Fix css focus
When you click on/select a cell, the cell is considered as a ":focus" element. When an element is focused, we want it to be highlighted. But it works only at the first time, when you click for the first time on a cell. We also wanted to display cell containing a wrong value with an other color.
Problem:
The problem comes from the way we display cell with error. Previously, when we are checking if there are wrong values, we set all cells with white background and then we set the cell with another background color when we detect an error. The problem is that when we set the color of the cell manually, it overwrite the :focus style property.
Solution:
The solution is to change the way we modify the background color of a cell. We should add new css class for cells with wrong values. When we detect a cell with an error, we add the new className to the cell instead of directly modifying the cell color.