There was a problem with the display of the site background, if the browser window size is less than the specified size. Let's say the width of the site is 1600px. If I reduce the width of the browser to 1500px, then scrolling to the side, the place of the background will be just empty, as if it was just cut: 
As you can see, the header is "adjusted". For phones, the solution is to set the minimum width. What is the solution for desktop browsers?
I will try to describe in more detail. I use bootstrap 4 c flexbox.
Container code:
container-fixed { margin-left: auto; margin-right: auto; padding-left: 15px; padding-right: 15px; width: 1600px; } In general, a copy of the bootstrap, only with a given width.
The construction is approximately as follows:
<container-fixed> <row> <block class="col-xs-12 headbg"></block> </row> </container-fixed> Tag row an analog of class row .
block { flex: 1; padding-left: 15px; padding-right: 15px; } Background set in this way
.headbg { background-image: url(".."); background-position: center; background-repeat: no-repeat; } section { width: 100%; min-width: 100%; margin: 0 auto; }