Mermaid Class Diagram has wrong font size for class title

Summary

Mermaid Class Diagrams in Markdown are rendered incorrectly. The class mames are too large and don't look right. See the example below:

classDiagram
Class01 <|-- AveryLongClass : Cool
<<interface>> Class01
Class09 --> C2 : Where am i?
Class09 --* C3
Class09 --|> Class07
Class07 : equals()
Class07 : Object[] elementData
Class01 : size()
Class01 : int chimp
Class01 : int gorilla
class Class10 {
 <<service>>
 int id
 size()
}

this should be rendered as seen in the link below:

Steps to reproduce

Its reproduced in this issue. Just post the markdown

```mermaid
classDiagram
Class01 <|-- AveryLongClass : Cool
<<interface>> Class01
Class09 --> C2 : Where am i?
Class09 --* C3
Class09 --|> Class07
Class07 : equals()
Class07 : Object[] elementData
Class01 : size()
Class01 : int chimp
Class01 : int gorilla
class Class10 {
  <<service>>
  int id
  size()
}
`` `

into any Gitlab that supports mermaid until at least 12.9.0.

What is the current bug behavior?

The mermaid diagram looks wrong with too large class names.

What is the expected correct behavior?

The rendered mermaid diagram looks as in the reference image. See also the mermaid live version:

https://mermaid-js.github.io/mermaid-live-editor/#/edit/eyJjb2RlIjoiY2xhc3NEaWFncmFtXG5DbGFzczAxIDx8LS0gQXZlcnlMb25nQ2xhc3MgOiBDb29sXG48PGludGVyZmFjZT4-IENsYXNzMDFcbkNsYXNzMDkgLS0-IEMyIDogV2hlcmUgYW0gaT9cbkNsYXNzMDkgLS0qIEMzXG5DbGFzczA5IC0tfD4gQ2xhc3MwN1xuQ2xhc3MwNyA6IGVxdWFscygpXG5DbGFzczA3IDogT2JqZWN0W10gZWxlbWVudERhdGFcbkNsYXNzMDEgOiBzaXplKClcbkNsYXNzMDEgOiBpbnQgY2hpbXBcbkNsYXNzMDEgOiBpbnQgZ29yaWxsYVxuY2xhc3MgQ2xhc3MxMCB7XG4gID4-c2VydmljZT4-XG4gIGludCBpZFxuICBzaXplKClcbn0iLCJtZXJtYWlkIjp7InRoZW1lIjoibmV1dHJhbCJ9fQ

Output of checks

This bug happens on GitLab.com

Possible fixes

From what I've been able to glean so far this stems from the fact that mermaid uses the css class "title" for the class titles. This however already has a meaning in the Markdown context.