:root {
  --bg: #f3efe4;
  --bg-deep: #0f2d2c;
  --surface: rgba(255, 252, 244, 0.82);
  --surface-strong: rgba(255, 250, 240, 0.94);
  --ink: #14211f;
  --ink-soft: #4c5c58;
  --line: rgba(20, 33, 31, 0.12);
  --accent: #d76634;
  --accent-strong: #a33f16;
  --teal: #1f6b69;
  --gold: #f2b544;
  --state-zero: #e2dbcb;
  --state-one: #ffc96f;
  --state-x: #9cd5ce;
  --group-1: #d76634;
  --group-2: #1f6b69;
  --group-3: #8864d9;
  --group-4: #c94b71;
  --group-5: #4a8b2c;
  --group-6: #2576b8;
  --shadow: 0 24px 70px rgba(21, 39, 38, 0.12);
  --radius-xl: 32px;
  --radius-lg: 22px;
  --radius-md: 16px;
  --radius-sm: 12px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Avenir Next", "Trebuchet MS", sans-serif;
  color: var(--ink);
  background:
    radial-gradient(circle at top left, rgba(242, 181, 68, 0.26), transparent 28%),
    radial-gradient(circle at 85% 12%, rgba(31, 107, 105, 0.18), transparent 20%),
    linear-gradient(180deg, #f8f4e9 0%, var(--bg) 52%, #efe7d6 100%);
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(15, 45, 44, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(15, 45, 44, 0.03) 1px, transparent 1px);
  background-size: 34px 34px;
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.25), transparent 88%);
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  font: inherit;
}

.page-shell {
  max-width: 1280px;
  margin: 0 auto;
  padding: 24px;
}

.hero,
.rules-section,
.studio-section,
.examples-section,
.roadmap-section {
  position: relative;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(320px, 0.85fr);
  gap: 32px;
  padding: 24px 0 76px;
}

.topbar {
  grid-column: 1 / -1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 0 20px;
}

.brand {
  font-family: "Iowan Old Style", "Palatino Linotype", "Book Antiqua", serif;
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.nav-links {
  display: flex;
  gap: 22px;
  color: var(--ink-soft);
}

.hero-copy,
.hero-panel,
.studio-shell,
.rule-card,
.example-card,
.roadmap-step {
  background: var(--surface);
  backdrop-filter: blur(16px);
  border: 1px solid rgba(255, 255, 255, 0.5);
  box-shadow: var(--shadow);
}

.hero-copy {
  border-radius: var(--radius-xl);
  padding: 42px;
  min-height: 420px;
}

.hero-panel {
  border-radius: var(--radius-xl);
  padding: 22px;
  background:
    linear-gradient(160deg, rgba(15, 45, 44, 0.96), rgba(31, 107, 105, 0.86)),
    var(--surface);
  color: #f8f4ea;
  display: flex;
}

.hero-panel .panel-label {
  color: #f2c66c;
}

.panel-card {
  border-radius: calc(var(--radius-xl) - 6px);
  padding: 26px;
  border: 1px solid rgba(255, 255, 255, 0.12);
  width: 100%;
  background: rgba(255, 255, 255, 0.06);
}

.eyebrow,
.panel-label,
.summary-label,
.example-tag {
  text-transform: uppercase;
  letter-spacing: 0.14em;
  font-size: 0.76rem;
  font-weight: 700;
}

.eyebrow,
.panel-label,
.summary-label {
  color: var(--accent-strong);
}

.hero h1,
.section-heading h2,
.map-header h3,
.expression-card h3,
.example-card h3,
.roadmap-step h3 {
  font-family: "Iowan Old Style", "Palatino Linotype", "Book Antiqua", serif;
}

.hero h1 {
  margin: 14px 0 18px;
  max-width: 12ch;
  font-size: clamp(2.8rem, 5vw, 5.1rem);
  line-height: 0.96;
}

