Landing page, for 1440px and 375px screen using CSS Grid

Difficulties:

• error message with "!" i added using setInterval() for 2sec. But interval works only once, then it appeares for milliseconds.
• again problems with background for the left half (with text)

Finally I managed to copy both mobile and desktop version using Grid and ::after element to cover it with background pattern. All that give the sentiments of dissapointmen, looks like I regress