:root {
  --jp-grammar-indigo: #263d68;
  --jp-grammar-red: #a3313a;
  --jp-grammar-red-dark: #7d252d;
  --jp-grammar-gold: #c69a24;
  --jp-grammar-ink: #18212b;
  --jp-grammar-muted: #5d6874;
  --jp-grammar-border: #d9dfe4;
  --jp-grammar-surface: #ffffff;
  --jp-grammar-tint: #f5f7f7;
}

body.page-japanese-grammar {
  background: var(--jp-grammar-tint);
  color: var(--jp-grammar-ink);
}

body.page-japanese-grammar main.section.container {
  box-sizing: border-box;
  max-width: 860px;
  padding-top: 8rem;
  padding-bottom: 4rem;
}

.jp-grammar-article {
  max-width: 780px;
  margin: 0 auto;
  color: var(--jp-grammar-ink);
  line-height: 1.72;
}

.jp-grammar-back {
  display: inline-block;
  margin-bottom: 0.75rem;
  color: var(--jp-grammar-red-dark);
  font-size: 0.9rem;
  font-weight: 700;
  text-decoration: none;
}

.jp-grammar-back::before {
  content: '\2190';
  margin-right: 0.4rem;
}

.jp-topic-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  margin: 0 0 1.75rem;
  padding: 0.7rem;
  border: 1px solid var(--jp-grammar-border);
  border-radius: 8px;
  background: var(--jp-grammar-surface);
}

.jp-topic-nav a {
  padding: 0.42rem 0.72rem;
  border: 1px solid var(--jp-grammar-border);
  border-radius: 6px;
  color: var(--jp-grammar-red-dark);
  font-size: 0.83rem;
  font-weight: 700;
  line-height: 1.25;
  text-decoration: none;
  white-space: nowrap;
}

.jp-topic-nav a:hover {
  border-color: var(--jp-grammar-red);
  background: #fbf0f1;
}

.jp-topic-nav a.active {
  border-color: var(--jp-grammar-red);
  background: var(--jp-grammar-red);
  color: #ffffff;
  pointer-events: none;
}

.jp-grammar-kicker {
  margin: 0 0 0.4rem;
  color: var(--jp-grammar-red-dark);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.jp-grammar-article h1 {
  margin: 0 0 0.75rem;
  color: var(--jp-grammar-indigo);
  font-size: clamp(2rem, 5vw, 2.8rem);
  letter-spacing: 0;
}

.jp-title-reading {
  display: block;
  margin-top: 0.35rem;
  color: var(--jp-grammar-muted);
  font-size: 1rem;
  font-weight: 600;
}

.jp-grammar-lead {
  max-width: 68ch;
  margin-bottom: 2.1rem;
  color: var(--jp-grammar-muted);
  font-size: 1.06rem;
  line-height: 1.72;
}

.jp-grammar-section {
  margin: 0;
  padding: 1.65rem 0;
  border-top: 1px solid var(--jp-grammar-border);
}

.jp-grammar-section:first-of-type {
  border-top: 2px solid var(--jp-grammar-red);
}

.jp-grammar-section h2 {
  margin: 0 0 0.75rem;
  color: var(--jp-grammar-red-dark);
  font-size: 1.28rem;
  letter-spacing: 0;
}

.jp-grammar-section p,
.jp-grammar-section li {
  line-height: 1.72;
}

.jp-grammar-section ul,
.jp-grammar-section ol {
  margin-top: 0.75rem;
  padding-left: 1.3rem;
}

.jp-grammar-section li + li {
  margin-top: 0.55rem;
}

.jp-example {
  margin: 0.85rem 0;
  padding: 0.9rem 1rem;
  border-left: 3px solid var(--jp-grammar-indigo);
  background: #eef2f6;
}

.jp-example-japanese {
  display: block;
  color: #111820;
  font-size: 1.1rem;
  font-weight: 700;
}

