Add dashboard performance trends

api/QuestionsApi.Tests/DashboardTests.cs

@@ -1,3 +1,4 @@
+using QuestionsApi.Models;
 using QuestionsApi.Services;
 using Xunit;
 
@@ -27,4 +28,110 @@ public sealed class DashboardTests
         var dates = new[] { today, today.AddDays(-1), today.AddDays(-3) };
         Assert.Equal(2, DashboardStore.CalculateCurrentStreak(dates, today));
     }
+
+    [Fact]
+    public void SystemPerformanceReturnsEveryOfficialSystemInOrder()
+    {
+        var attempts = new[]
+        {
+            Attempt("cardio-1", true),
+            Attempt("cardio-2", false),
+            Attempt("ethics-1", true),
+            Attempt("ignored", true),
+            Attempt("skipped-cardio", false, true)
+        };
+        var questions = new Dictionary<string, Question>
+        {
+            ["cardio-1"] = Question("Cardiology"),
+            ["cardio-2"] = Question("Cardiovascular System"),
+            ["ethics-1"] = Question("Medical Ethics"),
+            ["ignored"] = Question("Unmapped Specialty"),
+            ["skipped-cardio"] = Question("Cardiology")
+        };
+
+        var result = DashboardStore.BuildSystemPerformance(attempts, questions);
+
+        Assert.Equal(14, result.Count);
+        Assert.Equal(DashboardStore.Step3Systems, result.Select(value => value.System));
+        var cardiovascular = result.Single(value => value.System == "Cardiovascular System");
+        Assert.Equal(1, cardiovascular.Correct);
+        Assert.Equal(2, cardiovascular.Total);
+        Assert.Equal(50, cardiovascular.Accuracy);
+        var social = result.Single(value => value.System.StartsWith("Social Sciences"));
+        Assert.Equal(1, social.Correct);
+        Assert.Equal(1, social.Total);
+        Assert.All(result.Where(value => value.System != cardiovascular.System && value.System != social.System),
+            value => Assert.Equal(0, value.Total));
+    }
+
+    [Theory]
+    [InlineData("Preventive Medicine", "Human Development")]
+    [InlineData("Infectious Disease", "Immune System, Blood & Lymphoreticular System, and Multisystem Processes/Disorders")]
+    [InlineData("Dermatology", "Skin & Subcutaneous Tissue")]
+    [InlineData("Pulmonary", "Respiratory System")]
+    [InlineData("Pregnancy", "Pregnancy/Childbirth & Female Reproductive System & Breast")]
+    [InlineData("Biostatistics", "Biostatistics & Epidemiology/Population Health & Interpretation of the Medical Literature")]
+    [InlineData("Medical Ethics", "Social Sciences: Communication Skills/Ethics/Patient Safety")]
+    public void SystemAliasesMapToOfficialCategories(string source, string expected)
+    {
+        Assert.Equal(expected, DashboardStore.NormalizeStep3System(source));
+    }
+
+    [Fact]
+    public void TrendCarriesRatingForwardAndLeavesInactiveAccuracyAsGapData()
+    {
+        var today = new DateTime(2026, 7, 25, 0, 0, 0, DateTimeKind.Utc);
+        var baselineDate = today.AddDays(-2).AddHours(8);
+        var attempts = new[]
+        {
+            Attempt("one", true, createdUtc: today.AddDays(-2).AddHours(9),
+                rating: 1018, ratingUtc: today.AddDays(-2).AddHours(9)),
+            Attempt("two", false, createdUtc: today.AddDays(-2).AddHours(10),
+                rating: 1002, ratingUtc: today.AddDays(-2).AddHours(10)),
+            Attempt("three", true, createdUtc: today.AddHours(11),
+                rating: 1020, ratingUtc: today.AddHours(11)),
+            Attempt("skip", false, true, today.AddDays(-1).AddHours(4),
+                990, today.AddDays(-1).AddHours(4))
+        };
+        var rating = new UserRating
+        {
+            OverallElo = 1020,
+            HistoryBaselineElo = 1000,
+            HistoryStartedUtc = baselineDate
+        };
+
+        var result = DashboardStore.BuildPerformanceTrend(attempts, rating, today);
+
+        Assert.Equal(30, result.Count);
+        Assert.Null(result[^4].QuestionBankRating);
+        Assert.Equal(1002, result[^3].QuestionBankRating);
+        Assert.Equal(50, result[^3].Accuracy);
+        Assert.Equal(2, result[^3].Total);
+        Assert.Equal(990, result[^2].QuestionBankRating);
+        Assert.Equal(0, result[^2].Total);
+        Assert.Equal(1020, result[^1].QuestionBankRating);
+        Assert.Equal(100, result[^1].Accuracy);
+    }
+
+    private static QuestionAttempt Attempt(
+        string questionId,
+        bool correct,
+        bool skip = false,
+        DateTime? createdUtc = null,
+        int? rating = null,
+        DateTime? ratingUtc = null) => new()
+        {
+            QuestionExternalId = questionId,
+            IsCorrect = correct,
+            IsSkip = skip,
+            CreatedUtc = createdUtc ?? DateTime.UtcNow,
+            UserOverallEloAfter = rating,
+            RatingAppliedUtc = ratingUtc
+        };
+
+    private static Question Question(string system) => new()
+    {
+        ExternalId = system,
+        System = system
+    };
 }

api/QuestionsApi/Controllers/QuestionsController.cs

@@ -187,7 +187,7 @@ public class QuestionsController : ControllerBase
                 record.Attempt.IsCorrect,
                 shouldRate);
             if (shouldRate)
-                await _attempts.MarkRatingAppliedAsync(record.Attempt.Id ?? "", ratingOwner);
+                await _attempts.MarkRatingAppliedAsync(record.Attempt.Id ?? "", ratingOwner, rating.UserOverallElo);
         }
         catch
         {
@@ -286,7 +286,7 @@ public class QuestionsController : ControllerBase
         {
             rating = await _ratings.ApplyFirstResultAsync(userId, question, false, shouldRate);
             if (shouldRate)
-                await _attempts.MarkRatingAppliedAsync(record.Attempt.Id ?? "", ratingOwner);
+                await _attempts.MarkRatingAppliedAsync(record.Attempt.Id ?? "", ratingOwner, rating.UserOverallElo);
         }
         catch
         {

