一.浮动布局
1.先让固定宽度的div浮动！使其脱离文档流。
2.margin-left的值等于固定div的宽度相等。
.aside{
float: left;
width: 200px;
background-color: red;
}
.content{
margin-left: 200px;
background-color: blue;
}<div class="aside">
Lorem ipsum dolor sit amet, consectetur adipisicing elit. Labore provident dolor in voluptatum tempore non, placeat obcaecati totam ut delectus libero excepturi distinctio asperiores odit nobis soluta, esse aspernatur beatae.
</div>
<div class="content">
Lorem ipsum dolor sit amet, consectetur adipisicing elit. Labore provident dolor in voluptatum tempore non, placeat obcaecati totam ut delectus libero excepturi distinctio asperiores odit nobis soluta, esse aspernatur beatae.
</div>
二.margin的负值(3个div)
是固定宽度的div脱离文档流。
利用marin负值可以使得，后面的div可以与前面的div 保持同行显示。
给包裹内容的div加margin-left 可以使得与左边的文字不重叠
.aside{
float: left;
margin-right: -200px;
width: 200px;
background-color: red;
}
.content{
float: right;
}
.content .inner{
margin-left: 200px;
background-color: blue;
}
<div class="aside">
Lorem ipsum dolor sit amet, consectetur adipisicing elit. Labore provident dolor in voluptatum tempore non, placeat obcaecati totam ut delectus libero excepturi distinctio asperiores odit nobis soluta, esse aspernatur beatae.
</div>
<div class="content">
<div class="inner">
Lorem ipsum dolor sit amet, consectetur adipisicing elit. Mollitia labore facere delectus quaerat expedita, tenetur recusandae tempora eos natus suscipit voluptatum necessitatibus soluta voluptates modi ullam. Ab minima similique, illum!
</div>
</div>三.calc()计算属性
注意：使用calc计算属性的时候 运算符(- +等等)两边必须有空格
注意两个div必须一左一右浮动。
calc的宽度必须要减去的宽度要与固定宽度保持一致。
.aside{float: left;
width: 200px;
}
.content{
float: right;
calc:(100% - 200px);
}
<div class="aside">
Lorem ipsum dolor sit amet, consectetur adipisicing elit. Labore provident dolor in voluptatum tempore non, placeat obcaecati totam ut delectus libero excepturi distinctio asperiores odit nobis soluta, esse aspernatur beatae.
</div>
<div class="content">
Lorem ipsum dolor sit amet, consectetur adipisicing elit. Labore provident dolor in voluptatum tempore non, placeat obcaecati totam ut delectus libero excepturi distinctio asperiores odit nobis soluta, esse aspernatur beatae.
