1-1-1.登录表单样式

#phoneLabel{
  position: relative;
  display: block;
  .iconfont{
    position: absolute;
    top: 0.3em;
    left: 0.2em;
    font-size: 18px;
    color: #bbb;
    pointer-events: none;
   }
     #phone{
    font-weight: 400;
    text-indent: 1em;
    -webkit-appearance: none;
  }
}
<div class="form-group">
     <label for="phone" id="phoneLabel">
         <i class="iconfont">&#xe62d;</i>
         <input type="tel" class="form-control input-lg input-block" id="phone" name="phone" maxlength="11" placeholder="手机号" tabindex="1" required="" pattern="^(13[0-9]|14[57]|15[012356789]|17[0678]|18[0-9])\d{8}$" data-error="请输入正确的手机号">
     </label>
     <div class="help-block with-errors"></div>
</div>