/* ─────────────────────────────────────────────────────────────────────────────
   components.css — buttons, inputs, cards, badges, chips, hero, tree
   ───────────────────────────────────────────────────────────────────────────── */

/* BUTTONS ──────────────────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-2);
  padding: 0.62em 1.15em;
  font-size: var(--fs-body);
  font-weight: 500;
  line-height: 1.2;
  letter-spacing: 0.01em;
  border-radius: var(--r-md);
  border: 1px solid transparent;
  text-decoration: none;
  cursor: pointer;
  transition:
    background-color var(--dur-fast) var(--ease-standard),
    border-color var(--dur-fast) var(--ease-standard),
    color var(--dur-fast) var(--ease-standard),
    transform var(--dur-fast) var(--ease-standard);
}
.btn:active { transform: translateY(1px); }
.btn:focus-visible { outline: 2px solid var(--c-brand); outline-offset: 2px; }

.btn--solid {
  background: var(--c-ink);
  color: var(--c-paper);
  border-color: var(--c-ink);
}
.btn--solid:hover { background: var(--c-brand); border-color: var(--c-brand); color: var(--c-paper); }

.btn--brand {
  background: var(--c-brand);
  color: var(--c-paper);
  border-color: var(--c-brand);
}
.btn--brand:hover { background: var(--c-brand-soft); border-color: var(--c-brand-soft); }

.btn--outline {
  border-color: var(--c-line-strong);
  color: var(--c-ink);
  background: transparent;
}
.btn--outline:hover { border-color: var(--c-brand); color: var(--c-brand); background: var(--c-brand-glow); }

.btn--ghost {
  border-color: transparent;
  color: var(--c-ink-soft);
  background: transparent;
}
.btn--ghost:hover { color: var(--c-brand); background: var(--c-brand-glow); }

.btn--accent {
  background: var(--c-accent);
  color: var(--c-paper);
  border-color: var(--c-accent);
}
.btn--accent:hover { background: var(--c-accent-soft); border-color: var(--c-accent-soft); }

.btn--sm { padding: 0.4em 0.85em; font-size: var(--fs-small); }
.btn--lg { padding: 0.85em 1.5em; font-size: 1.05rem; }

/* INPUTS ─────────────────────────────────────────────────────────── */
.input,
input[type="text"],
input[type="email"],
input[type="password"],
input[type="search"],
input[type="datetime-local"],
input[type="number"],
select,
textarea {
  width: 100%;
  background: var(--c-paper);
  color: var(--c-ink);
  border: 1px solid var(--c-line-strong);
  padding: 0.65em 0.9em;
  border-radius: var(--r-md);
  font-size: var(--fs-body);
  line-height: 1.4;
  transition:
    border-color var(--dur-fast) var(--ease-standard),
    box-shadow var(--dur-fast) var(--ease-standard);
}
.input:focus,
input:focus,
select:focus,
textarea:focus {
  outline: none;
  border-color: var(--c-brand);
  box-shadow: 0 0 0 3px var(--c-brand-glow);
}

.field {
  display: flex; flex-direction: column;
  gap: var(--sp-2);
  margin-bottom: var(--sp-4);
}
.field__label {
  font-size: var(--fs-small);
  color: var(--c-ink-soft);
  font-weight: 500;
}
.field__hint { font-size: var(--fs-xs); color: var(--c-ink-mute); }
.field__error { font-size: var(--fs-small); color: var(--c-danger); }

.field__check {
  display: inline-flex;
  align-items: flex-start;
  gap: var(--sp-3);
  width: fit-content;
  color: var(--c-ink-soft);
  cursor: pointer;
}
.field__check input {
  width: 18px;
  height: 18px;
  margin-top: 0.15em;
  accent-color: var(--c-brand);
}

