edit jetback subscription widget css

This is the CSS I see in the wp-content folder for the jetpack subscription widget. I want the subscribe button width to be longer. I have tried updating the CSS but must be doing it wrong because nothing changes. I would prefer to do it in the jet pack “edit css” menu rather than in the wp-content folder. Any help is appreciated.

#subscribe-email input {
width: 95%;
padding: 1px 2px;
}

.comment-subscription-form .subscribe-label {
display: inline !important;
}