Cleanup spacing in code

[Malin-Malin]

I just received confirmation from the teachers that we are not supposed to update the API, so there was nothing for me to implement in this task. The student display already matches Figma.

What I did:
Reviewed and cleaned up the code.

[GustavBoe]

Hello Malin! A few, small things to be done before I can approve this PR! I´ve reviewed the mobile version as a width of 390px.

For Mobile

• Add the correct header.
• Check the placement and size of the arrows (maybe different font).
• Make sure that the H1 matches with the design (2 rows instead of 3)
• Decrease the spacing between h1,p and search bar.
• Lower the opacity on the placeholder text.
• Make sure that the elements included in the table are the correct ones.
• Make the arrows of the pagination match the ones in Figma.
• Increase border-width of the highlighted box.
• Change the color/opacity of the pagination boxes to match Figma.
• Decrease the size of the button.
• Add the footer image.

For desktop

• Add the header.
• Decrease the opacity of the placeholder.
• Increase the time of the hover-animation.
• Increase the spacing between search bar and table.
• Check the spacing between table headers.
• Ensure correct color of grey fields in the table (rgb 249X3)
• Ensure that the pagination matches Figma (arrows, color, etc.)
• Check the spacing between pagination and button.
• Add the footer image.