4 window
.addEventListener('load', () => {
5 const element
= document
.createElementNS('', 't')
6 document
.designMode
= 'on'
7 const range
= new Range()
8 range
.selectNodeContents(element
)
9 range
.surroundContents(document
.documentElement
)
10 document
.execCommand('insertHorizontalRule', false, null)