A few visual tweaks to the spell view flow.

app/styles/play/level/tome/spell.sass

@@ -33,7 +33,7 @@
   .ace_editor
     @include box-sizing(border-box)
     margin-top: 40px
-    width: 100%
+    width: 98%
     height: 83%
     height: -webkit-calc(100% - 60px - 40px)
     height: calc(100% - 60px - 40px)
@@ -63,7 +63,7 @@
     .executing
       background-color: rgba(216, 255, 255, 0.85)
     .executed
-      background-color: rgba(200, 200, 255, 0.25)
+      background-color: rgba(245, 255, 6, 0.18)
     .problem-marker-info
       background-color: rgba(96, 63, 84, 0.25)
     .problem-marker-warning
@@ -79,7 +79,7 @@
     .ace_marker-layer
       .ace_bracket
         // Override faint gray
-        border-color: #8FF
+        border-color: #BFF
 
     .ace_identifier
-      background-color: rgba(255, 128, 128, 0.15)
+      border-bottom: 1px dotted rgba(255, 128, 128, 0.45)

app/views/play/level/tome/spell_debug_view.coffee

@@ -25,18 +25,19 @@ module.exports = class DebugView extends View
   afterRender: ->
     super()
     @ace.on "mousemove", @onMouseMove
-    #@ace.on "click", onClick  # same ACE API as mousemove
 
   setVariableStates: (@variableStates) ->
     @update()
 
   onMouseMove: (e) =>
     pos = e.getDocumentPosition()
+    endOfDoc = pos.row is @ace.getSession().getDocument().getLength() - 1
     it = new TokenIterator e.editor.session, pos.row, pos.column
     isIdentifier = (t) -> t and (t.type is 'identifier' or t.value is 'this')
     while it.getCurrentTokenRow() is pos.row and not isIdentifier(token = it.getCurrentToken())
       it.stepBackward()
       break unless token
+      break if endOfDoc  # Don't iterate backward on last line, since we might be way below.
     if isIdentifier token
       # This could be a property access, like "enemy.target.pos" or "this.spawnedRectangles".
       # We have to realize this and dig into the nesting of the objects.

app/views/play/level/tome/spell_view.coffee

@@ -446,21 +446,19 @@ module.exports = class SpellView extends View
     marked = {}
     lastExecuted = lastExecuted[0 .. @toolbarView.statementIndex] if @toolbarView?.statementIndex?
     for state, i in lastExecuted
-      #clazz = if state.executing then 'executing' else 'executed'  # doesn't work
+      [start, end] = [offsetToPos(state.range[0]), offsetToPos(state.range[1])]
       clazz = if i is lastExecuted.length - 1 then 'executing' else 'executed'
       if clazz is 'executed'
-        key = state.range[0] + '_' + state.range[1]
-        continue if marked[key] > 2  # don't allow more than three of the same marker
-        marked[key] ?= 0
-        ++marked[key]
+        continue if marked[start.row]
+        marked[start.row] = true
+        markerType = "fullLine"
       else
         @debugView.setVariableStates state.variables
-        #console.log "at", state.userInfo.time, "vars are now:", state.variables
-      [start, end] = [offsetToPos(state.range[0]), offsetToPos(state.range[1])]
+        markerType = "text"
       markerRange = new Range(start.row, start.column, end.row, end.column)
       markerRange.start = @aceDoc.createAnchor markerRange.start
       markerRange.end = @aceDoc.createAnchor markerRange.end
-      markerRange.id = @aceSession.addMarker markerRange, clazz, "text"
+      markerRange.id = @aceSession.addMarker markerRange, clazz, markerType
       @markerRanges.push markerRange
       @aceSession.addGutterDecoration start.row, clazz if clazz is 'executing'
     null