/* ============================================================
   qa.css
   ------------------------------------------------------------
   Styles for the Q&A board (student-facing).
     .qa-board, .qa-bar, .qa-list, .qa-card,
     .qa-overlay, .qa-dialog, .qa-dialog__*,
     .qa-thread__*, .qa-answer, .qa-tag
   ============================================================ */

.qa-board {
  display: grid;
  gap: var(--space-4, 1rem);
  max-width: 960px;
  margin: 0 auto;
  padding: var(--space-4, 1rem);
}
.qa-board__head {
  display: grid;
  gap: 0.25rem;
}
.qa-board__title {
  margin: 0;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-text, #111827);
}
.qa-board__sub {
  margin: 0;
  font-size: 0.875rem;
  color: var(--color-text-muted, #6b7280);
}

/* ── Toolbar ─────────────────────────── */
.qa-bar {
  display: grid;
  grid-template-columns: minmax(10rem, 1fr) minmax(10rem, 2fr) auto;
  gap: var(--space-3, 0.75rem);
  align-items: end;
}
.qa-bar__field {
  display: grid;
  gap: 0.25rem;
}
.qa-bar__field--grow {
  min-width: 0;
}
.qa-bar__label {
  font-size: 0.75rem;
  color: var(--color-text-muted, #6b7280);
  font-weight: 600;
}
.qa-bar .input {
  height: 2.25rem;
  padding: 0 0.625rem;
  border: 1px solid var(--color-border, #e5e7eb);
  border-radius: var(--radius-sm, 6px);
  background: var(--color-surface, #fff);
  font-size: 0.875rem;
}

/* ── List ─────────────────────────────── */
.qa-list {
  display: grid;
  gap: var(--space-2, 0.5rem);
}
.qa-card {
  display: grid;
  gap: 0.4rem;
  padding: var(--space-3, 0.75rem) var(--space-4, 1rem);
  border: 1px solid var(--color-border, #e5e7eb);
  border-radius: var(--radius-md, 10px);
  background: var(--color-surface, #fff);
  cursor: pointer;
  transition: transform 120ms ease, box-shadow 120ms ease, border-color 120ms ease;
}
.qa-card:hover {
  transform: translateY(-1px);
  border-color: color-mix(in oklab, var(--color-primary, #2563eb) 35%, var(--color-border, #e5e7eb));
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.04);
}
.qa-card__title {
  margin: 0;
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-text, #111827);
}
.qa-card__body {
  margin: 0;
  font-size: 0.875rem;
  color: var(--color-text, #111827);
  line-height: 1.55;
  white-space: pre-wrap;
  word-break: break-word;
}
.qa-card__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  font-size: 0.75rem;
  color: var(--color-text-muted, #6b7280);
  align-items: center;
}

.qa-tag {
  display: inline-grid;
  place-items: center;
  padding: 0.1rem 0.55rem;
  font-size: 0.6875rem;
  font-weight: 700;
  border-radius: 999px;
  background: var(--color-surface-alt, #fafbfc);
  border: 1px solid var(--color-border, #e5e7eb);
  color: var(--color-text-muted, #6b7280);
  line-height: 1.5;
}
.qa-tag--ok {
  background: color-mix(in oklab, var(--color-success, #16a34a) 14%, #fff);
  border-color: color-mix(in oklab, var(--color-success, #16a34a) 50%, #fff);
  color: var(--color-success, #16a34a);
}
.qa-tag--best {
  background: color-mix(in oklab, var(--color-warning, #d97706) 14%, #fff);
  border-color: color-mix(in oklab, var(--color-warning, #d97706) 50%, #fff);
  color: var(--color-warning, #d97706);
}

.qa-empty {
  padding: var(--space-6, 2rem) var(--space-5, 1.5rem);
  text-align: center;
  color: var(--color-text-muted, #6b7280);
  font-style: italic;
  border: 1px dashed var(--color-border, #e5e7eb);
  border-radius: var(--radius-md, 10px);
  background: var(--color-surface-alt, #fafbfc);
}

