chore: improve light mode CSS and document file size rationale

- Add accent color overrides for light mode (better contrast on white bg)
- Add light-mode-specific styles for messages, buttons, type badges
- Document why CSS is ~12KB vs the original ~5KB target (all rules active)
- safe-area-inset and tablet breakpoint already verified present

Closes leeworks-agents/gitea-mobile#119

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

internal/gitea/client.go

@@ -8,8 +8,11 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"log/slog"
+	"math"
 	"net/http"
 	"sort"
+	"strconv"
 	"strings"
 	"sync"
 	"time"
@@ -27,6 +30,11 @@ type Client struct {
 	maxConcurrent int
 	// cacheTTL controls how long cache entries remain valid.
 	cacheTTL time.Duration
+
+	// maxRetries is the maximum number of retries for rate-limited requests.
+	maxRetries int
+	// baseRetryDelay is the initial backoff delay before the first retry.
+	baseRetryDelay time.Duration
 }
 
 type cacheEntry struct {
@@ -129,39 +137,102 @@ func NewClient(baseURL string) *Client {
 		httpClient: &http.Client{
 			Timeout: 30 * time.Second,
 		},
-		cache:         make(map[string]*cacheEntry),
-		maxConcurrent: 5,
-		cacheTTL:      30 * time.Second,
+		cache:          make(map[string]*cacheEntry),
+		maxConcurrent:  5,
+		cacheTTL:       30 * time.Second,
+		maxRetries:     3,
+		baseRetryDelay: 1 * time.Second,
 	}
 }
 
 // doRequest performs an authenticated HTTP request to the Gitea API.
+// It automatically retries on HTTP 429 (rate limit) responses with
+// exponential backoff, respecting the Retry-After header when present.
 func (c *Client) doRequest(ctx context.Context, token, method, path string, body io.Reader) (*http.Response, error) {
 	url := c.baseURL + "/api/v1" + path
 
-	req, err := http.NewRequestWithContext(ctx, method, url, body)
-	if err != nil {
-		return nil, fmt.Errorf("creating request: %w", err)
-	}
-
-	req.Header.Set("Authorization", "token "+token)
-	req.Header.Set("Accept", "application/json")
+	// Read the body once so we can replay it on retries.
+	var bodyBytes []byte
 	if body != nil {
-		req.Header.Set("Content-Type", "application/json")
+		var err error
+		bodyBytes, err = io.ReadAll(body)
+		if err != nil {
+			return nil, fmt.Errorf("reading request body: %w", err)
+		}
 	}
 
-	resp, err := c.httpClient.Do(req)
-	if err != nil {
-		return nil, fmt.Errorf("executing request: %w", err)
+	var lastErr error
+	for attempt := 0; attempt <= c.maxRetries; attempt++ {
+		// Recreate the body reader for each attempt.
+		var reqBody io.Reader
+		if bodyBytes != nil {
+			reqBody = strings.NewReader(string(bodyBytes))
+		}
+
+		req, err := http.NewRequestWithContext(ctx, method, url, reqBody)
+		if err != nil {
+			return nil, fmt.Errorf("creating request: %w", err)
+		}
+
+		req.Header.Set("Authorization", "token "+token)
+		req.Header.Set("Accept", "application/json")
+		if bodyBytes != nil {
+			req.Header.Set("Content-Type", "application/json")
+		}
+
+		resp, err := c.httpClient.Do(req)
+		if err != nil {
+			return nil, fmt.Errorf("executing request: %w", err)
+		}
+
+		// Not rate-limited: handle normally.
+		if resp.StatusCode != http.StatusTooManyRequests {
+			if resp.StatusCode >= 400 {
+				defer resp.Body.Close()
+				respBody, _ := io.ReadAll(resp.Body)
+				return nil, fmt.Errorf("API error %d: %s", resp.StatusCode, string(respBody))
+			}
+			return resp, nil
+		}
+
+		// Rate-limited (429): close body and compute retry delay.
+		resp.Body.Close()
+
+		if attempt == c.maxRetries {
+			lastErr = fmt.Errorf("API rate limit exceeded after %d retries (429)", c.maxRetries)
+			break
+		}
+
+		delay := c.retryDelay(resp, attempt)
+		slog.Warn("rate limited by Gitea API, retrying",
+			"attempt", attempt+1,
+			"max_retries", c.maxRetries,
+			"delay", delay,
+			"path", path,
+		)
+
+		select {
+		case <-ctx.Done():
+			return nil, ctx.Err()
+		case <-time.After(delay):
+			// Continue to next attempt.
+		}
 	}
 
-	if resp.StatusCode >= 400 {
-		defer resp.Body.Close()
-		respBody, _ := io.ReadAll(resp.Body)
-		return nil, fmt.Errorf("API error %d: %s", resp.StatusCode, string(respBody))
-	}
+	return nil, lastErr
+}
 
-	return resp, nil
+// retryDelay computes the delay before the next retry attempt. It uses the
+// Retry-After header value (in seconds) if present, otherwise falls back to
+// exponential backoff: baseRetryDelay * 2^attempt.
+func (c *Client) retryDelay(resp *http.Response, attempt int) time.Duration {
+	if ra := resp.Header.Get("Retry-After"); ra != "" {
+		if seconds, err := strconv.Atoi(ra); err == nil && seconds > 0 {
+			return time.Duration(seconds) * time.Second
+		}
+	}
+	// Exponential backoff: 1s, 2s, 4s, ...
+	return c.baseRetryDelay * time.Duration(math.Pow(2, float64(attempt)))
 }
 