.jp-example-reading {
  display: block;
  margin-top: 0.15rem;
  color: var(--jp-grammar-muted);
  font-size: 0.88rem;
}

.jp-example-translation {
  display: block;
  margin-top: 0.25rem;
  font-size: 0.93rem;
}

.jp-grammar-note {
  margin: 1rem 0;
  padding: 0.95rem 1rem;
  border: 1px solid #dfc4c7;
  border-left: 4px solid var(--jp-grammar-red);
  border-radius: 6px;
  background: #fcf3f4;
}

.jp-summary-list {
  margin-bottom: 0;
  padding: 1rem 1rem 1rem 2rem;
  border: 1px solid var(--jp-grammar-border);
  border-top: 3px solid var(--jp-grammar-gold);
  border-radius: 6px;
  background: var(--jp-grammar-surface);
}

.jp-table-scroll {
  margin-top: 1rem;
  overflow-x: auto;
  border: 1px solid var(--jp-grammar-border);
  border-radius: 6px;
  background: var(--jp-grammar-surface);
}

.jp-grammar-table {
  width: 100%;
  min-width: 600px;
  border-collapse: collapse;
}

.jp-grammar-table th,
.jp-grammar-table td {
  padding: 0.72rem 0.85rem;
  border-bottom: 1px solid var(--jp-grammar-border);
  text-align: left;
  vertical-align: top;
}

.jp-grammar-table th {
  background: #edf1f4;
  color: #34414d;
  font-size: 0.88rem;
}

.jp-grammar-table td {
  font-size: 0.94rem;
}

.jp-grammar-table tr:last-child td {
  border-bottom: 0;
}

.jp-practice-link {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  margin-top: 0.75rem;
  color: var(--jp-grammar-indigo);
  font-weight: 700;
  text-decoration: none;
}

.jp-practice-link:hover {
  text-decoration: underline;
}

.jp-grammar-article a:focus-visible,
.jp-topic-nav a:focus-visible,
#japaneseGrammarExplorer a:focus-visible,
#japaneseGrammarExplorer summary:focus-visible,
#japaneseGrammarSearch:focus-visible {
  outline: 3px solid rgba(163, 49, 58, 0.22);
  outline-offset: 2px;
}

#japaneseGrammarExplorer {
  max-width: 1040px;
}

.jp-explorer-header {
  max-width: 900px;
  margin: 0 auto 2rem;
}

.jp-explorer-header h1 {
  margin: 0 0 0.65rem;
  color: var(--jp-grammar-indigo);
  font-size: clamp(2.1rem, 5vw, 3rem);
  letter-spacing: 0;
}

.jp-explorer-intro {
  max-width: 72ch;
  margin: 0;
  color: var(--jp-grammar-muted);
  line-height: 1.7;
}

.jp-explorer-note {
  margin-top: 0.7rem;
  color: var(--jp-grammar-muted);
  font-size: 0.9rem;
}

.jp-explorer-tools {
  display: grid;
  grid-template-columns: minmax(260px, 1fr) auto;
  gap: 0.9rem;
  align-items: end;
  margin-top: 1.35rem;
}

.jp-grammar-search {
  position: relative;
}

.jp-grammar-search i {
  position: absolute;
  top: 50%;
  left: 0.9rem;
  color: var(--jp-grammar-muted);
  transform: translateY(-50%);
}

#japaneseGrammarSearch {
  box-sizing: border-box;
  width: 100%;
  min-height: 44px;
  padding: 0.72rem 0.9rem 0.72rem 2.55rem;
  border: 1px solid var(--jp-grammar-border);
  border-radius: 6px;
  background: var(--jp-grammar-surface);
  color: var(--jp-grammar-ink);
  font: inherit;
}

.jp-topic-filter {
  display: flex;
  gap: 0.25rem;
  margin: 0;
  padding: 0.25rem;
  border: 1px solid var(--jp-grammar-border);
  border-radius: 7px;
  background: var(--jp-grammar-surface);
}