/* ── Overlay / Dialog ─────────────────── */
.qa-overlay {
  position: fixed;
  inset: 0;
  background: rgba(17, 24, 39, 0.55);
  display: grid;
  place-items: center;
  padding: 1rem;
  z-index: 55;
  overflow: auto;
}
.qa-dialog {
  display: grid;
  grid-template-rows: auto 1fr auto;
  width: min(720px, 100%);
  max-height: min(90vh, 780px);
  background: var(--color-surface, #fff);
  border-radius: var(--radius-lg, 14px);
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.25);
  overflow: hidden;
}
.qa-dialog--thread {
  width: min(780px, 100%);
}
.qa-dialog__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-3, 0.75rem) var(--space-4, 1rem);
  border-bottom: 1px solid var(--color-border, #e5e7eb);
}
.qa-dialog__title {
  margin: 0;
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-text, #111827);
}
.qa-dialog__close {
  appearance: none;
  border: 0;
  background: transparent;
  font-size: 1.25rem;
  line-height: 1;
  color: var(--color-text-muted, #6b7280);
  cursor: pointer;
  padding: 0.25rem 0.5rem;
  border-radius: var(--radius-sm, 6px);
}
.qa-dialog__close:hover {
  background: var(--color-surface-alt, #fafbfc);
}
.qa-dialog__body {
  display: grid;
  gap: var(--space-3, 0.75rem);
  padding: var(--space-4, 1rem);
  overflow: auto;
}
.qa-dialog__textarea {
  min-height: 6rem;
  resize: vertical;
  line-height: 1.55;
  font-family: inherit;
}
.qa-dialog__foot {
  display: flex;
  justify-content: flex-end;
  gap: 0.5rem;
  padding: var(--space-3, 0.75rem) var(--space-4, 1rem);
  border-top: 1px solid var(--color-border, #e5e7eb);
  background: var(--color-surface-alt, #fafbfc);
}

/* ── Thread ────────────────────────────── */
.qa-thread__question {
  display: grid;
  gap: 0.5rem;
  padding: var(--space-3, 0.75rem);
  border: 1px solid var(--color-border, #e5e7eb);
  border-radius: var(--radius-md, 10px);
  background: var(--color-surface-alt, #fafbfc);
}
.qa-thread__body {
  margin: 0;
  font-size: 0.9375rem;
  color: var(--color-text, #111827);
  line-height: 1.6;
  white-space: pre-wrap;
  word-break: break-word;
}
.qa-thread__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  align-items: center;
  font-size: 0.75rem;
  color: var(--color-text-muted, #6b7280);
}

.qa-thread__answers {
  display: grid;
  gap: 0.5rem;
}
.qa-answer {
  display: grid;
  gap: 0.35rem;
  padding: var(--space-3, 0.75rem);
  border: 1px solid var(--color-border, #e5e7eb);
  border-radius: var(--radius-md, 10px);
  background: var(--color-surface, #fff);
}
.qa-answer.is-best {
  border-color: color-mix(in oklab, var(--color-warning, #d97706) 45%, var(--color-border, #e5e7eb));
  background: color-mix(in oklab, var(--color-warning, #d97706) 6%, var(--color-surface, #fff));
}
.qa-answer__body {
  margin: 0;
  font-size: 0.875rem;
  color: var(--color-text, #111827);
  line-height: 1.55;
  white-space: pre-wrap;
  word-break: break-word;
}
.qa-answer__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  align-items: center;
  font-size: 0.75rem;
  color: var(--color-text-muted, #6b7280);
}

.qa-thread__composer {
  display: grid;
  gap: 0.5rem;
  padding: var(--space-3, 0.75rem);
  border: 1px dashed var(--color-border, #e5e7eb);
  border-radius: var(--radius-md, 10px);
  background: var(--color-surface-alt, #fafbfc);
}
.qa-thread__composer textarea {
  width: 100%;
  resize: vertical;
}

/* ── Responsive ───────────────────────── */
@media (max-width: 720px) {
  .qa-bar {
    grid-template-columns: 1fr;
  }
}