Mobile experience improvments

[hmellow]

Improvement list (comment for more requests)

Home Page

• Increase spacing between elements
• Make main title size appropriate

Leaderboard

• Feels crowded --> may be good if it doesn't stretch all of the way across the screen

Tag-Report page

• More margin between title and instructions

Modals

Error Modal

• Error Yoshi gets squished

  Success Modal

• Looks pretty good
• Maybe make the OK button a bit bigger (it might be the same for the Error Modal)
  
• Experiment with modals not extending all the way across the screen in vertical orientation

Footer

• Footer: Margin above footer on mobile MAY be too big
• Footer: Login button on footer has too big a left margin

Other

• Titles need improvement very badly: see #37

[hmellow]

Fixed all footer issues

[hmellow]

Will fix the following in future PR: related --> #37

• Homepage
• Other

[hmellow]

Many other visual issues will be solved with fixed titles