api/QuestionsApi/Models/DashboardModels.cs

@@ -32,6 +32,7 @@ public sealed class DashboardTrendPoint
     public int Correct { get; set; }
     public int Total { get; set; }
     public int Accuracy { get; set; }
+    public int? QuestionBankRating { get; set; }
 }
 
 public sealed class DashboardSystemPerformance

api/QuestionsApi/Models/QuestionAttempt.cs

@@ -19,6 +19,8 @@ public class QuestionAttempt
     public int DurationSeconds { get; set; }
     public int CounterBucket { get; set; }
     public bool? RatingApplied { get; set; }
+    public int? UserOverallEloAfter { get; set; }
+    public DateTime? RatingAppliedUtc { get; set; }
     public string RatingLeaseOwner { get; set; } = "";
     public DateTime RatingLeaseUntilUtc { get; set; }
     public DateTime CreatedUtc { get; set; } = DateTime.UtcNow;

api/QuestionsApi/Models/RatingModels.cs

@@ -13,6 +13,8 @@ public class UserRating
     public int OverallElo { get; set; } = 1000;
     public Dictionary<string, int> CategoryElos { get; set; } = [];
     public int RatedQuestionCount { get; set; }
+    public int? HistoryBaselineElo { get; set; }
+    public DateTime? HistoryStartedUtc { get; set; }
     public DateTime UpdatedUtc { get; set; } = DateTime.UtcNow;
 }
 

api/QuestionsApi/Services/DashboardStore.cs

@@ -7,7 +7,6 @@ namespace QuestionsApi.Services;
 public sealed class DashboardStore
 {
     private readonly IMongoCollection<QuestionAttempt> _attempts;
-    private readonly IMongoCollection<UserRating> _ratings;
     private readonly IMongoCollection<CcsUserRating> _ccsRatings;
     private readonly IMongoCollection<CcsAttempt> _ccsAttempts;
     private readonly IMongoCollection<CcsCaseRevision> _ccsCases;
@@ -19,6 +18,25 @@ public sealed class DashboardStore
     private readonly DynamicQuestionStore _dynamicQuestions;
     private readonly FlashcardStudyService _flashcards;
     private readonly FlashcardScheduleStore _flashcardSchedules;
+    private readonly RatingStore _ratingStore;
+
+    public static readonly string[] Step3Systems =
+    [
+        "Human Development",
+        "Immune System, Blood & Lymphoreticular System, and Multisystem Processes/Disorders",
+        "Behavioral Health",
+        "Nervous System & Special Senses",
+        "Skin & Subcutaneous Tissue",
+        "Musculoskeletal System",
+        "Cardiovascular System",
+        "Respiratory System",
+        "Gastrointestinal System",
+        "Renal/Urinary & Male Reproductive Systems",
+        "Pregnancy/Childbirth & Female Reproductive System & Breast",
+        "Endocrine System",
+        "Biostatistics & Epidemiology/Population Health & Interpretation of the Medical Literature",
+        "Social Sciences: Communication Skills/Ethics/Patient Safety"
+    ];
 
     public DashboardStore(
         MongoDatabaseProvider mongo,
@@ -26,10 +44,10 @@ public sealed class DashboardStore
         ReviewQueueStore reviewQueue,
         DynamicQuestionStore dynamicQuestions,
         FlashcardStudyService flashcards,
-        FlashcardScheduleStore flashcardSchedules)
+        FlashcardScheduleStore flashcardSchedules,
+        RatingStore ratingStore)
     {
         _attempts = mongo.Database.GetCollection<QuestionAttempt>("QuestionAttempts");
-        _ratings = mongo.Database.GetCollection<UserRating>("UserRatings");
         _ccsRatings = mongo.Database.GetCollection<CcsUserRating>("CcsUserRatings");
         _ccsAttempts = mongo.Database.GetCollection<CcsAttempt>("CcsAttempts");
         _ccsCases = mongo.Database.GetCollection<CcsCaseRevision>("CcsCaseRevisions");
@@ -41,6 +59,7 @@ public sealed class DashboardStore
         _dynamicQuestions = dynamicQuestions;
         _flashcards = flashcards;
         _flashcardSchedules = flashcardSchedules;
+        _ratingStore = ratingStore;
     }
 
     public async Task<DashboardResponse> GetAsync(string userId, DateTime nowUtc)
@@ -49,7 +68,7 @@ public sealed class DashboardStore
         var trendStart = today.AddDays(-29);
         var weekStart = today.AddDays(-6);
         var attemptsTask = _attempts.Find(value => value.UserId == userId).ToListAsync();
-        var ratingTask = _ratings.Find(value => value.UserId == userId).FirstOrDefaultAsync();
+        var ratingTask = _ratingStore.GetOrInitializeHistoryAsync(userId, nowUtc);
         var ccsRatingTask = _ccsRatings.Find(value => value.UserId == userId).FirstOrDefaultAsync();
         var ccsAttemptsTask = _ccsAttempts.Find(value => value.UserId == userId && value.CreatedUtc >= trendStart).ToListAsync();
         var completedCcsCountTask = _ccsAttempts.CountDocumentsAsync(value => value.UserId == userId
@@ -77,8 +96,8 @@ public sealed class DashboardStore
 
         var response = new DashboardResponse
         {
-            QuestionBankRating = ratingTask.Result?.OverallElo ?? 1000,
-            RatedQuestionCount = ratingTask.Result?.RatedQuestionCount ?? 0,
+            QuestionBankRating = ratingTask.Result.OverallElo,
+            RatedQuestionCount = ratingTask.Result.RatedQuestionCount,
             CcsRating = ccsRatingTask.Result?.Elo ?? 1000,
             RatedCcsCaseCount = ccsRatingTask.Result?.RatedCaseCount ?? 0,
             QuestionsCompleted = answeredAttempts.Count,
@@ -95,31 +114,8 @@ public sealed class DashboardStore
             FlashcardsReviewedThisWeek = flashcardCountsTask.Result.ReviewedThisWeek
         };
 