/* QUESTIONS & REPLIES ───────────────────────────────────────────── */
.question-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--sp-4);
  margin-bottom: var(--sp-5);
}
.question-filters { display: flex; flex-wrap: wrap; gap: var(--sp-2); }
.question-list { display: grid; gap: var(--sp-3); }
.pagination {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: var(--sp-4);
  margin-top: var(--sp-6);
}
.question-card {
  border: 1px solid var(--c-paper-edge);
  border-radius: var(--r-md);
  background: var(--c-paper);
  transition: border-color var(--dur-fast) var(--ease-standard),
              background var(--dur-fast) var(--ease-standard);
}
.question-card:hover {
  border-color: var(--c-line-strong);
  background: var(--c-paper-soft);
}
.question-card__link {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: var(--sp-2) var(--sp-5);
  min-height: 88px;
  padding: var(--sp-4) var(--sp-5);
  color: inherit;
  text-decoration: none;
}
.question-card__title {
  margin: 0;
  font-size: var(--fs-body);
  line-height: 1.45;
}
.question-card__meta,
.discussion-meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-2);
  color: var(--c-ink-mute);
  font-size: var(--fs-small);
}
.question-card__status { align-self: start; }
.discussion-back { display: inline-flex; margin-bottom: var(--sp-4); }
.discussion-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--sp-5);
  padding-bottom: var(--sp-5);
  border-bottom: 1px solid var(--c-line);
}
.discussion-title { margin: var(--sp-2) 0 var(--sp-3); }
.discussion-body { padding-block: var(--sp-5); }
.reply-section {
  padding-top: var(--sp-5);
  border-top: 1px solid var(--c-line);
}
.reply-list { display: grid; margin-top: var(--sp-4); }
.reply-item {
  padding: var(--sp-5) 0;
  border-bottom: 1px solid var(--c-line);
  scroll-margin-top: 7rem;
}
.reply-item__body { margin-top: var(--sp-3); }
.discussion-form {
  max-width: 760px;
  padding-top: var(--sp-6);
}
.discussion-textarea { resize: vertical; min-height: 9rem; }
@media (max-width: 640px) {
  .question-card__link { grid-template-columns: 1fr; padding: var(--sp-4); }
  .question-card__status { justify-self: start; }
  .discussion-head { flex-direction: column; }
}

/* CARDS ──────────────────────────────────────────────────────────── */
.card {
  background: var(--c-paper);
  border: 1px solid var(--c-paper-edge);
  border-radius: var(--r-md);
  padding: var(--sp-5);
  display: flex;
  flex-direction: column;
  gap: var(--sp-3);
  transition:
    border-color var(--dur-fast) var(--ease-standard),
    transform var(--dur-base) var(--ease-emph),
    box-shadow var(--dur-base) var(--ease-emph);
}
.card:hover {
  border-color: var(--c-line-strong);
  transform: translateY(-2px);
  box-shadow: var(--sh-3);
}
.card--quiet {
  background: var(--c-paper-soft);
  border-color: transparent;
}
.card--quiet:hover { border-color: var(--c-line); }

.card__eyebrow {
  font-size: var(--fs-xs);
  text-transform: uppercase;
  letter-spacing: var(--tracking-caps);
  color: var(--c-ink-mute);
  margin: 0;
}
.card__title {
  font-size: var(--fs-4);
  font-weight: 600;
  margin: 0;
  text-wrap: balance;
}
.card__title a { text-decoration: none; }
.card__title a:hover { color: var(--c-brand); }
.card__meta { font-size: var(--fs-small); color: var(--c-ink-mute); }
.card__body { color: var(--c-ink-soft); line-height: var(--lh-snug); }
.card__foot {
  margin-top: auto;
  padding-top: var(--sp-3);
  border-top: 1px dashed var(--c-paper-edge);
  display: flex; justify-content: space-between;
  font-size: var(--fs-xs); color: var(--c-ink-mute);
}

.grid {
  display: grid;
  gap: var(--sp-5);
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
}
.grid--cozy { gap: var(--sp-4); }
/* Form + list two-pane layout (invite / permission pages). Collapses to a
   single column on narrow screens instead of crushing the 1fr/2fr split. */
.grid--sidebar {
  grid-template-columns: minmax(0, 1fr) minmax(0, 2fr);
  gap: var(--sp-7);
  align-items: start;
}
@media (max-width: 720px) {
  .grid--sidebar { grid-template-columns: 1fr; }
}

/* BADGES & CHIPS ─────────────────────────────────────────────────── */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.35em;
  font-size: var(--fs-xs);
  letter-spacing: 0.04em;
  padding: 0.2em 0.7em;
  border-radius: var(--r-pill);
  background: var(--c-paper-soft);
  color: var(--c-ink-soft);
  border: 1px solid var(--c-paper-edge);
  font-family: var(--ff-sans);
}
.badge--brand   { color: var(--c-brand); background: var(--c-brand-glow); border-color: transparent; }
.badge--accent  { color: var(--c-accent); background: rgba(15, 118, 110, 0.09); border-color: transparent; }
.badge--gold    { color: var(--c-gold); background: rgba(180, 138, 58, 0.10); border-color: transparent; }
.badge--azure   { color: var(--c-azure); background: rgba(44, 79, 107, 0.10); border-color: transparent; }
.badge--violet  { color: var(--c-violet); background: rgba(94, 74, 120, 0.10); border-color: transparent; }
.badge--success { color: var(--c-success); background: rgba(61, 107, 74, 0.12); border-color: transparent; }
.badge--warn    { color: var(--c-warn); background: rgba(161, 115, 35, 0.12); border-color: transparent; }
.badge--danger  { color: var(--c-danger); background: rgba(142, 42, 31, 0.10); border-color: transparent; }

