Footer widget CSS issue

Hi Team,

I want to make the footer widget-1 width 50%, and rest two widgets width 25% each. To do so, I have added the below code

footer-widget-1 {
float: left;
width: 50%;
}

.footer-widget-2 {
float: left;
width: 25%;
}

.footer-widget-3 {
float: left;
width: 25%;
}

but the changes are not getting reflected.

Could you please help me.