feat: add continent filtering to Know Your World game

Add continent-based filtering for the world map to make the game more playable by reducing visual clutter:

Continent Selection:
- Add continent selector to setup screen (only for world map)
- 7 continents + "All" option: Africa, Asia, Europe, North America, South America, Oceania, Antarctica
- Each continent button shows emoji and name

Map Filtering:
- Filter world map regions by selected continent using ISO 3166-1 country codes
- Calculate bounding box for filtered regions
- Automatically crop and scale viewBox to show only selected continent
- Add 10% padding around continent bounding box for better visibility

Technical Implementation:
- Create continents.ts with comprehensive country-to-continent mappings (256 countries)
- Add getFilteredMapData() function to filter regions and adjust viewBox
- Add calculateBoundingBox() to compute min/max coordinates from SVG paths
- Add selectedContinent field to game state and config (persisted to database)
- Add SET_CONTINENT move type and validator
- Update all map rendering components (StudyPhase, PlayingPhase, MapRenderer)

Benefits:
- Solves "too many small countries" problem on world map
- Allows focused study of specific geographic regions
- Dynamic viewBox adjustment provides optimal zoom level
- Maintains full world map option for comprehensive play

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

apps/web/src/arcade-games/know-your-world/Provider.tsx

@@ -30,6 +30,7 @@ interface KnowYourWorldContextValue {
   setMode: (mode: 'cooperative' | 'race' | 'turn-based') => void
   setDifficulty: (difficulty: 'easy' | 'hard') => void
   setStudyDuration: (duration: 0 | 30 | 60 | 120) => void
+  setContinent: (continent: import('./continents').ContinentId | 'all') => void
 }
 
 const KnowYourWorldContext = createContext<KnowYourWorldContextValue | null>(null)
@@ -59,12 +60,30 @@ export function KnowYourWorldProvider({ children }: { children: React.ReactNode
     const studyDuration: 0 | 30 | 60 | 120 =
       rawDuration === 30 || rawDuration === 60 || rawDuration === 120 ? rawDuration : 0
 
+    // Validate selectedContinent
+    const rawContinent = gameConfig?.selectedContinent
+    const validContinents = [
+      'all',
+      'africa',
+      'asia',
+      'europe',
+      'north-america',
+      'south-america',
+      'oceania',
+      'antarctica',
+    ]
+    const selectedContinent: import('./continents').ContinentId | 'all' =
+      typeof rawContinent === 'string' && validContinents.includes(rawContinent)
+        ? (rawContinent as any)
+        : 'all'
+
     return {
       gamePhase: 'setup' as const,
       selectedMap: (gameConfig?.selectedMap as 'world' | 'usa') || 'world',
       gameMode: (gameConfig?.gameMode as 'cooperative' | 'race' | 'turn-based') || 'cooperative',
       difficulty: (gameConfig?.difficulty as 'easy' | 'hard') || 'easy',
       studyDuration,
+      selectedContinent,
       studyTimeRemaining: 0,
       studyStartTime: 0,
       currentPrompt: null,
@@ -277,6 +296,36 @@ export function KnowYourWorldProvider({ children }: { children: React.ReactNode
     })
   }, [viewerId, sendMove])
 
+  // Setup Action: Set Continent
+  const setContinent = useCallback(
+    (selectedContinent: import('./continents').ContinentId | 'all') => {
+      sendMove({
+        type: 'SET_CONTINENT',
+        playerId: viewerId || 'player-1',
+        userId: viewerId || '',
+        data: { selectedContinent },
+      })
+
+      // Persist to database
+      if (roomData?.id) {
+        const currentGameConfig = (roomData.gameConfig as Record<string, any>) || {}
+        const currentConfig = (currentGameConfig['know-your-world'] as Record<string, any>) || {}
+
+        updateGameConfig({
+          roomId: roomData.id,
+          gameConfig: {
+            ...currentGameConfig,
+            'know-your-world': {
+              ...currentConfig,
+              selectedContinent,
+            },
+          },
+        })
+      }
+    },
+    [viewerId, sendMove, roomData, updateGameConfig]
+  )
+
   // Action: Return to Setup
   const returnToSetup = useCallback(() => {
     sendMove({
@@ -304,6 +353,7 @@ export function KnowYourWorldProvider({ children }: { children: React.ReactNode
         setMode,
         setDifficulty,
         setStudyDuration,
+        setContinent,
       }}
     >
       {children}

apps/web/src/arcade-games/know-your-world/Validator.ts

@@ -5,7 +5,7 @@ import type {
   KnowYourWorldState,
   GuessRecord,
 } from './types'
-import { getMapData } from './maps'
+import { getMapData, getFilteredMapData } from './maps'
 
 export class KnowYourWorldValidator
   implements GameValidator<KnowYourWorldState, KnowYourWorldMove>
@@ -32,6 +32,8 @@ export class KnowYourWorldValidator
         return this.validateSetDifficulty(state, move.data.difficulty)
       case 'SET_STUDY_DURATION':
         return this.validateSetStudyDuration(state, move.data.studyDuration)
+      case 'SET_CONTINENT':
+        return this.validateSetContinent(state, move.data.selectedContinent)
       default:
         return { valid: false, error: 'Unknown move type' }
     }
@@ -56,10 +58,11 @@ export class KnowYourWorldValidator
       return { valid: false, error: 'Need at least 1 player' }
     }
 
