文本超出一定宽度显示省略号，鼠标移动上去之后显示完整内容

.ellipsis{
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    max-width: 200px; //自定义
}

.ellipsis:hover {
    cursor: pointer;
    text-overflow: inherit;
    overflow: visible;
    white-space: pre-line;
}