How text-align achieves alignment at both ends

<p>
        <p class="item">
            <label for="name" class="itemLabel">姓名</label>
            <input type="text" class="itemContent" id="name">
            
        </p>
        <p class="item">
            <label for="phone" class="itemLabel">手机号</label>
            <input type="text" class="itemContent" id="phone">
        </p>
        
 </p>

 .itemLabel{
            display: inline-block;
            width: 60px;
            text-align-last:justify;
    }

        .item{
            position: relative;
        }
        .itemContent{
            position: absolute;
            left:70px;
        }
        .itemLabel{
            display: inline-block;
            width: 60px;
            text-align: justify;
        }
       .itemLabel:after{
            display: inline-block ;
            content: ''; 
            width: 100%;
        }