.article-filters {
  position: fixed;
  z-index: 10;
  isolation: isolate;
  right: calc(clamp(1rem, 3vw, 2rem) + env(safe-area-inset-right, 0px));
  bottom: calc(clamp(1rem, 3vw, 2rem) + env(safe-area-inset-bottom, 0px));
  display: flex;
  align-items: center;
  justify-content: flex-end;
  flex-wrap: wrap;
  gap: 0.45rem 0.55rem;
  max-width: calc(100% - (2 * (clamp(1rem, 3vw, 2rem) + env(safe-area-inset-right, 0px))));
  margin: 0;
  padding: 0.55rem;
  border: 1px solid color-mix(in srgb, white 70%, transparent);
  border-radius: 999px;
  color: var(--ink);
  background: color-mix(in srgb, white 12%, transparent);
  box-shadow:
    inset 0 1px 1px color-mix(in srgb, white 82%, transparent),
    inset 0 -0.5px 0 color-mix(in srgb, var(--ink) 10%, transparent),
    0 10px 32px color-mix(in srgb, var(--ink) 12%, transparent);
  -webkit-backdrop-filter: blur(2rem) saturate(200%);
  backdrop-filter: blur(2rem) saturate(200%);
  zoom: 0.8;
}

.article-filters::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  border-radius: inherit;
  background: linear-gradient(
    165deg,
    color-mix(in srgb, white 28%, transparent) 0%,
    color-mix(in srgb, white 6%, transparent) 40%,
    transparent 64%
  );
  pointer-events: none;
}

.article-filters > * {
  position: relative;
  z-index: 1;
}

.article-filters[hidden] {
  display: none;
}

.articles [hidden] {
  display: none;
}

body:has(.article-filters:not([hidden])) main {
  padding-bottom: max(8rem, calc(var(--article-filters-height, 6.5rem) + 2.5rem + env(safe-area-inset-bottom, 0px)));
}

.level-filter,
.content-type-filter {
  position: relative;
  isolation: isolate;
  display: inline-flex;
  gap: 0.25rem;
  max-width: 100%;
  padding: 0.25rem;
  border: 1px solid color-mix(in srgb, var(--ink) 8%, transparent);
  border-radius: 999px;
  background: color-mix(in srgb, var(--ink) 4%, transparent);
}

.level-filter::before,
.content-type-filter::before {
  content: "";
  position: absolute;
  z-index: 0;
  top: var(--filter-indicator-top, 0.25rem);
  left: var(--filter-indicator-left, 0.25rem);
  width: var(--filter-indicator-width, 0);
  height: var(--filter-indicator-height, calc(100% - 0.5rem));
  border-radius: 999px;
  background: var(--accent-deep, var(--theme-green));
  pointer-events: none;
}

.level-filter.is-animated::before,
.content-type-filter.is-animated::before {
  transition:
    left 280ms cubic-bezier(0.22, 1, 0.36, 1),
    width 280ms cubic-bezier(0.22, 1, 0.36, 1),
    top 280ms cubic-bezier(0.22, 1, 0.36, 1),
    height 280ms cubic-bezier(0.22, 1, 0.36, 1);
}

.level-filter__button {
  position: relative;
  z-index: 1;
  min-height: 2.75rem;
  padding: 0.5rem 1rem;
  border: 0;
  border-radius: 999px;
  color: var(--ink);
  background: transparent;
  font: inherit;
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  touch-action: manipulation;
  transition: color 220ms ease, background-color 160ms ease;
}

.level-filter__button:hover:not([aria-pressed="true"]) {
  background: color-mix(in srgb, var(--ink) 7%, transparent);
}

.level-filter__button[aria-pressed="true"] {
  color: var(--theme-on-accent);
  background: transparent;
}

.level-filter__button:focus-visible {
  outline: 3px solid var(--theme-focus);
  outline-offset: 0.125rem;
}

.content-type-filter {
  gap: 0.125rem;
}

.content-type-filter .level-filter__button {
  padding-inline: 0.625rem;
  white-space: nowrap;
}

.content-type-filter .content-type-filter__icon-button {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.75rem;
  flex-shrink: 0;
  padding: 0;
}

