/* ── Nav ── */

/* Page header (sticky) */
.page-header {
  position: sticky;
  top: 0;
  background: var(--color-bg);
  padding: 14px 0 10px;
  margin-bottom: 28px;
  z-index: 100;
  isolation: isolate;
}
.page-header::after {
  content: "";
  position: absolute;
  left: -28px;
  right: -28px;
  top: 0;
  bottom: 0;
  background: var(--color-bg);
  z-index: -1;
}
.page-header-label {
  font-family: var(--font-display);
  font-size: var(--text-3xs);
  letter-spacing: 0.5px;
  color: var(--color-text-tertiary);
  margin-bottom: 2px;
}
.page-header-top-row {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 12px;
}
.page-header-top-row .breadcrumb-back,
.page-header-top-row .breadcrumb-context {
  margin-bottom: 0;
}
.page-header-top-row .breadcrumb-context {
  flex: 1 1 auto;
  min-width: 0;
}
.page-header-actions {
  margin-left: auto;
  flex-shrink: 0;
}
@media (max-width: 600px) {
  .page-header-top-row {
    display: block;
    margin-bottom: 0;
  }
  .page-header-top-row .breadcrumb-back {
    margin-bottom: 16px;
  }
  .page-header-top-row .breadcrumb-context {
    margin-bottom: 4px;
  }
  .page-header-actions {
    display: none;
  }
}
.page-header-title {
  font-family: var(--font-display);
  font-size: var(--text-display);
  font-weight: var(--weight-medium);
  text-transform: uppercase;
  letter-spacing: 2px;
  color: var(--color-charcoal);
  margin: 0;
  transition: opacity 0.25s ease, max-height 0.3s ease;
  max-height: 120px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* Collapsed header state — title hidden, page name appended to breadcrumb */
.page-header--collapsed .page-header-title {
  opacity: 0;
  max-height: 0;
  pointer-events: none;
}
.breadcrumb-page-name {
  font-family: var(--font-display);
  text-transform: uppercase;
  letter-spacing: 2px;
  color: var(--color-charcoal);
  display: inline-block;
  vertical-align: bottom;
  max-width: 0;
  opacity: 0;
  overflow: hidden;
  white-space: nowrap;
  transition: max-width 0.4s ease, opacity 0.3s ease;
  line-height: inherit;
  padding-left: 6px;
}
.page-header--collapsed .breadcrumb-page-name {
  max-width: min(300px, 40vw);
  opacity: 1;
  text-overflow: ellipsis;
}

/* Scroll fade — subtle gradient below sticky header */
.page-header--collapsed::before {
  content: "";
  position: absolute;
  left: -28px;
  right: -28px;
  top: 100%;
  height: 24px;
  background: linear-gradient(to bottom, var(--color-bg), transparent);
  pointer-events: none;
  z-index: 99;
  animation: fade-in 0.3s ease forwards;
}
@keyframes fade-in {
  from { opacity: 0; }
  to   { opacity: 1; }
}

/* Breadcrumb navigation */
.breadcrumb-back {
  display: inline-block;
  text-decoration: none;
  margin-bottom: 16px;
}
.breadcrumb-context {
  font-family: var(--font-display);
  font-size: var(--text-3xs);
  font-weight: var(--weight-semibold);
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--color-text-secondary);
  margin-bottom: 4px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}