What is the CSS underline glow effect?

The CSS underline glow effect is a visual enhancement applied to text underlines, making them appear to emit a soft, luminous glow. This effect is achieved using CSS properties like box-shadow, text-shadow, and sometimes pseudo-elements like ::before or ::after. It adds a subtle yet eye-catching highlight to links or emphasized text, improving the user experience by drawing attention to interactive or important elements.

Here's a breakdown of how it's typically implemented:

1. Using `box-shadow`:

- The box-shadow property can be used to create a glow effect around the text. By setting a blur radius and a color, you can simulate a soft glow. This method is often used in conjunction with a text-decoration underline.

2. Using `text-shadow`:

- The text-shadow property can also be used to create a glow effect around the text. This method is more suitable for creating a glow around the text itself, but can be combined with a text-decoration underline to achieve a glow effect around the underline.

3. Using Pseudo-elements:

- Pseudo-elements like ::before or ::after can be used to create a separate element that acts as the underline. This allows for more control over the underline's appearance, including the glow effect. You can then apply a box-shadow or text-shadow to this pseudo-element.

4. Example Code using `box-shadow`:

.glow-underline {
  text-decoration: underline;
  text-decoration-color: transparent; / Make the default underline transparent /
  box-shadow: inset 0 -0.2em 0 rgba(0, 123, 255, 0.5), 0 0 0.5em rgba(0, 123, 255, 0.3); / Glow effect /
  transition: box-shadow 0.3s ease; / Smooth transition /
}

.glow-underline:hover {
  box-shadow: inset 0 -0.2em 0 rgba(0, 123, 255, 0.8), 0 0 0.8em rgba(0, 123, 255, 0.5); / Stronger glow on hover /
}

5. Example Code using Pseudo-elements:

.glow-underline-pseudo {
  position: relative;
  display: inline-block;
}

.glow-underline-pseudo::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -0.2em; / Adjust position /
  width: 100%;
  height: 0.1em; / Adjust thickness /
  background-color: rgba(0, 123, 255, 0.5); / Underline color /
  box-shadow: 0 0 0.5em rgba(0, 123, 255, 0.3); / Glow effect /
  transition: box-shadow 0.3s ease;
}

.glow-underline-pseudo:hover::after {
  box-shadow: 0 0 0.8em rgba(0, 123, 255, 0.5); / Stronger glow on hover /
}

The CSS underline glow effect is a versatile technique that can be customized to match the design of your website. It's important to use it judiciously to avoid overwhelming the user with too many glowing elements.

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