Daily UI 004: Calculator

Daily UI Challenge 004: Calculator
(1) History: show operation history to avoid repetitively operate on the same problem; Easy to track and erase history.
(2) Currency: Real-time currency conversion.
(3) Interactive buttons

HEX Colours:
Turquoise #36d7b7
Bright Turquoise #29f1c3
Aqua Island #a2ded0
Tall poppy #c0392b
Thunderbird #f64747