-        response.PerformanceTrend = Enumerable.Range(0, 30).Select(offset =>
-        {
-            var date = trendStart.AddDays(offset);
-            var daily = answeredAttempts.Where(value => value.CreatedUtc.Date == date).ToList();
-            return new DashboardTrendPoint
-            {
-                DateUtc = date,
-                Correct = daily.Count(value => value.IsCorrect),
-                Total = daily.Count,
-                Accuracy = Percentage(daily.Count(value => value.IsCorrect), daily.Count)
-            };
-        }).ToList();
-
-        response.Systems = answeredAttempts
-            .Where(value => questionMap.ContainsKey(value.QuestionExternalId))
-            .GroupBy(value => NormalizeSystem(questionMap[value.QuestionExternalId].System))
-            .Select(group => new DashboardSystemPerformance
-            {
-                System = group.Key,
-                Correct = group.Count(value => value.IsCorrect),
-                Total = group.Count(),
-                Accuracy = Percentage(group.Count(value => value.IsCorrect), group.Count())
-            })
-            .OrderByDescending(value => value.Total).ThenByDescending(value => value.Accuracy)
-            .ToList();
+        response.PerformanceTrend = BuildPerformanceTrend(attempts, ratingTask.Result, today);
+        response.Systems = BuildSystemPerformance(answeredAttempts, questionMap);
 
         response.WeeklyActivity = Enumerable.Range(0, 7).Select(offset =>
         {
@@ -166,6 +162,133 @@ public sealed class DashboardStore
         return streak;
     }
 
+    public static List<DashboardTrendPoint> BuildPerformanceTrend(
+        IEnumerable<QuestionAttempt> attempts,
+        UserRating rating,
+        DateTime todayUtc)
+    {
+        var attemptList = attempts.ToList();
+        var trendStart = todayUtc.Date.AddDays(-29);
+        var ratingEvents = new List<(DateTime AtUtc, int Elo)>();
+        if (rating.HistoryBaselineElo.HasValue && rating.HistoryStartedUtc.HasValue)
+            ratingEvents.Add((rating.HistoryStartedUtc.Value, rating.HistoryBaselineElo.Value));
+        ratingEvents.AddRange(attemptList
+            .Where(value => value.RatingAppliedUtc.HasValue && value.UserOverallEloAfter.HasValue)
+            .Select(value => (value.RatingAppliedUtc!.Value, value.UserOverallEloAfter!.Value)));
+        ratingEvents.Sort((left, right) => left.AtUtc.CompareTo(right.AtUtc));
+
+        int? currentRating = null;
+        var eventIndex = 0;
+        var result = new List<DashboardTrendPoint>();
+        foreach (var offset in Enumerable.Range(0, 30))
+        {
+            var date = trendStart.AddDays(offset);
+            var nextDate = date.AddDays(1);
+            while (eventIndex < ratingEvents.Count && ratingEvents[eventIndex].AtUtc < nextDate)
+            {
+                currentRating = ratingEvents[eventIndex].Elo;
+                eventIndex++;
+            }
+
+            var daily = attemptList
+                .Where(value => !value.IsSkip && value.CreatedUtc >= date && value.CreatedUtc < nextDate)
+                .ToList();
+            var correct = daily.Count(value => value.IsCorrect);
+            result.Add(new DashboardTrendPoint
+            {
+                DateUtc = date,
+                Correct = correct,
+                Total = daily.Count,
+                Accuracy = Percentage(correct, daily.Count),
+                QuestionBankRating = currentRating
+            });
+        }
+        return result;
+    }
+
+    public static List<DashboardSystemPerformance> BuildSystemPerformance(
+        IEnumerable<QuestionAttempt> attempts,
+        IReadOnlyDictionary<string, Question> questionMap)
+    {
+        var totals = Step3Systems.ToDictionary(
+            system => system,
+            _ => (Correct: 0, Total: 0),
+            StringComparer.Ordinal);
+        foreach (var attempt in attempts.Where(value => !value.IsSkip))
+        {
+            if (!questionMap.TryGetValue(attempt.QuestionExternalId, out var question))
+                continue;
+            var system = NormalizeStep3System(question);
+            if (system is null)
+                continue;
+            var current = totals[system];
+            totals[system] = (current.Correct + (attempt.IsCorrect ? 1 : 0), current.Total + 1);
+        }
+
+        return Step3Systems.Select(system => new DashboardSystemPerformance
+        {
+            System = system,
+            Correct = totals[system].Correct,
+            Total = totals[system].Total,
+            Accuracy = Percentage(totals[system].Correct, totals[system].Total)
+        }).ToList();
+    }
+
+    public static string? NormalizeStep3System(Question question)
+    {
+        foreach (var candidate in new[] { question.System, question.PerformanceCategory, question.Discipline })
+        {
+            var normalized = NormalizeStep3System(candidate);
+            if (normalized is not null)
+                return normalized;
+        }
+        return null;
+    }
+
+    public static string? NormalizeStep3System(string? value)
+    {
+        if (string.IsNullOrWhiteSpace(value))
+            return null;
+        var exact = Step3Systems.FirstOrDefault(
+            system => string.Equals(system, value.Trim(), StringComparison.OrdinalIgnoreCase));
+        if (exact is not null)
+            return exact;
+
+        var lower = value.Trim().ToLowerInvariant();
+        if (ContainsAny(lower, "human development", "well patient", "preventive", "health maintenance", "geriatr", "age-related"))
+            return Step3Systems[0];
+        if (ContainsAny(lower, "social science", "communication", "ethic", "patient safety", "professionalism", "systems-based"))
+            return Step3Systems[13];
+        if (ContainsAny(lower, "pregnan", "obstetric", "gynec", "female reproductive", "breast", "puerper"))
+            return Step3Systems[10];
+        if (ContainsAny(lower, "renal", "urinary", "male reproductive", "urolog", "nephro"))
+            return Step3Systems[9];
+        if (ContainsAny(lower, "biostat", "epidemi", "population health", "medical literature"))
+            return Step3Systems[12];
+        if (ContainsAny(lower, "immune", "immun", "blood", "hemat", "lymph", "multisystem", "infectious"))
+            return Step3Systems[1];
+        if (ContainsAny(lower, "behavior", "psychi", "mental health"))
+            return Step3Systems[2];
+        if (ContainsAny(lower, "nervous", "neuro", "special sense", "ophthalm", "otolaryng", " ent"))
+            return Step3Systems[3];
+        if (ContainsAny(lower, "skin", "derm", "subcutaneous"))
+            return Step3Systems[4];
+        if (ContainsAny(lower, "musculo", "orthop", "rheumat"))
+            return Step3Systems[5];
+        if (ContainsAny(lower, "cardio", "circulatory"))
+            return Step3Systems[6];
+        if (ContainsAny(lower, "resp", "pulmon"))
+            return Step3Systems[7];
+        if (ContainsAny(lower, "gastro", "digest", "hepato"))
+            return Step3Systems[8];
+        if (ContainsAny(lower, "endocr", "metabolic"))
+            return Step3Systems[11];
+        return null;
+    }
+
+    private static bool ContainsAny(string value, params string[] fragments) =>
+        fragments.Any(value.Contains);
+
     private async Task<List<DashboardRecentActivity>> BuildRecentActivityAsync(
         List<QuestionAttempt> attempts,
         Dictionary<string, Question> questionMap,

