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

body {
    background-color: whitesmoke;
    font-family: 'Times New Roman', Times, serif;
    
}

.container {
    max-width: 600px;
    background-color: white;
    width: 80%;
    margin: 50px auto;
    padding: 25px;
    border-radius: 10px;
    box-shadow: 0px 4px 13px black;
}

.center {
    text-align: center;
    margin-bottom: 30px;
    margin-top: 30px;
}

form {
    text-align: left;
}

input:not(.radio-group-inp), select, textarea {
    display: block;
    width: 100%;
    padding: 10px;
    border-radius: 5px;
    margin: 8px 0;
    font-size: 0.7rem;
}


input:invalid, select:invalid, textarea:invalid {
    border: 1px solid red;
}
input:valid, select:valid, textarea:valid {
    border: 1px solid green;
}
input:focus, select:focus, textarea:focus {
    outline: none;
}

.radio-group {
    padding: 15px;  
}

textarea {
    columns: 3;
}

#position {
    width: 100%;
    padding: 5px;
}

.radio-group-inp {
    appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    border: 2px solid gray;
    vertical-align: top;
}

.radio-group-inp::before {
    display: block;
    content: " ";
    width: 12px;
    height: 12px;
    border-radius: 50%;
    transform: translate(3px, 3px) scale(0);
    transition: all 0.3s ease-in;
}

.radio-group-inp:checked::before {
    transform: translate(3px, 3px) scale(1);
    background-color: green;
}

.submit-btn {
    width: 100%;
    margin: 20px 0px auto;
    background-color: green;
    color: white;
    padding: 10px 5px;
    border: none;
    border-radius: 5px;
}

.submit-btn:hover {
    background-color: black;
}