CODE EXAMPLE FOR HTML

altair resize image embedded in html

<div id="visInteractiveYear" class="vega-embed">
<canvas width="1366" height="960" class="marks" style="width: 976px; height: 686px;"></canvas>
</div>


#add to css this:
canvas.marks {
    max-width: 100%!important;
    height: auto!important;
}