/* Keep the learning browser within Material's typography and theme palette. */
.ar-learning-browser,
.ar-learning-featured,
.ar-learning-topics {
  --ar-learning-line: var(--md-default-fg-color--lightest);
  --ar-learning-link: var(--md-typeset-a-color);
}

.ar-learning-controls {
  display: flex;
  flex-wrap: wrap;
  align-items: end;
  gap: 0.65rem;
  margin: 1rem 0 0.45rem;
}

.ar-learning-actions > p {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.ar-learning-actions .md-button {
  margin: 0;
}

.ar-learning-controls label {
  display: grid;
  flex: 1 1 12rem;
  gap: 0.25rem;
  color: var(--md-default-fg-color--light);
  font-size: 0.72rem;
}

.ar-learning-controls label:has([data-learning-search]) {
  flex-basis: 20rem;
}

.ar-learning-levels {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.35rem;
  margin: 0.8rem 0;
  font-size: 0.7rem;
}

.ar-learning-levels > span {
  margin-inline-end: 0.3rem;
  color: var(--md-default-fg-color--light);
}

.ar-learning-levels button {
  padding: 0.3rem 0.6rem;
  border: 0.05rem solid var(--ar-learning-line);
  border-radius: 0.25rem;
  font: inherit;
  cursor: pointer;
}

.ar-learning-levels button[aria-pressed="true"] {
  border-color: var(--ar-learning-link);
  color: var(--ar-learning-link);
  background: var(--md-code-bg-color);
}

.md-typeset .ar-learning-qa .ar-learning-level {
  font-size: 0.65rem;
  font-weight: 600;
  color: var(--md-default-fg-color--light);
}

.ar-learning-browser [data-learning-search],
.ar-learning-browser select {
  box-sizing: border-box;
  width: 100%;
  min-width: 0;
  min-height: 2.3rem;
  padding: 0.45rem 0.65rem;
  border: 0.05rem solid var(--ar-learning-line);
  border-radius: 0.35rem;
  color: var(--md-default-fg-color);
  background: var(--md-default-bg-color);
  font: inherit;
}

.ar-learning-browser [data-learning-search]::placeholder {
  color: var(--md-default-fg-color--light);
  opacity: 1;
}

.ar-learning-browser [data-learning-status] {
  margin: 0.55rem 0 0.9rem;
  color: var(--md-default-fg-color--light);
  font-size: 0.7rem;
  font-variant-numeric: tabular-nums;
}

.ar-learning-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  align-items: stretch;
  gap: 0.8rem;
}

.ar-learning-card {
  display: flex;
  min-width: 0;
  flex-direction: column;
  gap: 0.6rem;
  padding: 1rem;
  border: 0.05rem solid var(--ar-learning-line);
  border-radius: 0.45rem;
  background: var(--md-default-bg-color);
}

/* Questions are a reading list. Answers open inline without competing panels. */
[data-learning-unit="问"] .ar-learning-grid {
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
}

.ar-learning-qa {
  gap: 0.4rem;
  padding: 1.15rem 0;
  border: 0;
  border-bottom: 0.05rem solid var(--ar-learning-line);
  border-radius: 0;
  scroll-margin-top: 5rem;
}

.ar-learning-qa .ar-learning-card__domain {
  padding: 0;
  background: none;
}

.md-typeset .ar-learning-qa .ar-learning-card__domain {
  font-size: 0.65rem;
}

.ar-learning-browser summary:focus-visible {
  outline: 0.12rem solid var(--ar-learning-link);
  outline-offset: 0.15rem;
}

.md-typeset .ar-learning-qa .ar-learning-paper {
  color: var(--md-default-fg-color--light);
  font-size: 0.68rem;
}

.md-typeset .ar-learning-qa .ar-learning-card__meta {
  font-size: 0.62rem;
}

.md-typeset details.ar-learning-answer,
.md-typeset details.ar-learning-guide {
  margin: 0;
  padding: 0;
  border: 0;
  background: none;
  box-shadow: none;
}

.md-typeset .ar-learning-answer > summary,
.md-typeset .ar-learning-guide > summary {
  display: list-item;
  margin: 0;
  padding: 0.35rem 0;
  background: none;
  color: var(--md-typeset-a-color);
  list-style: disclosure-closed inside;
  font-size: 0.76rem;
  font-weight: 500;
  cursor: pointer;
}

.md-typeset .ar-learning-answer[open] > summary,
.md-typeset .ar-learning-guide[open] > summary {
  list-style-type: disclosure-open;
}

.md-typeset :is(.ar-learning-answer,.ar-learning-guide) > summary::before,
.md-typeset :is(.ar-learning-answer,.ar-learning-guide) > summary::after {
  display: none;
}

