c676786144
Press '?' to open a styled overlay showing all keyboard shortcuts, Esc to close. Lists Space (play/pause), arrow keys (seek/volume), F (fullscreen), M (mute), ? (help), Esc (close). Files: - frontend/app.js: toggleShortcutHelp(), wireShortcutHelp(), '?' and Esc handlers - frontend/index.html: shortcut-overlay markup with .shortcut-grid - frontend/styles.css: .shortcut-overlay, .shortcut-panel, .shortcut-row, kbd styles