This PR is the solution to the 'terrarium' #<2>

[sunilswain7]

• What all did you learn?
• I learnt about building a static page and design it using css and work with dom objects to directly manipulate the page's components.
• Any difficulties that you faced, and how you solved it?
• I am not that comfortable with css so that made my brain red sometimes giving me some difficulties but hit and trial i did at the end.
• Did you have to learn anything new to do the assignments?
• Learnt new event handlers when creating my own event handler.
• Any thing else you would like to share about the topic?
• Nothing for now.

[sunilswain7]

@JATAYU000 kindly review this pull request