Question

css点击按钮之后出现边框怎么去除

Answer 1

声明DOCTYPE后都没有outline这个东西
你先试下outline：none
不行用下面这个
filter:chroma(color=#000000);

Answer 2

input,button,select,textarea{outline:none;}

Answer 3

.btn:focus,
.btn:active:focus,
.btn.active:focus,
.btn.focus,
.btn:active.focus,
.btn.active.focus {
outline: none;
border-color: transparent;
box-shadow:none;
}