.hero-text,
.rule-card p,
.example-card p,
.roadmap-step p,
.map-legend,
#expression-caption,
#logic-caption,
#challenge-copy,
#canonical-sop-expression,
#canonical-pos-expression {
  color: var(--ink-soft);
  line-height: 1.65;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 28px;
}

.button,
.chip {
  border: 0;
  border-radius: 999px;
  padding: 12px 18px;
  cursor: pointer;
  transition: transform 180ms ease, box-shadow 180ms ease, background 180ms ease;
}

.button:hover,
.chip:hover,
.group-item:hover,
.kmap-cell:hover {
  transform: translateY(-1px);
}

.button-primary {
  background: linear-gradient(135deg, var(--accent), #f28e4a);
  color: #fff8f0;
  box-shadow: 0 12px 24px rgba(215, 102, 52, 0.24);
}

.button-secondary {
  background: rgba(255, 255, 255, 0.7);
  color: var(--ink);
  border: 1px solid rgba(20, 33, 31, 0.1);
}

.chip {
  background: rgba(255, 255, 255, 0.72);
  border: 1px solid rgba(20, 33, 31, 0.08);
  color: var(--ink);
  padding: 10px 16px;
}

.quick-facts {
  margin: 20px 0 0;
  padding-left: 18px;
  display: grid;
  gap: 14px;
  line-height: 1.55;
}

.section-heading {
  margin-bottom: 24px;
}

.section-heading h2 {
  margin: 10px 0 0;
  font-size: clamp(2rem, 3.4vw, 3rem);
}

.rules-section,
.studio-section,
.examples-section,
.roadmap-section {
  padding: 28px 0 40px;
}

.rule-grid,
.example-grid,
.roadmap-grid {
  display: grid;
  gap: 18px;
}

.rule-grid {
  grid-template-columns: repeat(5, minmax(0, 1fr));
}

.example-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.roadmap-grid {
  grid-template-columns: repeat(5, minmax(0, 1fr));
}

.rule-card,
.example-card,
.roadmap-step {
  border-radius: var(--radius-lg);
  padding: 24px;
}

.rule-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: rgba(31, 107, 105, 0.12);
  color: var(--teal);
  font-weight: 700;
}

.rule-card h3,
.example-card h3,
.roadmap-step h3 {
  margin: 18px 0 12px;
  font-size: 1.3rem;
}

.studio-shell {
  border-radius: var(--radius-xl);
  padding: 28px;
}

.studio-toolbar {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 18px;
  flex-wrap: wrap;
  margin-bottom: 28px;
}

.toolbar-group {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.variable-group,
.preset-group {
  flex-direction: column;
  align-items: flex-start;
  flex-wrap: nowrap;
}

.chip-row {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.toolbar-label {
  color: var(--ink-soft);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.chip.is-active {
  background: linear-gradient(135deg, rgba(215, 102, 52, 0.18), rgba(242, 181, 68, 0.36));
  border-color: rgba(163, 63, 22, 0.24);
  color: var(--accent-strong);
  box-shadow: 0 10px 20px rgba(215, 102, 52, 0.12);
}

.studio-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(320px, 0.9fr);
  gap: 22px;
}

.studio-layout.is-multi-panel {
  grid-template-columns: minmax(0, 1fr);
}

.map-panel,
.analysis-panel {
  background: rgba(255, 251, 243, 0.68);
  border: 1px solid rgba(20, 33, 31, 0.08);
  border-radius: var(--radius-lg);
}

.map-panel {
  padding: 24px;
  min-width: 0;
}

.map-panel.is-multi-panel .map-header {
  align-items: flex-start;
}

.map-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 16px;
  margin-bottom: 18px;
}

.map-header h3 {
  margin: 8px 0 0;
  font-size: 1.5rem;
}

.map-header h3 span:nth-child(1) {
  color: var(--accent-strong);
}

.map-header h3 span:nth-child(2) {
  color: var(--teal);
}

.analysis-panel {
  padding: 20px;
  display: grid;
  gap: 16px;
  align-content: start;
  min-width: 0;
}