.content-type-filter__icon-button svg {
  width: 1.375rem;
  height: 1.375rem;
}

.article-filters .theme-toggle {
  position: relative;
  flex: 0 0 44px;
  align-self: center;
  width: 44px;
  height: 44px;
  min-height: 44px;
  margin-inline-start: 0.15rem;
  border: 0;
  background: transparent;
  box-shadow: none;
}

.article-filters .theme-toggle::before {
  content: "";
  position: absolute;
  top: 20%;
  bottom: 20%;
  left: -0.35rem;
  width: 1px;
  background: color-mix(in srgb, var(--ink) 16%, transparent);
}

.article-filters .theme-toggle:hover {
  background: color-mix(in srgb, var(--ink) 7%, transparent);
}

.article-filters .theme-toggle:active {
  background: var(--theme-selected);
}

:root[data-theme="dark"] .article-filters {
  border-color: color-mix(in srgb, white 22%, transparent);
  background: color-mix(in srgb, var(--theme-raised) 16%, transparent);
  box-shadow:
    inset 0 1px 1px color-mix(in srgb, white 18%, transparent),
    inset 0 -0.5px 0 color-mix(in srgb, black 40%, transparent),
    0 10px 32px rgba(0, 0, 0, 0.42);
}

:root[data-theme="dark"] .article-filters::before {
  background: linear-gradient(
    165deg,
    color-mix(in srgb, white 16%, transparent) 0%,
    color-mix(in srgb, white 4%, transparent) 36%,
    transparent 62%
  );
}

:root[data-theme="dark"] .level-filter,
:root[data-theme="dark"] .content-type-filter {
  border-color: color-mix(in srgb, white 12%, transparent);
  background: color-mix(in srgb, white 5%, transparent);
}

.filter-tooltip {
  position: absolute;
  z-index: 2;
  bottom: calc(100% + 0.5rem);
  left: 50%;
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--line);
  border-radius: 0.5rem;
  color: var(--ink);
  background: var(--card);
  box-shadow: var(--shadow-hover);
  font-size: 0.8125rem;
  font-weight: 500;
  line-height: 1.4;
  white-space: nowrap;
  visibility: hidden;
  opacity: 0;
  transform: translateX(-50%);
  pointer-events: none;
}

.level-filter__button:is(:hover, :focus-visible) .filter-tooltip {
  visibility: visible;
  opacity: 1;
}

.filter-empty {
  margin: 0;
  padding: 1.5rem;
  border: 1px solid var(--line);
  border-radius: 0.75rem;
  color: var(--ink-soft);
  background: var(--card);
}

@media (max-width: 40rem) {
  .article-filters {
    right: calc(0.75rem + env(safe-area-inset-right, 0px));
    bottom: calc(0.75rem + env(safe-area-inset-bottom, 0px));
    left: calc(0.75rem + env(safe-area-inset-left, 0px));
    max-width: none;
    border-radius: 1.15rem;
    justify-content: space-between;
  }

  /* With the theme switch inside, the panel becomes a full-width bar docked
     to the bottom edge, matching the reading controls on content pages. */
  .article-filters--with-theme {
    right: 0;
    bottom: 0;
    left: 0;
    padding-right: max(0.55rem, env(safe-area-inset-right, 0px));
    padding-bottom: max(0.55rem, env(safe-area-inset-bottom, 0px));
    padding-left: max(0.55rem, env(safe-area-inset-left, 0px));
    border-right: 0;
    border-bottom: 0;
    border-left: 0;
    border-radius: 0;
  }

  body:has(.article-filters:not([hidden])) main {
    padding-bottom: max(11rem, calc(var(--article-filters-height, 9rem) + 2rem + env(safe-area-inset-bottom, 0px)));
  }

  /* The buttons, their selected indicator and the theme switch share the
     groups' corner radius so the panel reads as one shape. */
  .level-filter,
  .content-type-filter,
  .level-filter::before,
  .content-type-filter::before,
  .level-filter__button,
  .article-filters .theme-toggle {
    border-radius: 0.85rem;
  }

  .level-filter__button {
    padding-inline: 0.75rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .level-filter.is-animated::before,
  .content-type-filter.is-animated::before,
  .level-filter__button {
    transition: none;
  }
}

@media print {
  .article-filters {
    display: none !important;
  }
}