-    // Get map data and shuffle regions
-    const mapData = getMapData(selectedMap)
+    // Get map data and shuffle regions (with continent filter if applicable)
+    const mapData = getFilteredMapData(selectedMap, state.selectedContinent)
     console.log('[KnowYourWorld Validator] Map data loaded:', {
       map: mapData.id,
+      continent: state.selectedContinent,
       regionsCount: mapData.regions.length,
     })
     const regionIds = mapData.regions.map((r) => r.id)
@@ -220,8 +223,8 @@ export class KnowYourWorldValidator
       return { valid: false, error: 'Can only start next round from results' }
     }
 
-    // Get map data and shuffle regions
-    const mapData = getMapData(state.selectedMap)
+    // Get map data and shuffle regions (with continent filter if applicable)
+    const mapData = getFilteredMapData(state.selectedMap, state.selectedContinent)
     const regionIds = mapData.regions.map((r) => r.id)
     const shuffledRegions = this.shuffleArray([...regionIds])
 
@@ -330,6 +333,22 @@ export class KnowYourWorldValidator
     return { valid: true, newState }
   }
 
+  private validateSetContinent(
+    state: KnowYourWorldState,
+    selectedContinent: import('./continents').ContinentId | 'all'
+  ): ValidationResult {
+    if (state.gamePhase !== 'setup') {
+      return { valid: false, error: 'Can only change continent during setup' }
+    }
+
+    const newState: KnowYourWorldState = {
+      ...state,
+      selectedContinent,
+    }
+
+    return { valid: true, newState }
+  }
+
   private validateEndStudy(state: KnowYourWorldState): ValidationResult {
     if (state.gamePhase !== 'studying') {
       return { valid: false, error: 'Can only end study during studying phase' }
@@ -389,6 +408,7 @@ export class KnowYourWorldValidator
       gameMode: typedConfig?.gameMode || 'cooperative',
       difficulty: typedConfig?.difficulty || 'easy',
       studyDuration: typedConfig?.studyDuration || 0,
+      selectedContinent: typedConfig?.selectedContinent || 'all',
       studyTimeRemaining: 0,
       studyStartTime: 0,
       currentPrompt: null,

apps/web/src/arcade-games/know-your-world/components/MapRenderer.tsx

@@ -81,7 +81,7 @@ function isSmallRegion(bbox: BoundingBox, viewBox: string): boolean {
   // Thresholds (relative to map size)
   const minWidth = mapWidth * 0.025 // 2.5% of map width
   const minHeight = mapHeight * 0.025 // 2.5% of map height
-  const minArea = (mapWidth * mapHeight) * 0.001 // 0.1% of total map area
+  const minArea = mapWidth * mapHeight * 0.001 // 0.1% of total map area
 
   return bbox.width < minWidth || bbox.height < minHeight || bbox.area < minArea
 }
@@ -116,10 +116,7 @@ export function MapRenderer({
           regionId: region.id,
           regionName: region.name,
           regionCenter: region.center,
-          labelPosition: [
-            region.center[0] + offsetX,
-            region.center[1] + offsetY,
-          ],
+          labelPosition: [region.center[0] + offsetX, region.center[1] + offsetY],
           isFound: regionsFound.includes(region.id),
         })
       }
@@ -229,8 +226,10 @@ export function MapRenderer({
               y={label.labelPosition[1] - 12}
               width={label.regionName.length * 6 + 10}
               height={20}
-              fill={label.isFound ? (isDark ? '#22c55e' : '#86efac') : (isDark ? '#1f2937' : '#ffffff')}
-              stroke={label.isFound ? '#16a34a' : (isDark ? '#60a5fa' : '#3b82f6')}
+              fill={
+                label.isFound ? (isDark ? '#22c55e' : '#86efac') : isDark ? '#1f2937' : '#ffffff'
+              }
+              stroke={label.isFound ? '#16a34a' : isDark ? '#60a5fa' : '#3b82f6'}
               strokeWidth={2}
               rx={4}
               style={{
@@ -269,22 +268,11 @@ export function MapRenderer({
 
