.app-shell {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-3) var(--space-4);
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
}

.app-title {
  margin: 0;
  font-size: 1.15rem;
}

.app-header > a {
  display: inline-flex;
  align-items: center;
  min-height: var(--touch);
}

.app-main {
  flex: 1;
  width: min(44rem, 100%);
  margin: 0 auto;
  padding: var(--space-5) var(--space-4) 6rem;
}

.app-nav {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  display: flex;
  justify-content: space-around;
  gap: var(--space-1);
  padding: var(--space-2);
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
}

.app-nav a,
.side-nav a {
  min-height: var(--touch);
  min-width: var(--touch);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0 var(--space-3);
  text-decoration: none;
  color: var(--color-text);
  border-radius: var(--radius);
}

.app-nav a[aria-current="page"],
.side-nav a[aria-current="page"] {
  background: var(--color-surface-muted);
  font-weight: 600;
}

.side-nav {
  display: none;
}

.capture-slot,
.placeholder-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: var(--space-5);
  box-shadow: var(--shadow);
}

.kpi-secondary {
  margin-top: var(--space-5);
  color: var(--color-text-muted);
}

@media (min-width: 840px) {
  .app-shell {
    display: grid;
    grid-template-columns: 14rem 1fr;
    grid-template-rows: auto 1fr;
  }

  .app-header {
    grid-column: 1 / -1;
  }

  .side-nav {
    display: flex;
    flex-direction: column;
    align-items: stretch;
    padding: var(--space-4);
    border-right: 1px solid var(--color-border);
    background: var(--color-surface);
  }

  .app-nav {
    display: none;
  }

  .app-main {
    padding-bottom: var(--space-6);
  }
}