Why aren't my base styles updating in the preview?
If you're removing styling from a base style, those styles still apply until you have saved the base style.
Acquia Cohesion renames to Site Studio from version 6.2. Tell me more.
Base styles are CSS styles for HTML elements.
The 'Range' in the menu list item element sets which list items at the current level the settings should apply to.
You can use Elements to create content but we don't recommend doing so for multiple reasons.
The Youtube video embed is responsive so it should expand to the width of its parent. If you do need to set a width you can apply the Width CSS property through the Style Builder.