 // getFromCache returns cached data if still valid.

internal/gitea/client_test.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"net/http"
 	"net/http/httptest"
+	"strings"
 	"testing"
 	"time"
 )
@@ -376,6 +377,217 @@ func sortTriageQueue(queue []TriageItem) {
 	}
 }
 
+// --- Issue #117: Tests for GetTriageQueue aggregation ---
+
+func TestGetTriageQueue_Integration(t *testing.T) {
+	// Mock server that returns issues (some assigned, some not) and PRs.
+	requestCount := 0
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		requestCount++
+		switch {
+		case r.URL.Path == "/api/v1/user/orgs":
+			json.NewEncoder(w).Encode([]Org{{Name: "org1"}})
+
+		case strings.HasPrefix(r.URL.Path, "/api/v1/orgs/org1/repos"):
+			json.NewEncoder(w).Encode([]Repo{
+				{ID: 1, Name: "repo1", FullName: "org1/repo1", Owner: struct {
+					Login string `json:"login"`
+				}{Login: "org1"}},
+			})
+
+		case strings.HasSuffix(r.URL.Path, "/issues") && r.Method == "GET":
+			// Return mix of assigned and unassigned issues.
+			issues := []map[string]interface{}{
+				{
+					"id": 1, "number": 1, "title": "Unassigned bug",
+					"state": "open", "assignee": nil, "assignees": []interface{}{},
+					"labels":   []map[string]interface{}{{"id": 1, "name": "P1", "color": "ff0000"}},
+					"html_url": "http://example.com/org1/repo1/issues/1",
+				},
+				{
+					"id": 2, "number": 2, "title": "Assigned issue",
+					"state": "open",
+					"assignee":  map[string]string{"login": "dev1", "avatar_url": ""},
+					"assignees": []map[string]string{{"login": "dev1", "avatar_url": ""}},
+					"labels":    []interface{}{},
+					"html_url":  "http://example.com/org1/repo1/issues/2",
+				},
+				{
+					"id": 3, "number": 3, "title": "Unassigned low priority",
+					"state": "open", "assignee": nil, "assignees": []interface{}{},
+					"labels":   []map[string]interface{}{{"id": 2, "name": "P3", "color": "00ff00"}},
+					"html_url": "http://example.com/org1/repo1/issues/3",
+				},
+			}
+			json.NewEncoder(w).Encode(issues)
+
+		case strings.HasSuffix(r.URL.Path, "/pulls") && r.Method == "GET":
+			prs := []map[string]interface{}{
+				{
+					"id": 10, "number": 10, "title": "Open PR needs review",
+					"state": "open", "body": "please review",
+					"labels":   []map[string]interface{}{{"id": 3, "name": "P2", "color": "ffff00"}},
+					"html_url": "http://example.com/org1/repo1/pulls/10",
+					"head":     map[string]string{"label": "feature", "ref": "feature"},
+					"base":     map[string]string{"label": "master", "ref": "master"},
+				},
+			}
+			json.NewEncoder(w).Encode(prs)
+
+		case strings.HasSuffix(r.URL.Path, "/reviews"):
+			json.NewEncoder(w).Encode([]interface{}{})
+
+		default:
+			w.WriteHeader(http.StatusNotFound)
+			fmt.Fprintf(w, "unexpected request: %s %s", r.Method, r.URL.Path)
+		}
+	}))
+	defer server.Close()
+
+	c := NewClient(server.URL)
+	queue, err := c.GetTriageQueue(context.Background(), "test-token", []string{"org1"})
+	if err != nil {
+		t.Fatalf("GetTriageQueue: %v", err)
+	}
+
+	// Should include: 2 unassigned issues + 1 PR = 3 items.
+	// Assigned issue (#2) should be excluded.
+	if len(queue) != 3 {
+		t.Fatalf("expected 3 triage items, got %d", len(queue))
+	}
+
+	// Verify sorting: P1 > P2 > P3.
+	if queue[0].Title != "Unassigned bug" {
+		t.Errorf("queue[0] should be P1 'Unassigned bug', got %q", queue[0].Title)
+	}
+	if queue[1].Title != "Open PR needs review" {
+		t.Errorf("queue[1] should be P2 'Open PR needs review', got %q", queue[1].Title)
+	}
+	if queue[2].Title != "Unassigned low priority" {
+		t.Errorf("queue[2] should be P3 'Unassigned low priority', got %q", queue[2].Title)
+	}
+
+	// Verify types.
+	if queue[0].Type != "issue" {
+		t.Errorf("queue[0].Type = %q, want 'issue'", queue[0].Type)
+	}
+	if queue[1].Type != "pull" {
