*{box-sizing:border-box}#card{margin:auto;min-width:320px;max-width:400px}.card-validation-form{display:flex;flex-direction:column}.paySystemsImages{display:flex}.paySystemIMG{margin-left:5px;opacity:.4}.paySystemIMG:first-child{margin-left:0}.valid{border-color:green}#input{border-width:3px;margin-top:10px;margin-bottom:10px}#btn-validate{cursor:pointer;margin:auto;width:200px}.invalid{border-color:red}