body{background-color:cadetblue; margin-left:auto; margin-right:auto; font-family:Arial, Helvetica, sans-serif}
input:focus, textarea:focus{outline:none; border:1px solid red;}
input:invalid, select:invalid, textarea:invalid{outline:none; border:1px solid red}
input:valid, select:valid, textarea:valid{outline:none; border:1px solid green;}
button:hover{background-color:cornflowerblue}
.radio-group input[type="radio"]:checked{background-color:blueviolet;box-shadow:0 0 5px blueviolet; border: 1px solid red}
input[type="radio"]:checked + label{color:blueviolet}
input:first-of-type{border-radius: 5px;}
fieldset{width:250px; border-radius: 5px; padding: 10px;}
.container {
    width: 80%;
    max-width: 600px;
    border-radius: 10px;
    margin: 20px auto;
    padding: 10px 20px;
    box-shadow: 0 5px 15px black; 
    background-color:azure;
    text-align: left;
}
textarea{width:95%;}