/*
  Math tool only (landing hub copy + the arithmetic game). Everything shared with
  the other practice tools lives in /tutoring/shared/practice.css, which must be
  loaded before this file.
*/

/* ---- arithmetic: setup ---- */
.cat { border: 1px solid var(--line); border-radius: var(--radius); padding: 10px 14px; margin-bottom: 12px; }
.cat-head { display: flex; align-items: center; gap: 10px; font-weight: 700; cursor: pointer; padding: 4px 0; }
.cat-head input, .opt input, .toggle input { accent-color: var(--accent); width: 18px; height: 18px; margin: 0; flex: none; }
.cat-body { padding: 6px 0 2px 28px; }
.cat-body[hidden] { display: none; }
.cat-body .muted { margin: 8px 0 4px; }
.op-row { display: flex; flex-wrap: wrap; align-items: center; gap: 8px 18px; padding: 6px 0; }
.opt { display: inline-flex; align-items: center; gap: 8px; cursor: pointer; }
.range { display: inline-flex; flex-wrap: wrap; align-items: center; gap: 6px; color: var(--ink-soft); font-size: 0.95rem; }
.range-sep { padding: 0 4px; font-weight: 700; color: var(--ink); }
.range-pair { white-space: nowrap; display: inline-flex; align-items: center; gap: 6px; }
.num {
  font: inherit;
  width: 4.8em;
  padding: 5px 8px;
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--ink);
  background: var(--paper);
  -moz-appearance: textfield;
}
.num::-webkit-outer-spin-button, .num::-webkit-inner-spin-button { -webkit-appearance: none; margin: 0; }
.options { display: flex; flex-wrap: wrap; align-items: center; gap: 6px 14px; margin-top: 20px; }
.options .toggle { display: inline-flex; margin: 0; font-weight: 700; }
.options .muted { margin: 0; }
.mode-note { max-width: 52ch; }
.start-row { margin-top: 22px; }
.btn-big { font-size: 1.15rem; padding: 12px 28px; }
.error { color: var(--bad); margin: 10px 0 0; }
.error[hidden], #best-line[hidden] { display: none; }

/* ---- arithmetic: play ---- */
.hud { display: flex; justify-content: space-between; align-items: baseline; gap: 12px; color: var(--ink-soft); font-variant-numeric: tabular-nums; }
.hud .link { background: none; border: 0; padding: 0; color: var(--accent); text-decoration: underline; font-size: 0.95rem; }
.problem { margin: 28px 0 18px; }
.prompt-line { font-size: clamp(1.35rem, 5vw, 1.8rem); font-weight: 700; line-height: 1.35; margin-bottom: 16px; }
.prompt-line[hidden], .expr[hidden], .eq[hidden] { display: none; }
.answer-row {
  display: flex; flex-wrap: wrap; align-items: center; gap: 14px;
  font-size: clamp(1.9rem, 7vw, 2.7rem); font-weight: 700; line-height: 1.2;
}
.expr { white-space: nowrap; }
.answer-wrap { display: inline-flex; align-items: center; gap: 8px; }
.answer {
  font: inherit;
  width: 7.5ch;
  min-width: 0;
  padding: 4px 10px;
  border: 2px solid var(--line);
  border-radius: var(--radius);
  color: var(--ink);
  background: var(--paper);
}
.answer.is-correct { border-color: var(--good); background: var(--good-tint); }
.answer.is-wrong { border-color: var(--bad); background: var(--bad-tint); }
.suffix { font-weight: 700; }
.suffix[hidden] { display: none; }
.hint { margin-top: 4px; }
.practice-controls { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 8px; }
.practice-controls .btn[hidden] { display: none; }
.fb-neutral { margin: 0; font-size: 1.05rem; }
.solution-box { margin-top: 18px; padding: 14px 18px; border-left: 4px solid var(--accent); background: var(--tint); border-radius: 0 var(--radius) var(--radius) 0; }
.solution-box[hidden] { display: none; }

/* stacked fractions and mixed numbers */
.frac { display: inline-flex; flex-direction: column; align-items: center; vertical-align: middle; line-height: 1.15; margin: 0 0.1em; font-size: 0.85em; }
.frac-n { padding: 0 0.25em 0.06em; border-bottom: 0.09em solid currentColor; }
.frac-d { padding: 0.06em 0.25em 0; }
.frac-wrap { display: inline-flex; align-items: center; }
.paren { font-weight: 400; font-size: 1.25em; line-height: 1; vertical-align: middle; }
.review-problem .paren, .solution .paren { font-size: 1.1em; }
.mixed { display: inline-flex; align-items: center; gap: 0.12em; }
.mixed .frac { font-size: 0.75em; }

/* worked solutions */
.solution { margin: 0; padding-left: 1.3em; }
.solution li { margin: 0 0 8px; line-height: 1.6; }
.solution li:last-child { margin-bottom: 0; }
.solution .frac { font-size: 0.95em; line-height: 1.1; }
.column {
  display: inline-flex; flex-direction: column; align-items: flex-end;
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace; font-size: 1rem;
  margin: 6px 0 0 0; padding: 8px 14px; background: var(--paper); border: 1px solid var(--line); border-radius: 8px;
  line-height: 1.35; white-space: pre;
}
.column-row.is-sum { border-top: 2px solid currentColor; padding-top: 3px; margin-top: 2px; }

/* results review */
.review-item { padding: 12px 0; border-top: 1px solid var(--line); }
.review-item:first-of-type { border-top: 0; }
.review-problem { font-size: 1.15rem; }
.review-problem .frac { font-size: 0.9em; }
.review-item details { margin-top: 6px; }
.review-item summary { cursor: pointer; color: var(--accent); font-size: 0.95rem; }
.review-item .solution { margin-top: 8px; }
.results .muted { margin: 8px 0 0; }