效果示例

代码实现
<!DOCTYPE html>
<html><head><meta charset="utf-8"><title>一颗不甘坠落的流星</title><style>body {padding: 120px;}.tooltip {position: relative;display: inline-block;border-bottom: 1px dotted black;cursor: pointer;}.tooltip .tooltiptext {visibility: hidden;background-color: black;color: #fff;text-align: center;border-radius: 6px;padding: 5px 0;position: absolute;z-index: 1;opacity: 0.8;}.tooltip .tooltiptext::after {content: "";position: absolute;border-width: 5px;border-style: solid;}.tooltip:hover .tooltiptext {visibility: visible;}#top .tooltiptext {width: 120px;bottom: 100%;left: 50%;margin-left: -60px;}#top .tooltiptext::after {top: 100%;left: 50%;margin-left: -5px;border-color: black transparent transparent transparent;}#bottom .tooltiptext {width: 120px;top: 100%;left: 50%;margin-left: -60px;}#bottom .tooltiptext::after {bottom: 100%;left: 50%;margin-left: -5px;border-color: transparent transparent black transparent;}#left .tooltiptext {width: 120px;top: -5px;right: 105%;}#left .tooltiptext::after {top: 50%;left: 100%;margin-top: -5px;border-color: transparent transparent transparent black;}#right .tooltiptext {width: 120px;top: -5px;left: 105%;}#right .tooltiptext::after {top: 50%;right: 100%;margin-top: -5px;border-color: transparent black transparent transparent;}</style><body><div class="tooltip" id="top"><span>上悬浮展示</span><span class="tooltiptext">Tooltip text</span></div><div class="tooltip" id="bottom"><span>下悬浮展示</span><span class="tooltiptext">Tooltip text</span></div><div class="tooltip" id="left"><span>左悬浮展示</span><span class="tooltiptext">Tooltip text</span></div><div class="tooltip" id="right"><span>右悬浮展示</span><span class="tooltiptext">Tooltip text</span></div></body><script type="text/javascript"></script>
</html>
