常用状态伪类演示

{
fieldset :focus {
background-color: lightgreen;
transition: 0.4s;
}

input[type=’checkbox’]:checked + label{
color: red;
}

button :hover {
cursor: pointer;
opacity: 0.8s;

}

input:default {
box-shadow: 0 0 5px 5px coral;
}

}