/* Dark theme: light-tuned tints vanish on the ink card, so raise them. */
[data-theme="ink"] .badge--accent,  :root[data-theme="auto"] .badge--accent  { background: rgba(84, 200, 186, 0.16); }
[data-theme="ink"] .badge--gold,    :root[data-theme="auto"] .badge--gold    { background: rgba(217, 164, 65, 0.16); }
[data-theme="ink"] .badge--azure,   :root[data-theme="auto"] .badge--azure   { background: rgba(74, 159, 212, 0.16); }
[data-theme="ink"] .badge--violet,  :root[data-theme="auto"] .badge--violet  { background: rgba(155, 138, 224, 0.16); }
[data-theme="ink"] .badge--success, :root[data-theme="auto"] .badge--success { background: rgba(76, 168, 106, 0.18); }
[data-theme="ink"] .badge--warn,    :root[data-theme="auto"] .badge--warn    { background: rgba(214, 138, 58, 0.18); }
[data-theme="ink"] .badge--danger,  :root[data-theme="auto"] .badge--danger  { background: rgba(224, 115, 111, 0.16); }

/* Pinned badge chip — shown next to a username in the leaderboard, comments and
   member lists. Defined here (not only in learning.css) because those pages do
   NOT load learning.css; without a rule the badge <img> falls back to the global
   `img { display:block }` and drops onto its own oversized line. */
.pinned-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.35em;
  vertical-align: middle;
  white-space: nowrap;
  font-size: var(--fs-xs);
  color: var(--c-ink-soft);
}
.pinned-badge img {
  display: inline-block;
  flex: 0 0 auto;
  width: 20px;
  height: 20px;
  object-fit: contain;
}

.chip-row {
  display: flex; flex-wrap: wrap; gap: var(--sp-2);
}

/* HERO ───────────────────────────────────────────────────────────── */
.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) minmax(280px, 0.9fr);
  gap: var(--sp-7);
  align-items: center;
  padding: clamp(2.5rem, 5vw, 5rem);
  position: relative;
  overflow: hidden;
  border: 1px solid rgba(37, 99, 235, 0.18);
  border-radius: 28px;
  background:
    radial-gradient(circle at 18% 18%, rgba(20, 184, 166, 0.24), transparent 28%),
    radial-gradient(circle at 84% 20%, rgba(37, 99, 235, 0.22), transparent 30%),
    linear-gradient(135deg, rgba(255, 255, 255, 0.96), rgba(237, 242, 247, 0.88));
  box-shadow: 0 24px 80px -48px rgba(15, 23, 42, 0.55);
}
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(37, 99, 235, 0.08) 1px, transparent 1px),
    linear-gradient(90deg, rgba(37, 99, 235, 0.08) 1px, transparent 1px);
  background-size: 28px 28px;
  mask-image: linear-gradient(135deg, rgba(0, 0, 0, 0.35), transparent 68%);
  pointer-events: none;
}
.hero::after {
  content: "";
  position: absolute;
  right: clamp(1rem, 5vw, 4rem);
  top: clamp(1rem, 4vw, 3rem);
  width: 160px;
  height: 160px;
  border: 1px solid rgba(37, 99, 235, 0.24);
  border-radius: 36px;
  transform: rotate(18deg);
  background: rgba(255, 255, 255, 0.25);
  backdrop-filter: blur(10px);
}
.hero__lead,
.hero__side {
  position: relative;
  z-index: 1;
}
@media (max-width: 880px) { .hero { grid-template-columns: 1fr; padding: var(--sp-6); } }

.hero__eyebrow {
  display: inline-flex; align-items: center; gap: var(--sp-2);
  margin-bottom: var(--sp-4);
  font-size: var(--fs-xs);
  text-transform: uppercase;
  letter-spacing: var(--tracking-caps);
  color: var(--c-ink-mute);
}
.hero__eyebrow::before {
  content: ""; width: 1.6em; height: 1px; background: var(--c-line-strong);
}

.hero__title {
  font-family: var(--ff-sans);
  font-size: var(--fs-1);
  font-weight: 800;
  line-height: 1.02;
  letter-spacing: -0.045em;
  margin: 0 0 var(--sp-4);
  text-wrap: balance;
}
.hero__title--stacked {
  display: flex;
  flex-direction: column;
  gap: 0.12em;
}
.hero__title--stacked > span {
  display: inline-flex;
  width: fit-content;
  align-items: baseline;
  gap: 0.12em;
  position: relative;
}
.hero__title--stacked > span:not(.accent)::after {
  content: "";
  position: absolute;
  left: calc(100% + 0.22em);
  top: 50%;
  width: clamp(3rem, 11vw, 8rem);
  height: 1px;
  background: linear-gradient(90deg, var(--c-brand), transparent);
  opacity: 0.45;
}
.hero__title--stacked .accent {
  margin-top: 0.08em;
  padding: 0.08em 0.18em 0.12em 0;
  font-size: 0.72em;
  letter-spacing: -0.03em;
}

