Https://www.codecademy.com/practice/projects/independent-project-html-documentation

https://www.codecademy.com/practice/projects/independent-project-html-documentation.
I am unable to link HTML and CSS sheet. I have written following code in HTML
under Head element
image

In CSS sheet I am writing
h1{color:red;}
But the effects are not coming in preview window.

there is a huge difference between / and ./, using a slash only means root directory, while . is current working directory. the value of href attribute points to where the css file is located

Thanks !!
Its done now.