/* /css/MedusaLesson.css
// ==========================================================
// Sudoku Paradise — 3D Medusa Lesson
// ----------------------------------------------------------
// Extends the existing lesson system with candidate-state
// coloring, a Blue/Gold Medusa palette, and two live examples.
// ========================================================== */

:root {
  --medusa-blue-bg: #d8e8f8;
  --medusa-blue-border: #4d86bb;
  --medusa-blue-ink: #174f82;

  --medusa-gold-bg: #f2dda0;
  --medusa-gold-border: #b58a22;
  --medusa-gold-ink: #6d4c00;

  --medusa-red-bg: #f3c5c1;
  --medusa-red-border: #b94b43;
  --medusa-red-ink: #7d2722;

  --medusa-teal: #174f55;
  --medusa-line: rgba(11, 104, 112, 0.24);
  --medusa-soft: #f7fbfb;
}

.medusa-difference-grid,
.medusa-link-grid,
.two-road-proof,
.medusa-rule-grid {
  display: grid;
  gap: 1rem;
}

.medusa-difference-grid,
.medusa-link-grid,
.two-road-proof {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.medusa-difference-grid article,
.medusa-link-grid article,
.two-road-proof article,
.medusa-rule-grid article {
  padding: 1rem;
  border: 1px solid var(--medusa-line);
  border-radius: 11px;
  background: var(--medusa-soft);
}

.medusa-difference-grid h3,
.medusa-link-grid h3,
.two-road-proof h3,
.medusa-rule-grid h3 {
  margin-top: 0;
  color: var(--medusa-teal);
}

.featured-difference,
.rule-featured {
  box-shadow: inset 0 0 0 2px rgba(181, 138, 34, 0.28);
}

.mini-chain {
  margin-bottom: 0;
  font-weight: 800;
  text-align: center;
}

.medusa-equation {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
  margin-top: 1rem;
}

.medusa-blue,
.medusa-gold,
.medusa-red {
  border: 2px solid;
}

.medusa-blue {
  border-color: var(--medusa-blue-border);
  background: var(--medusa-blue-bg);
  color: var(--medusa-blue-ink);
}

.medusa-gold {
  border-color: var(--medusa-gold-border);
  background: var(--medusa-gold-bg);
  color: var(--medusa-gold-ink);
}

.medusa-red {
  border-color: var(--medusa-red-border);
  background: var(--medusa-red-bg);
  color: var(--medusa-red-ink);
}

.candidate-chip {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 7.6rem;
  padding: 0.65rem 0.8rem;
  border-radius: 9px;
  font-family: Consolas, "Courier New", monospace;
  font-weight: 850;
}

.medusa-walk {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  margin: 1rem 0;
  padding: 1rem;
  border: 1px solid var(--medusa-line);
  border-radius: 12px;
  background: linear-gradient(145deg, #f7fbfb, #ffffff);
}

.medusa-node,
.medusa-link {
  opacity: 0.16;
  transform: translateY(4px);
  transition:
    opacity 160ms ease,
    transform 160ms ease,
    box-shadow 160ms ease;
}

.medusa-node.is-visible,
.medusa-link.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.medusa-node {
  padding: 0.65rem 0.72rem;
  border-radius: 9px;
  font-family: Consolas, "Courier New", monospace;
  font-weight: 850;
}

.medusa-node.is-visible {
  box-shadow: 0 4px 12px rgba(23, 79, 85, 0.12);
}

.medusa-link {
  color: #5d7274;
  font-size: 0.86rem;
  font-weight: 800;
}

.medusa-figure {
  width: fit-content;
  max-width: 100%;
  margin: 1rem auto 1.3rem;
  padding: 0.8rem;
  border: 1px solid var(--medusa-line);
  border-radius: 12px;
  background: #ffffff;
  box-shadow: 0 8px 24px rgba(23, 79, 85, 0.08);
}

.medusa-figure img {
  display: block;
  width: min(100%, 420px);
  height: auto;
  margin: 0 auto;
}

.medusa-figure figcaption {
  max-width: 42rem;
  margin-top: 0.7rem;
  color: #4d6567;
  font-size: 0.92rem;
  line-height: 1.55;
}

.medusa-blue-road {
  border-color: rgba(77, 134, 187, 0.45) !important;
  background: #f1f7fd !important;
}

.medusa-gold-road {
  border-color: rgba(181, 138, 34, 0.48) !important;
  background: #fff9e9 !important;
}

.medusa-conclusion {
  margin: 1rem 0;
  padding: 0.9rem 1rem;
  border-left: 5px solid var(--medusa-red-border);
  border-radius: 9px;
  background: #fff4f3;
  color: var(--medusa-red-ink);
}

.medusa-rule-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.medusa-rule-grid article {
  position: relative;
  min-height: 9rem;
}

.medusa-rule-grid .rule-number {
  display: inline-flex;
  width: 2rem;
  height: 2rem;
  align-items: center;
  justify-content: center;
  margin-bottom: 0.45rem;
  border-radius: 50%;
  background: var(--medusa-teal);
  color: #ffffff;
  font-weight: 900;
}

.medusa-proof-list li + li {
  margin-top: 0.55rem;
}

.medusa-routine-grid article {
  min-height: 9.2rem;
}

.component-warning {
  margin: 1rem 0;
}

@media (max-width: 760px) {
  .medusa-difference-grid,
  .medusa-link-grid,
  .two-road-proof,
  .medusa-rule-grid {
    grid-template-columns: 1fr;
  }

  .medusa-walk {
    justify-content: flex-start;
  }

  .medusa-link {
    flex-basis: 100%;
    padding-left: 0.35rem;
  }
}