.md-typeset .ar-learning-qa .ar-learning-answer p {
  margin: 0.65rem 0;
}

.md-typeset .ar-learning-qa .ar-learning-sources {
  color: var(--md-default-fg-color--light);
  font-size: 0.65rem;
}

.ar-learning-guide {
  margin-top: 1.5rem !important;
}

.ar-learning-recent ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

.ar-learning-recent li {
  display: grid;
  gap: 0.25rem;
  padding: 0.65rem 0;
  border-bottom: 0.05rem solid var(--md-default-fg-color--lightest);
}

.ar-learning-recent li span {
  color: var(--md-default-fg-color--light);
  font-size: 0.65rem;
}

.ar-learning-paper-filter {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0.4rem 0.8rem;
  padding: 0.6rem 0;
  border-bottom: 0.05rem solid var(--ar-learning-line);
  font-size: 0.76rem;
}

.ar-learning-paper-filter button {
  color: var(--md-typeset-a-color);
  font: inherit;
  cursor: pointer;
  text-decoration: underline;
  text-underline-offset: 0.2em;
}

[data-paper-filtered="true"] .ar-learning-controls label:has(select),
[data-paper-filtered="true"] .ar-learning-paper {
  display: none;
}

.md-typeset .ar-learning-card h2 {
  margin: 0;
  font-size: 1rem;
  font-weight: 650;
  line-height: 1.5;
  letter-spacing: normal;
  overflow-wrap: anywhere;
}

.md-typeset .ar-learning-card p {
  margin: 0;
  font-size: 0.76rem;
  line-height: 1.75;
  overflow-wrap: anywhere;
}

.ar-learning-card__meta,
.ar-learning-featured__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 0.6rem;
  align-items: center;
  color: var(--md-default-fg-color--light);
  font-size: 0.68rem;
}

.ar-learning-card__domain {
  padding: 0.1rem 0.4rem;
  border-radius: 0.2rem;
  color: var(--ar-learning-link);
  background: var(--md-code-bg-color);
}

.ar-learning-card__links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 0.8rem;
  align-items: baseline;
  margin-top: auto;
  padding-top: 0.2rem;
  font-size: 0.74rem;
}

.ar-learning-browser a,
.ar-learning-featured a {
  color: var(--ar-learning-link);
  text-decoration-thickness: 0.06em;
  text-underline-offset: 0.18em;
}

.ar-learning-browser a:hover,
.ar-learning-featured a:hover {
  text-decoration-line: underline;
}

.ar-learning-browser [data-learning-more] {
  display: block;
  min-height: 2.3rem;
  margin: 1.1rem auto 0;
  padding: 0.45rem 1rem;
  border: 0.05rem solid var(--ar-learning-link);
  border-radius: 0.35rem;
  color: var(--ar-learning-link);
  background: var(--md-default-bg-color);
  font: inherit;
  font-size: 0.76rem;
  cursor: pointer;
}

.ar-learning-browser [data-learning-more]:hover {
  background: var(--md-code-bg-color);
}

/* Theme shelves keep the landing page finite; paper lists live one level deeper. */
.ar-learning-topics {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.85rem;
  margin: 1rem 0 1.4rem;
}

.ar-learning-topic-tile {
  min-width: 0;
  padding: 1rem;
  border: 0.05rem solid var(--ar-learning-line);
  border-top: 0.15rem solid var(--ar-learning-link);
  border-radius: 0.35rem;
}

.md-typeset .ar-learning-topic-tile h2 {
  margin: 0 0 0.5rem;
  font-size: 1rem;
  font-weight: 650;
}

.md-typeset .ar-learning-topic-tile p,
.md-typeset .ar-learning-topic-tile li {
  font-size: 0.76rem;
}

.md-typeset .ar-learning-topic-tile details {
  margin-bottom: 0;
  box-shadow: none;
}

.md-typeset .ar-learning-topic-tile ul {
  margin: 0.7rem 0 0;
  padding: 0;
  list-style: none;
}

.md-typeset .ar-learning-topic-tile li {
  display: flex;
  justify-content: space-between;
  gap: 0.5rem;
  margin: 0;
  padding: 0.4rem 0;
  border-bottom: 0.05rem solid var(--ar-learning-line);
}

.ar-learning-topic-tile li span,
.ar-learning-topic-meta {
  color: var(--md-default-fg-color--light);
  font-variant-numeric: tabular-nums;
}

.ar-learning-topic-tile li > span {
  flex-shrink: 0;
  text-align: end;
}

.ar-learning-deep-link {
  display: block;
  font-size: 0.68rem;
}

/* A shelf is one theme; opening it reveals a finite set of authored readings. */
.md-typeset .ar-deep-shelf {
  border-color: var(--md-default-fg-color--lightest);
  box-shadow: none;
}