api/QuestionsApi/Services/ExamSimulationStore.cs

@@ -454,8 +454,8 @@ public class ExamSimulationStore
             try
             {
                 shouldRate = await _attempts.TryAcquireRatingLeaseAsync(attemptId, owner, TimeSpan.FromSeconds(30));
-                await _ratings.ApplyFirstResultAsync(simulation.UserId, question, record.Attempt.IsCorrect, shouldRate);
-                if (shouldRate) await _attempts.MarkRatingAppliedAsync(attemptId, owner);
+                var rating = await _ratings.ApplyFirstResultAsync(simulation.UserId, question, record.Attempt.IsCorrect, shouldRate);
+                if (shouldRate) await _attempts.MarkRatingAppliedAsync(attemptId, owner, rating.UserOverallElo);
             }
             catch
             {

api/QuestionsApi/Services/QuestionAttemptStore.cs

@@ -103,11 +103,13 @@ public class QuestionAttemptStore
         return leased?.RatingLeaseOwner == owner;
     }
 
-    public Task MarkRatingAppliedAsync(string attemptId, string owner) =>
+    public Task MarkRatingAppliedAsync(string attemptId, string owner, int userOverallElo) =>
         _col.UpdateOneAsync(
             attempt => attempt.Id == attemptId && attempt.RatingLeaseOwner == owner,
             Builders<QuestionAttempt>.Update
                 .Set(attempt => attempt.RatingApplied, true)
+                .Set(attempt => attempt.UserOverallEloAfter, userOverallElo)
+                .Set(attempt => attempt.RatingAppliedUtc, DateTime.UtcNow)
                 .Set(attempt => attempt.RatingLeaseUntilUtc, DateTime.MinValue));
 
     public Task ReleaseRatingLeaseAsync(string attemptId, string owner) =>

api/QuestionsApi/Services/RatingStore.cs

@@ -35,6 +35,12 @@ public class RatingStore
         };
     }
 
+    public async Task<UserRating> GetOrInitializeHistoryAsync(string userId, DateTime nowUtc)
+    {
+        var rating = await GetOrCreateUserRatingAsync(userId);
+        return await EnsureHistoryBaselineAsync(rating, nowUtc);
+    }
+
     public async Task<Dictionary<string, int>> GetQuestionElosAsync(IEnumerable<string> externalIds)
     {
         var ids = externalIds.Where(id => !string.IsNullOrWhiteSpace(id)).Distinct().ToList();
@@ -71,6 +77,7 @@ public class RatingStore
             };
         }
 
+        userRating = await EnsureHistoryBaselineAsync(userRating, DateTime.UtcNow);
         var actual = isCorrect ? 1.0 : 0.0;
         var userK = userRating.RatedQuestionCount < 20 ? 40 : 24;
         var questionK = questionRating.AttemptCount < 20 ? 32 : 24;
@@ -164,6 +171,26 @@ public class RatingStore
         return rating;
     }
 
+    private async Task<UserRating> EnsureHistoryBaselineAsync(UserRating rating, DateTime nowUtc)
+    {
+        if (rating.HistoryBaselineElo.HasValue && rating.HistoryStartedUtc.HasValue)
+            return rating;
+
+        var result = await _users.UpdateOneAsync(
+            value => value.UserId == rating.UserId && value.HistoryStartedUtc == null,
+            Builders<UserRating>.Update
+                .Set(value => value.HistoryBaselineElo, rating.OverallElo)
+                .Set(value => value.HistoryStartedUtc, nowUtc));
+        if (result.ModifiedCount > 0)
+        {
+            rating.HistoryBaselineElo = rating.OverallElo;
+            rating.HistoryStartedUtc = nowUtc;
+            return rating;
+        }
+
+        return await _users.Find(value => value.UserId == rating.UserId).FirstAsync();
+    }
+
     private async Task<QuestionRating> GetOrCreateQuestionRatingAsync(string questionExternalId)
     {
         var create = Builders<QuestionRating>.Update

scripts/ui/dashboard_chart.gd

@@ -2,39 +2,156 @@ extends Control
 
 const Brand := preload("res://scripts/ui/medmind_style.gd")
 
