Monospace for Unicode characters

Currently unicode characters don't always display correctly in code blocks, for example:

┌─────────────────────────────┐
│Current Roll: ⚃ ⚀ ⚄ ⚀ ⚂      │
│Numer:        4 1 5 1 3      │
│Holds:        ○ ○ ○ ○ ○      │

Notice that the dice symbols consume slightly more than one cell, whereas in other displays, it shows correctly:

Only some unicode characters display slightly wider than they should, whilst others are perfectly fine, can you fix this by using a truly monospace font?