:root {
  --feat-aspect: 2;
  --nav-height: 60px;
}

#site {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  > main {
    flex: 1 1 auto;
    height: auto;
  }
}

.trademark-banner {
  height: 40px;
  background: gray;
}

.site-header, .site-footer {
  flex: 0 1 auto;
  min-height: max-content;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 1;
}

.site-nav {
  height: var(--nav-height);
  background-color: lightblue;
}