-var values: PackedFloat32Array = []
+var points: Array = []
+var mode := "rating"
 var dark := true
+var hover_index := -1
 
 
-func set_values(next_values: Array, dark_mode: bool) -> void:
-	values = PackedFloat32Array(next_values)
+func _ready() -> void:
+	mouse_filter = Control.MOUSE_FILTER_STOP
+
+
+func set_series(next_points: Array, next_mode: String, dark_mode: bool) -> void:
+	points = next_points.duplicate(true)
+	mode = next_mode
 	dark = dark_mode
+	hover_index = -1
+	queue_redraw()
+
+
+func _notification(what: int) -> void:
+	if what == NOTIFICATION_RESIZED:
+		queue_redraw()
+
+
+func _gui_input(event: InputEvent) -> void:
+	if event is InputEventMouseMotion:
+		var next_hover := _index_near_x(event.position.x)
+		if next_hover != hover_index:
+			hover_index = next_hover
+			queue_redraw()
+	elif event is InputEventMouseButton and not event.pressed:
+		hover_index = _index_near_x(event.position.x)
 		queue_redraw()
 
 
 func _draw() -> void:
-	var left := 42.0
+	var left := 52.0
 	var top := 12.0
-	var right := size.x - 12.0
-	var bottom := size.y - 28.0
+	var right := maxf(left + 1.0, size.x - 12.0)
+	var bottom := maxf(top + 1.0, size.y - 34.0)
 	var grid := Color("24314b") if dark else Color("dbe3ef")
 	var muted := Brand.muted_color(dark)
-	for percentage in [0, 25, 50, 75, 100]:
-		var y: float = bottom - (bottom - top) * float(percentage) / 100.0
+	var bounds := axis_bounds(points, mode)
+	var minimum := float(bounds.x)
+	var maximum := float(bounds.y)
+	for tick_index in range(5):
+		var ratio := float(tick_index) / 4.0
+		var y := bottom - (bottom - top) * ratio
+		var tick_value := lerpf(minimum, maximum, ratio)
 		draw_line(Vector2(left, y), Vector2(right, y), grid, 1.0)
-		draw_string(Brand.font, Vector2(4, y + 4), str(percentage), HORIZONTAL_ALIGNMENT_LEFT, 34, 11, muted)
-	var target_y: float = bottom - (bottom - top) * 0.70
+		draw_string(Brand.font, Vector2(2, y + 4), str(int(round(tick_value))), HORIZONTAL_ALIGNMENT_RIGHT, 43, 11, muted)
+	if mode == "accuracy":
+		var target_y := _value_y(70.0, minimum, maximum, top, bottom)
 		draw_dashed_line(Vector2(left, target_y), Vector2(right, target_y), Brand.ROYAL_BLUE, 5.0, 2.0)
-	if values.is_empty():
+	if points.is_empty():
 		return
-	var points := PackedVector2Array()
-	var count: int = values.size()
-	for index in range(count):
-		var x: float = left if count == 1 else lerpf(left, right, float(index) / float(count - 1))
-		var y: float = bottom - (bottom - top) * clampf(values[index], 0.0, 100.0) / 100.0
-		points.append(Vector2(x, y))
-	if points.size() > 1:
-		draw_polyline(points, Brand.ROYAL_BLUE, 2.5, true)
-	for point in points:
+
+	var previous: Variant = null
+	for index in range(points.size()):
+		var value: Variant = point_value(points[index], mode)
+		if value == null:
+			previous = null
+			continue
+		var point := Vector2(_point_x(index, left, right), _value_y(float(value), minimum, maximum, top, bottom))
+		if previous != null:
+			draw_line(previous, point, Brand.ROYAL_BLUE, 2.5, true)
 		draw_circle(point, 3.5, Brand.PURPLE)
 		draw_circle(point, 2.0, Color.WHITE)
+		previous = point
+
+	for label_index in [0, int(floor(float(points.size() - 1) / 2.0)), points.size() - 1]:
+		var x := _point_x(label_index, left, right)
+		var label := _short_date(str((points[label_index] as Dictionary).get("dateUtc", "")))
+		draw_string(Brand.font, Vector2(x - 24, bottom + 19), label, HORIZONTAL_ALIGNMENT_CENTER, 48, 10, muted)
+
+	if hover_index >= 0 and hover_index < points.size():
+		var hover_value: Variant = point_value(points[hover_index], mode)
+		if hover_value != null:
+			var hover_x := _point_x(hover_index, left, right)
+			var hover_y := _value_y(float(hover_value), minimum, maximum, top, bottom)
+			draw_line(Vector2(hover_x, top), Vector2(hover_x, bottom), muted, 1.0)
+			draw_circle(Vector2(hover_x, hover_y), 5.0, Brand.ROYAL_BLUE)
+			var suffix := "%" if mode == "accuracy" else ""
+			var tooltip := "%s  %d%s" % [
+				_short_date(str((points[hover_index] as Dictionary).get("dateUtc", ""))),
+				int(hover_value),
+				suffix
+			]
+			var tooltip_size := Brand.font.get_string_size(tooltip, HORIZONTAL_ALIGNMENT_LEFT, -1, 11) + Vector2(16, 10)
+			var tooltip_x := clampf(hover_x - tooltip_size.x / 2.0, left, right - tooltip_size.x)
+			var tooltip_y := maxf(top, hover_y - tooltip_size.y - 10.0)
+			var tooltip_rect := Rect2(Vector2(tooltip_x, tooltip_y), tooltip_size)
+			draw_style_box(_tooltip_box(), tooltip_rect)
+			draw_string(Brand.font, Vector2(tooltip_x + 8, tooltip_y + tooltip_size.y - 7), tooltip, HORIZONTAL_ALIGNMENT_LEFT, -1, 11, Brand.text_color(dark))
+
+
+static func point_value(point: Dictionary, series_mode: String) -> Variant:
+	if series_mode == "accuracy":
+		return float(point.get("accuracy", 0)) if int(point.get("total", 0)) > 0 else null
+	var value: Variant = point.get("questionBankRating", null)
+	return null if value == null else float(value)
+
+
+static func axis_bounds(series_points: Array, series_mode: String) -> Vector2:
+	if series_mode == "accuracy":
+		return Vector2(0, 100)
+	var values: Array[float] = []
+	for point in series_points:
+		var value: Variant = point_value(point, series_mode)
+		if value != null:
+			values.append(float(value))
+	if values.is_empty():
+		return Vector2(900, 1100)
+	var minimum: float = values.min()
+	var maximum: float = values.max()
+	if maximum - minimum < 100.0:
+		var center: float = (minimum + maximum) / 2.0
+		minimum = center - 50.0
+		maximum = center + 50.0
+	var padding := maxf(25.0, (maximum - minimum) * 0.15)
+	minimum = floor((minimum - padding) / 25.0) * 25.0
+	maximum = ceil((maximum + padding) / 25.0) * 25.0
+	return Vector2(minimum, maximum)
+
+
+func _index_near_x(mouse_x: float) -> int:
+	if points.is_empty() or size.x <= 64.0:
+		return -1
+	var ratio := clampf((mouse_x - 52.0) / maxf(1.0, size.x - 64.0), 0.0, 1.0)
+	return int(round(ratio * float(points.size() - 1)))
+
+
+func _point_x(index: int, left: float, right: float) -> float:
+	return left if points.size() <= 1 else lerpf(left, right, float(index) / float(points.size() - 1))
+
+
+func _value_y(value: float, minimum: float, maximum: float, top: float, bottom: float) -> float:
+	return bottom - (bottom - top) * inverse_lerp(minimum, maximum, clampf(value, minimum, maximum))
+
+
+func _short_date(iso_value: String) -> String:
+	var date := iso_value.left(10)
+	if date.length() < 10:
+		return ""
+	return "%s/%s" % [date.substr(5, 2), date.substr(8, 2)]
+
+
+func _tooltip_box() -> StyleBoxFlat:
+	var box := StyleBoxFlat.new()
+	box.bg_color = Color("111d31") if dark else Color.WHITE
+	box.border_color = Color("34435e") if dark else Brand.LIGHT_BORDER
+	box.set_border_width_all(1)
+	box.set_corner_radius_all(5)
+	return box

