diff --git a/internal/tui/view.go b/internal/tui/view.go
index 67dc485..18bed57 100644
--- a/internal/tui/view.go
+++ b/internal/tui/view.go
@@ -365,6 +365,16 @@ func (m Model) renderStats() string {
 	return m.statsViewport.View()
 }
 
+// line renders s in a style and terminates it.
+//
+// The newline has to stay outside Render: lipgloss pads every line of a styled
+// block out to its widest line, so a trailing newline inside the block produces
+// a second line made entirely of padding, and whatever is written next starts
+// after that padding instead of at the left margin.
+func line(style lipgloss.Style, s string) string {
+	return style.Render(s) + "\n"
+}
+
 // ── Content builders ───────────────────────────────────────────────────────
 
 func buildIncidentDetailContent(inc api.Incident, timeline []api.IncidentEvent, cursor, width int) string {
@@ -391,7 +401,7 @@ func buildIncidentDetailContent(inc api.Incident, timeline []api.IncidentEvent,
 	if inc.AssignedTo != "" {
 		b.WriteString(fmt.Sprintf("  Assigned:   %s\n", styleBold.Render(inc.AssignedTo)))
 	} else {
-		b.WriteString(styleMuted.Render("  Assigned:   nobody\n"))
+		b.WriteString(line(styleMuted, "  Assigned:   nobody"))
 	}
 
 	if inc.AcknowledgedByID != nil {
@@ -399,14 +409,14 @@ func buildIncidentDetailContent(inc api.Incident, timeline []api.IncidentEvent,
 		if inc.AcknowledgedAt != nil {
 			ackAt = "  at " + inc.AcknowledgedAt.UTC().Format("2006-01-02 15:04 UTC")
 		}
-		b.WriteString(styleResolved.Render(
-			fmt.Sprintf("  Acked:      %s%s\n", inc.AcknowledgedBy, ackAt)))
+		b.WriteString(line(styleResolved,
+			fmt.Sprintf("  Acked:      %s%s", inc.AcknowledgedBy, ackAt)))
 	} else {
-		b.WriteString(styleMuted.Render("  Acked:      not acknowledged\n"))
+		b.WriteString(line(styleMuted, "  Acked:      not acknowledged"))
 	}
 
 	if inc.IsSnoozed() {
-		b.WriteString(styleSnoozed.Render(fmt.Sprintf("  Snoozed:    until %s  (%s)\n",
+		b.WriteString(line(styleSnoozed, fmt.Sprintf("  Snoozed:    until %s  (%s)",
 			inc.SnoozedUntil.UTC().Format("2006-01-02 15:04 UTC"), humanUntil(now, *inc.SnoozedUntil))))
 	}
 
@@ -419,8 +429,8 @@ func buildIncidentDetailContent(inc api.Incident, timeline []api.IncidentEvent,
 			inc.ResolvedAt.UTC().Format("2006-01-02 15:04 UTC"), humanAgo(now, *inc.ResolvedAt), source))
 	}
 	if inc.ArchivedAt != nil {
-		b.WriteString(styleMuted.Render("  Archived:   " +
-			inc.ArchivedAt.UTC().Format("2006-01-02 15:04 UTC") + "\n"))
+		b.WriteString(line(styleMuted, "  Archived:   "+
+			inc.ArchivedAt.UTC().Format("2006-01-02 15:04 UTC")))
 	}
 	b.WriteString("\n")
 
@@ -436,7 +446,7 @@ func buildIncidentDetailContent(inc api.Incident, timeline []api.IncidentEvent,
 	// Member alerts
 	b.WriteString(divider(fmt.Sprintf("Alerts (%d)", len(inc.Alerts)), width))
 	if len(inc.Alerts) == 0 {
-		b.WriteString(styleMuted.Render("  No alerts.\n"))
+		b.WriteString(line(styleMuted, "  No alerts."))
 	} else {
 		for _, a := range inc.Alerts {
 			marker := styleFiring.Render("●")
@@ -458,7 +468,7 @@ func buildIncidentDetailContent(inc api.Incident, timeline []api.IncidentEvent,
 	notes := noteEvents(timeline)
 	b.WriteString(divider(fmt.Sprintf("Timeline (%d events, %d notes)", len(timeline), len(notes)), width))
 	if len(timeline) == 0 {
-		b.WriteString(styleMuted.Render("  Nothing recorded yet.\n"))
+		b.WriteString(line(styleMuted, "  Nothing recorded yet."))
 	} else {
 		noteIndex := 0
 		for _, e := range timeline {
@@ -584,7 +594,7 @@ func buildAlertDetailContent(alert api.Alert, width int) string {
 			styleBold.Render(fmt.Sprintf("#%d", *alert.IncidentID)),
 			styleMuted.Render("press i to open it")))
 	} else {
-		b.WriteString(styleMuted.Render("  Incident:   none\n"))
+		b.WriteString(line(styleMuted, "  Incident:   none"))
 	}
 	b.WriteString("\n")
 
