Surviving enlargement.
THE REQUIREMENT
Content must remain usable when enlarged to 200 per cent, and when the browser window is narrow.
WHAT BREAKS
Fixed heights, causing text to overflow or be cut off Absolute positioning that overlaps when things grow Horizontal scrolling appearing Navigation becoming unreachable Content hidden rather than reflowed
WHY IT MATTERS
People with low vision routinely browse at high zoom levels.
The experience should degrade gracefully, not collapse.
HOW TO TEST
Press the browser zoom keys until the page is at 200 per cent. Then 400.
Check you can still read everything, reach the navigation, and complete a form.
Then narrow the browser window to phone width and repeat.
THE OVERLAP WITH MOBILE
A site that works properly on a phone usually survives zoom, because both require content to reflow rather than break.
Building mobile-first covers much of this.
WHAT TO AVOID
Fixed pixel heights on containers holding text Layouts that assume a minimum width Anything that produces horizontal scrolling
