site/src/scss/_masthead.scss

.bd-masthead {
  --bd-pink-rgb: #{to-rgb($pink)};
  padding: 3rem 0;
  // stylelint-disable
  background-image: linear-gradient(180deg, rgba(var(--bs-body-bg-rgb), .01), rgba(var(--bs-body-bg-rgb), 1) 85%),
                    radial-gradient(ellipse at top left, rgba(var(--bs-primary-rgb), .5), transparent 50%),
                    radial-gradient(ellipse at top right, rgba(var(--bd-accent-rgb), .5), transparent 50%),
                    radial-gradient(ellipse at center right, rgba(var(--bd-violet-rgb), .5), transparent 50%),
                    radial-gradient(ellipse at center left, rgba(var(--bd-pink-rgb), .5), transparent 50%);
  // stylelint-enable

  h1 {
    --bs-heading-color: var(--bs-emphasis-color);
    @include font-size(4rem);
  }

  .lead {
    @include font-size(1rem);
    font-weight: 400;
    color: var(--bs-secondary-color);
  }

  .bd-code-snippet {
    margin: 0;
    border-color: var(--bs-border-color-translucent);
    border-width: 1px;
    @include border-radius(.5rem);
  }

  .highlight {
    width: 100%;
    padding: .5rem 1rem;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    background-color: rgba(var(--bs-body-color-rgb), .075);
    @include border-radius(calc(.5rem - 1px));

    @include media-breakpoint-up(lg) {
      padding-right: 4rem;
    }

    pre {
      padding: 0;
      margin: .625rem 0;
      overflow: hidden;
    }
  }
  .btn-clipboard {
    position: absolute;
    top: -.625rem;
    right: 0;
    background-color: transparent;
  }

  #carbonads { // stylelint-disable-line selector-max-id
    margin-inline: auto;
  }

  @include media-breakpoint-up(md) {
    .lead {
      @include font-size(1.5rem);
    }
  }
}

.masthead-followup {
  h2,
  h3,
  h4 {
    --bs-heading-color: var(--bs-emphasis-color);
  }

  .lead {
    @include font-size(1rem);
  }

  @include media-breakpoint-up(md) {
    .lead {
      @include font-size(1.25rem);
    }
  }
}

.masthead-followup-icon {
  padding: 1rem;
  color: rgba(var(--bg-rgb), 1);
  background-color: rgba(var(--bg-rgb), .1);
  background-blend-mode: multiply;
  @include border-radius(1rem);
  mix-blend-mode: darken;

  svg {
    filter: drop-shadow(0 1px 1px var(--bs-body-bg));
  }
}

.masthead-notice {
  background-color: var(--bd-accent);
  box-shadow: inset 0 -1px 1px rgba(var(--bs-body-color-rgb), .15), 0 .25rem 1.5rem rgba(var(--bs-body-bg-rgb), .75);
}

.animate-img {
  > img {
    @include transition(transform .2s ease-in-out);
  }

  &:hover > img {
    transform: scale(1.1);
  }

  &:active > img {
    transform: scale(1);
  }
}

@if $enable-dark-mode {
  [data-bs-theme="dark"] {
    .masthead-followup-icon {
      mix-blend-mode: lighten;
    }
  }
}