Sticky Navigation part for Long Contents
When you do content based SEO, each content become longer than usual case. Then you will use links for named anchor.
In this website, it is used for main contents. They are long and have index part at the top of article body part.
It is very useful, because when you write a content, there are many opportunities when you divide it into multiple pages or not. But the page's usability is up to the content, and it have to cover much information for current theme as possible as we can.
It is appreciated by the search engines, therefore we have to think how to make the page useful, if the page become long.
Then the sticky index is useful. It appears on the left side of the page.
As you scroll down the page, it marks current section of the page by bold styled font on the list. Therefore, you can recognize where you are reading.
It is especially useful when you come to the pages named anchor from a link, you can know what is written in the page by a glance. We can recognize next topics and previous topics soon.
And by clicking the link of the navigation, the page scrolls to the content's position.
This part is included in the default set of the CMS template. The template of main contents contains it.
This CMS can graphically set the template's component.
After that, by checking the scroll position, and mark up the list element which means current scroll position.