If you look at line 1096, you’ll see this –
.sidebar .enews-widget input,
.footer-widgets .enews-widget input {
width: 55%;
}
That’s what controls the width of the fields.
Do you want both fields and the Go button to be on the same line? If so, change the above code to 34% or less. If you want the fields to be on each on their own separate line, then change it to 100%.
Since the widget area is kind of small, we’re limited to how much can fit inside the area.
BTW, that code above will work for both the footer and the sidebar.
Let me know if that helps.