CSS for "download and verify" page

Originally created by @sajolida on #9385 (Redmine)

Feature Branch: web/10631-DAVE-CSS

Attachments

• download-and-install-wip.png
• smaller progress indicators.png
• 0001-fixed-width-of-the-header-element-for-langs-with-lon.patch
• css error after.png
• css error before.png

Parent Task: #8566 (closed)

Related issues

• Related to #10631 (closed)
• Blocked by #9384 (closed)