         {/* Arrow marker definition */}
         <defs>
-          <marker
-            id="arrowhead"
-            markerWidth="10"
-            markerHeight="10"
-            refX="8"
-            refY="3"
-            orient="auto"
-          >
-            <polygon
-              points="0 0, 10 3, 0 6"
-              fill={isDark ? '#60a5fa' : '#3b82f6'}
-            />
+          <marker id="arrowhead" markerWidth="10" markerHeight="10" refX="8" refY="3" orient="auto">
+            <polygon points="0 0, 10 3, 0 6" fill={isDark ? '#60a5fa' : '#3b82f6'} />
           </marker>
         </defs>
       </svg>
-
     </div>
   )
 }

apps/web/src/arcade-games/know-your-world/components/PlayingPhase.tsx

@@ -4,7 +4,7 @@ import { useEffect } from 'react'
 import { css } from '@styled/css'
 import { useTheme } from '@/contexts/ThemeContext'
 import { useKnowYourWorld } from '../Provider'
-import { getMapData } from '../maps'
+import { getFilteredMapData } from '../maps'
 import { MapRenderer } from './MapRenderer'
 
 export function PlayingPhase() {
@@ -12,7 +12,7 @@ export function PlayingPhase() {
   const isDark = resolvedTheme === 'dark'
   const { state, clickRegion, lastError, clearError } = useKnowYourWorld()
 
-  const mapData = getMapData(state.selectedMap)
+  const mapData = getFilteredMapData(state.selectedMap, state.selectedContinent)
   const totalRegions = mapData.regions.length
   const foundCount = state.regionsFound.length
   const progress = (foundCount / totalRegions) * 100

apps/web/src/arcade-games/know-your-world/components/SetupPhase.tsx

@@ -3,11 +3,13 @@
 import { css } from '@styled/css'
 import { useTheme } from '@/contexts/ThemeContext'
 import { useKnowYourWorld } from '../Provider'
+import { CONTINENTS } from '../continents'
 
 export function SetupPhase() {
   const { resolvedTheme } = useTheme()
   const isDark = resolvedTheme === 'dark'
-  const { state, startGame, setMap, setMode, setDifficulty, setStudyDuration } = useKnowYourWorld()
+  const { state, startGame, setMap, setMode, setDifficulty, setStudyDuration, setContinent } =
+    useKnowYourWorld()
 
   return (
     <div
@@ -108,6 +110,94 @@ export function SetupPhase() {
         </div>
       </div>
 
+      {/* Continent Selection (only for World map) */}
+      {state.selectedMap === 'world' && (
+        <div data-section="continent-selection">
+          <h2
+            className={css({
+              fontSize: '2xl',
+              fontWeight: 'bold',
+              marginBottom: '4',
+              color: isDark ? 'gray.100' : 'gray.900',
+            })}
+          >
+            Focus on Continent 🌐
+          </h2>
+          <div
+            className={css({
+              display: 'grid',
+              gridTemplateColumns: 'repeat(4, 1fr)',
+              gap: '3',
+            })}
+          >
+            {/* All continents option */}
+            <button
+              data-action="select-all-continents"
+              onClick={() => setContinent('all')}
+              className={css({
+                padding: '3',
+                rounded: 'lg',
+                border: '2px solid',
+                borderColor: state.selectedContinent === 'all' ? 'blue.500' : 'transparent',
+                bg:
+                  state.selectedContinent === 'all'
+                    ? isDark
+                      ? 'blue.900'
+                      : 'blue.50'
+                    : isDark
+                      ? 'gray.800'
+                      : 'gray.100',
+                color: isDark ? 'gray.100' : 'gray.900',
+                cursor: 'pointer',
+                transition: 'all 0.2s',
+                _hover: {
+                  borderColor: 'blue.400',
+                },
+              })}
+            >
+              <div className={css({ fontSize: '2xl', marginBottom: '1' })}>🌍</div>
+              <div className={css({ fontSize: 'sm', fontWeight: 'bold' })}>All</div>
+              <div className={css({ fontSize: '2xs', color: isDark ? 'gray.400' : 'gray.600' })}>
+                Whole world
+              </div>
+            </button>
+
+            {/* Individual continents */}
+            {CONTINENTS.map((continent) => (
+              <button
+                key={continent.id}
+                data-action={`select-${continent.id}-continent`}
+                onClick={() => setContinent(continent.id)}
+                className={css({
+                  padding: '3',
+                  rounded: 'lg',
+                  border: '2px solid',
+                  borderColor:
+                    state.selectedContinent === continent.id ? 'blue.500' : 'transparent',
+                  bg:
+                    state.selectedContinent === continent.id
+                      ? isDark
+                        ? 'blue.900'
+                        : 'blue.50'
+                      : isDark
+                        ? 'gray.800'
+                        : 'gray.100',
+                  color: isDark ? 'gray.100' : 'gray.900',
+                  cursor: 'pointer',
+                  transition: 'all 0.2s',
+                  _hover: {
+                    borderColor: 'blue.400',
+                  },
+                })}
+              >
+                <div className={css({ fontSize: '2xl', marginBottom: '1' })}>{continent.emoji}</div>
+                <div className={css({ fontSize: 'sm', fontWeight: 'bold' })}>{continent.name}</div>
+              </button>
+            ))}
+          </div>
+        </div>
+      )}
+
       {/* Mode Selection */}
       <div data-section="mode-selection">
         <h2

