Menu
A menu is a row of commands. It is the <menu> element with class="toolbar", laid out as a horizontal strip of buttons with a rule to group them.
<menu class="toolbar">
<li><button>Bold</button></li>
<li><button>Italic</button></li>
<li><button>Underline</button></li>
</menu>A toolbar
Adding class="toolbar" to a <menu> lines its buttons up in a boxed strip.
<menu class="toolbar">
<li><button>Cut</button></li>
<li><button>Copy</button></li>
<li><button>Paste</button></li>
</menu>Groups
An <hr> between items splits the strip into groups.
<menu class="toolbar">
<li><button>Bold</button></li>
<li><button>Italic</button></li>
<li><hr></li>
<li><button class="secondary">Link</button></li>
</menu>