header{
    width: 100%;
    height: 30px;
    text-align: center;
    color: aliceblue;
    background-color: #222222;
    margin: 0;
    padding: 10px;
}
.header h2{
    font-size: 25px;
    margin: 0;
}
.val_form{
    display:flex;
    padding: 10px;
    justify-content: center;
    border-bottom: 2px solid #222222;
    border-radius: 20px;
    background-color: rgb(247, 247, 247);
}
.val_form label{
    font-size: 16px;
    margin-left: 8px;
    font-weight: 600;
}
.val_form input{
    height: 20px;
    width: 150px;
    margin-left: 8px;
    margin-right: 40px;
}
.val_form select{
    height: 22px;
    width: 150px;
    padding: 2px;
    margin-left: 8px;
    margin-right: 40px;
}
.val_form textarea{
    margin-left: 8px;
}
.val_form .form_row{
    display: flex;
    justify-content: center;
    margin-bottom: 10px;
}
.simulate-btn{
    display: flex;
    justify-content: center;
}
.val_row{
    display: flex;
    height: 30px;
    border: 1px solid black;
    border-bottom: 2px solid #222222;
}
.val_col{
    width: 100%;
    font-size: 18px;
    border: 1px solid #222222;
    padding: 2px;
    text-align: center;
}
.fun_type{
    color: brown;
}
.operation{
    color: blue;
}
.con{
    height: 600px;
    overflow: scroll;
}
.change{
    color: blue;
    background-color: blanchedalmond;
    font-weight: 800;
}
.p_val{
    font-size: 14px;
    font-weight: 500;
    display: inline-block;
    background-color: rgb(193, 251, 251);
    border: 2px solid rgb(0, 120, 120);
    border-radius: 10px;
    margin: 15px 20px ;
    padding: 5px;
}
::-webkit-scrollbar {
    width: 0px;
}