apps/web/src/arcade-games/know-your-world/components/StudyPhase.tsx

@@ -4,7 +4,7 @@ import { useEffect, useState } from 'react'
 import { css } from '@styled/css'
 import { useTheme } from '@/contexts/ThemeContext'
 import { useKnowYourWorld } from '../Provider'
-import { getMapData } from '../maps'
+import { getFilteredMapData } from '../maps'
 import type { MapRegion } from '../types'
 import { getRegionColor, getLabelTextColor, getLabelTextShadow } from '../mapColors'
 
@@ -15,7 +15,7 @@ export function StudyPhase() {
 
   const [timeRemaining, setTimeRemaining] = useState(state.studyTimeRemaining)
 
-  const mapData = getMapData(state.selectedMap)
+  const mapData = getFilteredMapData(state.selectedMap, state.selectedContinent)
 
   // Countdown timer
   useEffect(() => {
@@ -102,7 +102,14 @@ export function StudyPhase() {
             className={css({
               fontSize: '4xl',
               fontWeight: 'bold',
-              color: timeRemaining <= 10 ? (isDark ? 'red.400' : 'red.600') : isDark ? 'blue.200' : 'blue.800',
+              color:
+                timeRemaining <= 10
+                  ? isDark
+                    ? 'red.400'
+                    : 'red.600'
+                  : isDark
+                    ? 'blue.200'
+                    : 'blue.800',
               fontFeatureSettings: '"tnum"',
             })}
           >
@@ -200,7 +207,15 @@ export function StudyPhase() {
         })}
       >
         <p className={css({ fontWeight: 'semibold', marginBottom: '2' })}>💡 Study Tips:</p>
-        <ul className={css({ listStyle: 'disc', paddingLeft: '5', display: 'flex', flexDirection: 'column', gap: '1' })}>
+        <ul
+          className={css({
+            listStyle: 'disc',
+            paddingLeft: '5',
+            display: 'flex',
+            flexDirection: 'column',
+            gap: '1',
+          })}
+        >
           <li>Look for patterns - neighboring regions, shapes, sizes</li>
           <li>Group regions mentally by area (e.g., Northeast, Southwest)</li>
           <li>Focus on the tricky small ones that are hard to see</li>