@@ -606,8 +616,8 @@ func buildAlertDetailContent(alert api.Alert, width int) string {
 
 	// Alerts carry no workflow state: it all lives on the incident.
 	b.WriteString(divider("", width))
-	b.WriteString(styleMuted.Render(
-		"  Alerts are read-only — acknowledge, assign, note and resolve on the incident.\n"))
+	b.WriteString(line(styleMuted,
+		"  Alerts are read-only — acknowledge, assign, note and resolve on the incident."))
 
 	return b.String()
 }
@@ -627,7 +637,7 @@ func buildStatsContent(incidents *api.IncidentStats, top []api.TopAlert, byHour
 	// Response times first: they are what a rota is actually judged on.
 	b.WriteString(divider("Incident Response", width))
 	if incidents == nil {
-		b.WriteString(styleMuted.Render("  No data.\n"))
+		b.WriteString(line(styleMuted, "  No data."))
 	} else {
 		b.WriteString(fmt.Sprintf("  %-28s %s\n", "Incidents total",
 			styleBold.Render(fmt.Sprintf("%d", incidents.Total))))
@@ -642,14 +652,14 @@ func buildStatsContent(incidents *api.IncidentStats, top []api.TopAlert, byHour
 		b.WriteString(fmt.Sprintf("  %-28s %s\n", "Mean time to resolve",
 			styleBold.Render(humanSeconds(incidents.MTTRSeconds))))
 		if incidents.MTTASeconds == nil || incidents.MTTRSeconds == nil {
-			b.WriteString(styleMuted.Render("  (— means nothing has been acknowledged or resolved yet)\n"))
+			b.WriteString(line(styleMuted, "  (— means nothing has been acknowledged or resolved yet)"))
 		}
 	}
 	b.WriteString("\n")
 
 	b.WriteString(divider("Top Alerts", width))
 	if len(top) == 0 {
-		b.WriteString(styleMuted.Render("  No data.\n"))
+		b.WriteString(line(styleMuted, "  No data."))
 	} else {
 		maxCount := top[0].Count
 		for i, a := range top {
@@ -672,7 +682,7 @@ func buildStatsContent(incidents *api.IncidentStats, top []api.TopAlert, byHour
 			b.WriteString(fmt.Sprintf("  %2dh  %-*s %d\n", h.Hour, barWidth, bar, h.Count))
 		}
 	} else {
-		b.WriteString(styleMuted.Render("  No data.\n"))
+		b.WriteString(line(styleMuted, "  No data."))
 	}
 	b.WriteString("\n")
 
@@ -689,7 +699,7 @@ func buildStatsContent(incidents *api.IncidentStats, top []api.TopAlert, byHour
 			b.WriteString(fmt.Sprintf("  %-4s  %-*s %d\n", d.DayName[:3], barWidth, bar, d.Count))
 		}
 	} else {
-		b.WriteString(styleMuted.Render("  No data.\n"))
+		b.WriteString(line(styleMuted, "  No data."))
 	}
 
 	return b.String()
@@ -723,7 +733,7 @@ func (m Model) renderUserCreate() string {
 
 func (m Model) renderAPIKeyMenu() string {
 	header := fmt.Sprintf("\n  API keys for %s\n", styleBold.Render(m.selectedUser.Username))
-	warning := styleMuted.Render("  Keys cannot be listed — only new keys can be created,\n  or existing ones revoked by their integer ID.\n")
+	warning := line(styleMuted, "  Keys cannot be listed — only new keys can be created,\n  or existing ones revoked by their integer ID.")
 	options := "\n" +
 		styleAccent.Render("  n") + "  · create a new API key\n" +
 		styleAccent.Render("  r") + "  · revoke a key by ID\n"
@@ -757,7 +767,7 @@ func (m Model) renderAPIKeyReveal() string {
 
