纯css生成+、-

.c1{

  border: 1px solid #6699cc;/*标准.net色 #6699cc*/

  width: 9px;

  height: 9px;

  margin-right:3px;

  color: #ccc;

  transition: color .25s;

  position: relative;

  border-radius:2px;

  display:inline-block;

}

.c1:before{

  content: '';

  position: absolute;

  left: 1px;

  top: 4px;

  width: 7px;

  height:1px;

  background-color:#333;

}

.c1:after{

 content: '';

 position: absolute;

 left: 4px;

 top: 1px;

 height: 7px;

 width:1px;

 background-color:#333;

}

.c1after{

  border: 1px solid #6699cc;

  width: 9px;

  height: 9px;

  margin-right:3px;

  color: #ccc;

  transition: color .25s;

  position: relative;

  border-radius:2px;

  display:inline-block;

}

.c1after:after{

  content: '';

  position: absolute;

  left: 1px;

  top: 4px;

  width: 7px;

  height:1px;

  background-color:#333;

}

生成的加号、减号：