Pretty text underline

A nicer alternative to text-decoration: underline or <u></u> where descenders do not clip the underline. Natively implemented as text-decoration-skip-ink: auto but it has less control over the underline.

<p class="pretty-text-underline">Pretty text underline without clipping descending letters.</p>

.pretty-text-underline {
  display: inline;
  text-shadow: 1px 1px #f5f6f9, -1px 1px #f5f6f9, -1px -1px #f5f6f9, 1px -1px #f5f6f9;
  background-image: linear-gradient(90deg, currentColor 100%, transparent 100%);
  background-position: bottom;
  background-repeat: no-repeat;
  background-size: 100% 1px;
}
.pretty-text-underline::-moz-selection {
  background-color: rgba(0, 150, 255, 0.3);
  text-shadow: none;
}
.pretty-text-underline::selection {
  background-color: rgba(0, 150, 255, 0.3);
  text-shadow: none;
}

Explanation

text-shadow uses 4 values with offsets that cover a 4x4 px area to ensure the underline has a “thick” shadow that covers the line where descenders clip it. Use a color that matches the background. For a larger font, use a larger px size. Additional values can create an even thicker shadow, and subpixel values can also be used.
background-image: linear-gradient(...) creates a 90deg gradient using the text color (currentColor).
The background-* properties size the gradient as 100% of the width of the block and 1px in height at the bottom and disables repetition, which creates a 1px underline beneath the text.
The ::selection pseudo selector rule ensures the text shadow does not interfere with text selection.