 func (m Model) renderAPIKeyRevokeByID() string {
 	header := fmt.Sprintf("\n  Revoke API key for %s\n", styleBold.Render(m.selectedUser.Username))
-	hint := styleMuted.Render("  Enter the integer key ID (shown when the key was created).\n")
+	hint := line(styleMuted, "  Enter the integer key ID (shown when the key was created).")
 	label := styleSelected.Render("  Key ID:  ")
 	return header + "\n" + hint + "\n" + label + m.apiKeyRevokeInput.View() + "\n"
 }
diff --git a/internal/tui/view_test.go b/internal/tui/view_test.go
new file mode 100644
index 0000000..e48fd0b
--- /dev/null
+++ b/internal/tui/view_test.go
@@ -0,0 +1,286 @@
+package tui
+
+import (
+	"regexp"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/yeniklas/terdut-tui/internal/api"
+)
+
+// ansi matches the escape sequences lipgloss emits when it decides the output
+// supports colour, so assertions can be made against the text alone.
+var ansi = regexp.MustCompile(`\x1b\[[0-9;]*m`)
+
+func plain(s string) string { return ansi.ReplaceAllString(s, "") }
+
+func mustContain(t *testing.T, got string, wants ...string) {
+	t.Helper()
+	got = plain(got)
+	for _, w := range wants {
+		if !strings.Contains(got, w) {
+			t.Errorf("expected output to contain %q\n--- got ---\n%s", w, got)
+		}
+	}
+}
+
+func TestIncidentDetail_RendersTheWholeStory(t *testing.T) {
+	now := time.Now()
+	ackID := int64(1)
+	alertID := int64(3)
+	inc := api.Incident{
+		ID: 1, Title: "DiskFull (namespace=prod)", Status: api.StatusAcknowledged,
+		Severity:    "critical",
+		GroupLabels: map[string]string{"alertname": "DiskFull", "namespace": "prod"},
+		TriggeredAt: now.Add(-2 * time.Hour),
+		AssignedTo:  "admin", AcknowledgedByID: &ackID, AcknowledgedBy: "admin",
+		AcknowledgedAt: &now,
+		Alerts: []api.Alert{
+			{ID: 3, Name: "DiskFull", Status: "firing",
+				Labels: map[string]string{"instance": "node-1"}, ReceivedAt: now},
+			{ID: 4, Name: "DiskFull", Status: "resolved",
+				Labels: map[string]string{"instance": "node-2"}, ReceivedAt: now},
+		},
+	}
+	timeline := []api.IncidentEvent{
+		{Type: api.EventTriggered, CreatedAt: now},
+		{Type: api.EventAssigned, Username: "admin", CreatedAt: now},
+		{Type: api.EventAlertAdded, AlertID: &alertID, CreatedAt: now},
+		{Type: api.EventAcknowledged, Username: "admin", CreatedAt: now},
+		{Type: api.EventNote, Username: "admin", Detail: "draining node-2", CreatedAt: now},
+	}
+
+	out := buildIncidentDetailContent(inc, timeline, -1, 110)
+	mustContain(t, out,
+		"DiskFull (namespace=prod)", "ACKNOWLEDGED", "CRITICAL",
+		"Assigned:", "admin",
+		"Grouped By", "namespace", "prod",
+		"Alerts (2)", "node-1", "node-2",
+		"Timeline (5 events, 1 notes)",
+		"Incident opened", "Assigned to admin", "Alert #3 joined", "Acknowledged by admin",
+		"admin wrote", "draining node-2",
+	)
+}
+
+func TestIncidentDetail_ShowsSnooze(t *testing.T) {
+	future := time.Now().Add(2 * time.Hour)
+	inc := api.Incident{
+		Title: "Noisy", Status: api.StatusTriggered,
+		TriggeredAt: time.Now(), SnoozedUntil: &future,
+	}
+	// The exact remaining time is humanUntil's business, not this test's — a few
+	// microseconds of elapsed clock turn "in 2h" into "in 1h 59m".
+	mustContain(t, buildIncidentDetailContent(inc, nil, -1, 110),
+		"TRIGGERED (snoozed)", "Snoozed:", "until", "in 1h")
+}
+
+// An expired snooze is not a snooze, so it must not be reported as one.
+func TestIncidentDetail_HidesExpiredSnooze(t *testing.T) {
+	past := time.Now().Add(-time.Hour)
+	inc := api.Incident{
+		Title: "Noisy", Status: api.StatusTriggered,
+		TriggeredAt: time.Now(), SnoozedUntil: &past,
+	}
+	if strings.Contains(plain(buildIncidentDetailContent(inc, nil, -1, 110)), "Snoozed:") {
+		t.Error("an expired snooze should not be rendered")
+	}
+}
+
