Linux
Other
<p>Edit ~/.config/gtk-3.0/gtk.css and log out / in.</p>
<pre><code>.header-bar {
padding-top: 2.5px;
padding-bottom: 2.5px;
}
.header-bar .button { padding-top: 4px; padding-bottom: 4px; }
.header-bar.default-decoration { padding-top: 2px; padding-bottom: 2px; }
.header-bar.default-decoration .button.titlebutton { padding-top: 3px; padding-bottom: 3px; } </code></pre>