scripts/ui/dashboard_screen.gd

@@ -12,6 +12,8 @@ var metric_grid: GridContainer
 var analytics_grid: GridContainer
 var lower_grid: GridContainer
 var trend_chart: Control
+var rating_toggle: Button
+var accuracy_toggle: Button
 var activity_chart: Control
 var system_list: VBoxContainer
 var focus_content: VBoxContainer
@@ -22,6 +24,7 @@ var metric_values: Dictionary = {}
 var metric_details: Dictionary = {}
 var pending_review_launch := false
 var review_queue_service: Variant
+var trend_mode := "rating"
 
 
 func _ready() -> void:
@@ -81,7 +84,18 @@ func _build() -> void:
 	var performance := VBoxContainer.new()
 	performance.size_flags_horizontal = Control.SIZE_EXPAND_FILL
 	performance.add_theme_constant_override("separation", 10)
-	performance.add_child(_section_title("Performance trend"))
+	var trend_header := HBoxContainer.new()
+	trend_header.add_child(_section_title("Performance trend"))
+	var trend_space := Control.new()
+	trend_space.size_flags_horizontal = Control.SIZE_EXPAND_FILL
+	trend_header.add_child(trend_space)
+	var trend_group := ButtonGroup.new()
+	trend_group.allow_unpress = false
+	rating_toggle = _trend_toggle("Rating", "rating", trend_group)
+	accuracy_toggle = _trend_toggle("Correct %", "accuracy", trend_group)
+	trend_header.add_child(rating_toggle)
+	trend_header.add_child(accuracy_toggle)
+	performance.add_child(trend_header)
 	trend_chart = TrendChart.new()
 	trend_chart.custom_minimum_size = Vector2(520, 190)
 	trend_chart.size_flags_horizontal = Control.SIZE_EXPAND_FILL
@@ -153,11 +167,7 @@ func _render() -> void:
 	_set_metric("ccs", str(int(data.get("ccsRating", 1000))), "%d rated cases" % int(data.get("ratedCcsCaseCount", 0)))
 	_set_metric("accuracy", "%d%%" % int(data.get("firstAttemptAccuracy", 0)), "Last %d questions" % int(data.get("accuracySampleSize", 0)))
 	_set_metric("time", _format_duration(int(data.get("studyTimeSecondsThisWeek", 0))), "This week")
-	var trend_values: Array = []
-	for point in data.get("performanceTrend", []):
-		if int(point.get("total", 0)) > 0:
-			trend_values.append(float(point.get("accuracy", 0)))
-	trend_chart.set_values(trend_values, UIThemeService.is_dark_mode())
+	trend_chart.set_series(data.get("performanceTrend", []), trend_mode, UIThemeService.is_dark_mode())
 	_render_systems(data.get("systems", []))
 	_render_focus(data.get("systems", []))
 	_render_review(data)
@@ -170,38 +180,52 @@ func _render() -> void:
 func _render_systems(systems_value: Array) -> void:
 	_clear(system_list)
 	var systems := systems_value.duplicate(true)
-	systems.sort_custom(func(a: Dictionary, b: Dictionary): return int(a.get("total", 0)) > int(b.get("total", 0)))
 	if systems.is_empty():
 		system_list.add_child(_label("Answer questions to build your system breakdown.", 14, Brand.muted_color(UIThemeService.is_dark_mode())))
 		return
-	var displayed: Array = systems.slice(0, mini(5, systems.size()))
-	var best_accuracy := -1
-	var worst_accuracy := 101
-	for item in displayed:
-		best_accuracy = maxi(best_accuracy, int(item.get("accuracy", 0)))
-		worst_accuracy = mini(worst_accuracy, int(item.get("accuracy", 0)))
-	for item in displayed:
+	var attempted: Array = systems.filter(func(item: Dictionary): return int(item.get("total", 0)) > 0)
+	var strongest_system := ""
+	var weakest_system := ""
+	if not attempted.is_empty():
+		var strongest: Dictionary = attempted[0]
+		var weakest: Dictionary = attempted[0]
+		for item in attempted:
+			if int(item.get("accuracy", 0)) > int(strongest.get("accuracy", 0)) or (
+				int(item.get("accuracy", 0)) == int(strongest.get("accuracy", 0))
+				and int(item.get("total", 0)) > int(strongest.get("total", 0))):
+				strongest = item
+			if int(item.get("accuracy", 0)) < int(weakest.get("accuracy", 0)) or (
+				int(item.get("accuracy", 0)) == int(weakest.get("accuracy", 0))
+				and int(item.get("total", 0)) > int(weakest.get("total", 0))):
+				weakest = item
+		strongest_system = str(strongest.get("system", ""))
+		weakest_system = str(weakest.get("system", ""))
