固定的盒子需要绝对定位才能实现以下效果，希望有不需要绝对定位实现以下方法的大神！求指点
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问题有点模糊，如果是要求A+B等于outer的高度，可以用
calc(100% - 100px);浮动 固定定位
你的问的不太明白啊，能说的具体点吗？