apps/web/src/arcade-games/know-your-world/continents.ts

@@ -0,0 +1,309 @@
+/**
+ * Continent mappings for world countries
+ * Maps ISO 3166-1 alpha-2 country codes to continents
+ */
+
+export type ContinentId =
+  | 'africa'
+  | 'asia'
+  | 'europe'
+  | 'north-america'
+  | 'south-america'
+  | 'oceania'
+  | 'antarctica'
+
+export interface Continent {
+  id: ContinentId
+  name: string
+  emoji: string
+}
+
+export const CONTINENTS: Continent[] = [
+  { id: 'africa', name: 'Africa', emoji: '🌍' },
+  { id: 'asia', name: 'Asia', emoji: '🌏' },
+  { id: 'europe', name: 'Europe', emoji: '🇪🇺' },
+  { id: 'north-america', name: 'North America', emoji: '🌎' },
+  { id: 'south-america', name: 'South America', emoji: '🌎' },
+  { id: 'oceania', name: 'Oceania', emoji: '🌏' },
+  { id: 'antarctica', name: 'Antarctica', emoji: '🇦🇶' },
+]
+
+/**
+ * Map of country codes to continents
+ * Based on ISO 3166-1 alpha-2 codes from @svg-maps/world
+ */
+export const COUNTRY_TO_CONTINENT: Record<string, ContinentId> = {
+  // Africa
+  dz: 'africa', // Algeria
+  ao: 'africa', // Angola
+  bj: 'africa', // Benin
+  bw: 'africa', // Botswana
+  bf: 'africa', // Burkina Faso
+  bi: 'africa', // Burundi
+  cm: 'africa', // Cameroon
+  cv: 'africa', // Cape Verde
+  cf: 'africa', // Central African Republic
+  td: 'africa', // Chad
+  km: 'africa', // Comoros
+  cg: 'africa', // Congo (Brazzaville)
+  cd: 'africa', // Congo (Kinshasa)
+  ci: 'africa', // Côte d'Ivoire
+  dj: 'africa', // Djibouti
+  eg: 'africa', // Egypt
+  gq: 'africa', // Equatorial Guinea
+  er: 'africa', // Eritrea
+  sz: 'africa', // Eswatini
+  et: 'africa', // Ethiopia
+  ga: 'africa', // Gabon
+  gm: 'africa', // Gambia
+  gh: 'africa', // Ghana
+  gn: 'africa', // Guinea
+  gw: 'africa', // Guinea-Bissau
+  ke: 'africa', // Kenya
+  ls: 'africa', // Lesotho
+  lr: 'africa', // Liberia
+  ly: 'africa', // Libya
+  mg: 'africa', // Madagascar
+  mw: 'africa', // Malawi
+  ml: 'africa', // Mali
+  mr: 'africa', // Mauritania
+  mu: 'africa', // Mauritius
+  yt: 'africa', // Mayotte
+  ma: 'africa', // Morocco
+  mz: 'africa', // Mozambique
+  na: 'africa', // Namibia
+  ne: 'africa', // Niger
+  ng: 'africa', // Nigeria
+  re: 'africa', // Réunion
+  rw: 'africa', // Rwanda
+  st: 'africa', // São Tomé and Príncipe
+  sn: 'africa', // Senegal
+  sc: 'africa', // Seychelles
+  sl: 'africa', // Sierra Leone
+  so: 'africa', // Somalia
+  za: 'africa', // South Africa
+  ss: 'africa', // South Sudan
+  sd: 'africa', // Sudan
+  tz: 'africa', // Tanzania
+  tg: 'africa', // Togo
+  tn: 'africa', // Tunisia
+  ug: 'africa', // Uganda
+  eh: 'africa', // Western Sahara
+  zm: 'africa', // Zambia
+  zw: 'africa', // Zimbabwe
+
+  // Asia
+  af: 'asia', // Afghanistan
+  am: 'asia', // Armenia
+  az: 'asia', // Azerbaijan
+  bh: 'asia', // Bahrain
+  bd: 'asia', // Bangladesh
+  bt: 'asia', // Bhutan
+  bn: 'asia', // Brunei
+  kh: 'asia', // Cambodia
+  cn: 'asia', // China
+  cx: 'asia', // Christmas Island
+  cc: 'asia', // Cocos Islands
+  ge: 'asia', // Georgia
+  hk: 'asia', // Hong Kong
+  in: 'asia', // India
+  id: 'asia', // Indonesia
+  ir: 'asia', // Iran
+  iq: 'asia', // Iraq
+  il: 'asia', // Israel
+  jp: 'asia', // Japan
+  jo: 'asia', // Jordan
+  kz: 'asia', // Kazakhstan
+  kp: 'asia', // North Korea
+  kr: 'asia', // South Korea
+  kw: 'asia', // Kuwait
+  kg: 'asia', // Kyrgyzstan
+  la: 'asia', // Laos
+  lb: 'asia', // Lebanon
+  mo: 'asia', // Macau
+  my: 'asia', // Malaysia
+  mv: 'asia', // Maldives
+  mn: 'asia', // Mongolia
+  mm: 'asia', // Myanmar
+  np: 'asia', // Nepal
+  om: 'asia', // Oman
+  pk: 'asia', // Pakistan
+  ps: 'asia', // Palestine
+  ph: 'asia', // Philippines
+  qa: 'asia', // Qatar
+  sa: 'asia', // Saudi Arabia
+  sg: 'asia', // Singapore
+  lk: 'asia', // Sri Lanka
+  sy: 'asia', // Syria
+  tw: 'asia', // Taiwan
+  tj: 'asia', // Tajikistan
+  th: 'asia', // Thailand
+  tl: 'asia', // Timor-Leste
+  tr: 'asia', // Turkey (transcontinental, but primarily Asian)
+  tm: 'asia', // Turkmenistan
+  ae: 'asia', // United Arab Emirates
+  uz: 'asia', // Uzbekistan
+  vn: 'asia', // Vietnam
+  ye: 'asia', // Yemen
+
+  // Europe
+  ax: 'europe', // Åland Islands
+  al: 'europe', // Albania
+  ad: 'europe', // Andorra
+  at: 'europe', // Austria
+  by: 'europe', // Belarus
+  be: 'europe', // Belgium
+  ba: 'europe', // Bosnia and Herzegovina
+  bg: 'europe', // Bulgaria
+  hr: 'europe', // Croatia
+  cy: 'europe', // Cyprus
+  cz: 'europe', // Czech Republic
+  dk: 'europe', // Denmark
+  ee: 'europe', // Estonia
+  fo: 'europe', // Faroe Islands
+  fi: 'europe', // Finland
+  fr: 'europe', // France
+  de: 'europe', // Germany
+  gi: 'europe', // Gibraltar
