If you take a look around line 2157 in your css file you’ll see this –
input,
select,
textarea {
background-color: #FFFFFF;
border: 1px solid #DDDDDD;
padding: 0.3125rem 0.625rem;
width: 100%;
}
The width is what is causing that issue. You could either remove that, or individually create a separate class for that particular image so it shows up the size you want……whichever way would be easier for you.