MDL-41152 theme_bootstrapbase: Optimise width for gradebook tree view

theme/bootstrapbase/less/moodle.less

@@ -48,6 +48,7 @@ body {
 @import "moodle/backup-restore";
 @import "moodle/tables";
 @import "moodle/buttons";
+@import "moodle/grade";
 
 // Anything below this line is considered expendable,
 // so it doesn't matter if it doesn't show up in ie < 9

theme/bootstrapbase/less/moodle/grade.less

@@ -0,0 +1,18 @@
+// The class gradetreebox matches the pages displaying the gradebook
+// "Categories and items" > "Simple view" and "Full view".
+.gradetreebox {
+    h4 {
+        // Force back the base font-size to minimise width.
+        font-size: @baseFontSize;
+    }
+    th.cell,
+    input[type=text] {
+        // Fallback on the minimum width.
+        width: auto;
+    }
+    input[type=text],
+    select {
+        // Remove the bottom margin to gain height.
+        margin-bottom: 0;
+    }
+}