.hero__title em {
  font-style: normal;
  color: var(--c-brand);
  font-family: var(--ff-sans);
  font-weight: 700;
}
.hero__title .accent {
  color: transparent;
  font-style: normal;
  background: linear-gradient(90deg, var(--c-brand), var(--c-accent));
  -webkit-background-clip: text;
  background-clip: text;
}

.hero__lede {
  font-size: 1.18rem;
  color: var(--c-ink-soft);
  line-height: var(--lh-snug);
  max-width: 36em;
  text-wrap: pretty;
}

.hero__cta {
  display: flex; gap: var(--sp-3); flex-wrap: wrap;
  margin-top: var(--sp-5);
}

.hero__side {
  border: 1px solid rgba(37, 99, 235, 0.16);
  border-radius: 20px;
  padding: var(--sp-4);
  font-size: var(--fs-small);
  color: var(--c-ink-soft);
  line-height: var(--lh-snug);
  background: rgba(255, 255, 255, 0.58);
  backdrop-filter: blur(14px);
}
.hero__metric {
  display: flex; align-items: baseline; gap: var(--sp-3);
  padding-block: var(--sp-3);
  border-bottom: 1px dashed var(--c-paper-edge);
}
.hero__metric:last-child { border-bottom: 0; }
.hero__metric-value {
  font-family: var(--ff-serif);
  font-size: 1.85rem;
  font-weight: 500;
  color: var(--c-ink);
  font-variant-numeric: oldstyle-nums;
  line-height: 1;
}
.hero__metric-label { color: var(--c-ink-mute); }
.hero__metric-link { display: block; text-decoration: none; }
.hero__metric-link:hover .hero__metric-value { color: var(--c-brand); }
.hero__metric-link:hover .hero__metric-label { color: var(--c-brand); }

[data-theme="ink"] .hero,
:root[data-theme="auto"] .hero {
  background:
    radial-gradient(circle at 18% 18%, rgba(84, 200, 186, 0.10), transparent 30%),
    radial-gradient(circle at 84% 20%, rgba(111, 147, 216, 0.12), transparent 32%),
    linear-gradient(135deg, #101722, #0d1117 72%);
  border-color: rgba(111, 147, 216, 0.16);
  box-shadow: 0 24px 80px -54px rgba(0, 0, 0, 0.9);
}
[data-theme="ink"] .hero::after,
:root[data-theme="auto"] .hero::after {
  background: rgba(18, 24, 33, 0.55);
  border-color: rgba(111, 147, 216, 0.16);
}
[data-theme="ink"] .hero__side,
:root[data-theme="auto"] .hero__side {
  background: rgba(18, 24, 33, 0.72);
  border-color: rgba(111, 147, 216, 0.14);
}
[data-theme="ink"] .card,
[data-theme="ink"] .entry-card,
:root[data-theme="auto"] .card,
:root[data-theme="auto"] .entry-card {
  background: #101722;
}
[data-theme="ink"] .card--quiet,
:root[data-theme="auto"] .card--quiet {
  background: #121821;
}

/* MODALITY DOTS ─────────────────────────────────────────────────── */
.modality-dot {
  display: inline-block;
  width: 0.55em; height: 0.55em;
  border-radius: 50%;
  margin-right: 0.4em;
  vertical-align: 0.05em;
}
.dot-scrna   { background: var(--c-brand); }
.dot-scatac  { background: var(--c-azure); }
.dot-schic   { background: var(--c-violet); }
.dot-spatial { background: var(--c-gold); }
.dot-multi   { background: var(--c-accent); }

/* FLASH MESSAGES ─────────────────────────────────────────────── */
.flash-stack { display: flex; flex-direction: column; gap: var(--sp-2); margin-top: var(--sp-4); }
.flash {
  padding: var(--sp-3) var(--sp-4);
  border: 1px solid var(--c-line);
  border-radius: var(--r-md);
  background: var(--c-paper-soft);
  font-size: var(--fs-small);
}
.flash--success { border-color: var(--c-success); }
.flash--warning { border-color: var(--c-warn); }
.flash--error   { border-color: var(--c-danger); color: var(--c-danger); }

/* BREADCRUMBS ───────────────────────────────────────────────── */
.crumbs {
  display: flex; align-items: center; gap: var(--sp-2);
  font-size: var(--fs-small);
  color: var(--c-ink-mute);
  margin-bottom: var(--sp-3);
  flex-wrap: wrap;
}
.crumbs a { text-decoration: none; color: var(--c-ink-soft); }
.crumbs a:hover { color: var(--c-brand); }
.crumbs .sep { color: var(--c-ink-faint); }