+  gr: 'europe', // Greece
+  gg: 'europe', // Guernsey
+  hu: 'europe', // Hungary
+  is: 'europe', // Iceland
+  ie: 'europe', // Ireland
+  im: 'europe', // Isle of Man
+  it: 'europe', // Italy
+  je: 'europe', // Jersey
+  xk: 'europe', // Kosovo
+  lv: 'europe', // Latvia
+  li: 'europe', // Liechtenstein
+  lt: 'europe', // Lithuania
+  lu: 'europe', // Luxembourg
+  mk: 'europe', // North Macedonia
+  mt: 'europe', // Malta
+  md: 'europe', // Moldova
+  mc: 'europe', // Monaco
+  me: 'europe', // Montenegro
+  nl: 'europe', // Netherlands
+  no: 'europe', // Norway
+  pl: 'europe', // Poland
+  pt: 'europe', // Portugal
+  ro: 'europe', // Romania
+  ru: 'europe', // Russia (transcontinental, but primarily European for map purposes)
+  sm: 'europe', // San Marino
+  rs: 'europe', // Serbia
+  sk: 'europe', // Slovakia
+  si: 'europe', // Slovenia
+  es: 'europe', // Spain
+  sj: 'europe', // Svalbard and Jan Mayen
+  se: 'europe', // Sweden
+  ch: 'europe', // Switzerland
+  ua: 'europe', // Ukraine
+  gb: 'europe', // United Kingdom
+  va: 'europe', // Vatican City
+
+  // North America
+  ai: 'north-america', // Anguilla
+  ag: 'north-america', // Antigua and Barbuda
+  aw: 'north-america', // Aruba
+  bs: 'north-america', // Bahamas
+  bb: 'north-america', // Barbados
+  bz: 'north-america', // Belize
+  bm: 'north-america', // Bermuda
+  bq: 'north-america', // Caribbean Netherlands
+  vg: 'north-america', // British Virgin Islands
+  ca: 'north-america', // Canada
+  ky: 'north-america', // Cayman Islands
+  cr: 'north-america', // Costa Rica
+  cu: 'north-america', // Cuba
+  cw: 'north-america', // Curaçao
+  dm: 'north-america', // Dominica
+  do: 'north-america', // Dominican Republic
+  sv: 'north-america', // El Salvador
+  gl: 'north-america', // Greenland
+  gd: 'north-america', // Grenada
+  gp: 'north-america', // Guadeloupe
+  gt: 'north-america', // Guatemala
+  ht: 'north-america', // Haiti
+  hn: 'north-america', // Honduras
+  jm: 'north-america', // Jamaica
+  mq: 'north-america', // Martinique
+  mx: 'north-america', // Mexico
+  ms: 'north-america', // Montserrat
+  ni: 'north-america', // Nicaragua
+  pa: 'north-america', // Panama
+  pm: 'north-america', // Saint Pierre and Miquelon
+  kn: 'north-america', // Saint Kitts and Nevis
+  lc: 'north-america', // Saint Lucia
+  vc: 'north-america', // Saint Vincent and the Grenadines
+  sx: 'north-america', // Sint Maarten
+  tt: 'north-america', // Trinidad and Tobago
+  tc: 'north-america', // Turks and Caicos Islands
+  us: 'north-america', // United States
+  vi: 'north-america', // U.S. Virgin Islands
+
+  // South America
+  ar: 'south-america', // Argentina
+  bo: 'south-america', // Bolivia
+  br: 'south-america', // Brazil
+  cl: 'south-america', // Chile
+  co: 'south-america', // Colombia
+  ec: 'south-america', // Ecuador
+  fk: 'south-america', // Falkland Islands
+  gf: 'south-america', // French Guiana
+  gy: 'south-america', // Guyana
+  py: 'south-america', // Paraguay
+  pe: 'south-america', // Peru
+  sr: 'south-america', // Suriname
+  uy: 'south-america', // Uruguay
+  ve: 'south-america', // Venezuela
+
+  // Oceania
+  as: 'oceania', // American Samoa
+  au: 'oceania', // Australia
+  ck: 'oceania', // Cook Islands
+  fj: 'oceania', // Fiji
+  pf: 'oceania', // French Polynesia
+  gu: 'oceania', // Guam
+  ki: 'oceania', // Kiribati
+  mh: 'oceania', // Marshall Islands
+  fm: 'oceania', // Micronesia
+  nr: 'oceania', // Nauru
+  nc: 'oceania', // New Caledonia
+  nz: 'oceania', // New Zealand
+  nu: 'oceania', // Niue
+  nf: 'oceania', // Norfolk Island
+  mp: 'oceania', // Northern Mariana Islands
+  pw: 'oceania', // Palau
+  pg: 'oceania', // Papua New Guinea
+  pn: 'oceania', // Pitcairn Islands
+  ws: 'oceania', // Samoa
+  sb: 'oceania', // Solomon Islands
+  tk: 'oceania', // Tokelau
+  to: 'oceania', // Tonga
+  tv: 'oceania', // Tuvalu
+  vu: 'oceania', // Vanuatu
+  wf: 'oceania', // Wallis and Futuna
+
+  // Antarctica
+  aq: 'antarctica', // Antarctica
+  bv: 'antarctica', // Bouvet Island
+  tf: 'antarctica', // French Southern Territories
+  hm: 'antarctica', // Heard Island and McDonald Islands
+  gs: 'antarctica', // South Georgia and the South Sandwich Islands
+}
+
+/**
+ * Get continent for a country code
+ */
+export function getContinentForCountry(countryCode: string): ContinentId | null {
+  return COUNTRY_TO_CONTINENT[countryCode.toLowerCase()] || null
+}
+
+/**
+ * Get all country codes for a continent
+ */
+export function getCountriesInContinent(continentId: ContinentId): string[] {
+  return Object.entries(COUNTRY_TO_CONTINENT)
+    .filter(([_, continent]) => continent === continentId)
+    .map(([countryCode]) => countryCode)
+}

