/* spa.css — styles for the client-rendered SPA views.
   Layered on top of the service's existing assets/css/style.css. Kept minimal
   and self-contained so it works even where style.css selectors don't match. */

:root {
  --spa-gap: 1rem;
  --spa-radius: 12px;
  --spa-border: #e2e5ea;
  --spa-fg: #1b1d22;
  --spa-muted: #5b6675;
  --spa-accent: #2f6df6;
  --spa-card-bg: #ffffff;
  --spa-bg: #f7f8fa;
}
[data-theme='dark'] {
  --spa-border: #2a2f3a;
  --spa-fg: #e7eaf0;
  --spa-muted: #9aa4b2;
  --spa-accent: #6ea0ff;
  --spa-card-bg: #181b21;
  --spa-bg: #0f1115;
}

body {
  background: var(--spa-bg);
  color: var(--spa-fg);
}

.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 1rem;
}

.site-header {
  border-bottom: 1px solid var(--spa-border);
  background: var(--spa-card-bg);
}
.header-inner {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 0.75rem 1rem;
  flex-wrap: wrap;
}
.site-title {
  font-weight: 700;
  font-size: 1.15rem;
  text-decoration: none;
  color: var(--spa-fg);
}
.header-search {
  margin-left: auto;
  display: flex;
  gap: 0.4rem;
  flex: 1 1 280px;
  max-width: 480px;
}
.lang-switch {
  background: var(--spa-card-bg);
  color: var(--spa-fg);
  border: 1px solid var(--spa-border);
  border-radius: var(--spa-radius);
  padding: 0.4rem 0.5rem;
  font: inherit;
  cursor: pointer;
}
.header-search input {
  flex: 1;
  padding: 0.5rem 0.7rem;
  border: 1px solid var(--spa-border);
  border-radius: var(--spa-radius);
  background: var(--spa-bg);
  color: var(--spa-fg);
  font-size: 0.95rem;
}
.header-search button {
  padding: 0.5rem 0.9rem;
  border: 0;
  border-radius: var(--spa-radius);
  background: var(--spa-accent);
  color: #fff;
  cursor: pointer;
}

.spa-loading,
.spa-empty,
.spa-error {
  padding: 2rem 0;
  color: var(--spa-muted);
}

/* CLS reservation (ACQ-13) --------------------------------------------- *
 * #main-content ships as `<p class="spa-loading">Loading…</p>` (see
 * scripts/build-spa.mjs) until app.js fetches data.json and replaces it
 * with the real category-grid home view (also reused as the loading state
 * on subsequent in-app navigations, per app.js's renderLoading()). Without
 * a size hint the ~90px loading paragraph is replaced by ~2000+px of real
 * content in one jump, shoving the footer down — measured as CLS 0.770 on
 * /ja/formula-ref/ (see sv/docs/qa/external-metrics-2026-07-12.md).
 *
 * Reserve a min-height on `.spa-loading` sized to the Home category-grid
 * view (the heaviest of the SPA's views) per rendered language + width
 * tier, so the footer is already ~in place the first time `.spa-loading`
 * paints. Once real content replaces it, `.spa-loading` is removed from the
 * DOM entirely, so this rule stops applying and the real content's own
 * height (which already matches the reservation) causes no further visible
 * movement. Same technique as ACQ-11.1's `#app:empty` fix for /everyday/.
 * Other (shorter) views reusing this loading state may see a small residual
 * shrink once their content mounts — documented trade-off, not solved here
 * to keep the fix minimal. `html[lang]` is set per deployed language copy
 * at assemble time (scripts/inject-seo-head.mjs), before this stylesheet is
 * parsed. */
.spa-loading {
  min-height: 900px; /* generic fallback (unrecognized lang, desktop-ish) */
}
@media (max-width: 900px) {
  .spa-loading {
    min-height: 1300px;
  }
}
@media (max-width: 480px) {
  .spa-loading {
    min-height: 2250px;
  }
}

html[lang='en'] .spa-loading {
  min-height: 940px;
}
html[lang='ja'] .spa-loading {
  min-height: 810px;
}
html[lang='es'] .spa-loading {
  min-height: 995px;
}
html[lang='zh'] .spa-loading {
  min-height: 785px;
}
html[lang='de'] .spa-loading {
  min-height: 965px;
}

@media (max-width: 900px) {
  html[lang='en'] .spa-loading {
    min-height: 1275px;
  }
  html[lang='ja'] .spa-loading {
    min-height: 1255px;
  }
  html[lang='es'] .spa-loading {
    min-height: 1370px;
  }
  html[lang='zh'] .spa-loading {
    min-height: 1190px;
  }
  html[lang='de'] .spa-loading {
    min-height: 1370px;
  }
}
@media (max-width: 480px) {
  html[lang='en'] .spa-loading {
    min-height: 2215px;
  }
  html[lang='ja'] .spa-loading {
    min-height: 2110px;
  }
  html[lang='es'] .spa-loading {
    min-height: 2305px;
  }
  html[lang='zh'] .spa-loading {
    min-height: 1955px;
  }
  html[lang='de'] .spa-loading {
    min-height: 2375px;
  }
}

.spa-hero {
  padding: 1.5rem 0 0.5rem;
}
.spa-hero h1 {
  margin: 0 0 0.3rem;
}
.spa-hero__meta {
  color: var(--spa-muted);
  margin: 0;
}

