Markdown and Repo header tweaks (#13744)

* Markdown and Repo header tweaks

- Use CSS vars for all markdown colors
- Tweak repo header, removing double borders and adjust sizes
- Use menu instead of buttons for issue open/close switcher
- Add emoji inversion for select emoji glyphs in arc-green
- Use border over box-shadow for all buttons
- Add spacing element to login form without openid

* repo settings navbar fix

* use shared template in more places and adjust dashboard

* fix remaining open/close combos

templates/shared/issuelist.tmpl

@@ -22,9 +22,9 @@
 						{{end}}
 					{{else}}
 						{{if .IsClosed}}
-							{{svg "octicon-issue-opened" 16 "text red"}}
+							{{svg "octicon-issue-closed" 16 "text red"}}
 						{{else}}
-							{{svg "octicon-issue-closed" 16 "text green"}}
+							{{svg "octicon-issue-opened" 16 "text green"}}
 						{{end}}
 					{{end}}
 				</div>
@@ -74,7 +74,10 @@
 					{{end}}
 					{{if ne .DeadlineUnix 0}}
 						<span class="due-date poping up" data-content="{{$.i18n.Tr "repo.issues.due_date"}}" data-variation="tiny inverted" data-position="right center">
-							{{svg "octicon-calendar" 14 "mr-2"}}<span{{if .IsOverdue}} class="overdue"{{end}}>{{.DeadlineUnix.FormatShort}}</span>
+							<span{{if .IsOverdue}} class="overdue"{{end}}>
+								{{svg "octicon-calendar" 14 "mr-2"}}
+								{{.DeadlineUnix.FormatShort}}
+							</span>
 						</span>
 					{{end}}
 					{{if .IsPull}}