diff --git a/playwright/app.spec.ts b/playwright/app.spec.ts
index 5258370..d56316f 100644
--- a/playwright/app.spec.ts
+++ b/playwright/app.spec.ts
@@ -74,6 +74,28 @@ const ensurePanelToolsVisible = async (page: Page, panelName: 'component' | 'sty
   }
 }
 
+const ensureDiagnosticsDrawerOpen = async (page: Page) => {
+  const toggle = page.locator('#diagnostics-toggle')
+  const isExpanded = await toggle.getAttribute('aria-expanded')
+
+  if (isExpanded !== 'true') {
+    await toggle.click()
+  }
+
+  await expect(page.locator('#diagnostics-drawer')).toBeVisible()
+}
+
+const ensureDiagnosticsDrawerClosed = async (page: Page) => {
+  const toggle = page.locator('#diagnostics-toggle')
+  const isExpanded = await toggle.getAttribute('aria-expanded')
+
+  if (isExpanded === 'true') {
+    await page.locator('#diagnostics-close').click()
+  }
+
+  await expect(page.locator('#diagnostics-drawer')).toBeHidden()
+}
+
 const expectCollapseButtonState = async (
   page: Page,
   panelName: 'component' | 'styles' | 'preview',
@@ -383,7 +405,7 @@ test('react mode typecheck loads types without malformed URL fetches', async ({
   await page.locator('#render-mode').selectOption('react')
   await page.getByRole('button', { name: 'Typecheck' }).click()
 
-  await page.locator('#diagnostics-toggle').click()
+  await ensureDiagnosticsDrawerOpen(page)
   await expect(page.locator('#diagnostics-component')).toContainText(
     'No TypeScript errors found.',
   )
@@ -558,7 +580,7 @@ test('style compilation errors populate styles diagnostics scope', async ({ page
     /diagnostics-toggle--error/,
   )
 
-  await page.locator('#diagnostics-toggle').click()
+  await ensureDiagnosticsDrawerOpen(page)
   await expect(page.locator('#diagnostics-styles')).toContainText(
     'Style compilation failed.',
   )
@@ -627,6 +649,7 @@ test('clearing styles keeps diagnostics error state but resets status styling',
   )
 
   const dialog = page.locator('#clear-confirm-dialog')
+  await ensureDiagnosticsDrawerClosed(page)
   await page.getByLabel('Clear styles source').click()
   await expect(dialog).toHaveAttribute('open', '')
   await dialog.getByRole('button', { name: 'Clear' }).click()
@@ -659,7 +682,7 @@ test('clear component diagnostics removes type errors and restores rendered stat
   )
   await expect(page.locator('#status')).toHaveText(/Rendered \(Type errors: [1-9]\d*\)/)
 
-  await page.locator('#diagnostics-toggle').click()
+  await ensureDiagnosticsDrawerOpen(page)
   await page.locator('#diagnostics-clear-component').click()
 
   await expect(page.locator('#diagnostics-component')).toContainText(
@@ -685,7 +708,7 @@ test('clear all diagnostics removes style compile diagnostics', async ({ page })
     /diagnostics-toggle--error/,
   )
 
-  await page.locator('#diagnostics-toggle').click()
+  await ensureDiagnosticsDrawerOpen(page)
   await expect(page.locator('#diagnostics-styles')).toContainText(
     'Style compilation failed.',
   )
@@ -713,7 +736,7 @@ test('clear styles diagnostics removes style compile diagnostics', async ({ page
     /diagnostics-toggle--error/,
   )
 
-  await page.locator('#diagnostics-toggle').click()
+  await ensureDiagnosticsDrawerOpen(page)
   await expect(page.locator('#diagnostics-styles')).toContainText(
     'Style compilation failed.',
   )
@@ -740,7 +763,7 @@ test('typecheck success reports ok diagnostics state in button and drawer', asyn
   await expect(page.locator('#diagnostics-toggle')).toHaveClass(/diagnostics-toggle--ok/)
   await expect(page.locator('#diagnostics-toggle')).toHaveText('Diagnostics')
 
-  await page.locator('#diagnostics-toggle').click()
+  await ensureDiagnosticsDrawerOpen(page)
   await expect(page.locator('#diagnostics-component')).toContainText(
     'No TypeScript errors found.',
   )
@@ -766,7 +789,7 @@ test('typecheck error reports diagnostics count in button and details in drawer'
   )
   await expect(page.locator('#diagnostics-toggle')).toHaveText(/Diagnostics \([1-9]\d*\)/)
 
-  await page.locator('#diagnostics-toggle').click()
+  await expect(page.locator('#diagnostics-drawer')).toBeVisible()
   await expect(page.locator('#diagnostics-component')).toContainText('TypeScript found')
   await expect(page.locator('#diagnostics-component')).toContainText('TS')
 })
@@ -787,7 +810,7 @@ test('component diagnostics rows navigate editor to reported line', async ({ pag
   await expect(page.locator('#diagnostics-toggle')).toHaveClass(
     /diagnostics-toggle--error/,
   )
-  await page.locator('#diagnostics-toggle').click()
+  await ensureDiagnosticsDrawerOpen(page)
 
   const targetDiagnostic = page
     .locator('#diagnostics-component .diagnostic-line-button[data-diagnostic-line="2"]')
@@ -817,7 +840,7 @@ test('component diagnostics support arrow navigation and enter jump', async ({
     /diagnostics-toggle--error/,
   )
 