/* Category cards */
.category-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: var(--spa-gap);
  padding: 1.25rem 0 2rem;
}
.category-card {
  display: flex;
  gap: 0.75rem;
  align-items: flex-start;
  padding: 1rem;
  border: 1px solid var(--spa-border);
  border-radius: var(--spa-radius);
  background: var(--spa-card-bg);
  text-decoration: none;
  color: inherit;
  transition: border-color 0.15s, transform 0.15s;
}
.category-card:hover {
  border-color: var(--spa-accent);
  transform: translateY(-2px);
}
.category-card__icon {
  display: inline-flex;
  align-items: center;
  font-size: 1.6rem;
  line-height: 1;
  flex: none;
}

/* Icon prefixed to the category-detail <h1> (see viewCategory in app.js) */
.category-detail__icon {
  display: inline-flex;
  align-items: center;
  vertical-align: -0.15em;
}
.category-card__name {
  display: block;
  font-weight: 600;
  margin-bottom: 0.2rem;
}
.category-card__desc {
  display: block;
  font-size: 0.85rem;
  color: var(--spa-muted);
}

/* Breadcrumb */
.breadcrumb {
  padding: 1rem 0 0.25rem;
  font-size: 0.9rem;
  color: var(--spa-muted);
}
.breadcrumb a {
  color: var(--spa-accent);
  text-decoration: none;
}

.spa-section-head {
  padding: 0.5rem 0 1rem;
  border-bottom: 1px solid var(--spa-border);
  margin-bottom: 1rem;
}
.spa-section-head h1 {
  margin: 0 0 0.3rem;
}
.spa-count {
  color: var(--spa-muted);
  margin: 0.2rem 0 0;
  font-size: 0.9rem;
}

/* Formula list / rows */
.formula-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.5rem;
}
.formula-row__link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.7rem 0.9rem;
  border: 1px solid var(--spa-border);
  border-radius: var(--spa-radius);
  background: var(--spa-card-bg);
  text-decoration: none;
  color: inherit;
}
.formula-row__link:hover {
  border-color: var(--spa-accent);
}
.formula-row__name {
  font-weight: 600;
}
.formula-row__tex,
.formula-row__cat {
  color: var(--spa-muted);
  font-size: 0.9rem;
  text-align: right;
}

/* Formula detail */
.formula-detail {
  padding-bottom: 3rem;
}
.formula-detail h1 {
  margin: 0 0 0.4rem;
}
.formula-detail__desc {
  color: var(--spa-muted);
}
.formula-detail__formula {
  margin: 1.25rem 0;
  padding: 1.25rem;
  border: 1px solid var(--spa-border);
  border-radius: var(--spa-radius);
  background: var(--spa-card-bg);
  overflow-x: auto;
}
.formula-display {
  font-size: 1.3rem;
}
.formula-plain {
  margin: 0.6rem 0 0;
  color: var(--spa-muted);
}
.formula-detail section {
  margin: 1.5rem 0;
}
.formula-detail h2 {
  font-size: 1.1rem;
  border-bottom: 1px solid var(--spa-border);
  padding-bottom: 0.3rem;
  margin-bottom: 0.75rem;
}

.symbol-table {
  width: 100%;
  border-collapse: collapse;
}
.symbol-table th,
.symbol-table td {
  border: 1px solid var(--spa-border);
  padding: 0.5rem 0.7rem;
  text-align: left;
  vertical-align: top;
}

.example {
  margin-bottom: 1.25rem;
  padding: 1rem;
  border: 1px solid var(--spa-border);
  border-radius: var(--spa-radius);
  background: var(--spa-card-bg);
}
.example h3 {
  margin: 0 0 0.5rem;
  font-size: 1rem;
}
.example__given,
.example__steps,
.example__answer {
  margin: 0.3rem 0 0.8rem;
}
.example__given {
  list-style: none;
  padding: 0;
}
.step,
.example__answer {
  padding: 0.4rem 0;
  overflow-x: auto;
}
.example__given-label,
.example__steps-label,
.example__answer-label {
  font-weight: 600;
  margin: 0.4rem 0 0.2rem;
}

.tag-list,
.related-list,
.ref-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}
.related-list,
.ref-list {
  flex-direction: column;
}
.tag-chip {
  padding: 0.25rem 0.6rem;
  border: 1px solid var(--spa-border);
  border-radius: 999px;
  background: var(--spa-card-bg);
  font-size: 0.85rem;
}
.related-list a,
.ref-list a {
  color: var(--spa-accent);
}

.site-footer {
  border-top: 1px solid var(--spa-border);
  padding: 1.5rem 0;
  color: var(--spa-muted);
  margin-top: 2rem;
}

/* Pagination controls (category / all list views) */
.pagination {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  margin: 1rem 0;
  flex-wrap: wrap;
}
.pagination__btn {
  display: inline-block;
  padding: 0.5rem 1rem;
  border: 1px solid var(--spa-border);
  border-radius: var(--spa-radius);
  background: var(--spa-card-bg);
  color: inherit;
  text-decoration: none;
  font-weight: 600;
  min-height: 44px;
  line-height: 1.6;
}
.pagination__btn:hover {
  border-color: var(--spa-accent);
}
.pagination__btn--disabled {
  opacity: 0.45;
  pointer-events: none;
}
.pagination__status {
  color: var(--spa-muted);
  font-size: 0.9rem;
}