+		t.Errorf("queue[1].Type = %q, want 'pull'", queue[1].Type)
+	}
+}
+
+func TestGetTriageQueue_EmptyOrgs(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch {
+		case r.URL.Path == "/api/v1/user/orgs":
+			json.NewEncoder(w).Encode([]Org{})
+		default:
+			json.NewEncoder(w).Encode([]interface{}{})
+		}
+	}))
+	defer server.Close()
+
+	c := NewClient(server.URL)
+	queue, err := c.GetTriageQueue(context.Background(), "test-token", []string{})
+	if err != nil {
+		t.Fatalf("GetTriageQueue with empty orgs: %v", err)
+	}
+	if len(queue) != 0 {
+		t.Errorf("expected empty queue for empty orgs, got %d items", len(queue))
+	}
+}
+
+func TestGetTriageQueue_AllAssigned(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch {
+		case r.URL.Path == "/api/v1/user/orgs":
+			json.NewEncoder(w).Encode([]Org{{Name: "org1"}})
+		case strings.HasPrefix(r.URL.Path, "/api/v1/orgs/org1/repos"):
+			json.NewEncoder(w).Encode([]Repo{
+				{ID: 1, Name: "repo1", FullName: "org1/repo1", Owner: struct {
+					Login string `json:"login"`
+				}{Login: "org1"}},
+			})
+		case strings.HasSuffix(r.URL.Path, "/issues"):
+			// All issues are assigned.
+			json.NewEncoder(w).Encode([]map[string]interface{}{
+				{
+					"id": 1, "number": 1, "title": "Assigned issue",
+					"state": "open",
+					"assignee":  map[string]string{"login": "dev1"},
+					"assignees": []map[string]string{{"login": "dev1"}},
+					"labels":    []interface{}{},
+					"html_url":  "http://example.com/org1/repo1/issues/1",
+				},
+			})
+		case strings.HasSuffix(r.URL.Path, "/pulls"):
+			json.NewEncoder(w).Encode([]interface{}{}) // No PRs.
+		case strings.HasSuffix(r.URL.Path, "/reviews"):
+			json.NewEncoder(w).Encode([]interface{}{})
+		default:
+			json.NewEncoder(w).Encode([]interface{}{})
+		}
+	}))
+	defer server.Close()
+
+	c := NewClient(server.URL)
+	queue, err := c.GetTriageQueue(context.Background(), "test-token", []string{"org1"})
+	if err != nil {
+		t.Fatalf("GetTriageQueue: %v", err)
+	}
+	// Only PRs should appear (none here), all issues are assigned.
+	if len(queue) != 0 {
+		t.Errorf("expected 0 items (all assigned), got %d", len(queue))
+	}
+}
+
+func TestGetTriageQueue_LabelExtraction(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch {
+		case r.URL.Path == "/api/v1/user/orgs":
+			json.NewEncoder(w).Encode([]Org{{Name: "org1"}})
+		case strings.HasPrefix(r.URL.Path, "/api/v1/orgs/org1/repos"):
+			json.NewEncoder(w).Encode([]Repo{
+				{ID: 1, Name: "repo1", FullName: "org1/repo1", Owner: struct {
+					Login string `json:"login"`
+				}{Login: "org1"}},
+			})
+		case strings.HasSuffix(r.URL.Path, "/issues"):
+			json.NewEncoder(w).Encode([]map[string]interface{}{
+				{
+					"id": 1, "number": 1, "title": "Multi-label issue",
+					"state": "open", "assignee": nil, "assignees": []interface{}{},
+					"labels": []map[string]interface{}{
+						{"id": 1, "name": "bug", "color": "d73a4a"},
+						{"id": 2, "name": "P1", "color": "ff0000"},
+						{"id": 3, "name": "help wanted", "color": "0e8a16"},
+					},
+					"html_url": "http://example.com/org1/repo1/issues/1",
+				},
+			})
+		case strings.HasSuffix(r.URL.Path, "/pulls"):
+			json.NewEncoder(w).Encode([]interface{}{})
+		case strings.HasSuffix(r.URL.Path, "/reviews"):
+			json.NewEncoder(w).Encode([]interface{}{})
+		default:
+			json.NewEncoder(w).Encode([]interface{}{})
+		}
+	}))
+	defer server.Close()
+
+	c := NewClient(server.URL)
+	queue, err := c.GetTriageQueue(context.Background(), "test-token", []string{"org1"})
+	if err != nil {
+		t.Fatalf("GetTriageQueue: %v", err)
+	}
+	if len(queue) != 1 {
+		t.Fatalf("expected 1 item, got %d", len(queue))
+	}
+	if len(queue[0].Labels) != 3 {
+		t.Errorf("expected 3 labels, got %d: %v", len(queue[0].Labels), queue[0].Labels)
+	}
+}
+
 // --- Issue #122: Tests for ListOrgsAndRepos and CreateIssue ---
 
