最近仿一个网站导航有三级的下拉菜单有两种样式（如下图）

<div class="navigation_main">
            <div class="navigationlist_depth1">
                <div class="navigationlist_depth1_item">
                    <a href='{SITE_URL}' target="_self" class='channel1 depth1name current'>首页</a>
                </div>
                {category module=share pid=0 num=10}
                {if $t.child}
                <div class="navigationlist_depth1_item">
                    <a href='{$t.url}' target="_self" class='channel144 depth1name '>{$t.name}</a>
                    {category module=share pid=$t.id return=t2}
                    {if $t2.child}
                    <!-- 三级导航样式 -->
                    <div class="navigationlist_depth3_wrap">
                        <ul class="navigationlist_depth3">
                            {category module=share pid=$t.id return=a2}
                            <li class="navigationlist_depth3_item">
                                <span class="Depth2Title">{$a2.name}</span>
                                {category module=share pid=$a2.id return=a3}
                                <a href="{$a3.url}" target="_self">
                                    <span class="title">{$a3.name}</span>
                                </a>
                                {/category}
                            </li>
                            {/category}
                        </ul>
                    </div>
                    {else}
                    <!-- 二级导航样式 -->
                    <div class="navigationlist_depth2_wrap">
                        <ul class="navigationlist_depth2">
                            {category module=share pid=$t.id return=b2}
                            <li class="navigationlist_depth2_item">
                                <a class="n1" href="{$b2.url}" target="_self">
                                    <div class="ChannelName">{$b2.name}</div>
                                    <div class="ChannelSContent"></div>
                                </a>
                            </li>
                            {/category}
                        </ul>
                    </div> {/category}
                    {/if}
                </div>
                {else}<div class="navigationlist_depth1_item">
                <a href='{$t.url}' target="_self" class='channel150 depth1name '>{$t.name}</a></div>
                {/if}
                {/category}