/* KNOWLEDGE TREE — editorial, modality-coloured, multi-column ─────── */
#knowledge-tree-app,
.tree-loading-shell,
.knowledge-tree-shell {
  min-height: 34rem;
}
.tree {
  font-family: var(--ff-sans);
  line-height: 1.5;
  /* Deterministic grid, NOT height-balanced `columns` masonry: each root branch
     keeps a fixed slot by DOM order, so branches auto-expanding and lazy-loading
     their children at different times can never reshuffle which branch sits on
     top of a column (that reflow was the "06→04" flash). Rows are top-aligned. */
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  align-items: start;
  gap: var(--sp-5) var(--sp-7);
}
.tree--loading { pointer-events: none; }
.tree__search-placeholder {
  display: flex;
  align-items: center;
  min-height: 44px;
  color: var(--c-ink-mute);
}
.tree__skeleton-branch {
  display: grid;
  align-content: start;
  gap: var(--sp-3);
  min-height: 10rem;
  padding: var(--sp-3) var(--sp-2);
  border-left: 3px solid var(--c-line);
}
.tree__skeleton-line {
  display: block;
  width: 82%;
  height: 0.75rem;
  border-radius: var(--r-sm);
  background: var(--c-paper-soft);
}
.tree__skeleton-line--title { width: 62%; height: 1rem; }
.tree__skeleton-line--short { width: 46%; }
.tree__node--root {
  --tree-accent: var(--c-brand);   /* JS sets a real modality colour per branch */
  min-width: 0;                    /* allow grid cell to shrink; prevents overflow */
}
.tree__node { padding-left: 0; }

/* nested groups get a faint rail tinted by the branch's colour */
.tree__children {
  margin-left: 0.6em;
  padding-left: 0.9em;
  border-left: 1px solid var(--c-paper-edge);
  border-left-color: color-mix(in srgb, var(--tree-accent) 32%, var(--c-paper-edge));
}

.tree__row {
  display: flex; align-items: center; gap: 0.5em;
  padding: 0.34em 0.5em;
  border-radius: var(--r-sm);
  cursor: pointer;
  color: var(--c-ink-soft);
  transition: background var(--dur-fast) var(--ease-standard),
              color var(--dur-fast) var(--ease-standard);
}
.tree__row:hover { background: var(--c-paper-soft); color: var(--c-ink); }
.tree__row.is-active {
  background: var(--c-brand-glow);
  background: color-mix(in srgb, var(--tree-accent) 14%, transparent);
  color: var(--tree-accent);
  font-weight: 600;
}
/* Search hit: tint the row so matches stand out, not just the highlighted word. */
.tree__row.is-match {
  background: color-mix(in srgb, var(--c-warn) 15%, transparent);
  box-shadow: inset 2px 0 0 var(--c-warn);
}

/* top-level branch = modality header: serif, larger, colour bar */
.tree__node--root > .tree__row {
  font-family: var(--ff-serif);
  font-size: 1.16rem;
  font-weight: 600;
  color: var(--c-ink);
  padding: 0.42em 0.6em;
  margin-bottom: 0.25em;
  border-left: 3px solid var(--tree-accent);
  border-radius: 0 var(--r-sm) var(--r-sm) 0;
}
.tree__node--root > .tree__row:hover {
  background: color-mix(in srgb, var(--tree-accent) 8%, var(--c-paper-soft));
}
.tree__node--root > .tree__row .tree__caret { color: var(--tree-accent); }
.tree__node--root > .tree__row .tree__icon { display: none; }

.tree__caret {
  display: inline-flex; align-items: center; justify-content: center;
  width: 1em; height: 1em; flex: none;
  color: var(--c-ink-mute);
  transition: transform var(--dur-base) var(--ease-out);
}
.tree__caret.is-open { transform: rotate(90deg); }
.tree__icon { color: var(--c-ink-faint); font-size: 0.85em; flex: none; }
.tree__title {
  flex: 1; min-width: 0;
  text-decoration: none; color: inherit;
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.tree__title:hover { color: var(--tree-accent); }
.tree__count {
  flex: none;
  font-size: var(--fs-xs);
  font-variant-numeric: tabular-nums;
  color: var(--c-ink-mute);
  background: var(--c-paper-soft);
  padding: 0.05em 0.55em;
  border-radius: var(--r-pill);
}

.tree__search {
  margin-bottom: var(--sp-5);
  position: relative;
  max-width: 34rem;
}
.tree__search input { padding-left: 2.4em; }
.tree__search-icon {
  position: absolute; left: 0.85em; top: 50%; transform: translateY(-50%);
  color: var(--c-ink-mute);
  pointer-events: none;
}