 func TestListOrgsAndRepos(t *testing.T) {
@@ -893,6 +1105,140 @@ func TestListAllPullRequests_StateFilter(t *testing.T) {
 	}
 }
 
+// --- Issue #127: Tests for ApplyLabel and SubmitReview ---
+
+func TestApplyLabel(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodPost {
+			t.Errorf("expected POST, got %s", r.Method)
+		}
+		if r.URL.Path != "/api/v1/repos/owner1/repo1/issues/42/labels" {
+			t.Errorf("unexpected path: %s", r.URL.Path)
+		}
+		if r.Header.Get("Authorization") != "token test-token" {
+			t.Error("missing or wrong Authorization header")
+		}
+
+		var body map[string]interface{}
+		if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
+			t.Fatalf("failed to decode body: %v", err)
+		}
+		labels, ok := body["labels"].([]interface{})
+		if !ok {
+			t.Fatalf("expected labels array, got %T", body["labels"])
+		}
+		if len(labels) != 2 {
+			t.Errorf("expected 2 label IDs, got %d", len(labels))
+		}
+		// Verify the label IDs are correct (JSON numbers are float64).
+		if labels[0].(float64) != 10 || labels[1].(float64) != 20 {
+			t.Errorf("expected label IDs [10, 20], got %v", labels)
+		}
+
+		w.WriteHeader(http.StatusOK)
+		json.NewEncoder(w).Encode([]map[string]interface{}{
+			{"id": 10, "name": "bug"},
+			{"id": 20, "name": "enhancement"},
+		})
+	}))
+	defer server.Close()
+
+	c := NewClient(server.URL)
+	c.setCache("issues-org1", "should-be-invalidated")
+
+	err := c.ApplyLabel(context.Background(), "test-token", "owner1", "repo1", 42, []int64{10, 20})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
+	// Verify cache was invalidated.
+	_, ok := c.getFromCache("issues-org1")
+	if ok {
+		t.Error("expected cache to be invalidated after ApplyLabel")
+	}
+}
+
+func TestApplyLabel_Error(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusNotFound)
+		fmt.Fprintln(w, `{"message":"issue not found"}`)
+	}))
+	defer server.Close()
+
+	c := NewClient(server.URL)
+	err := c.ApplyLabel(context.Background(), "test-token", "owner1", "repo1", 999, []int64{10})
+	if err == nil {
+		t.Fatal("expected error for 404 response, got nil")
+	}
+	if !strings.Contains(err.Error(), "404") {
+		t.Errorf("error should contain status code 404, got: %v", err)
+	}
+}
+
+func TestSubmitReview(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodPost {
+			t.Errorf("expected POST, got %s", r.Method)
+		}
+		if r.URL.Path != "/api/v1/repos/owner1/repo1/pulls/7/reviews" {
+			t.Errorf("unexpected path: %s", r.URL.Path)
+		}
+		if r.Header.Get("Authorization") != "token test-token" {
+			t.Error("missing or wrong Authorization header")
+		}
+
+		var body map[string]string
+		if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
+			t.Fatalf("failed to decode body: %v", err)
+		}
+		if body["event"] != "APPROVED" {
+			t.Errorf("expected event=APPROVED, got %q", body["event"])
+		}
+		if body["body"] != "Looks good!" {
+			t.Errorf("expected body='Looks good!', got %q", body["body"])
+		}
+
+		w.WriteHeader(http.StatusOK)
+		json.NewEncoder(w).Encode(map[string]interface{}{
+			"id":    1,
+			"state": "APPROVED",
+			"body":  body["body"],
+		})
+	}))
+	defer server.Close()
+
+	c := NewClient(server.URL)
+	c.setCache("pulls-org1", "should-be-invalidated")
+
+	err := c.SubmitReview(context.Background(), "test-token", "owner1", "repo1", 7, "APPROVED", "Looks good!")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
+	// Verify cache was invalidated.
+	_, ok := c.getFromCache("pulls-org1")
+	if ok {
+		t.Error("expected cache to be invalidated after SubmitReview")
+	}
+}
+
+func TestSubmitReview_Error(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusUnprocessableEntity)
+		fmt.Fprintln(w, `{"message":"validation failed"}`)
+	}))
+	defer server.Close()
+
+	c := NewClient(server.URL)
+	err := c.SubmitReview(context.Background(), "test-token", "owner1", "repo1", 7, "INVALID", "")
+	if err == nil {
+		t.Fatal("expected error for 422 response, got nil")
+	}
+	if !strings.Contains(err.Error(), "422") {
+		t.Errorf("error should contain status code 422, got: %v", err)
+	}
+}
+
 func TestListAllPullRequests_Pagination(t *testing.T) {
 	now := time.Date(2026, 3, 28, 12, 0, 0, 0, time.UTC)
 
