changed the design of theme toggle button, made some ui changes in card, footer and fixed spacing between gallery and search bar.

These are the changes that I have made:

Added a new design for the theme toggle button
The footer was not sticking to the bottom perfectly, so fixed it
I have added some spacing between the search bar and gallery to improve its UI.
The contribution on the book cards will always show on the bottom left side of the card before it was getting placed according to the description height.

Here are the screenshot and video for the changes:

vishaaal / BookCase