点击某一事件让其改变 style，但让其他区域恢复原本 style，求思路

<div class="exp-about exp-left-block">
     <p class="exp-left-pagh">声明与条款</p>
    <div class="exp-over-upright"></div>
</div>

<div class="exp-change-log exp-left-block">
     <p class="exp-left-pagh">更改日志</p>
     <div class="exp-over-upright"></div>
</div>

<div class="exp-other exp-left-block">
     <p class="exp-left-pagh">赞助商</p>
     <div class="exp-over-upright"></div>
</div>

function add3Events(){
  for (var i=0; i < bar_list.length; i++) {
    bar_list[i].onclick = function(num) {

        return function() {
         // 点击改变 css
          this.getElementsByTagName('div')[0].style.display = 'block';
          this.style.backgroundColor = '#00A2CA';
          this.style.color = '#ffffff';

         // 其他 div 恢复默认 css
          [].forEach.call(bar_list, function(ele, index, arr) {
            if (index == num) return;
            ele.getElementsByTagName('div')[0].style.display = 'none';
            ele.style.backgroundColor = '#F4F4F4';
            ele.style.color = '#333333';
          });
        };

     }(i);

  }
}