Is this what you want to achieve?
In this case you have to modify boost main templates (colums2.php, ...) to add a node for your banner between boost's navbar (<nav> tag) and page div (<div id="page">), make it the height (and max-height of your image) with fixed position of 50px to be placed just beneath boost's navbar. You'll also have to adapt positioning of nav-drawer and top margin of <div id="page".
Hope it helps !
Thanks Jean for your time. I wouldn't like to edit files. Just using CSS, SCSS or additional HTML.
Then try adding html code for your banner in Admin -> Appearance -> Additional HTML.
ex: <div class="mybanner"></div>
You will still have to adapt positioning of nav-drawer, div with id="page" and blocks column in (s)css.
Good luck
Thanks for your suggestion. I got it without positioning of nav-drawer, div with id="page" and blocks column in (s)css. My temporary solution is to add
<div class="banner">
<img class="mybanner" src="https://...............jpg" alt="truong thpt trian" style="margin:60px 0 -55px 0; width:100%; padding-left:1%; padding-right:1%;">
</div>
in additional HTML.
Top ! Good for you
Cheers
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