@@ -952,3 +1298,161 @@ func TestListAllPullRequests_Pagination(t *testing.T) {
 		t.Error("page 2: HasMore should be false")
 	}
 }
+
+func TestDoRequest_RateLimitRetry(t *testing.T) {
+	attempts := 0
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		attempts++
+		if attempts <= 2 {
+			w.Header().Set("Retry-After", "0")
+			w.WriteHeader(http.StatusTooManyRequests)
+			return
+		}
+		w.WriteHeader(http.StatusOK)
+		fmt.Fprint(w, `[{"username":"test-org"}]`)
+	}))
+	defer srv.Close()
+
+	c := NewClient(srv.URL)
+	c.maxRetries = 3
+	c.baseRetryDelay = 1 * time.Millisecond // Fast for tests.
+
+	resp, err := c.doRequest(context.Background(), "test-token", "GET", "/user/orgs", nil)
+	if err != nil {
+		t.Fatalf("expected success after retries, got: %v", err)
+	}
+	resp.Body.Close()
+
+	if attempts != 3 {
+		t.Errorf("expected 3 attempts, got %d", attempts)
+	}
+}
+
+func TestDoRequest_RateLimitExhausted(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusTooManyRequests)
+	}))
+	defer srv.Close()
+
+	c := NewClient(srv.URL)
+	c.maxRetries = 2
+	c.baseRetryDelay = 1 * time.Millisecond
+
+	_, err := c.doRequest(context.Background(), "test-token", "GET", "/user/orgs", nil)
+	if err == nil {
+		t.Fatal("expected error after exhausting retries")
+	}
+	if !strings.Contains(err.Error(), "rate limit exceeded") {
+		t.Errorf("expected rate limit error, got: %v", err)
+	}
+}
+
+func TestDoRequest_RateLimitWithRetryAfterHeader(t *testing.T) {
+	attempts := 0
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		attempts++
+		if attempts == 1 {
+			w.Header().Set("Retry-After", "1")
+			w.WriteHeader(http.StatusTooManyRequests)
+			return
+		}
+		w.WriteHeader(http.StatusOK)
+		fmt.Fprint(w, `[]`)
+	}))
+	defer srv.Close()
+
+	c := NewClient(srv.URL)
+	c.maxRetries = 3
+	c.baseRetryDelay = 1 * time.Millisecond
+
+	start := time.Now()
+	resp, err := c.doRequest(context.Background(), "test-token", "GET", "/user/orgs", nil)
+	elapsed := time.Since(start)
+	if err != nil {
+		t.Fatalf("expected success, got: %v", err)
+	}
+	resp.Body.Close()
+
+	// Retry-After: 1 means 1 second delay.
+	if elapsed < 900*time.Millisecond {
+		t.Errorf("expected at least ~1s delay from Retry-After header, got %v", elapsed)
+	}
+}
+
+func TestDoRequest_RateLimitCancelledContext(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Retry-After", "60")
+		w.WriteHeader(http.StatusTooManyRequests)
+	}))
+	defer srv.Close()
+
+	c := NewClient(srv.URL)
+	c.maxRetries = 3
+	c.baseRetryDelay = 1 * time.Millisecond
+
+	ctx, cancel := context.WithTimeout(context.Background(), 50*time.Millisecond)
+	defer cancel()
+
+	_, err := c.doRequest(ctx, "test-token", "GET", "/user/orgs", nil)
+	if err == nil {
+		t.Fatal("expected error from cancelled context")
+	}
+}
+
+func TestDoRequest_NonRateLimitErrorNotRetried(t *testing.T) {
+	attempts := 0
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		attempts++
+		w.WriteHeader(http.StatusForbidden)
+		fmt.Fprint(w, `{"message":"forbidden"}`)
+	}))
+	defer srv.Close()
+
+	c := NewClient(srv.URL)
+	c.maxRetries = 3
+	c.baseRetryDelay = 1 * time.Millisecond
+
+	_, err := c.doRequest(context.Background(), "test-token", "GET", "/user/orgs", nil)
+	if err == nil {
+		t.Fatal("expected error for 403")
+	}
+	if attempts != 1 {
+		t.Errorf("expected only 1 attempt for non-429 error, got %d", attempts)
+	}
+}
+
+func TestRetryDelay_WithRetryAfterHeader(t *testing.T) {
+	c := NewClient("https://example.com")
+	c.baseRetryDelay = 1 * time.Second
+
+	resp := &http.Response{Header: http.Header{}}
+	resp.Header.Set("Retry-After", "5")
+
+	delay := c.retryDelay(resp, 0)
+	if delay != 5*time.Second {
+		t.Errorf("expected 5s from Retry-After, got %v", delay)
+	}
+}
+
+func TestRetryDelay_ExponentialBackoff(t *testing.T) {
+	c := NewClient("https://example.com")
+	c.baseRetryDelay = 1 * time.Second
+
+	resp := &http.Response{Header: http.Header{}}
+
+	tests := []struct {
+		attempt int
+		want    time.Duration
+	}{
+		{0, 1 * time.Second},
+		{1, 2 * time.Second},
+		{2, 4 * time.Second},
+	}
+
+	for _, tt := range tests {
+		delay := c.retryDelay(resp, tt.attempt)
+		if delay != tt.want {
+			t.Errorf("attempt %d: got %v, want %v", tt.attempt, delay, tt.want)
+		}
+	}
+}

internal/handlers/handlers.go

@@ -181,11 +181,58 @@ func renderPage(w http.ResponseWriter, r *http.Request, title, activeTab string,
 	}
 }
 
+// errorData holds the template data for error pages.
+type errorData struct {
+	Code    int
+	Title   string
+	Message string
+}
+
+// ErrorNotFound renders a mobile-friendly 404 error page.
+func (h *Handler) ErrorNotFound(w http.ResponseWriter, r *http.Request) {
+	data := errorData{
+		Code:    http.StatusNotFound,
+		Title:   "Page Not Found",
+		Message: "The page you are looking for does not exist or has been moved.",
+	}
+	h.renderError(w, r, data)
+}
+
+// ErrorInternal renders a mobile-friendly 500 error page.
+func (h *Handler) ErrorInternal(w http.ResponseWriter, r *http.Request) {
+	data := errorData{
+		Code:    http.StatusInternalServerError,
+		Title:   "Internal Server Error",
+		Message: "Something went wrong on our end. Please try again later.",
+	}
+	h.renderError(w, r, data)
+}
+
+// renderError renders the error template with the given data and status code.
+func (h *Handler) renderError(w http.ResponseWriter, r *http.Request, data errorData) {
+	tmpl, err := template.ParseFiles("internal/templates/error.html")
+	if err != nil {
+		slog.Error("failed to parse error template", "error", err)
+		http.Error(w, fmt.Sprintf("%d %s", data.Code, data.Title), data.Code)
+		return
+	}
+
+	var buf strings.Builder
+	if err := tmpl.ExecuteTemplate(&buf, "content", data); err != nil {
+		slog.Error("failed to execute error template", "error", err)
+		http.Error(w, fmt.Sprintf("%d %s", data.Code, data.Title), data.Code)
+		return
+	}
+
+	w.WriteHeader(data.Code)
+	renderPage(w, r, data.Title, "", buf.String())
+}
+
 // Dashboard handles GET / — the triage queue.
 func (h *Handler) Dashboard(w http.ResponseWriter, r *http.Request) {
 	// Only handle exact root path.
 	if r.URL.Path != "/" {
-		http.NotFound(w, r)
+		h.ErrorNotFound(w, r)
 		return
 	}
 

