Fix text fields so they don't look so dorky

Now using <input type="number" pattern="\d*" step="1"> so that
the text field will pop up the numeric keyboard on both iOS and
Android. However this makes the "size=<blah>" no longer function.
So we set a fixed size for all <input type="number"> text fields
using CSS. Kinda hackish, but it works.

web_app/css/sif-tools.css

@@ -21,3 +21,7 @@ strong {
 table {
   table-layout: fixed;
 }
+
+input[type=number]{
+    width: 80px;
+}