/* Knowledge tree controls: directory labels stay in place; only documents link. */
.knowledge-tree-shell {
  display: grid;
  grid-template-columns: minmax(190px, 240px) minmax(0, 1fr);
  gap: var(--sp-6);
  align-items: start;
}
.tree-main { min-width: 0; }
.knowledge-tree-shell .tree {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--sp-5) var(--sp-6);
}
.tree-nav {
  position: sticky;
  top: calc(var(--sp-5) + 3.5rem);
  max-height: calc(100vh - 7rem);
  overflow: auto;
  border-right: 1px solid var(--c-paper-edge);
  padding-right: var(--sp-3);
}
.tree-nav__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--sp-2) var(--sp-2);
  color: var(--c-ink-mute);
  font-size: var(--fs-xs);
}
.tree-nav__list { display: flex; flex-direction: column; gap: 0.1rem; }
.tree-nav__row {
  display: flex;
  align-items: center;
  min-width: 0;
  padding-left: 0.2rem;
}
.tree-nav__toggle {
  display: inline-grid;
  place-items: center;
  flex: 0 0 1.5rem;
  width: 1.5rem;
  height: 1.5rem;
  padding: 0;
  border: 0;
  border-radius: var(--r-sm);
  background: transparent;
  color: var(--c-ink-mute);
  cursor: pointer;
  transition: transform 160ms ease, color 160ms ease, background 160ms ease;
}
.tree-nav__toggle:hover { background: var(--c-paper-soft); color: var(--c-ink); }
.tree-nav__toggle.is-open { transform: rotate(90deg); }
.tree-nav__toggle--empty { pointer-events: none; }
.tree-nav__item {
  flex: 1;
  min-width: 0;
  padding: 0.35rem 0.45rem;
  border: 0;
  border-radius: var(--r-sm);
  background: transparent;
  color: var(--c-ink-soft);
  cursor: pointer;
  font: inherit;
  font-size: var(--fs-small);
  line-height: 1.35;
  text-align: left;
}
.tree-nav__item:hover { background: var(--c-paper-soft); color: var(--c-ink); }
.tree-nav__documents {
  display: flex;
  flex-direction: column;
  gap: 0.1rem;
  margin: 0.1rem 0 0.35rem 1.1rem;
  padding-left: 0.85rem;
  border-left: 1px solid var(--c-paper-edge);
}
.tree-nav__document {
  display: block;
  padding: 0.25rem 0.4rem;
  border-radius: var(--r-sm);
  color: var(--c-ink-mute);
  font-size: var(--fs-xs);
  line-height: 1.35;
  text-decoration: none;
}
.tree-nav__document:hover { background: var(--c-paper-soft); color: var(--c-ink); }
.tree-nav__mobile-toggle,
.tree-nav__close { display: none; }

.tree__row {
  cursor: default;
  gap: 0.45rem;
  border-radius: var(--r-sm);
}
.tree__node--root > .tree__row { margin-bottom: 0.35rem; }
.tree__toggle {
  display: inline-grid;
  place-items: center;
  width: 1.6rem;
  height: 1.6rem;
  flex: none;
  border: 0;
  border-radius: var(--r-sm);
  background: transparent;
  color: var(--c-ink-mute);
  cursor: pointer;
  font: inherit;
  line-height: 1;
  transition: transform var(--dur-base) var(--ease-out), background var(--dur-fast) var(--ease-standard);
}
.tree__toggle:hover { background: var(--c-paper-soft); color: var(--c-ink); }
.tree__toggle.is-open { transform: rotate(90deg); }
.tree__toggle--empty { cursor: default; }
.tree__toggle--empty:hover { background: transparent; }
.tree__directory-title {
  flex: 1;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  color: inherit;
  cursor: default;
}
.tree__directory-title:hover { color: var(--c-ink); }
.tree__children {
  display: flex;
  flex-direction: column;
  gap: 0.1rem;
  margin-top: 0.15rem;
}
.tree__document {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  min-height: 1.85rem;
  padding: 0.25rem 0.5rem;
  border-radius: var(--r-sm);
  font-size: var(--fs-small);
  text-decoration: none;
}
.tree__document { color: var(--c-ink-soft); }
.tree__document:hover,
.tree__document.is-match { background: var(--c-paper-soft); color: var(--c-ink); }
.tree__document-icon { color: var(--c-ink-faint); }
.tree__loading { padding: 0.4rem 0.5rem 0.4rem 2.1rem; color: var(--c-ink-mute); font-size: var(--fs-xs); }

