Chrome devtools change layout of Elements tab

In Chrome DevTools Tab, At Top-Right Corner, Go To Dropdown -> Settings -> Click on Restore Defaults. It will work..

Click the menu bar in the top right corner. Goto settings => preferences. Under the appearance setting there is an option called panel layout which allows you to change the layout.

https://makandracards.com/makandra/41536-how-to-force-horizontal-panel-layout-for-chrome