Tweaks

Here's the CSS structure  of any Matrix theme that helps you to understand which part of your CSS you need to customize:

+----------------------------------------------------+
        TABLE OF CONTENTS
+----------------------------------------------------+

    [1] COLOR SETTINGS
    [2] TYPOGRAPHY
    [3] LAYOUT
    [4] RESPONSIVE CAROUSEL
    [5] MAGNIFIC POPUP
    [6] WIDGETS AND CUSTOM ELEMENTS
    [7] HELPER CLASSES
    [8] MEDIA QUERIES
    [9] ADVANCED CUSTOMIZATIONS 
    [10] ADDITIONAL LIBRARIES       
    

In this section you setup the brand colors of your website:

• bg-primary
• bg-secondary
• bg-primary-dark
• bg-secondary-dark

The detailed tutorial about setting the brand colors can be found in section quick setup

You setup your brand google font here and some style  for the navigation and headings.

More details about font setting you fill find in this post

This section is the most important as it's different in each template. It includes

• layout structure
• hero image
• main navigation
• mobile navigation

At the beginning of layout section, you will find  "Tweaks and small customizations". Here you can add your own style and additional  customization of Matrix themes without changing the default template styles.

Let's take an example of a button. If you change  the button style in html with the classes mid-round-btn, round-btn, you might need to change the padding as well so you don't browse other sections and  change the button style here:

/* -------------------------------------------------------------------------------- /
        [3]     LAYOUT
/ -------------------------------------------------------------------------------- */

/*** template tweaks ***/
#cc-inner #hs-container .j-formnew input[type='submit'],#cc-inner .matrix-hero .hs-button,#cc-inner .hs-content .hs-button,#cc-inner .hs-footer .hs-button {
    padding:15px 45px;
} 
...  
    

The following sections are the same in all Matrix themes:

• responsive carousel
• magnific popup
• widgets and custom elements
• helper classes
• media queries
• advanced

The section advanced customization includes the class "snip-nav" for animated navigation.

The underlined animated navigation style is different  in many templates like style but also for the elements ( in multilingual themes it has been applied for the second level, in templates with megamenu - only for the main items etc ), so therefore you can't use it the same style for multilingual  or multi purpose versions