-  await page.locator('#diagnostics-toggle').click()
+  await ensureDiagnosticsDrawerOpen(page)
 
   const firstDiagnostic = page
     .locator('#diagnostics-component .diagnostic-line-button')
@@ -854,7 +877,7 @@ test('component lint error reports diagnostics count and details', async ({ page
   )
   await expect(page.locator('#diagnostics-toggle')).toHaveText(/Diagnostics \([1-9]\d*\)/)
 
-  await page.locator('#diagnostics-toggle').click()
+  await expect(page.locator('#diagnostics-drawer')).toBeVisible()
   await expect(page.locator('#diagnostics-component')).toContainText(
     'Biome reported issues.',
   )
@@ -874,7 +897,7 @@ test('styles diagnostics rows navigate editor to reported line', async ({ page }
   await expect(page.locator('#diagnostics-toggle')).toHaveClass(
     /diagnostics-toggle--error/,
   )
-  await page.locator('#diagnostics-toggle').click()
+  await ensureDiagnosticsDrawerOpen(page)
 
   const targetDiagnostic = page
     .locator('#diagnostics-styles .diagnostic-line-button[data-diagnostic-line="3"]')
@@ -904,7 +927,7 @@ test('clear component diagnostics resets rendered lint-issue status pill', async
   await expect(page.locator('#status')).toHaveText(/Rendered \(Lint issues: [1-9]\d*\)/)
   await expect(page.locator('#status')).toHaveClass(/status--error/)
 
-  await page.locator('#diagnostics-toggle').click()
+  await ensureDiagnosticsDrawerOpen(page)
   await page.locator('#diagnostics-clear-component').click()
 
   await expect(page.locator('#diagnostics-component')).toContainText(
@@ -932,7 +955,7 @@ test('component lint ignores unused App View and render bindings', async ({ page
 
   await runComponentLint(page)
 
-  await page.locator('#diagnostics-toggle').click()
+  await ensureDiagnosticsDrawerOpen(page)
   await expect(page.locator('#diagnostics-component')).toContainText(
     'No Biome issues found.',
   )
@@ -1018,7 +1041,7 @@ test('changing css dialect resets diagnostics after lint and typecheck runs', as
   )
   await expect(page.locator('#diagnostics-toggle')).toHaveText('Diagnostics')
 
-  await page.locator('#diagnostics-toggle').click()
+  await ensureDiagnosticsDrawerOpen(page)
   await expect(page.locator('#diagnostics-component')).toContainText(
     'No diagnostics yet.',
   )
diff --git a/src/app.js b/src/app.js
index 236f535..9926d41 100644
--- a/src/app.js
+++ b/src/app.js
@@ -504,6 +504,11 @@ const typeDiagnostics = createTypeDiagnosticsController({
   incrementTypeDiagnosticsRuns,
   decrementTypeDiagnosticsRuns,
   getActiveTypeDiagnosticsRuns,
+  onIssuesDetected: ({ issueCount }) => {
+    if (issueCount > 0) {
+      setDiagnosticsDrawerOpen(true)
+    }
+  },
 })
 
 const lintDiagnostics = createLintDiagnosticsController({
@@ -515,6 +520,11 @@ const lintDiagnostics = createLintDiagnosticsController({
   setComponentDiagnostics: setTypeDiagnosticsDetails,
   setStyleDiagnostics: setStyleDiagnosticsDetails,
   setStatus,
+  onIssuesDetected: ({ issueCount }) => {
+    if (issueCount > 0) {
+      setDiagnosticsDrawerOpen(true)
+    }
+  },
 })
 
 let activeComponentLintAbortController = null
@@ -544,7 +554,7 @@ const syncLintPendingState = () => {
   setLintDiagnosticsPending(componentLintPending || stylesLintPending)
 }
 
-const runComponentLint = async () => {
+const runComponentLint = async ({ userInitiated = false } = {}) => {
   activeComponentLintAbortController?.abort()
   const controller = new AbortController()
   activeComponentLintAbortController = controller
@@ -557,6 +567,7 @@ const runComponentLint = async () => {
   try {
     const result = await lintDiagnostics.lintComponent({
       signal: controller.signal,
+      userInitiated,
     })
     if (result) {
       lastComponentLintIssueCount = result.issueCount
@@ -570,7 +581,7 @@ const runComponentLint = async () => {
   }
 }
 
