:root {
  --bg: #ffffff;
  --text: #111111;
  --muted: #6b7280;
  --faint: #9ca3af;
  --border: #e5e7eb;
  --border-strong: #d1d5db;
  --pill-bg: #f3f4f6;
  --pill-text: #374151;
  --hover: #f9fafb;
  --col: 156px; /* fixed left column so all question text starts at the same x */
  --gap: 16px;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

main { max-width: 860px; margin: 0 auto; padding: 28px 24px 64px; }

/* ---------- Deck bar (top) ---------- */
.deckbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 16px 20px;
  border: 1px solid var(--border);
  border-radius: 14px;
  margin-bottom: 22px;
  flex-wrap: wrap;
}
.counter { font-size: 14px; color: var(--muted); }
.counter .big { font-size: 22px; font-weight: 800; color: var(--text); letter-spacing: -0.5px; }
.counter .lbl { font-weight: 600; color: var(--muted); }
.counter .sep { margin: 0 8px; color: var(--faint); }

.tools { display: flex; align-items: center; gap: 12px; }
.tools select {
  background: var(--bg);
  color: var(--text);
  border: 1px solid var(--border-strong);
  border-radius: 9px;
  padding: 8px 12px;
  font-size: 14px;
  cursor: pointer;
}
.tools select:focus { outline: none; border-color: var(--text); }
.link {
  background: none;
  border: none;
  color: var(--muted);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  padding: 4px;
}
.link:hover { color: var(--text); text-decoration: underline; }

/* ---------- Question rows ---------- */
.row {
  position: relative;
  border-top: 1px solid var(--border);
  cursor: pointer;
}
.row:last-child { border-bottom: 1px solid var(--border); }

.rowhead {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 16px 8px;
}
.rowhead:hover { background: var(--hover); }

/* star — click to fill */
.starbtn {
  width: 16px;
  flex: none;
  text-align: center;
  font-size: 16px;
  line-height: 1.6;
  color: var(--faint);
  cursor: pointer;
  user-select: none;
  transition: color 0.12s ease, transform 0.12s ease;
}
.starbtn:hover { color: #f5b301; transform: scale(1.15); }
.starbtn.on { color: #f5b301; }

.qtext { flex: 1; min-width: 0; font-size: 15.5px; font-weight: 500; color: var(--text); }

/* ---------- Answer (expand) ---------- */
.answer { display: none; padding: 0 8px 18px; }
.row.open .answer { display: block; }
.answer .atext { margin: 0 0 14px 26px; color: #374151; font-size: 14.5px; }
.answer .atext > :first-child { margin-top: 0; }
.answer .atext > :last-child { margin-bottom: 0; }
.atext p { margin: 0 0 11px; }
.atext ul, .atext ol { margin: 0 0 11px; padding-left: 22px; }
.atext li { margin: 4px 0; }
.atext li::marker { color: var(--faint); }
.atext strong { font-weight: 700; color: var(--text); }
.atext code { background: #f3f4f6; padding: 1px 5px; border-radius: 5px; font-size: 13px; }
.atext .katex { font-size: 1.04em; }
.atext .katex-display { margin: 12px 0; overflow-x: auto; overflow-y: hidden; }
.atext table { border-collapse: collapse; width: 100%; margin: 2px 0 12px; font-size: 13.5px; }
.atext th, .atext td { border: 1px solid var(--border); padding: 7px 10px; text-align: left; vertical-align: top; }
.atext th { background: #f9fafb; font-weight: 700; color: var(--text); white-space: nowrap; }
.atext td strong { color: var(--text); }

/* Hide button spans the full width of the card */
.hidebtn {
  display: block;
  width: 100%;
  background: var(--bg);
  border: 1px solid var(--border-strong);
  color: var(--text);
  font-size: 13px;
  font-weight: 600;
  padding: 9px 14px;
  border-radius: 9px;
  cursor: pointer;
  transition: background 0.12s ease, border-color 0.12s ease;
}
.hidebtn:hover { background: var(--hover); border-color: var(--text); }

/* ---------- Starred (gold star is the only indicator) ---------- */
.row.starred { background: #fcfcfc; }

/* ---------- Hidden (greyed, sent to bottom) ---------- */
.row.hidden .qtext { color: var(--faint) !important; }
.row.hidden .rowhead { opacity: 0.6; }
.row.hidden .rowhead:hover { opacity: 0.85; }

@media (max-width: 560px) {
  main { padding: 20px 16px 48px; }
}