+func TestIncidentDetail_ShowsResolutionSource(t *testing.T) {
+	now := time.Now()
+	source := "manual"
+	inc := api.Incident{
+		Title: "Done", Status: api.StatusResolved, TriggeredAt: now.Add(-time.Hour),
+		ResolvedAt: &now, ResolutionSource: &source,
+	}
+	mustContain(t, buildIncidentDetailContent(inc, nil, -1, 110),
+		"RESOLVED", "Resolved:", "manual")
+}
+
+func TestIncidentDetail_UnassignedAndUnacknowledged(t *testing.T) {
+	inc := api.Incident{Title: "Fresh", Status: api.StatusTriggered, TriggeredAt: time.Now()}
+	mustContain(t, buildIncidentDetailContent(inc, nil, -1, 110), "nobody", "not acknowledged")
+}
+
+func TestIncidentDetail_EmptyTimeline(t *testing.T) {
+	inc := api.Incident{Title: "Fresh", Status: api.StatusTriggered, TriggeredAt: time.Now()}
+	mustContain(t, buildIncidentDetailContent(inc, nil, -1, 110), "Nothing recorded yet")
+}
+
+func TestIncidentDetail_MarksSelectedNote(t *testing.T) {
+	now := time.Now()
+	timeline := []api.IncidentEvent{
+		{Type: api.EventNote, Username: "admin", Detail: "first", CreatedAt: now},
+		{Type: api.EventNote, Username: "alice", Detail: "second", CreatedAt: now},
+	}
+	inc := api.Incident{Title: "X", Status: api.StatusTriggered, TriggeredAt: now}
+
+	out := plain(buildIncidentDetailContent(inc, timeline, 1, 110))
+	for _, line := range strings.Split(out, "\n") {
+		if strings.Contains(line, "alice") && !strings.HasPrefix(line, "> ") {
+			t.Errorf("expected the selected note marked, got %q", line)
+		}
+		if strings.Contains(line, "admin wrote") && strings.HasPrefix(line, "> ") {
+			t.Errorf("expected the unselected note unmarked, got %q", line)
+		}
+	}
+}
+
+func TestIncidentStatusLabel(t *testing.T) {
+	future := time.Now().Add(time.Hour)
+	tests := []struct {
+		name string
+		inc  api.Incident
+		want string
+	}{
+		{"triggered", api.Incident{Status: api.StatusTriggered}, "● TRIGGERED"},
+		{"acknowledged", api.Incident{Status: api.StatusAcknowledged}, "◐ ACKNOWLEDGED"},
+		{"resolved", api.Incident{Status: api.StatusResolved}, "✓ RESOLVED"},
+		{"snoozed", api.Incident{Status: api.StatusTriggered, SnoozedUntil: &future},
+			"● TRIGGERED (snoozed)"},
+		// A status this client does not know about still has to render.
+		{"unknown", api.Incident{Status: "escalated"}, "ESCALATED"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := incidentStatusLabel(tt.inc); got != tt.want {
+				t.Errorf("expected %q, got %q", tt.want, got)
+			}
+		})
+	}
+}
+
+// The server may add event types after this client ships. An unknown one must
+// still appear on the timeline rather than silently vanishing.
+func TestEventLabel_UnknownTypeFallsBackToItsName(t *testing.T) {
+	got := eventLabel(api.IncidentEvent{Type: "escalated", Detail: "to sre-oncall"})
+	mustContain(t, got, "escalated", "to sre-oncall")
+}
+
+func TestEventLabel_KnownTypes(t *testing.T) {
+	alertID := int64(9)
+	tests := []struct {
+		event api.IncidentEvent
+		want  string
+	}{
+		{api.IncidentEvent{Type: api.EventTriggered}, "Incident opened"},
+		{api.IncidentEvent{Type: api.EventAlertAdded, AlertID: &alertID}, "Alert #9 joined"},
+		{api.IncidentEvent{Type: api.EventAlertResolved, AlertID: &alertID}, "Alert #9 resolved"},
+		{api.IncidentEvent{Type: api.EventAcknowledged, Username: "bo"}, "Acknowledged by bo"},
+		{api.IncidentEvent{Type: api.EventAssigned, Username: "bo"}, "Assigned to bo"},
+		{api.IncidentEvent{Type: api.EventSnoozed, Detail: "2026-08-01T00:00:00Z"},
+			"Snoozed until 2026-08-01T00:00:00Z"},
+		{api.IncidentEvent{Type: api.EventResolved, Username: "bo"}, "Resolved by bo"},
+		// No user means the server closed it via the alert cascade.
+		{api.IncidentEvent{Type: api.EventResolved}, "all alerts stopped firing"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.event.Type, func(t *testing.T) {
