*{margin:0;padding:0;box-sizing:border-box}body{font-family:Arial,Helvetica,sans-serif;line-height:1.6}form{max-width:500px;margin:3em auto;padding:1em;border:solid 1px darkslateblue;border-radius:5px;background-color:#e8eff1}.form-group{display:flex;flex-direction:column}input{margin-bottom:1em;padding:.3em}button{padding:.25em .5em}.invalido{color:red}