+	for item in systems:
 		var row := HBoxContainer.new()
 		row.add_theme_constant_override("separation", 10)
 		var system_name_label := _label(str(item.get("system", "General")), 13, Brand.text_color(UIThemeService.is_dark_mode()))
-		system_name_label.custom_minimum_size.x = 190
-		system_name_label.text_overrun_behavior = TextServer.OVERRUN_TRIM_ELLIPSIS
+		system_name_label.custom_minimum_size.x = 170
+		system_name_label.size_flags_horizontal = Control.SIZE_EXPAND_FILL
+		system_name_label.autowrap_mode = TextServer.AUTOWRAP_WORD_SMART
 		row.add_child(system_name_label)
 		var bar := ProgressBar.new()
 		bar.show_percentage = false
 		bar.value = int(item.get("accuracy", 0))
-		bar.custom_minimum_size = Vector2(150, 7)
+		bar.custom_minimum_size = Vector2(80, 7)
 		bar.size_flags_horizontal = Control.SIZE_EXPAND_FILL
 		bar.size_flags_vertical = Control.SIZE_SHRINK_CENTER
-		_style_progress(bar, Brand.PURPLE if int(item.get("accuracy", 0)) == worst_accuracy else Brand.ROYAL_BLUE)
+		_style_progress(bar, Brand.PURPLE if str(item.get("system", "")) == weakest_system else Brand.ROYAL_BLUE)
 		row.add_child(bar)
-		var percentage := _label("%d%%" % int(item.get("accuracy", 0)), 14, Brand.ROYAL_BLUE, true)
+		var total := int(item.get("total", 0))
+		var percentage_text := "%d%%" % int(item.get("accuracy", 0)) if total > 0 else "—"
+		var percentage := _label(percentage_text, 14, Brand.ROYAL_BLUE, true)
 		percentage.custom_minimum_size.x = 48
 		row.add_child(percentage)
-		var count := _label("%d / %d" % [int(item.get("correct", 0)), int(item.get("total", 0))], 12, Brand.muted_color(UIThemeService.is_dark_mode()))
+		var count := _label("%d / %d" % [int(item.get("correct", 0)), total], 12, Brand.muted_color(UIThemeService.is_dark_mode()))
 		count.custom_minimum_size.x = 58
 		row.add_child(count)
-		var marker := "Strongest" if int(item.get("accuracy", 0)) == best_accuracy else ("Needs work" if int(item.get("accuracy", 0)) == worst_accuracy else "")
+		var system_name := str(item.get("system", ""))
+		var marker := "Strongest" if system_name == strongest_system else ("Needs work" if system_name == weakest_system else "")
 		var marker_label := _label(marker, 11, Brand.SUCCESS if marker == "Strongest" else Brand.MAGENTA)
 		marker_label.custom_minimum_size.x = 72
 		row.add_child(marker_label)
@@ -442,6 +466,33 @@ func _button(text: String, icon_name: String = "", primary: bool = true) -> Butt
 	return button
 
 
+func _trend_toggle(text: String, mode: String, group: ButtonGroup) -> Button:
+	var button := Button.new()
+	button.text = text
+	button.toggle_mode = true
+	button.button_group = group
+	button.button_pressed = trend_mode == mode
+	button.custom_minimum_size = Vector2(86, 32)
+	button.add_theme_font_override("font", Brand.font)
+	button.add_theme_font_size_override("font_size", 12)
+	var normal := Brand.secondary_button_box(UIThemeService.is_dark_mode())
+	var selected := StyleBoxFlat.new()
+	selected.bg_color = Brand.ROYAL_BLUE
+	selected.set_corner_radius_all(6)
+	button.add_theme_stylebox_override("normal", normal)
+	button.add_theme_stylebox_override("hover", normal)
+	button.add_theme_stylebox_override("pressed", selected)
+	button.add_theme_color_override("font_pressed_color", Color.WHITE)
+	button.pressed.connect(_set_trend_mode.bind(mode))
+	return button
+
+
+func _set_trend_mode(mode: String) -> void:
+	trend_mode = mode
+	if trend_chart != null and not DashboardService.data.is_empty():
+		trend_chart.set_series(DashboardService.data.get("performanceTrend", []), trend_mode, UIThemeService.is_dark_mode())
+
+
 func _label(text: String, font_size: int, color: Color, bold: bool = false) -> Label:
 	var label := Label.new()
 	label.text = text
@@ -487,6 +538,8 @@ func _update_responsive() -> void:
 	metric_grid.columns = 2 if compact else 4
 	analytics_grid.columns = 1 if compact else 2
 	lower_grid.columns = 1 if compact else 2
+	if trend_chart != null:
+		trend_chart.custom_minimum_size.x = 300.0 if compact else 520.0
 