.jp-topic-filter legend,
.jp-sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.jp-topic-filter label {
  cursor: pointer;
}

.jp-topic-filter input {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.jp-topic-filter span {
  display: block;
  padding: 0.48rem 0.7rem;
  border-radius: 5px;
  color: var(--jp-grammar-muted);
  font-size: 0.84rem;
  font-weight: 700;
}

.jp-topic-filter input:checked + span {
  background: var(--jp-grammar-indigo);
  color: #ffffff;
}

.jp-topic-filter input:focus-visible + span {
  outline: 3px solid rgba(38, 61, 104, 0.22);
}

.jp-search-status {
  min-height: 1.35rem;
  margin: 0.65rem 0 0;
  color: var(--jp-grammar-muted);
  font-size: 0.86rem;
}

.jp-grammar-accordion {
  max-width: 900px;
  margin: 0 auto;
}

.jp-level {
  margin-bottom: 0.75rem;
  border: 1px solid var(--jp-grammar-border);
  border-radius: 7px;
  background: var(--jp-grammar-surface);
}

.jp-level > summary,
.jp-group > summary {
  position: relative;
  list-style: none;
  cursor: pointer;
}

.jp-level > summary::-webkit-details-marker,
.jp-group > summary::-webkit-details-marker {
  display: none;
}

.jp-level > summary {
  padding: 1rem 3rem 1rem 1.15rem;
}

.jp-level > summary::after,
.jp-group > summary::after {
  content: '+';
  position: absolute;
  top: 50%;
  right: 1rem;
  width: auto;
  height: auto;
  border: 0;
  background: none;
  color: var(--jp-grammar-red-dark);
  font-size: 1.25rem;
  font-weight: 700;
  line-height: 1;
  transform: translateY(-50%);
}

.jp-level[open] > summary::after,
.jp-group[open] > summary::after {
  content: '\2212';
}

.jp-level > summary h2 {
  margin: 0;
  color: var(--jp-grammar-indigo);
  font-size: 1.2rem;
  letter-spacing: 0;
}

.jp-level-content {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.75rem;
  padding: 0 1rem 1rem;
}

.jp-group {
  align-self: start;
  border: 1px solid var(--jp-grammar-border);
  border-radius: 6px;
  background: #fafbfb;
}

.jp-group.live {
  border-left: 3px solid var(--jp-grammar-red);
}

.jp-group > summary {
  padding: 0.8rem 2.4rem 0.8rem 0.85rem;
  color: #303b46;
  font-size: 0.94rem;
  font-weight: 700;
}

.jp-group > summary::after {
  right: 0.8rem;
  font-size: 1rem;
}

.jp-topic-list {
  margin: 0;
  padding: 0 0.85rem 0.85rem 1.95rem;
}

.jp-topic-list li {
  margin: 0.45rem 0;
  color: var(--jp-grammar-muted);
  font-size: 0.9rem;
  line-height: 1.45;
}

.jp-topic-list a {
  color: var(--jp-grammar-indigo);
  font-weight: 700;
  text-decoration: none;
}

.jp-topic-list a:hover {
  text-decoration: underline;
}

.jp-topic-hidden,
.jp-group-hidden,
.jp-level-hidden {
  display: none;
}

@media (max-width: 720px) {
  body.page-japanese-grammar main.section.container {
    padding-top: 6.6rem;
  }

  .jp-explorer-tools,
  .jp-level-content {
    grid-template-columns: 1fr;
  }

  .jp-topic-filter {
    width: 100%;
  }

  .jp-topic-filter label {
    flex: 1;
    text-align: center;
  }

  .jp-topic-nav {
    flex-wrap: nowrap;
    overflow-x: auto;
  }

  .jp-grammar-article h1 {
    font-size: 2rem;
  }
}

@media (max-width: 420px) {
  .jp-topic-filter span {
    padding-inline: 0.45rem;
    font-size: 0.78rem;
  }

  .jp-grammar-table {
    min-width: 540px;
  }
}