1、span直接一行

<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8" />
        <title></title>
        <style type="text/css">
            span{
                background-color: red;
            }
        </style>
    </head>
    <body>
            <span>1</span><span>2</span>
    </body>
</html>

2、float浮动

<style type="text/css">
            span{
                background-color: red;
                float: left;
            }
        </style>
    </head>
    <body>
            <span>1</span>
            <span>2</span>
    </body>

3、父级元素添加font-size:0;子集元素font-size:自己根据效果添加数值

<style type="text/css">
            .div{
                font-size: 0px;
            }
            span{
                font-size: 12px;
            }
        </style>
    </head>
    <body>
        <div class="div">
            <span>1</span>
            <span>2</span>
        </div>
    </body>

4、由于内层border和外层border引起的空隙

border-right:根据效果自己调整数值

12-21 21:04