/* ============================================================
   Mathematics — Chapter-specific styles
   Dark notebook theme · uses existing CSS custom properties
   ============================================================ */

/* ── Inline Math Expression Highlight ── */
.math-hl {
  display: inline;
  background: rgba(255, 236, 179, 0.12);
  padding: 1px 7px;
  border-radius: 4px;
  font-weight: 600;
  font-family: var(--font-mono);
  color: #ffe082;
  letter-spacing: 0.3px;
  border: 1px solid rgba(255, 224, 130, 0.18);
}

/* ── Step-by-Step Solution ── */
.math-steps {
  background: rgba(184, 169, 212, 0.06);
  border-left: 3px solid rgba(184, 169, 212, 0.4);
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: 14px 18px;
  margin: 12px 0;
}

.math-step {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 5px 0;
  font-family: var(--font-body);
  font-size: 0.92rem;
  color: var(--ink-white);
}

.math-step .step-label {
  color: var(--accent-lav);
  font-weight: 600;
  min-width: 18px;
  flex-shrink: 0;
}

/* ── Highlighted Final Answer ── */
.math-ans {
  display: inline-block;
  background: rgba(126, 206, 193, 0.15);
  border: 1px solid rgba(126, 206, 193, 0.3);
  padding: 2px 10px;
  border-radius: 6px;
  font-weight: 700;
  color: var(--accent-mint);
  font-family: var(--font-mono);
}

/* ── Example Label Badge ── */
.example-label {
  display: inline-block;
  background: rgba(244, 166, 160, 0.15);
  border: 1px solid rgba(244, 166, 160, 0.25);
  color: var(--accent-peach);
  padding: 3px 14px;
  border-radius: 10px;
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 0.88rem;
  margin-bottom: 8px;
}

/* ── Try It! Interactive Box ── */
.try-box {
  border: 2px dashed rgba(184, 169, 212, 0.4);
  background: rgba(184, 169, 212, 0.04);
  border-radius: 12px;
  padding: 16px 18px;
  margin: 14px 0;
}

.try-box-title {
  font-family: var(--font-sub);
  font-size: 1.1rem;
  color: var(--accent-lav);
  margin-bottom: 8px;
  font-weight: 600;
}

/* ── Rule / Formula Strip ── */
.rule-box {
  background: rgba(126, 206, 193, 0.08);
  border: 2px solid rgba(126, 206, 193, 0.22);
  border-radius: 12px;
  padding: 14px 18px;
  margin: 14px 0;
  text-align: center;
  font-weight: 600;
  font-family: var(--font-body);
  color: var(--accent-mint);
  font-size: 1rem;
}

/* ── Word Problem Card ── */
.word-problem {
  background: rgba(244, 166, 160, 0.05);
  border: 1px solid rgba(244, 166, 160, 0.18);
  border-radius: 10px;
  padding: 14px 18px;
  margin: 12px 0;
}

.wp-label {
  color: var(--accent-peach);
  font-family: var(--font-sub);
  font-size: 1rem;
  margin-bottom: 6px;
  font-weight: 600;
}

/* ── Activity Box (Toothpick etc.) ── */
.activity-box {
  border: 2px dashed rgba(126, 206, 193, 0.28);
  background: rgba(126, 206, 193, 0.03);
  border-radius: 12px;
  padding: 16px 18px;
  margin: 14px 0;
}

.activity-title {
  font-family: var(--font-sub);
  font-size: 1.12rem;
  color: var(--accent-mint);
  margin-bottom: 8px;
  font-weight: 600;
}

/* ── Definition Cards Grid ── */
.def-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 10px;
  margin: 12px 0;
}

.def-card {
  background: rgba(255, 255, 255, 0.025);
  border: 1px solid rgba(255, 255, 255, 0.07);
  border-radius: var(--radius);
  padding: 12px 14px;
}

.def-card .def-term {
  font-weight: 700;
  font-size: 0.92rem;
  color: var(--accent-lav);
  margin-bottom: 4px;
}

.def-card .def-desc {
  font-size: 0.86rem;
  color: var(--ink-dim);
  line-height: 1.45;
}

/* ── Pattern Table ── */
.pattern-table {
  width: 100%;
  border-collapse: collapse;
  margin: 12px 0;
  font-size: 0.88rem;
}

.pattern-table th {
  background: rgba(126, 206, 193, 0.1);
  color: var(--accent-mint);
  padding: 8px 12px;
  text-align: center;
  font-weight: 600;
  border: 1px solid rgba(255, 255, 255, 0.07);
}

.pattern-table td {
  padding: 8px 12px;
  text-align: center;
  border: 1px solid rgba(255, 255, 255, 0.05);
  color: var(--ink-white);
}

/* ── Tip / Hint Box ── */
.tip-box {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  background: rgba(255, 236, 179, 0.05);
  border: 1px solid rgba(255, 236, 179, 0.12);
  border-radius: var(--radius);
  padding: 10px 14px;
  margin: 10px 0;
  font-size: 0.88rem;
  color: #ffe082;
}

.tip-box .tip-icon {
  flex-shrink: 0;
  font-size: 1.1rem;
}

/* ── Fraction Display (stacked) ── */
.frac {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  vertical-align: middle;
  font-size: 0.88em;
  line-height: 1.15;
  margin: 0 3px;
}

.frac-num {
  border-bottom: 1.5px solid var(--ink-dim);
  padding: 0 4px 1px;
}

.frac-den {
  padding: 1px 4px 0;
}

/* ── Marks Tag (per step) ── */
.marks-tag {
  display: inline-block;
  background: rgba(126, 206, 193, 0.12);
  color: var(--accent-mint);
  font-size: 0.62rem;
  padding: 1px 5px;
  border-radius: 3px;
  margin-left: 4px;
  font-weight: 600;
  font-family: var(--font-mono);
  vertical-align: middle;
}

/* ── Must Memorize (Mug Up) Box ── */
.mugup {
  background: rgba(244, 166, 160, 0.06);
  border: 2px solid rgba(244, 166, 160, 0.25);
  border-radius: 12px;
  padding: 16px 18px;
  margin: 14px 0;
}

.mugup-title {
  color: var(--accent-peach);
  font-family: var(--font-sub);
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 10px;
}

.mugup ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.mugup li {
  padding: 3px 0;
  font-size: 0.88rem;
  color: var(--ink-white);
  line-height: 1.5;
}

.mugup li::before {
  content: '▸ ';
  color: var(--accent-peach);
  font-weight: 700;
}

/* ── Problem Container ── */
.problem-box {
  margin: 16px 0;
  padding: 14px 16px;
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: 10px;
  background: rgba(255, 255, 255, 0.015);
}

.problem-num {
  color: var(--accent-lav);
  font-family: var(--font-sub);
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 8px;
}

.total-marks {
  color: var(--accent-mint);
  font-size: 0.82rem;
  font-family: var(--font-mono);
  margin-left: 6px;
}

/* ── Responsive ── */
@media (max-width: 480px) {
  .def-grid { grid-template-columns: 1fr; }
  .math-steps { padding: 10px 12px; }
  .try-box, .activity-box { padding: 12px 14px; }
  .mugup { padding: 12px 14px; }
  .problem-box { padding: 10px 12px; }
}