/* ============================================
   LESSON 31 – Synonyms in Lectures
   ============================================ */

/* ── Inline explanation panels ── */
.l31-inline-exp {
  margin: 4px 0 10px 0;
  padding: 10px 14px;
  border-radius: 8px;
  font-size: .97rem;
  line-height: 1.8;
  border: 1px solid var(--border);
}
.l31-exp-ok  { background: rgba(72,199,116,.08); border-color: var(--success); }
.l31-exp-err { background: rgba(255,100,100,.07); border-color: var(--error); }

/* Options legend bar */
.l31-opt-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: 10px;
  padding: 12px 14px;
  margin-bottom: 18px;
}
.l31-opt-label {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 1rem;
  min-width: 110px;
}
.l31-opt-letter {
  background: rgba(251,191,36,0.15);
  color: var(--gold);
  font-weight: 700;
  padding: 2px 7px;
  border-radius: 4px;
  font-size: .8rem;
}
.l31-opt-text { color: var(--text-muted); }

/* Row list */
.l31-row-list { display: flex; flex-direction: column; gap: 10px; }

.l31-row {
  display: flex;
  align-items: center;
  gap: 12px;
  background: rgba(255,255,255,0.03);
  border: 1.5px solid rgba(255,255,255,0.08);
  border-radius: 10px;
  padding: 10px 14px;
  transition: border-color .25s, background .25s;
}
.l31-row-correct {
  border-color: var(--success) !important;
  background: rgba(74,222,128,0.07) !important;
}
.l31-row-wrong {
  border-color: var(--error) !important;
  background: rgba(248,113,113,0.07) !important;
}

.l31-word-cell {
  display: flex;
  align-items: center;
  gap: 8px;
  min-width: 140px;
}
.l31-word-num {
  color: var(--gold);
  font-weight: 700;
  font-size: .97rem;
  min-width: 18px;
}
.l31-word-text {
  color: var(--text-primary);
  font-size: 1rem;
  font-weight: 600;
}

/* Option buttons (A–H) */
.l31-opts {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  flex: 1;
}
.l31-opt-btn {
  background: rgba(255,255,255,0.06);
  border: 1.5px solid rgba(255,255,255,0.12);
  color: var(--text-muted);
  border-radius: 6px;
  width: 34px;
  height: 34px;
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  transition: background .15s, border-color .15s, color .15s;
  display: flex;
  align-items: center;
  justify-content: center;
}
.l31-opt-btn:hover:not(:disabled) {
  background: rgba(251,191,36,0.12);
  border-color: var(--gold);
  color: var(--gold);
}
.l31-opt-btn.l31-opt-active {
  background: rgba(251,191,36,0.2);
  border-color: var(--gold);
  color: var(--gold);
}
.l31-opt-btn:disabled { opacity: .55; cursor: default; }

/* Shake animation */
@keyframes l31-shake {
  0%,100%{ transform:translateX(0); }
  20%    { transform:translateX(-5px); }
  40%    { transform:translateX(5px); }
  60%    { transform:translateX(-4px); }
  80%    { transform:translateX(4px); }
}
.l31-shake { animation: l31-shake .45s ease; }

/* Explanation */
.l31-exp-list { display: flex; flex-direction: column; gap: 10px; }
.l31-exp-row {
  display: flex;
  align-items: center;
  gap: 10px;
  background: rgba(255,255,255,0.03);
  border: 1px solid rgba(255,255,255,0.07);
  border-radius: 8px;
  padding: 10px 14px;
  font-size: 1rem;
}
.l31-exp-word  { color: var(--gold); font-weight: 600; min-width: 130px; }
.l31-exp-arrow { color: var(--text-muted); }
.l31-exp-syn   { color: var(--text-primary); }

/* Study Tip */
.l31-tip-box { display: flex; flex-direction: column; gap: 14px; }
.l31-tip-item {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  background: rgba(255,255,255,0.03);
  border: 1px solid rgba(255,255,255,0.07);
  border-radius: 10px;
  padding: 14px;
}
.l31-tip-icon  { font-size: 1.3rem; padding-top: 2px; }
.l31-tip-title { font-weight: 700; color: var(--gold); margin-bottom: 6px; font-size: 1rem; }
.l31-tip-body  { color: var(--text-muted); font-size: .97rem; margin: 0; }

.l31-chip-row  { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 8px; }
.l31-chip {
  background: rgba(251,191,36,0.12);
  color: var(--gold);
  border-radius: 20px;
  padding: 3px 10px;
  font-size: .8rem;
  font-weight: 600;
}