How do have the dropdown list the same width as the browser?

Design help General
#1

Yea as im trying to to the design but unable to figure out in the webflow UI
Anyone has the solution ?

Here is my site Read-Only: **https://preview.webflow.com/preview/idc-web-page?preview=8dca3d0c308df431f7bd8ce56eeb0f55)