How to achieve cascading effect of elements in HTML?

Question

I wanted to make a custom tooltip for this element, but it's contained within a box that doesn't have enough room to display the tooltip, so it just gets cropped (actually I can scroll to It's showing because overflow is set to auto, but I want it to be visible without scrolling). Is there a way to make it display beyond the bounds? I've tried using z-index but that didn't work.

This is what I said:

.box {
  width: 100px;
  height: 100px;
  overflow: auto;
  border-style: solid;
  border-color: red;
}

.tooltip{
  padding-top: 20px;
  position: relative;
  display: inline-block;
}


.tooltip .tooltiptext {
  display: none;
  max-width: 60vw;
  min-width: 15vw;
  background-color: white;
  border-style: solid;
  border-color: #1a7bd9;
  position: absolute;
  z-index: 1000000;
}

.tooltip:hover .tooltiptext {
  display: block;
}

<div class='box'>
  <div class='tooltip'> Display tooltip on mouse hover
    <div class='tooltiptext'>
      Wow, this is awesome, this is an epic tooltip text
    </div>
  </div>
</div>

EDIT: The important thing is that hovering works on the element, not the box it's in.

Answer 1

One way to do this is to create a ::before pseudo-element above and next to the hovered text.

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

.box {
  width: 100px;
  height: 100px;
  padding-top: 20px;
  border-style: solid;
  border-color: red;
}

.tooltip {
  position: relative;
  display: inline-block;
}

.tooltip::before {
  content: "哇，这太棒了，这是一个史诗般的工具提示文本";
  position: absolute;
  left: 25%;
  bottom: -75%;
  display: none;
  width: 500px;
  background-color: white;
  border: 2px solid pink;
}

.tooltip:hover::before {
  display: flex;
}

<div class='box'>
  <div class='tooltip'>
    鼠标悬停查看工具提示
  </div>
</div>

Answer 2

There are many ways to do this, but if you just want the tooltip to be visible outside the container, you don't need to use z-index or overflow. You just need to move the tooltip into a positioning context inside the relative container.

Based on your comments, since you want the tooltip to only appear when hovering over the text, I would recommend that your relative container wrap exactly what you want to hover. To illustrate this, I added a border to the outer frame, compared to where you decide to use a relative container.

Then just change box:hover to relative-container:hover to target the correct element.

I tried to organize the HTML and class names to be more semantic and concise for illustration. Hope this helps!

Example

.box {
  padding: 30px;
  border: blue solid;
  width: 300px;
  display: flex;
  align-items: center;
}

.relative-container {
  position: relative;
}

.box-content {
  border-style: solid;
  border-color: red;
  padding: 10px;
}

.tooltip {
  position: absolute;
  left: 0;
  top: 0;
  max-width: 60vw;
  min-width: 15vw;
  background-color: white;
  border: #1a7bd9 solid;
  display: none;
}

.relative-container:hover .tooltip {
  display: block;
  cursor: pointer;
}

<div class='box'>
  <div class='relative-container'>
    <div class='box-content'>
      Hover for tooltip. I have a little padding to give the text some room.
    </div>
    <div class='tooltip'>
    Wow, this is amazing, such an epic tooltip text. I'm aligned with the top of the box content containing text and take up the full width. I only appear when hovering over the box content (red outline), not the surrounding container (blue outline).
    </div>
  </div>
</div>