I decrease opacity of <ul> when mouse over the <ul> tag area and then set full opacity for <li> which user is on that.
like this sample: Image change opacity on hover without jQuery
now, the problem is in tablet and phones, because on touch devices we don't have hover event and user should click (touch) on <li> so all another <li> will decrease the opacity and user cannot unselect (unhover) that <li> so they should refresh the page.
How can I solve this problem?