.md-typeset .ar-deep-shelf > summary {
  background: var(--md-code-bg-color);
}

.ar-deep-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.7rem;
  padding-top: 0.6rem;
}

.ar-deep-tile {
  min-width: 0;
  padding: 0.8rem;
  border-inline-start: 0.12rem solid var(--md-typeset-a-color);
  background: var(--md-code-bg-color);
  overflow-wrap: anywhere;
}

.md-typeset .ar-deep-tile h2 {
  margin: 0 0 0.4rem;
  font-size: 0.9rem;
  font-weight: 600;
}

.md-typeset .ar-deep-tile p {
  font-size: 0.72rem;
  line-height: 1.7;
}

.ar-deep-shelf :is(a, summary):focus-visible,
.ar-deep-catalog > summary:focus-visible {
  outline: 0.12rem solid var(--md-typeset-a-color);
  outline-offset: 0.15rem;
}

.md-typeset .ar-deep-comparison :is(.md-typeset__scrollwrap, .md-typeset__table) {
  display: block;
  width: 100%;
  max-width: 100%;
  margin-inline: 0;
  padding: 0;
}

.md-typeset .ar-deep-comparison table:not([class]) {
  width: 100%;
  min-width: 0;
  table-layout: fixed;
}

.md-typeset .ar-deep-comparison :is(th, td) {
  min-width: 0;
  padding: 0.65rem;
  vertical-align: top;
  overflow-wrap: anywhere;
  white-space: normal;
  line-height: 1.75;
}

.md-typeset .ar-deep-comparison th:nth-child(1) { width: 28%; }
.md-typeset .ar-deep-comparison th:nth-child(2) { width: 34%; }
.md-typeset .ar-deep-comparison th:nth-child(3) { width: 38%; }

.md-typeset .ar-learning-boundary {
  margin: 0;
  padding: 0 0.6rem;
  border-color: var(--ar-learning-line);
  box-shadow: none;
}

.ar-learning-topic-tile summary,
.ar-learning-boundary summary {
  font-size: 0.74rem;
  cursor: pointer;
}

.ar-learning-topics :is(a, summary):focus-visible {
  outline: 0.12rem solid var(--ar-learning-link);
  outline-offset: 0.16rem;
}

.ar-learning-browser :is(a, input, select, button):focus-visible,
.ar-learning-featured a:focus-visible {
  outline: 0.12rem solid var(--ar-learning-link);
  outline-offset: 0.16rem;
}

.ar-learning-browser .ar-learning-empty {
  margin: 0.8rem 0;
  padding: 0.85rem 1rem;
  border-inline-start: 0.15rem solid var(--ar-learning-line);
  color: var(--md-default-fg-color--light);
  background: var(--md-code-bg-color);
  font-size: 0.76rem;
}

.ar-learning-featured {
  margin: 1rem 0 1.3rem;
  padding: 1.1rem 1.2rem;
  border: 0.05rem solid var(--ar-learning-line);
  border-inline-start: 0.18rem solid var(--ar-learning-link);
  border-radius: 0.45rem;
  background: var(--md-code-bg-color);
}

.md-typeset .ar-learning-featured h2 {
  margin: 0 0 0.45rem;
  font-size: 1.1rem;
  font-weight: 650;
  line-height: 1.5;
}

.md-typeset .ar-learning-featured p {
  margin: 0.45rem 0;
}

/* Material or card layout rules must never override native hidden semantics. */
.ar-learning-browser[hidden],
.ar-learning-browser [hidden],
.ar-learning-featured[hidden],
.ar-learning-featured [hidden] {
  display: none !important;
}

@media (max-width: 44rem) {
  .ar-learning-grid,
  .ar-learning-topics,
  .ar-deep-grid {
    grid-template-columns: minmax(0, 1fr);
  }

  .ar-learning-card,
  .ar-learning-featured {
    padding: 0.85rem;
  }

  .md-typeset .ar-deep-comparison :is(table, tbody, tr, td) {
    display: block;
    width: 100%;
  }

  .md-typeset .ar-deep-comparison thead {
    position: absolute;
    width: 1px;
    height: 1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
  }

  .md-typeset .ar-deep-comparison tr {
    margin-bottom: 0.8rem;
    border: 0.05rem solid var(--md-default-fg-color--lightest);
    border-radius: 0.35rem;
  }

  .md-typeset .ar-deep-comparison td::before {
    display: block;
    margin-bottom: 0.3rem;
    color: var(--md-default-fg-color--light);
    font-weight: 600;
  }

  .md-typeset .ar-deep-comparison td:nth-child(1)::before { content: "论文与来源"; }
  .md-typeset .ar-deep-comparison td:nth-child(2)::before { content: "机制定位"; }
  .md-typeset .ar-deep-comparison td:nth-child(3)::before { content: "得到与付出"; }
}