You can use command + F (or ctrl + F on Windows / Linux) to toggle Find panel, and use command + H (or ctrl + H on Windows / Linux) to toggle Find and Replace panel to find contents in current document and replace matches.

Please note when Regular Expression is enabled, the $0, $1, $3… in replacement string will be replaced by the matches in brackets.
You can open this search function by
File Tree or Articles sidebar is shown.View → Search from menu bar, or using the shortcut key displayed in the menu item directly.Similar with find and replace, it supports toggles of case sensitive / insensitive, match whole word, and match with regular expression.

You can press Command + Shift + O on macOS or Ctrl + P to toggle Quick Open panel, where you can use fuzzy search to locate files in current opened folder or used recently.
