wagtail/client/scss/elements/_elements.scss

*,
::before,
::after {
  // Reset border styles so tailwinds default border class works as expected
  // https://tailwindcss.com/docs/preflight#border-styles-are-reset-globally
  border-width: 0;
  border-style: solid;
  // Set all elements to inherit their parent’s (border-box) box-sizing.
  box-sizing: inherit;
}

::before,
::after {
  --tw-content: '';
}

html {
  background: $color-grey-4;
  height: 100%;
  // Set the whole admin to border-box by default.
  box-sizing: border-box;
}

body {
  overflow-x: hidden;
  position: relative;

  &:after {
    content: '';
    position: fixed;
    transition: visibility 0s linear 0s, opacity 0.2s ease-out;
    background: theme('colors.white-50');
    width: 100%;
    height: 100%;
    top: 0;
    inset-inline-start: 0;
    z-index: 5;
    opacity: 0;
    visibility: hidden;
  }
}

hr {
  border: 1px solid $color-grey-4;
  border-width: 1px 0 0;
  margin: 1.5em 0;
}

// general image style
img {
  max-width: 100%;
  height: auto;
}