Audit Learning mode Styles for specificity

[mikeyarce]

We had an issue in 4.7.0 where some Learning Mode styles ended up being applied outside of Learning Mode. To fix it, we added some specificity to the rules in https://github.com/Automattic/sensei/pull/5903

However, @renatho also found some more rules that could potentially be applied globally:

https://github.com/Automattic/sensei/pull/5903#pullrequestreview-1138149312

body {
  --sensei-primary-color: var(--sensei-primary-color-global, var(--sensei-course-theme-primary-color, var(--wp--preset--color--primary, #307771)));
  --sensei-background-color: var(--sensei-background-color-global, var(--sensei-course-theme-background-color, var(--wp--preset--color--background, #ffffff)));
  --sensei-primary-contrast-color: var(--sensei-background-color, #FFFFFF);
  --sensei-text-color: var(--sensei-text-color-global, var(--sensei-course-theme-foreground-color, var(--wp--preset--color--text, var(--wp--preset--color--foreground, #1E1E1E))));
  --border-color: rgba(125, 125, 125, 0.3);
  background-color: var(--sensei-background-color);
  color: var(--sensei-text-color);
}

.wp-block-site-logo .custom-logo-link {
  margin: 0;
}

.wp-site-blocks {
  display: block;
}

.entry-content img {
  max-width: 100%;
  height: auto;
}
.entry-content embed,
.entry-content iframe,
.entry-content object {
  max-width: 100%;
}

We should make sure to check these rules and that they only apply where intended.