fix: keep transcript visible when hiding sidebar (#1530)

js&css/extension/www.youtube.com/appearance/sidebar/sidebar.css

@@ -237,6 +237,16 @@ html[it-hide-sidebar='true'] div#secondary div#panels,
 html[it-hide-sidebar='true'] div#secondary div#donation-shelf {
 	display: none !important
 }
+/* #1530 */
+html[it-hide-sidebar='true'] div#secondary div#panels > *([target-id*='transcript']),
+html[it-hide-sidebar='true'] div#secondary div#panels > *([target-id*='chapters']) {
+	display: block !important
+}
+/* Ensure secondary has enough width for the transcript panel */
+html[it-hide-sidebar='true'][it-transcript='true'] ytd-watch-flexy[flexy] #secondary.ytd-watch-flexy {
+	width: fit-content !important;
+	min-width: max(445px, 17vw) !important
+}
 
 html[it-related-videos='collapsed'] #related > ytd-watch-next-secondary-results-renderer > #items:not([it-activated])::before {
 	content: 'Show more' !important;

tests/unit/hide-sidebar-transcript.test.js

@@ -0,0 +1,39 @@
+// Test for Issue #1530: Keep transcript visible when hiding the sidebar
+
+const fs = require('fs');
+const path = require('path');
+
+describe('Hide Sidebar + Transcript Visibility (#1530)', () => {
+	let sidebarCssContent;
+
+	beforeAll(() => {
+		const filePath = path.join(__dirname, '../../js&css/extension/www.youtube.com/appearance/sidebar/sidebar.css');
+		sidebarCssContent = fs.readFileSync(filePath, 'utf8');
+	});
+
+	test('should hide panels when sidebar is hidden but transcript is NOT enabled', () => {
+		expect(sidebarCssContent).toContain("html[it-hide-sidebar='true']:not([it-transcript='true']) div#secondary div#panels");
+	});
+
+	test('should show panels when both sidebar hidden and transcript enabled', () => {
+		expect(sidebarCssContent).toContain("html[it-hide-sidebar='true'][it-transcript='true'] div#secondary div#panels");
+		expect(sidebarCssContent).toMatch(/html\[it-hide-sidebar='true'\]\[it-transcript='true'\] div#secondary div#panels\s*\{[^}]*display:\s*block\s*!important/);
+	});
+
+	test('should hide non-transcript panels when sidebar hidden + transcript enabled', () => {
+		expect(sidebarCssContent).toContain("html[it-hide-sidebar='true'][it-transcript='true'] div#secondary div#panels > :not([target-id*='transcript'])");
+	});
+
+	test('should ensure secondary has proper width when both features active', () => {
+		expect(sidebarCssContent).toMatch(/html\[it-hide-sidebar='true'\]\[it-transcript='true'\] ytd-watch-flexy\[flexy\] #secondary\.ytd-watch-flexy/);
+		expect(sidebarCssContent).toMatch(/min-width:\s*max\(445px,\s*17vw\)/);
+	});
+
+	test('should still hide related videos when sidebar is hidden', () => {
+		expect(sidebarCssContent).toContain("html[it-hide-sidebar='true'] #related");
+	});
+
+	test('should still hide donation shelf when sidebar is hidden', () => {
+		expect(sidebarCssContent).toContain("html[it-hide-sidebar='true'] div#secondary div#donation-shelf");
+	});
+});