@media (max-width: 980px) {
  .knowledge-tree-shell { display: block; }
  .tree-nav__mobile-toggle {
    display: inline-flex;
    margin: 0 0 var(--sp-4);
    border: 1px solid var(--c-paper-edge);
    border-radius: var(--r-sm);
    background: var(--c-paper);
    color: var(--c-ink);
    padding: 0.45rem 0.75rem;
    font: inherit;
    cursor: pointer;
  }
  .tree-nav {
    display: none;
    position: fixed;
    z-index: 40;
    top: 0;
    left: 0;
    width: min(20rem, 86vw);
    max-height: 100vh;
    height: 100vh;
    padding: var(--sp-5);
    border-right: 1px solid var(--c-paper-edge);
    background: var(--c-paper);
    box-shadow: 18px 0 40px rgba(0, 0, 0, 0.16);
  }
  .tree-nav.is-open { display: block; }
  .tree-nav__close {
    display: inline-flex;
    border: 0;
    background: transparent;
    color: var(--c-ink-mute);
    font: inherit;
    cursor: pointer;
  }
}

@media (max-width: 680px) {
  .knowledge-tree-shell .tree { grid-template-columns: minmax(0, 1fr); }
}

/* WORKBENCH GRID ──────────────────────────────────────────── */
.workbench {
  display: grid;
  grid-template-columns: minmax(0, 2fr) minmax(0, 1fr);
  gap: var(--sp-7);
}
@media (max-width: 1000px) { .workbench { grid-template-columns: 1fr; } }

.entry-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: var(--sp-3);
}
.entry-card {
  display: flex; flex-direction: column; gap: var(--sp-1);
  padding: var(--sp-3) var(--sp-4);
  border: 1px solid var(--c-paper-edge);
  border-radius: var(--r-md);
  background: var(--c-paper);
  text-decoration: none;
  color: var(--c-ink);
  transition: all var(--dur-fast) var(--ease-standard);
  position: relative;
  overflow: hidden;
}
.entry-card::after {
  content: "";
  position: absolute; left: 0; top: 0; bottom: 0;
  width: 3px;
  background: var(--c-brand);
  transform: scaleY(0);
  transform-origin: top;
  transition: transform var(--dur-base) var(--ease-emph);
}
.entry-card:hover { border-color: var(--c-line-strong); }
.entry-card:hover::after { transform: scaleY(1); }
.entry-card__title { font-family: var(--ff-serif); font-size: 1.1rem; font-weight: 600; }
.entry-card__hint { font-size: var(--fs-small); color: var(--c-ink-mute); }
.entry-card__cta {
  margin-top: auto;
  padding-top: var(--sp-3);
  font-size: var(--fs-xs);
  letter-spacing: var(--tracking-caps);
  text-transform: uppercase;
  color: var(--c-brand);
}

/* RECENT LIST ─────────────────────────────────────────────── */
.recent-list { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; }
.recent-list li {
  padding-block: var(--sp-3);
  border-bottom: 1px dashed var(--c-paper-edge);
  display: flex; align-items: baseline; gap: var(--sp-3);
}
.recent-list li:last-child { border-bottom: 0; }
.recent-list a { text-decoration: none; flex: 1; }
.recent-list .when { font-size: var(--fs-xs); color: var(--c-ink-faint); font-variant-numeric: tabular-nums; }

/* TWO-LINE EMPTY STATE ─────────────────────────────────── */
.empty {
  text-align: center;
  padding: var(--sp-7) 0;
  color: var(--c-ink-mute);
}
.empty__title {
  font-family: var(--ff-serif);
  font-size: 1.3rem;
  color: var(--c-ink-soft);
  margin: 0 0 var(--sp-2);
}
.empty__hint { font-size: var(--fs-small); }

/* FANCY HEADLINE: ornament rule + serifs */
.headline {
  display: flex; align-items: center; gap: var(--sp-3);
  margin-bottom: var(--sp-4);
}
.headline__rule { flex: 1; height: 1px; background: var(--c-line); }
.headline__title {
  font-family: var(--ff-serif);
  font-size: 1.05rem;
  color: var(--c-ink-soft);
  letter-spacing: 0.02em;
}

