.app-header {
  --app-header-background: var(--color-surface);
  --app-header-border: var(--color-border);
  width: 100%;
  max-width: var(--app-max-width);
  height: var(--header-height);
  margin-inline: auto;
  position: relative;
  background: var(--app-header-background);
  color: var(--color-text-primary);
  transition: background-color var(--duration-standard), border-color var(--duration-standard), color var(--duration-standard);
}

.app-header::after {
  position: absolute;
  inset-inline: 0;
  inset-block-end: 0;
  height: var(--control-border-width);
  background: var(--app-header-border);
  content: '';
  pointer-events: none;
}

.app-header--sticky {
  position: sticky;
  inset-block-start: 0;
  z-index: var(--z-index-sticky-header);
}

.app-header--transparent {
  --app-header-background: transparent;
  --app-header-border: transparent;
}

.app-header__bar {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  width: 100%;
  min-width: 0;
  height: 100%;
  padding-inline: max(var(--page-padding-inline), var(--safe-area-left)) max(var(--page-padding-inline), var(--safe-area-right));
}

.app-header__actions {
  display: flex;
  align-items: center;
  min-width: 0;
  gap: var(--space-1);
}

.app-header__actions--left {
  justify-content: flex-start;
}

.app-header__actions--right {
  justify-content: flex-end;
}

.app-header__action-spacer {
  flex: 0 0 var(--touch-target-size);
  width: var(--touch-target-size);
  height: var(--touch-target-size);
}

.app-header__title-area {
  min-width: 0;
  padding-inline: var(--space-2);
  text-align: center;
}

.app-header__title {
  overflow: hidden;
  color: var(--color-text-primary);
  font-size: var(--font-size-control-lg);
  font-weight: var(--font-weight-control);
  line-height: 1.2;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.app-header__meta {
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 0;
  gap: var(--space-2);
  margin-block-start: var(--space-1);
  color: var(--color-text-secondary);
  font-size: var(--font-size-control-sm);
  line-height: 1;
}

.app-header__subtitle {
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.app-header__step {
  flex: 0 0 auto;
  white-space: nowrap;
}

.app-header--tabs .app-header__bar {
  grid-template-columns: minmax(0, 1fr);
  padding-inline: var(--safe-area-left) var(--safe-area-right);
}

.app-header--tabs .app-header__actions,
.app-header--tabs .app-header__title-area {
  display: none;
}

.app-header__tabs {
  min-width: 0;
  width: 100%;
  height: 100%;
}

.app-header__tabs[hidden] {
  display: none;
}

.app-header__tabs-list {
  display: grid;
  grid-template-columns: repeat(var(--app-header-tab-count, 2), minmax(0, 1fr));
  align-items: stretch;
  width: 100%;
  height: 100%;
  min-width: 0;
}

.app-header__tab {
  position: relative;
  display: grid;
  place-items: center;
  width: 100%;
  min-width: 0;
  height: 100%;
  min-height: var(--touch-target-size);
  padding-inline: var(--space-2);
  color: var(--color-text-secondary);
  font-size: var(--font-size-control-lg);
  font-weight: var(--font-weight-control);
  line-height: 1.2;
  text-align: center;
  text-decoration: none;
}

.app-header__tab:focus-visible {
  outline: var(--control-focus-width) solid var(--color-control-focus);
  outline-offset: calc(-1 * var(--control-focus-width));
}

.app-header__tab--active {
  color: var(--color-text-primary);
}

.app-header__tab--active::after {
  position: absolute;
  inset-inline: var(--space-4);
  inset-block-end: 0;
  height: var(--space-1);
  border-radius: var(--radius-sm);
  background: currentColor;
  content: '';
  pointer-events: none;
}