Dashboard - Cryptocurrency Exchange

Reworked on the Cryptocurrency Dashboard I had prepared earlier. Made some tweaks:
- Put the 'Buy' and 'Sell' option on header to make it more prominent and visible
- The currencies for exchange are now displayed in a cleaner way on the left panel and a popup opens for changing the values
- The blue color has been removed from the non-link texts, so as to remove the confusion
- The top bar containing currency exchange information changes its gradient (red, green) as per the currency trends

Let me know your thoughts on this one!