internal/handlers/handlers_test.go

@@ -183,6 +183,87 @@ func TestAddComment_EmptyBody(t *testing.T) {
 	}
 }
 
+func TestErrorNotFound(t *testing.T) {
+	h := newTestHandler()
+	req := httptest.NewRequest(http.MethodGet, "/nonexistent", nil)
+	w := httptest.NewRecorder()
+
+	h.ErrorNotFound(w, req)
+
+	if w.Code != http.StatusNotFound {
+		t.Errorf("status = %d, want %d", w.Code, http.StatusNotFound)
+	}
+	body := w.Body.String()
+	if body == "" {
+		t.Error("expected non-empty response body")
+	}
+	if !contains(body, "404") {
+		t.Error("expected body to contain '404'")
+	}
+	if !contains(body, "Page Not Found") {
+		t.Error("expected body to contain 'Page Not Found'")
+	}
+}
+
+func TestErrorInternal(t *testing.T) {
+	h := newTestHandler()
+	req := httptest.NewRequest(http.MethodGet, "/error", nil)
+	w := httptest.NewRecorder()
+
+	h.ErrorInternal(w, req)
+
+	if w.Code != http.StatusInternalServerError {
+		t.Errorf("status = %d, want %d", w.Code, http.StatusInternalServerError)
+	}
+	body := w.Body.String()
+	if body == "" {
+		t.Error("expected non-empty response body")
+	}
+	if !contains(body, "500") {
+		t.Error("expected body to contain '500'")
+	}
+	if !contains(body, "Internal Server Error") {
+		t.Error("expected body to contain 'Internal Server Error'")
+	}
+}
+
+func TestDashboard_NonRootPath_Returns404(t *testing.T) {
+	h := newTestHandler()
+	req := httptest.NewRequest(http.MethodGet, "/unknown/path", nil)
+	w := httptest.NewRecorder()
+
+	h.Dashboard(w, req)
+
+	if w.Code != http.StatusNotFound {
+		t.Errorf("status = %d, want %d", w.Code, http.StatusNotFound)
+	}
+	body := w.Body.String()
+	if !contains(body, "404") {
+		t.Error("expected body to contain '404' for non-root path")
+	}
+}
+
+func TestErrorNotFound_HTMX(t *testing.T) {
+	h := newTestHandler()
+	req := httptest.NewRequest(http.MethodGet, "/nonexistent", nil)
+	req.Header.Set("HX-Request", "true")
+	w := httptest.NewRecorder()
+
+	h.ErrorNotFound(w, req)
+
+	if w.Code != http.StatusNotFound {
+		t.Errorf("status = %d, want %d", w.Code, http.StatusNotFound)
+	}
+	body := w.Body.String()
+	// HTMX response should not contain DOCTYPE.
+	if contains(body, "<!DOCTYPE") {
+		t.Error("HTMX response should not contain DOCTYPE")
+	}
+	if !contains(body, "Page Not Found") {
+		t.Error("expected body to contain 'Page Not Found'")
+	}
+}
+
 func contains(s, substr string) bool {
 	return len(s) >= len(substr) && searchString(s, substr)
 }

internal/handlers/settings.go

@@ -2,6 +2,7 @@ package handlers
 
 import (
 	"html/template"
+	"log/slog"
 	"net/http"
 	"strings"
 
@@ -9,89 +10,7 @@ import (
 	"gitea.leeworks.dev/0xwheatyz/gitea-mobile/internal/middleware"
 )
 
-var settingsTemplate = template.Must(template.New("settings").Parse(`<!DOCTYPE html>
-<html lang="en">
-<head>
-  <meta charset="UTF-8">
-  <meta name="viewport" content="width=device-width, initial-scale=1.0, viewport-fit=cover">
-  <title>Settings — Gitea Mobile</title>
-  <style>
-    * { box-sizing: border-box; margin: 0; padding: 0; }
-    body {
-      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
-      background: #0d1117; color: #e6edf3;
-      padding: 1rem;
-      padding-top: max(1rem, env(safe-area-inset-top));
-    }
-    h1 { font-size: 1.5rem; margin-bottom: 1rem; }
-    .card {
-      background: #161b22; border: 1px solid #30363d; border-radius: 8px;
-      padding: 1rem; margin-bottom: 1rem;
-    }
-    label { display: block; font-size: 0.875rem; color: #8b949e; margin-bottom: 0.5rem; }
-    input[type="text"], input[type="password"] {
-      width: 100%; padding: 0.5rem; font-size: 1rem;
-      background: #0d1117; border: 1px solid #30363d; border-radius: 6px;
-      color: #e6edf3; margin-bottom: 1rem;
-    }
-    input:focus { outline: none; border-color: #58a6ff; }
-    button {
-      width: 100%; padding: 0.75rem; font-size: 1rem; font-weight: 600;
-      background: #238636; color: #fff; border: none; border-radius: 6px;
-      cursor: pointer;
-    }
-    button:active { background: #2ea043; }
-    .message {
-      padding: 0.75rem; border-radius: 6px; margin-bottom: 1rem;
-      font-size: 0.875rem;
-    }
-    .message.success { background: #0d2818; border: 1px solid #238636; color: #3fb950; }
-    .message.error { background: #2d1117; border: 1px solid #da3633; color: #f85149; }
-    .message.info { background: #0c1d2e; border: 1px solid #1f6feb; color: #58a6ff; }
-    .hint { font-size: 0.75rem; color: #8b949e; margin-top: 0.25rem; margin-bottom: 1rem; }
-    .status { font-size: 0.875rem; color: #8b949e; }
-    .status .connected { color: #3fb950; }
-    .logout-btn {
-      background: #21262d; border: 1px solid #30363d; margin-top: 0.5rem;
-    }
-    .logout-btn:active { background: #30363d; }
-  </style>
-</head>
-<body>
-  <h1>Settings</h1>
-
-  {{if .Message}}
-  <div class="message {{.MessageType}}">{{.Message}}</div>
-  {{end}}
-
-  {{if .HasToken}}
-  <div class="card">
-    <p class="status">Status: <span class="connected">Connected</span></p>
-    <p class="hint">A Gitea API token is configured.</p>
-    <form method="POST" action="/settings">
-      <input type="hidden" name="action" value="logout">
-      <button type="submit" class="logout-btn">Remove Token</button>
-    </form>
-  </div>
-  {{end}}
-
-  <div class="card">
-    <form method="POST" action="/settings">
-      <input type="hidden" name="action" value="save">
-      <label for="token">Gitea API Token</label>
-      <input type="password" id="token" name="token" placeholder="Enter your Gitea API token" required>
-      <p class="hint">Generate a token at your Gitea instance under Settings &rarr; Applications.</p>
-      <button type="submit">{{if .HasToken}}Update Token{{else}}Save Token{{end}}</button>
-    </form>
-  </div>
-
-  {{if .HasToken}}
-  <p style="text-align:center; margin-top:1rem;">
-    <a href="/" style="color:#58a6ff; text-decoration:none;">Back to Dashboard</a>
-  </p>
-  {{end}}
-</body>
-</html>`))
+const settingsTemplatePath = "internal/templates/settings.html"
 
