$sidebar-width: 220px;
$content-width: 720px;
$gap-width: 20px;
.container {
width: 220px+780px+20px;
margin: 0 auto;
}
.container{
width:$sidebar-width+$content-width+$gap-width;
}
.container {
width: 1020px;
margin: 0 auto; }
.container {
width: 960px; }
你变量写的220px 720px 20px 下面的运算中间你写的780px···················
你二啊????你自己写错了好吧·····