想要实现如下效果：

当点击右边的其中一栏时，增加选中效果，如图：

部分代码:`<p id="pic-right">

                <p class="right" id="right1">
                    <p class="pic1">PIC</p>
                    <p class="jieshao">
                        <h3>TITLE OF HIGHLIGHT</h3>
                        <h4>Short descriptions of the highlight on the left.</h4>
                    </p>
                    <p class="xiajiao">
                        <img src="images/xiajiao.png">
                    </p>
                </p>
                <p class="right" id="right2">
                    <p class="pic1">PIC</p>
                    <p class="jieshao">
                        <h3>TITLE OF HIGHLIGHT</h3>
                        <h4>Short descriptions of the highlight on the left.</h4>

                    </p>
                    <p class="xiajiao">
                        <img src="images/xiajiao.png">
                    </p>
                </p>
                <p class="right" id="right3">
                    <p class="pic1">PIC</p>
                    <p class="jieshao">
                        <h3>TITLE OF HIGHLIGHT</h3>
                        <h4>Short descriptions of the highlight on the left.</h4>

                    </p>
                    <p class="xiajiao">
                        <img src="images/xiajiao.png">
                    </p>
                </p>
            </p>`