disallow "in through <screen>"

calc.js

@@ -82,10 +82,12 @@ function buildLexer() {
   const Weather = createToken({
     name: "Weather",
     pattern: /Sun|Rain|Sand|Snow/,
+    pop_mode: true,
   });
   const Terrain = createToken({
     name: "Terrain",
     pattern: /(Electric|Grassy|Misty|Psychic) Terrain/,
+    pop_mode: true,
   });
 
   const screenEnter = createToken({
@@ -110,7 +112,7 @@ function buildLexer() {
         terrainEnter,
         screenEnter,
       ],
-      terrain_mode: [whitespace, screenEnter, Weather, Terrain],
+      terrain_mode: [whitespace, Weather, Terrain],
       screen_mode: [whitespace, Move],
     },
     defaultMode: "default_mode",