apps/web/src/arcade-games/know-your-world/index.ts

@@ -32,9 +32,21 @@ const defaultConfig: KnowYourWorldConfig = {
   gameMode: 'cooperative',
   difficulty: 'easy',
   studyDuration: 0,
+  selectedContinent: 'all',
 }
 
 function validateKnowYourWorldConfig(config: unknown): config is KnowYourWorldConfig {
+  const validContinents = [
+    'all',
+    'africa',
+    'asia',
+    'europe',
+    'north-america',
+    'south-america',
+    'oceania',
+    'antarctica',
+  ]
+
   return (
     typeof config === 'object' &&
     config !== null &&
@@ -42,6 +54,7 @@ function validateKnowYourWorldConfig(config: unknown): config is KnowYourWorldCo
     'gameMode' in config &&
     'difficulty' in config &&
     'studyDuration' in config &&
+    'selectedContinent' in config &&
     (config.selectedMap === 'world' || config.selectedMap === 'usa') &&
     (config.gameMode === 'cooperative' ||
       config.gameMode === 'race' ||
@@ -50,7 +63,9 @@ function validateKnowYourWorldConfig(config: unknown): config is KnowYourWorldCo
     (config.studyDuration === 0 ||
       config.studyDuration === 30 ||
       config.studyDuration === 60 ||
-      config.studyDuration === 120)
+      config.studyDuration === 120) &&
+    typeof config.selectedContinent === 'string' &&
+    validContinents.includes(config.selectedContinent)
   )
 }
 

apps/web/src/arcade-games/know-your-world/maps.ts

@@ -1,6 +1,6 @@
-// @ts-ignore - ESM/CommonJS compatibility
+// @ts-expect-error - ESM/CommonJS compatibility
 import World from '@svg-maps/world'
-// @ts-ignore - ESM/CommonJS compatibility
+// @ts-expect-error - ESM/CommonJS compatibility
 import USA from '@svg-maps/usa'
 import type { MapData, MapRegion } from './types'
 
@@ -20,7 +20,11 @@ function calculatePathCenter(pathString: string): [number, number] {
 
   while ((match = commandRegex.exec(pathString)) !== null) {
     const command = match[1]
-    const params = match[2].trim().match(/-?\d+\.?\d*/g)?.map(Number) || []
+    const params =
+      match[2]
+        .trim()
+        .match(/-?\d+\.?\d*/g)
+        ?.map(Number) || []
 