.analysis-panel > * {
  min-width: 0;
}

.expression-card,
.logic-card,
.canonical-card,
.challenge-card,
.summary-card,
.group-item {
  background: var(--surface-strong);
  border: 1px solid rgba(20, 33, 31, 0.08);
  border-radius: var(--radius-md);
}

.expression-card,
.logic-card,
.canonical-card,
.challenge-card {
  padding: 18px;
}

.expression-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin-top: 10px;
}

.expression-block {
  padding: 14px;
  border-radius: 14px;
  background: rgba(255, 251, 243, 0.8);
  border: 1px solid rgba(20, 33, 31, 0.08);
}

.expression-card h3 {
  margin: 8px 0 0;
  font-size: clamp(1.4rem, 2.3vw, 2rem);
  line-height: 1.25;
  word-break: break-word;
}

.summary-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
}

.logic-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 14px;
}

.logic-header p {
  margin: 0;
}

.logic-toggle {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.chip-small {
  padding: 8px 12px;
}

.logic-diagram {
  width: 100%;
  min-width: 0;
  overflow: hidden;
  border-radius: 14px;
  border: 1px solid rgba(20, 33, 31, 0.08);
  background:
    radial-gradient(circle at top left, rgba(242, 181, 68, 0.12), transparent 30%),
    rgba(255, 251, 243, 0.92);
  padding: 10px;
}

.logic-diagram svg {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
}

.summary-card {
  padding: 16px;
}

.summary-value {
  margin: 8px 0 0;
  font-weight: 700;
  line-height: 1.5;
  word-break: break-word;
}

#canonical-sop-expression,
#canonical-pos-expression {
  margin: 8px 0 0;
  color: var(--ink-soft);
  line-height: 1.6;
  word-break: break-word;
}

.kmap-stage {
  display: grid;
  width: 100%;
  overflow-x: auto;
  padding-bottom: 6px;
}

.kmap-stage.is-multi-panel {
  padding-bottom: 10px;
}

.panel-grid {
  display: grid;
  grid-template-columns: repeat(var(--panel-columns), minmax(0, 1fr));
  gap: 16px;
  width: max-content;
  min-width: 100%;
  align-items: start;
}

.map-board {
  display: grid;
  gap: 12px;
  min-width: 0;
}

.map-board-header {
  display: flex;
  justify-content: flex-end;
}

.panel-badge {
  margin: 0;
  padding: 8px 12px;
  border-radius: 999px;
  background: rgba(31, 107, 105, 0.12);
  color: var(--teal);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.kmap-grid {
  display: grid;
  grid-template-columns: var(--axis-size) repeat(var(--map-cols), minmax(72px, 1fr));
  gap: 10px;
  min-width: 0;
}

.axis-cell,
.corner-cell,
.kmap-cell {
  border-radius: var(--radius-sm);
  min-height: 84px;
}

.corner-cell,
.axis-cell {
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(31, 107, 105, 0.08);
  color: var(--teal);
  font-weight: 700;
}

.corner-cell {
  flex-direction: column;
  gap: 2px;
  min-height: 68px;
}

.kmap-cell {
  position: relative;
  border: 1px solid rgba(20, 33, 31, 0.08);
  background: rgba(255, 251, 243, 0.9);
  padding: 14px;
  text-align: left;
  overflow: hidden;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.6);
}

.kmap-cell::before {
  content: "";
  position: absolute;
  inset: auto -24px -40px auto;
  width: 88px;
  height: 88px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.55);
}

.kmap-cell.state-0 {
  background: linear-gradient(180deg, rgba(226, 219, 203, 0.82), rgba(255, 251, 243, 0.9));
}