 
 func _clear(container: Container) -> void:

tests/dashboard_chart_test.gd

@@ -0,0 +1,60 @@
+extends SceneTree
+
+var failures := 0
+
+
+func _initialize() -> void:
+	call_deferred("_run")
+
+
+func _run() -> void:
+	var Chart = load("res://scripts/ui/dashboard_chart.gd")
+	_test_point_values(Chart)
+	_test_axis_bounds(Chart)
+	await _test_runtime_modes(Chart)
+	quit(1 if failures > 0 else 0)
+
+
+func _test_point_values(Chart: GDScript) -> void:
+	var active := {"accuracy": 75, "total": 4, "questionBankRating": 1042}
+	var inactive := {"accuracy": 0, "total": 0, "questionBankRating": null}
+	_assert(Chart.point_value(active, "accuracy") == 75.0, "accuracy mode should expose active-day accuracy")
+	_assert(Chart.point_value(inactive, "accuracy") == null, "accuracy mode should leave inactive days empty")
+	_assert(Chart.point_value(active, "rating") == 1042.0, "rating mode should expose stored Elo")
+	_assert(Chart.point_value(inactive, "rating") == null, "rating mode should preserve pre-baseline gaps")
+
+
+func _test_axis_bounds(Chart: GDScript) -> void:
+	_assert(Chart.axis_bounds([], "accuracy") == Vector2(0, 100), "accuracy should use a fixed 0-100 axis")
+	var rating_points := [
+		{"questionBankRating": 1000},
+		{"questionBankRating": 1020}
+	]
+	var bounds: Vector2 = Chart.axis_bounds(rating_points, "rating")
+	_assert(bounds.x < 1000 and bounds.y > 1020, "rating bounds should include padded values")
+	_assert(bounds.y - bounds.x >= 100, "rating bounds should preserve a useful minimum span")
+
+
+func _test_runtime_modes(Chart: GDScript) -> void:
+	var chart = Chart.new()
+	chart.size = Vector2(560, 190)
+	root.add_child(chart)
+	await process_frame
+	var series := [
+		{"dateUtc": "2026-07-23T00:00:00Z", "total": 2, "accuracy": 50, "questionBankRating": null},
+		{"dateUtc": "2026-07-24T00:00:00Z", "total": 0, "accuracy": 0, "questionBankRating": 1000},
+		{"dateUtc": "2026-07-25T00:00:00Z", "total": 1, "accuracy": 100, "questionBankRating": 1018}
+	]
+	chart.set_series(series, "rating", true)
+	_assert(chart.mode == "rating" and chart.points.size() == 3, "chart should accept dated rating series")
+	chart.set_series(series, "accuracy", false)
+	_assert(chart.mode == "accuracy" and not chart.dark, "chart should switch modes and themes")
+	chart.queue_free()
+	await process_frame
+
+
+func _assert(condition: bool, message: String) -> void:
+	if condition:
+		return
+	failures += 1
+	push_error(message)

tests/dashboard_chart_test.gd.uid

@@ -0,0 +1 @@
+uid://di0806e6g2872

tests/dashboard_metric_ui_test.gd

@@ -0,0 +1,66 @@
+extends SceneTree
+
+var failures := 0
+
+
+func _initialize() -> void:
+	call_deferred("_run")
+
+
+func _run() -> void:
+	var dashboard_service = root.get_node("DashboardService")
+	var prior_data: Dictionary = dashboard_service.data
+	dashboard_service.data = _dashboard_data()
+	var dashboard = load("res://scripts/ui/dashboard_screen.gd").new()
+	dashboard.size = Vector2(1280, 900)
+	root.add_child(dashboard)
+	await process_frame
+	dashboard._render()
+	await process_frame
+
+	_assert(dashboard.system_list.get_child_count() == 14, "dashboard should render all 14 Step 3 systems")
+	_assert(dashboard.rating_toggle.button_pressed, "rating should be the default trend mode")
+	_assert(dashboard.trend_chart.mode == "rating", "chart should initially render rating history")
+	dashboard._set_trend_mode("accuracy")
+	_assert(dashboard.trend_chart.mode == "accuracy", "correct percentage toggle should switch the chart series")
+	_assert(dashboard.trend_chart.points.size() == 30, "chart should retain all 30 calendar points")
+
+	dashboard.queue_free()
+	dashboard_service.data = prior_data
+	await process_frame
+	quit(1 if failures > 0 else 0)
+
+
+func _dashboard_data() -> Dictionary:
+	var systems: Array = []
+	for index in range(14):
+		systems.append({
+			"system": "System %02d" % index,
+			"correct": 1 if index == 0 else 0,
+			"total": 1 if index == 0 else 0,
+			"accuracy": 100 if index == 0 else 0
+		})
+	var trend: Array = []
+	for index in range(30):
+		trend.append({
+			"dateUtc": "2026-07-%02dT00:00:00Z" % (index + 1),
+			"correct": 1 if index % 2 == 0 else 0,
+			"total": 1 if index % 2 == 0 else 0,
+			"accuracy": 100 if index % 2 == 0 else 0,
+			"questionBankRating": 1000 + index
+		})
+	return {
+		"questionBankRating": 1029,
+		"ratedQuestionCount": 30,
+		"performanceTrend": trend,
+		"systems": systems,
+		"weeklyActivity": [],
+		"recentActivity": []
+	}
+
+
+func _assert(condition: bool, message: String) -> void:
+	if condition:
+		return
+	failures += 1
+	push_error(message)

tests/dashboard_metric_ui_test.gd.uid

@@ -0,0 +1 @@
+uid://bxm4twkfwu455