Your page does not have a viewport specified. This causes mobile devices to render your page as it would appear on a desktop browser, scaling it down to fit on a mobile screen. Configure a viewport to allow your page to render properly on all devices.
Size tap targets appropriately
Some of the links/buttons on your webpage may be too small for a user to easily tap on a touchscreen. Consider making these tap targets larger to provide a better user experience.
The following tap targets are close to other nearby tap targets and may need additional spacing around them.
The tap target <a href="http://blog.twitter.com/">Blog</a> and 4 others are close to other tap targets.
Use legible font sizes
The following text on your page renders in a way that may be difficult for some of your visitors to read. Use legible font sizes to provide a better user experience.
The following text fragments have a small font size. Increase the font size to make them more legible.
Back to Twitter renders only 5 pixels tall (14 CSS pixels).
Learn more renders only 5 pixels tall (14 CSS pixels).
2017 Twitter and 1 others render only 4 pixels tall (11 CSS pixels).
About Us and 8 others render only 4 pixels tall (11 CSS pixels).
t.co Mobile Speed: 99/100
t.co Mobile Speed Test Quick Overview
Leverage browser caching
Setting an expiry date or a maximum age in the HTTP headers for static resources instructs the browser to load previously downloaded resources from local disk rather than over the network.