luci-theme-openwrt-2020: button rendering (wireguard/ advanced-reboot)

Hi

Using current OpenWrt/ master on ipq806x/ nbg6817 (also seen on ipq40xx/ map-ac2200)

master/r12964-35f208da3c
src-git packages https://git.openwrt.org/feed/packages.git^a4d19d8
src-git luci https://git.openwrt.org/project/luci.git^d0daa2c
src-git routing https://git.openwrt.org/feed/routing.git^f71d733
src-git telephony https://git.openwrt.org/feed/telephony.git^bf49bc5

I notice a strange rendering for the buttons used in luci-app-wireguard and luci-app-advanced-reboot, all other buttons I've seen so far seem to work fine - and it's working nicely using luci-theme-bootstrap.

<div class="cbi-section"><h3>Interface wg0</h3>
	<div class="cbi-value" id="button" style="padding: 5px">
		<input class="cbi-button cbi-button-apply" type="button" name="qrcode_wg0" value="Show/Hide QR-Code" onclick="toggle_qrcode(this)" />
	</div><div class="cbi-section-node">

			<div class="td"><form method="post" action="/cgi-bin/luci/admin/system/advanced_reboot/alternative_reboot">
				<input type="hidden" name="token" value="XXX" />
				<input id="altreboot-button" type="submit" class="cbi-button cbi-button-apply important" value="Reboot to alternative partition..." />
			</form></div>

			<div class="td"><form method="post" action="/cgi-bin/luci/admin/system/advanced_reboot/reboot">
						<input type="hidden" name="token" value="XXX" />
						<input id="reboot-button" type="submit" class="cbi-button cbi-button-apply important" value="Reboot to current partition" />
					</form></div>

</fieldset><hr /><form method="post" action="/cgi-bin/luci/admin/system/advanced_reboot/power_off">
	<input type="hidden" name="token" value="XXX" />
	<input id="poweroff-button" type="submit" class="cbi-button cbi-button-apply important" value="Perform power off..." />
</form>

The attached images have been made from firefox 74/ linux, but I'm seeing the same with chromium 81/ linux.

Start by reproducing the button rendering in luci-theme-openwrt-2020 with luci-app-wireguard and luci-app-advanced-reboot, using the HTML examples and the Firefox or Chromium versions described. Compare the same controls under luci-theme-bootstrap and inspect the cbi-button styles; done means the affected buttons render consistently with the other LuCI buttons in both applications.