如三条绿的变成三条白的 ~~~ <button type="button" class="navbar-toggle" data-toggle="collapse" data-target="#collapse"> <span class="sr-only">toggle</span> <span class="icon-bar"></span> <span class="icon-bar"></span> <span class="icon-bar"></span> </button> ~~~ 主要样式 ~~~ .navbar-toggle:hover .icon-bar{ background:white; } ~~~ 2 兄弟元素hover ~~~ <div class="one"></div> <div class="two"></div> one:hover+two{}; ~~~