+			mustContain(t, eventLabel(tt.event), tt.want)
+		})
+	}
+}
+
+func TestAlertDetail_SaysItIsReadOnlyAndLinksTheIncident(t *testing.T) {
+	now := time.Now()
+	id := int64(7)
+	alert := api.Alert{
+		ID: 3, Name: "DiskFull", Status: "firing", StartsAt: now.Add(-time.Hour),
+		ReceivedAt: now, IncidentID: &id,
+		Labels:      map[string]string{"instance": "node-1", "severity": "critical"},
+		Annotations: map[string]string{"summary": "disk 90%"},
+	}
+	mustContain(t, buildAlertDetailContent(alert, 110),
+		"DiskFull", "FIRING", "Incident:", "#7", "press i to open it",
+		"instance", "node-1", "summary", "disk 90%",
+		"Alerts are read-only")
+}
+
+func TestAlertDetail_NoIncident(t *testing.T) {
+	alert := api.Alert{ID: 3, Name: "Orphan", Status: "resolved", ReceivedAt: time.Now()}
+	mustContain(t, buildAlertDetailContent(alert, 110), "Incident:", "none")
+}
+
+func TestAlertDetail_ShowsResolutionSource(t *testing.T) {
+	source := "expiry"
+	alert := api.Alert{Name: "Gone", Status: "resolved", ReceivedAt: time.Now(),
+		ResolutionSource: &source}
+	mustContain(t, buildAlertDetailContent(alert, 110), "RESOLVED", "expiry")
+}
+
+// Null MTTA means nothing has been acknowledged, which is a different claim
+// from an instant response.
+func TestStats_RendersDashForMissingAverages(t *testing.T) {
+	stats := &api.IncidentStats{Total: 2, Triggered: 2}
+	out := buildStatsContent(stats, nil, nil, nil, 110)
+	mustContain(t, out, "Incident Response", "Mean time to acknowledge", "—",
+		"nothing has been acknowledged or resolved yet")
+}
+
+func TestStats_RendersAverages(t *testing.T) {
+	mtta, mttr := 150.0, 3600.0
+	stats := &api.IncidentStats{Total: 3, Resolved: 1, MTTASeconds: &mtta, MTTRSeconds: &mttr}
+	out := buildStatsContent(stats, []api.TopAlert{{Name: "DiskFull", Count: 4}}, nil, nil, 110)
+	mustContain(t, out, "2m", "1h", "Top Alerts", "DiskFull")
+}
+
+func TestStats_HandlesNoIncidentData(t *testing.T) {
+	mustContain(t, buildStatsContent(nil, nil, nil, nil, 110), "Incident Response", "No data")
+}
+
+func TestView_TabsAndDashboardRender(t *testing.T) {
+	m := sized()
+	m.incidents = []api.Incident{{
+		ID: 1, Title: "DiskFull", Status: api.StatusTriggered, Severity: "critical",
+		AssignedTo: "admin", TriggeredAt: time.Now(),
+	}}
+	m.incidentStats = &api.IncidentStats{Triggered: 1}
+	m.rebuildIncidentTable()
+
+	mustContain(t, m.View(),
+		"Incidents", "Alerts", "Archived", "Schedule", "Users",
+		"Triggered: 1", "filter: open",
+		"DiskFull", "critical", "admin",
+		"enter·detail")
+}
+
+func TestView_EmptyStates(t *testing.T) {
+	m := sized()
+	m.loading = false
+	mustContain(t, m.View(), "No open incidents.")
+
+	m.activeSection = sectionArchived
+	mustContain(t, m.View(), "No archived incidents.")
+}
+
+func TestView_ConnectionError(t *testing.T) {
+	m := sized()
+	m.connected = false
+	m.err = errFixture{}
+	mustContain(t, m.View(), "Error:", "Press r to retry")
+}
+
+// The footer is the only place the terminal states are explained, so the
+// destructive one has to be visible before it is pressed.
+func TestFooter_IncidentDetailOffersResolveOnlyWhileOpen(t *testing.T) {
+	open := onIncident(openIncidentFixture(), nil)
+	mustContain(t, open.renderFooter(), "R·resolve", "z·snooze", "a·ack")
+
+	closed := onIncident(resolvedIncidentFixture(), nil)
+	if strings.Contains(plain(closed.renderFooter()), "R·resolve") {
+		t.Error("a resolved incident should not offer resolve")
+	}
+	mustContain(t, closed.renderFooter(), "x·archive", "c·note")
+}
+
+func TestView_ZeroWidthRendersNothing(t *testing.T) {
+	m := NewModel(nil, "http://test", time.Minute)
+	if m.View() != "" {
+		t.Error("expected no output before the first window size message")
+	}
+}
+
+type errFixture struct{}
+
+func (errFixture) Error() string { return "connection refused" }