-const runStylesLint = async () => {
+const runStylesLint = async ({ userInitiated = false } = {}) => {
   activeStylesLintAbortController?.abort()
   const controller = new AbortController()
   activeStylesLintAbortController = controller
@@ -583,6 +594,7 @@ const runStylesLint = async () => {
   try {
     const result = await lintDiagnostics.lintStyles({
       signal: controller.signal,
+      userInitiated,
     })
     if (result) {
       lastStylesLintIssueCount = result.issueCount
@@ -901,17 +913,17 @@ if (diagnosticsClearAll) {
 }
 if (typecheckButton) {
   typecheckButton.addEventListener('click', () => {
-    typeDiagnostics.triggerTypeDiagnostics()
+    typeDiagnostics.triggerTypeDiagnostics({ userInitiated: true })
   })
 }
 if (lintComponentButton) {
   lintComponentButton.addEventListener('click', () => {
-    void runComponentLint()
+    void runComponentLint({ userInitiated: true })
   })
 }
 if (lintStylesButton) {
   lintStylesButton.addEventListener('click', () => {
-    void runStylesLint()
+    void runStylesLint({ userInitiated: true })
   })
 }
 renderButton.addEventListener('click', renderPreview)
diff --git a/src/modules/lint-diagnostics.js b/src/modules/lint-diagnostics.js
index 90a2770..8e91c17 100644
--- a/src/modules/lint-diagnostics.js
+++ b/src/modules/lint-diagnostics.js
@@ -210,6 +210,7 @@ export const createLintDiagnosticsController = ({
   setComponentDiagnostics,
   setStyleDiagnostics,
   setStatus,
+  onIssuesDetected = () => {},
 }) => {
   let biomeWorkspacePromise = null
   let componentLintRunId = 0
@@ -296,7 +297,7 @@ export const createLintDiagnosticsController = ({
     }
   }
 
-  const lintComponent = async ({ signal } = {}) => {
+  const lintComponent = async ({ signal, userInitiated = false } = {}) => {
     componentLintRunId += 1
     const runId = componentLintRunId
 
@@ -331,6 +332,15 @@ export const createLintDiagnosticsController = ({
           : 'Rendered',
         summary.level === 'error' ? 'error' : 'neutral',
       )
+
+      if (userInitiated && summary.lines.length > 0) {
+        onIssuesDetected({
+          kind: 'lint',
+          scope: 'component',
+          issueCount: summary.lines.length,
+        })
+      }
+
       return {
         issueCount: summary.lines.length,
       }
@@ -356,7 +366,7 @@ export const createLintDiagnosticsController = ({
     }
   }
 
-  const lintStyles = async ({ signal } = {}) => {
+  const lintStyles = async ({ signal, userInitiated = false } = {}) => {
     stylesLintRunId += 1
     const runId = stylesLintRunId
 
@@ -403,6 +413,15 @@ export const createLintDiagnosticsController = ({
           : 'Rendered',
         summary.level === 'error' ? 'error' : 'neutral',
       )
+
+      if (userInitiated && summary.lines.length > 0) {
+        onIssuesDetected({
+          kind: 'lint',
+          scope: 'styles',
+          issueCount: summary.lines.length,
+        })
+      }
+
       return {
         issueCount: summary.lines.length,
       }
diff --git a/src/modules/type-diagnostics.js b/src/modules/type-diagnostics.js
index 6fc7331..33a08dd 100644
--- a/src/modules/type-diagnostics.js
+++ b/src/modules/type-diagnostics.js
@@ -230,6 +230,7 @@ export const createTypeDiagnosticsController = ({
   incrementTypeDiagnosticsRuns,
   decrementTypeDiagnosticsRuns,
   getActiveTypeDiagnosticsRuns,
+  onIssuesDetected = () => {},
 }) => {
   let typeCheckRunId = 0
   let typeScriptCompiler = null
@@ -840,7 +841,7 @@ export const createTypeDiagnosticsController = ({
       .filter(diagnostic => !shouldIgnoreTypeDiagnostic(diagnostic))
   }
 
-  const runTypeDiagnostics = async runId => {
+  const runTypeDiagnostics = async (runId, { userInitiated = false } = {}) => {
     incrementTypeDiagnosticsRuns()
     setTypeDiagnosticsPending(false)
     setTypecheckButtonLoading(true)
@@ -879,6 +880,14 @@ export const createTypeDiagnosticsController = ({
           level: 'error',
         })
         setStatus(`Rendered (Type errors: ${errors.length})`, 'error')
+
+        if (userInitiated) {
+          onIssuesDetected({
+            kind: 'type',
+            scope: 'component',
+            issueCount: errors.length,
+          })
+        }
       }
 
       if (isRenderedStatus()) {
@@ -911,9 +920,9 @@ export const createTypeDiagnosticsController = ({
     }
   }
 
-  const triggerTypeDiagnostics = () => {
+  const triggerTypeDiagnostics = ({ userInitiated = false } = {}) => {
     typeCheckRunId += 1
-    void runTypeDiagnostics(typeCheckRunId)
+    void runTypeDiagnostics(typeCheckRunId, { userInitiated })
   }
 
   const scheduleTypeRecheck = () => {
diff --git a/src/styles/diagnostics.css b/src/styles/diagnostics.css
index d04b944..225cf7f 100644
--- a/src/styles/diagnostics.css
+++ b/src/styles/diagnostics.css
@@ -218,7 +218,7 @@
     top: auto;
     right: 12px;
     left: 12px;
-    bottom: 68px;
+    bottom: 12px;
     width: auto;
     max-height: 58vh;
   }