.page-shell {
  display: grid;
  grid-template-areas:
    "header header"
    "main   main"
    "footer footer";
  grid-template-rows: auto 1fr auto;
  min-height: 100vh;
}
.page-shell-header { grid-area: header; }
.page-shell-footer { grid-area: footer; }
.page-shell-body {
  grid-area: main;
  display: block;
}
.info-sidebar {
  padding: 3vh 5vw;
  background: var(--color-bg-alt);
  border-bottom: 1px solid var(--color-border);
}
.page-shell-main {
  display: block;
}
.page-content {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 5vw;
}

@media (min-width: 900px) {
  .page-shell-body {
    display: grid;
    grid-template-columns: 260px 1fr;
    align-items: start;
    gap: 0;
  }
  .info-sidebar {
    border-bottom: none;
    border-right: 1px solid var(--color-border);
    min-height: 100%;
    position: sticky;
    top: 0;
  }
}


.content-area {
  padding: 5vh 0 8vh;
}
.content-area:nth-child(odd) {
  padding: 5vh 0 8vh;
}
.content-area:nth-child(even) {
  padding: 8vh 0 5vh;
}
.content-area .page-content {
  padding-left: max(5vw, 1rem);
  padding-right: max(3vw, 1rem);
}

.container-narrow {
  max-width: 760px;
  margin: 0 auto;
}


.area-divider {
  position: relative;
  height: 9vh;
  min-height: 60px;
  overflow: hidden;
}
.area-divider .m {
  position: absolute;
  inset: 0;
  clip-path: polygon(0 100%, 25% 40%, 55% 80%, 80% 30%, 100% 70%, 100% 100%);
}
.area-divider .m1 { background: rgba(190, 18, 60, 0.12); }
.area-divider .m2 { background: rgba(190, 18, 60, 0.22); transform: translateY(12px); }