first i want to say thank you very mush for your templates. they are wonderfull
but i have a problame with helix freamwork.
i downloaded it and installed on a simple joomla to creat my template.(because helix is the best in all freamwork i think)

i changed my css style in template.css and template_rtl.css and bootstrap.css and ....
all things was good
but i wanted to change my template in extension > template manager . for example when i change to another template and again set to helix template , all css that i wrote will clean. as though i never write any css. and i must to design my template from first.
What do I do ?
what is the problame?