proothein
Hi
The permission of files must be writable and ownership would be for all users, it will be checked by your server side you can ask the hosting provider.
Also the correct way to make css override is via override css or custom css only.
As files will be override and your changes will be lost when you update the template.
I checked both the codes i shared are working perfectly on your site. There are different style used for different sections in the template, if you can give me part screenshot and page URl i can give each style code.
Here is style code for all heading tags
h1, h2, h3, h4, h5, h6 {
text-transform: inherit!important;
}