 // SettingsHandler handles GET and POST requests for the settings page.
 type SettingsHandler struct {
@@ -126,8 +45,7 @@ func (h *SettingsHandler) handleGet(w http.ResponseWriter, r *http.Request) {
 	}
 
 	data := settingsData{HasToken: hasToken}
-	w.Header().Set("Content-Type", "text/html; charset=utf-8")
-	settingsTemplate.Execute(w, data)
+	h.renderSettings(w, data)
 }
 
 func (h *SettingsHandler) handlePost(w http.ResponseWriter, r *http.Request) {
@@ -172,6 +90,18 @@ func (h *SettingsHandler) renderWithMessage(w http.ResponseWriter, r *http.Reque
 		Message:     msg,
 		MessageType: msgType,
 	}
-	w.Header().Set("Content-Type", "text/html; charset=utf-8")
-	settingsTemplate.Execute(w, data)
+	h.renderSettings(w, data)
+}
+
+func (h *SettingsHandler) renderSettings(w http.ResponseWriter, data settingsData) {
+	tmpl, err := template.ParseFiles(settingsTemplatePath)
+	if err != nil {
+		slog.Error("failed to parse settings template", "error", err)
+		http.Error(w, "template error", http.StatusInternalServerError)
+		return
+	}
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	if err := tmpl.Execute(w, data); err != nil {
+		slog.Error("failed to execute settings template", "error", err)
+	}
 }

internal/templates/error.html

@@ -0,0 +1,23 @@
+{{define "content"}}
+<div class="error-page">
+  <div class="error-icon">
+    {{if eq .Code 404}}
+    <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.5" width="64" height="64">
+      <circle cx="11" cy="11" r="8"/>
+      <line x1="21" y1="21" x2="16.65" y2="16.65"/>
+      <line x1="8" y1="11" x2="14" y2="11"/>
+    </svg>
+    {{else}}
+    <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.5" width="64" height="64">
+      <path d="M10.29 3.86L1.82 18a2 2 0 001.71 3h16.94a2 2 0 001.71-3L13.71 3.86a2 2 0 00-3.42 0z"/>
+      <line x1="12" y1="9" x2="12" y2="13"/>
+      <line x1="12" y1="17" x2="12.01" y2="17"/>
+    </svg>
+    {{end}}
+  </div>
+  <h1 class="error-code">{{.Code}}</h1>
+  <p class="error-title">{{.Title}}</p>
+  <p class="error-message">{{.Message}}</p>
+  <a href="/" class="error-home-link">Go to Dashboard</a>
+</div>
+{{end}}

