A native <select> sizes itself to the widest <option> text. With long
project titles in the matters filter, the select grew wider than the
viewport and the /events page scrolled horizontally on mobile.
The existing 480px media query forced .entity-select to width:100% on
phones, but the 481-1000px range (tablet portrait + landscape phones)
had no constraint at all and inherited the intrinsic select width.
Fix: cap .filter-group and .entity-select at max-width:100% with
min-width:0 so the cell can shrink to fit its flex container at every
viewport. Desktop layout is preserved — normal-length options still
sit in one row across the page; only pathological content (a single
title wider than the row) wraps onto its own line.
Approach: A — let the trigger respect its container at every width.
Verified: zero horizontal scroll at 320 / 375 / 414 / 768 px with a
realistic 130-character project title injected into the matters
selector. Desktop (1280px) keeps all four filter-groups in one row.