/* GitHub-like review page */
.review-page { --review-border: var(--c-line); }
.review-head {
  display: flex;
  justify-content: space-between;
  gap: var(--sp-4);
  align-items: flex-start;
  margin-bottom: var(--sp-5);
}
.review-title {
  margin: 0 0 var(--sp-2);
  font-family: var(--ff-sans);
  font-size: clamp(1.7rem, 3vw, 2.5rem);
  font-weight: 750;
  letter-spacing: -0.035em;
  line-height: 1.1;
}
.review-actions { display: flex; gap: var(--sp-2); flex-wrap: wrap; }
.review-filebar {
  display: flex;
  justify-content: space-between;
  gap: var(--sp-4);
  align-items: center;
  padding: var(--sp-3) var(--sp-4);
  border: 1px solid var(--review-border);
  border-bottom: 0;
  border-radius: var(--r-md) var(--r-md) 0 0;
  background: var(--c-paper-soft);
}
.review-filebar__label {
  display: block;
  margin-bottom: 0.25rem;
  color: var(--c-ink-mute);
  font-size: var(--fs-xs);
  letter-spacing: var(--tracking-caps);
  text-transform: uppercase;
}
.review-filebar__stats { display: flex; gap: var(--sp-2); flex-wrap: wrap; justify-content: flex-end; }
.review-stat {
  display: inline-flex;
  align-items: center;
  padding: 0.15rem 0.55rem;
  border-radius: var(--r-pill);
  background: var(--c-paper);
  border: 1px solid var(--c-paper-edge);
  color: var(--c-ink-soft);
  font-family: var(--ff-mono);
  font-size: var(--fs-xs);
}
.review-stat--add { color: var(--c-success); background: color-mix(in srgb, var(--c-success) 12%, transparent); }
.review-stat--del { color: var(--c-danger); background: color-mix(in srgb, var(--c-danger) 12%, transparent); }
.review-diff--github {
  margin-top: 0;
  border-radius: 0 0 var(--r-md) var(--r-md);
  border-color: var(--review-border);
  box-shadow: var(--sh-2);
}
.review-diff--github table.diff { table-layout: fixed; }
.review-diff--github table.diff th {
  background: var(--c-paper-soft);
  color: var(--c-ink-soft);
  font-family: var(--ff-sans);
  font-size: var(--fs-xs);
  letter-spacing: var(--tracking-caps);
  text-transform: uppercase;
}
.review-diff--github td.diff_header {
  width: 4.2rem;
  min-width: 4.2rem;
  color: var(--c-ink-faint);
  background: var(--c-paper-soft);
  border-right: 1px solid var(--c-paper-edge);
}
.review-diff--github td:not(.diff_header) {
  white-space: pre-wrap;
  word-break: break-word;
}
.review-diff--github .diff_next { display: none; }
/* Diff tints keyed off the semantic tokens so they read on both paper and ink
   themes (the tokens flip: success #15803d→#4ca86a, danger #b91c1c→#e0736f). */
.review-diff--github .diff_add { background: color-mix(in srgb, var(--c-success) 18%, transparent); }
.review-diff--github .diff_sub { background: color-mix(in srgb, var(--c-danger) 16%, transparent); }
.review-diff--github .diff_chg { background: color-mix(in srgb, var(--c-warn) 22%, transparent); }
@media (max-width: 800px) {
  .review-head,
  .review-filebar { flex-direction: column; align-items: stretch; }
  .review-actions--top { width: 100%; }
  .review-actions--top .btn { flex: 1; }
}

/* Current user row in leaderboard */
.leaderboard-row--me {
  background: var(--c-brand-glow);
  box-shadow: inset 3px 0 0 var(--c-brand);
}
[data-theme="ink"] .leaderboard-row--me,
:root[data-theme="auto"] .leaderboard-row--me {
  background: rgba(122, 162, 255, 0.14);
}

/* Health check page */
.health-page {
  max-width: 980px;
}
.health-hero {
  padding: var(--sp-6);
  border: 1px solid rgba(37, 99, 235, 0.16);
  border-radius: 24px;
  background:
    radial-gradient(circle at 15% 0%, rgba(20, 184, 166, 0.18), transparent 32%),
    radial-gradient(circle at 90% 15%, rgba(37, 99, 235, 0.18), transparent 28%),
    var(--c-paper);
  box-shadow: var(--sh-2);
}
.health-title {
  margin: var(--sp-2) 0;
  font-family: var(--ff-sans);
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 800;
  letter-spacing: -0.045em;
  line-height: 1.05;
}
.health-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(190px, 1fr));
  gap: var(--sp-4);
  margin-top: var(--sp-5);
}
.health-card {
  display: flex;
  flex-direction: column;
  gap: var(--sp-2);
  min-height: 140px;
  padding: var(--sp-4);
  border: 1px solid var(--c-paper-edge);
  border-radius: var(--r-lg);
  background: var(--c-paper);
  box-shadow: var(--sh-2);
}
.health-card--ok {
  border-color: rgba(21, 128, 61, 0.28);
  background: linear-gradient(135deg, rgba(21, 128, 61, 0.12), var(--c-paper));
}
.health-card__label {
  color: var(--c-ink-mute);
  font-size: var(--fs-xs);
  letter-spacing: var(--tracking-caps);
  text-transform: uppercase;
}
.health-card strong {
  color: var(--c-ink);
  font-family: var(--ff-sans);
  font-size: 1.55rem;
  line-height: 1;
}