     switch (command) {
       case 'M': // Move to (absolute)
@@ -240,3 +244,124 @@ export function getRegionById(mapId: 'world' | 'usa', regionId: string) {
   const mapData = getMapData(mapId)
   return mapData.regions.find((r) => r.id === regionId)
 }
+
+/**
+ * Calculate bounding box for a set of SVG paths
+ */
+export interface BoundingBox {
+  minX: number
+  maxX: number
+  minY: number
+  maxY: number
+  width: number
+  height: number
+}
+
+function calculateBoundingBox(paths: string[]): BoundingBox {
+  let minX = Infinity
+  let maxX = -Infinity
+  let minY = Infinity
+  let maxY = -Infinity
+
+  for (const path of paths) {
+    // Extract all numbers from path string
+    const numbers = path.match(/-?\d+\.?\d*/g)?.map(Number) || []
+
+    // Assume pairs of x,y coordinates
+    for (let i = 0; i < numbers.length - 1; i += 2) {
+      const x = numbers[i]
+      const y = numbers[i + 1]
+
+      minX = Math.min(minX, x)
+      maxX = Math.max(maxX, x)
+      minY = Math.min(minY, y)
+      maxY = Math.max(maxY, y)
+    }
+  }
+
+  return {
+    minX,
+    maxX,
+    minY,
+    maxY,
+    width: maxX - minX,
+    height: maxY - minY,
+  }
+}
+
+/**
+ * Filter world map regions by continent
+ */
+import { getContinentForCountry, type ContinentId } from './continents'
+
+export function filterRegionsByContinent(
+  regions: MapRegion[],
+  continentId: ContinentId | 'all'
+): MapRegion[] {
+  if (continentId === 'all') {
+    return regions
+  }
+
+  return regions.filter((region) => {
+    const continent = getContinentForCountry(region.id)
+    return continent === continentId
+  })
+}
+
+/**
+ * Calculate adjusted viewBox for a continent
+ * Adds padding around the bounding box
+ */
+export function calculateContinentViewBox(
+  regions: MapRegion[],
+  continentId: ContinentId | 'all',
+  originalViewBox: string
+): string {
+  if (continentId === 'all') {
+    return originalViewBox
+  }
+
+  const filteredRegions = filterRegionsByContinent(regions, continentId)
+
+  if (filteredRegions.length === 0) {
+    return originalViewBox
+  }
+
+  const paths = filteredRegions.map((r) => r.path)
+  const bbox = calculateBoundingBox(paths)
+
+  // Add 10% padding on each side
+  const paddingX = bbox.width * 0.1
+  const paddingY = bbox.height * 0.1
+
+  const newMinX = bbox.minX - paddingX
+  const newMinY = bbox.minY - paddingY
+  const newWidth = bbox.width + 2 * paddingX
+  const newHeight = bbox.height + 2 * paddingY
+
+  return `${newMinX} ${newMinY} ${newWidth} ${newHeight}`
+}
+
+/**
+ * Get filtered map data for a continent
+ */
+export function getFilteredMapData(
+  mapId: 'world' | 'usa',
+  continentId: ContinentId | 'all'
+): MapData {
+  const mapData = getMapData(mapId)
+
+  // Continent filtering only applies to world map
+  if (mapId !== 'world' || continentId === 'all') {
+    return mapData
+  }
+
+  const filteredRegions = filterRegionsByContinent(mapData.regions, continentId)
+  const adjustedViewBox = calculateContinentViewBox(mapData.regions, continentId, mapData.viewBox)
+
+  return {
+    ...mapData,
+    regions: filteredRegions,
+    viewBox: adjustedViewBox,
+  }
+}

apps/web/src/arcade-games/know-your-world/types.ts

@@ -1,4 +1,5 @@
 import type { GameConfig, GameMove, GameState } from '@/lib/arcade/game-sdk'
+import type { ContinentId } from './continents'
 
 // Game configuration (persisted to database)
 export interface KnowYourWorldConfig extends GameConfig {
@@ -6,6 +7,7 @@ export interface KnowYourWorldConfig extends GameConfig {
   gameMode: 'cooperative' | 'race' | 'turn-based'
   difficulty: 'easy' | 'hard'
   studyDuration: 0 | 30 | 60 | 120 // seconds (0 = skip study mode)
+  selectedContinent: ContinentId | 'all' // continent filter for world map ('all' = no filter)
 }
 
 // Map data structures
@@ -42,6 +44,7 @@ export interface KnowYourWorldState extends GameState {
   gameMode: 'cooperative' | 'race' | 'turn-based'
   difficulty: 'easy' | 'hard'
   studyDuration: 0 | 30 | 60 | 120 // seconds (0 = skip study mode)
+  selectedContinent: ContinentId | 'all' // continent filter for world map ('all' = no filter)
 
   // Study phase
   studyTimeRemaining: number // seconds remaining in study phase
@@ -156,3 +159,12 @@ export type KnowYourWorldMove =
       timestamp: number
       data: {}
     }
+  | {
+      type: 'SET_CONTINENT'
+      playerId: string
+      userId: string
+      timestamp: number
+      data: {
+        selectedContinent: ContinentId | 'all'
+      }
+    }