This members-only tutorial provides the steps to use the modal feature in Oxygen for sliding down a full-width search form covering the header when a magnifying glass icon in the header is clicked.
Clicking anywhere on the page outside the search form or the close button will fade away the search form.
Step 1
Let's
enable placeholder text for the search form by adding support for HTML5 markup
change the placeholder text from the default Search … to a custom "Type what are you looking for and hit return".