wiki/_sass/_header.scss

// ヘッダ
header {
  background: $header-background;
  box-sizing: border-box;
  font-weight: bold;
  padding: 1em;

  @include media-mobile {
    box-shadow: $header-mobile-box-shadow;
    position: fixed;
    width: 100%;
    z-index: 9999;
  }

  a {
    text-decoration: none;

    &:link,
    &:visited,
    &:hover,
    &:focus,
    &:active {
      color: $header-link-color;
    }

    > amp-img {
      float: left;
      margin: $header-img-vertical-adjustment 1em 0 0;
    }
  }

  button {
    background: transparent;
    border: none;
    float: right;
    object-fit: contain;
    padding: 0 1em;

    @include media-desktop {
      display: none;
    }
  }
}