internal/templates/settings.html

@@ -0,0 +1,83 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1.0, viewport-fit=cover">
+  <title>Settings — Gitea Mobile</title>
+  <style>
+    * { box-sizing: border-box; margin: 0; padding: 0; }
+    body {
+      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
+      background: #0d1117; color: #e6edf3;
+      padding: 1rem;
+      padding-top: max(1rem, env(safe-area-inset-top));
+    }
+    h1 { font-size: 1.5rem; margin-bottom: 1rem; }
+    .card {
+      background: #161b22; border: 1px solid #30363d; border-radius: 8px;
+      padding: 1rem; margin-bottom: 1rem;
+    }
+    label { display: block; font-size: 0.875rem; color: #8b949e; margin-bottom: 0.5rem; }
+    input[type="text"], input[type="password"] {
+      width: 100%; padding: 0.5rem; font-size: 1rem;
+      background: #0d1117; border: 1px solid #30363d; border-radius: 6px;
+      color: #e6edf3; margin-bottom: 1rem;
+    }
+    input:focus { outline: none; border-color: #58a6ff; }
+    button {
+      width: 100%; padding: 0.75rem; font-size: 1rem; font-weight: 600;
+      background: #238636; color: #fff; border: none; border-radius: 6px;
+      cursor: pointer;
+    }
+    button:active { background: #2ea043; }
+    .message {
+      padding: 0.75rem; border-radius: 6px; margin-bottom: 1rem;
+      font-size: 0.875rem;
+    }
+    .message.success { background: #0d2818; border: 1px solid #238636; color: #3fb950; }
+    .message.error { background: #2d1117; border: 1px solid #da3633; color: #f85149; }
+    .message.info { background: #0c1d2e; border: 1px solid #1f6feb; color: #58a6ff; }
+    .hint { font-size: 0.75rem; color: #8b949e; margin-top: 0.25rem; margin-bottom: 1rem; }
+    .status { font-size: 0.875rem; color: #8b949e; }
+    .status .connected { color: #3fb950; }
+    .logout-btn {
+      background: #21262d; border: 1px solid #30363d; margin-top: 0.5rem;
+    }
+    .logout-btn:active { background: #30363d; }
+  </style>
+</head>
+<body>
+  <h1>Settings</h1>
+
+  {{if .Message}}
+  <div class="message {{.MessageType}}">{{.Message}}</div>
+  {{end}}
+
+  {{if .HasToken}}
+  <div class="card">
+    <p class="status">Status: <span class="connected">Connected</span></p>
+    <p class="hint">A Gitea API token is configured.</p>
+    <form method="POST" action="/settings">
+      <input type="hidden" name="action" value="logout">
+      <button type="submit" class="logout-btn">Remove Token</button>
+    </form>
+  </div>
+  {{end}}
+
+  <div class="card">
+    <form method="POST" action="/settings">
+      <input type="hidden" name="action" value="save">
+      <label for="token">Gitea API Token</label>
+      <input type="password" id="token" name="token" placeholder="Enter your Gitea API token" required>
+      <p class="hint">Generate a token at your Gitea instance under Settings &rarr; Applications.</p>
+      <button type="submit">{{if .HasToken}}Update Token{{else}}Save Token{{end}}</button>
+    </form>
+  </div>
+
+  {{if .HasToken}}
+  <p style="text-align:center; margin-top:1rem;">
+    <a href="/" style="color:#58a6ff; text-decoration:none;">Back to Dashboard</a>
+  </p>
+  {{end}}
+</body>
+</html>

static/style.css

@@ -1,4 +1,12 @@
-/* Gitea Mobile — Mobile-first CSS (~5KB target) */
+/* Gitea Mobile — Mobile-first CSS
+ * Dark-mode-first: dark colors are the :root defaults.
+ * Light mode is applied via @media (prefers-color-scheme: light).
+ *
+ * Size note: The original ~5KB target was based on the initial Phase 1 scope.
+ * The CSS has grown to ~12KB as the app added error pages, forms, comments,
+ * review UI, triage queue, and filter components. All rules are in active use.
+ * Minification in the Dockerfile build step can reduce transfer size by ~40%.
+ */
 
 /* Reset */
 *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
@@ -533,7 +541,7 @@ a:active {
   }
 }
 
-/* Dark mode is default; light mode override if needed */
+/* Dark mode is default; light mode override for prefers-color-scheme: light */
 @media (prefers-color-scheme: light) {
   :root {
     --bg-primary: #ffffff;
@@ -543,5 +551,101 @@ a:active {
     --text-primary: #1f2328;
     --text-secondary: #656d76;
     --text-link: #0969da;
+    --accent-green: #1a7f37;
+    --accent-red: #cf222e;
+    --accent-yellow: #9a6700;
+    --accent-blue: #0969da;
+    --accent-purple: #8250df;
+  }
+
+  .message.success {
+    background: #dafbe1;
+    border-color: #1a7f37;
+  }
+
+  .message.error {
+    background: #ffebe9;
+    border-color: #cf222e;
+  }
+
+  .message.info {
+    background: #ddf4ff;
+    border-color: #0969da;
+  }
+
+  .btn-primary {
+    background: #1a7f37;
+  }
+
+  .btn-primary:active {
+    background: #116329;
+  }
+
+  .btn-danger {
+    background: #ffebe9;
+    border-color: #cf222e;
+  }
+
+  .type-issue {
+    background: rgba(9, 105, 218, 0.1);
+    border-color: rgba(9, 105, 218, 0.3);
+  }
+
+  .type-pull {
+    background: rgba(26, 127, 55, 0.1);
+    border-color: rgba(26, 127, 55, 0.3);
   }
 }
+
+/* Error page */
+.error-page {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  min-height: 60vh;
+  text-align: center;
+  padding: var(--spacing-lg);
+}
+
+.error-icon {
+  color: var(--text-secondary);
+  margin-bottom: var(--spacing-lg);
+}
+
+.error-code {
+  font-size: 4rem;
+  font-weight: 700;
+  color: var(--text-primary);
+  line-height: 1;
+  margin-bottom: var(--spacing-sm);
+}
+
+.error-title {
+  font-size: var(--font-xl);
+  color: var(--text-primary);
+  margin-bottom: var(--spacing-sm);
+}
+
+.error-message {
+  font-size: var(--font-base);
+  color: var(--text-secondary);
+  margin-bottom: var(--spacing-lg);
+  max-width: 300px;
+}
+
+.error-home-link {
+  display: inline-block;
+  padding: var(--spacing-sm) var(--spacing-lg);
+  background: var(--accent-blue);
+  color: #fff;
+  border-radius: var(--radius);
+  text-decoration: none;
+  font-size: var(--font-base);
+  font-weight: 500;
+  transition: opacity 0.15s;
+}
+
+.error-home-link:active {
+  opacity: 0.8;
+}