Pure CSS Tooltip

This snippet delivers a highly performant, accessible tooltip component built exclusively with HTML and CSS. It features a buttery-smooth fade and float animation, elegantly positioning itself above the target element upon hover.

Preview

Implementation Code

Copy the code below and drop it directly into your project.

<!-- index.html -->
<div class="tooltip-wrapper">
  <button class="tooltip-trigger">Hover me</button>
  <div class="tooltip-content">
    This is a pure CSS tooltip!
  </div>
</div>

/* styles.css */
.tooltip-wrapper {
  position: relative;
  display: inline-block;
}

.tooltip-trigger {
  padding: 10px 20px;
  border-radius: 8px;
  border: none;
  background-color: #3b82f6;
  color: #fff;
  cursor: pointer;
  font-weight: bold;
  transition: background-color 0.2s;
}

.tooltip-trigger:hover {
  background-color: #2563eb;
}

.tooltip-content {
  position: absolute;
  bottom: 130%;
  left: 50%;
  transform: translateX(-50%) translateY(10px);
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
  background-color: #1f2937;
  color: #fff;
  padding: 8px 12px;
  border-radius: 6px;
  font-size: 14px;
  white-space: nowrap;
  z-index: 10;
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
}

/* Downward triangle (arrow) */
.tooltip-content::after {
  content: "";
  position: absolute;
  top: 100%;
  left: 50%;
  margin-left: -6px;
  border-width: 6px;
  border-style: solid;
  border-color: #1f2937 transparent transparent transparent;
}

/* Hover behavior */
.tooltip-wrapper:hover .tooltip-content {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
}

Explanation

Positioning (relative & absolute): By applying position: relative to the .tooltip-wrapper, the child tooltip body (.tooltip-content) can be precisely anchored using position: absolute.
Visibility vs. Display: Because CSS transition properties ignore display: none, this implementation relies on a combination of visibility: hidden and opacity: 0 to manage the hidden state while still allowing for smooth fade-in animations.
Fluid Animation: The satisfying “float-up” effect is achieved by offsetting the tooltip slightly on the Y-axis (translateY(10px)) and animating it to its natural position (translateY(0)) alongside the opacity change when hovered.
CSS Triangle Indicator: The speech-bubble arrow (or tail) is ingeniously constructed using the .tooltip-content::after pseudo-element and transparent CSS borders.