style: reduce select border radius to 3px

They are a bit smaller then buttons so their border radius won't fit.

Signed-off-by: Conrad Zelck <git@simpel.cc>

style.css

@@ -223,10 +223,18 @@ input[type=checkbox]:focus {
 
 button, input, select {
   border: 2px solid white;
+}
+
+button, input {
   -webkit-border-radius: 5px;
   border-radius: 5px;
 }
 
+select {
+  -webkit-border-radius: 3px;
+  border-radius: 3px;
+}
+
 input[type="file"] {
   border: 0;
 }