.kmap-cell.state-1 {
  background: linear-gradient(180deg, rgba(255, 201, 111, 0.88), rgba(255, 240, 211, 0.92));
}

.kmap-cell.state-x {
  background: linear-gradient(180deg, rgba(156, 213, 206, 0.86), rgba(230, 247, 243, 0.95));
}

.kmap-cell.is-active-group {
  border-color: var(--group-accent);
  box-shadow:
    0 0 0 3px var(--group-accent),
    inset 0 1px 0 rgba(255, 255, 255, 0.65);
}

.cell-minterm,
.cell-bits {
  position: relative;
  z-index: 1;
}

.cell-minterm {
  color: rgba(20, 33, 31, 0.62);
  font-size: 0.82rem;
  font-weight: 700;
}

.cell-state {
  position: relative;
  z-index: 1;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-top: 18px;
  width: 46px;
  height: 46px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.56);
  font-size: 1.2rem;
  font-weight: 800;
}

.cell-bits {
  display: block;
  margin-top: 12px;
  color: rgba(20, 33, 31, 0.62);
  font-size: 0.8rem;
}

.state-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  margin-top: 18px;
  color: var(--ink-soft);
}

.legend-dot {
  display: inline-block;
  width: 10px;
  height: 10px;
  margin-right: 8px;
  border-radius: 50%;
}

.legend-dot.state-one {
  background: var(--gold);
}

.legend-dot.state-zero {
  background: #c8bea8;
}

.legend-dot.state-x {
  background: var(--teal);
}

.group-list {
  display: grid;
  gap: 12px;
}

.group-item {
  width: 100%;
  text-align: left;
  padding: 16px;
  cursor: pointer;
  transition: transform 180ms ease, box-shadow 180ms ease;
  box-shadow: inset 4px 0 0 var(--group-accent);
}

.group-item.is-selected {
  box-shadow:
    inset 5px 0 0 var(--group-accent),
    0 10px 22px rgba(20, 33, 31, 0.08);
}

.group-meta {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 8px;
  color: var(--ink-soft);
  font-size: 0.82rem;
  font-weight: 700;
}

.group-term {
  margin: 0;
  font-family: "Iowan Old Style", "Palatino Linotype", "Book Antiqua", serif;
  font-size: 1.35rem;
}

.group-cover,
.group-note {
  margin: 8px 0 0;
  color: var(--ink-soft);
  line-height: 1.5;
}

@media (max-width: 1180px) {
  .rule-grid,
  .roadmap-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .hero,
  .studio-layout {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 920px) {
  .example-grid {
    grid-template-columns: 1fr;
  }

  .panel-grid {
    grid-template-columns: 1fr;
  }

  .axis-cell,
  .corner-cell,
  .kmap-cell {
    min-height: 82px;
  }

  .kmap-cell {
    padding: 10px;
  }
}

@media (max-width: 720px) {
  .page-shell {
    padding: 16px;
  }

  .topbar,
  .map-header,
  .studio-toolbar {
    align-items: flex-start;
    flex-direction: column;
  }

  .nav-links {
    gap: 14px;
    flex-wrap: wrap;
  }

  .hero-copy,
  .hero-panel,
  .studio-shell,
  .rule-card,
  .example-card,
  .roadmap-step {
    padding: 20px;
  }

  .rule-grid,
  .roadmap-grid {
    grid-template-columns: 1fr;
  }

  .summary-grid {
    grid-template-columns: 1fr;
  }

  .expression-grid {
    grid-template-columns: 1fr;
  }

  .kmap-grid {
    gap: 6px;
  }

  .axis-cell,
  .corner-cell {
    min-height: 56px;
    font-size: 0.85rem;
  }

  .kmap-cell {
    min-height: 78px;
    border-radius: 10px;
    padding: 10px;
  }

  .cell-state {
    margin-top: 12px;
    width: 38px;
    height: 38px;
  }

  .panel-badge {
    font-size: 0.74rem;
  }
}