Chi-K
On article page of this template, there is typo tool so that you can change the font size. Based on this font size, the size for these headings are also different.
If you want to change globally, you can change via LESS file:
/templates/ja_magz_ii/less/joomla.less
look for this declaration:
// Use with Typo Tools
@media (min-width: @grid-float-breakpoint) {
// Size Control
// ------------
.fs-smaller .article-content {font-size: @font-size-large - 6px;}
.fs-small .article-content {font-size: @font-size-large - 4px;}
.fs-medium .article-content {font-size: @font-size-large - 2px;}
.fs-big .article-content {font-size: @font-size-large; }
.fs-bigger .article-content {font-size: @font-size-large + 2px;}
.fs-medium,
.fs-smaller,
.fs-small ,
.fs-big,
.fs-bigger {
h1, .h1 { font-size: round(unit(@font-size-h1) / unit(@font-size-base), 2) * 100%; }
h2, .h2 { font-size: round(unit(@font-size-h2) / unit(@font-size-base), 2) * 100%; }
h3, .h3 { font-size: round(unit(@font-size-h3) / unit(@font-size-base), 2) * 100%; }
h4, .h4 { font-size: round(unit(@font-size-h4) / unit(@font-size-base), 2) * 100%; }
h5, .h5 { font-size: round(unit(@font-size-h5) / unit(@font-size-base), 2) * 100%; }
h6, .h6 { font-size: round(unit(@font-size-h6) / unit(@font-size-base), 2) * 100%; }
}
Once done, you need to compile LESS to CSS (REMEMBER to backup your site first)
see this tip for how to compile: https://www.t3-framework.org/documentation/bs3-configuration#compile-less