:root {
  --paper: #f8f5ec;
  --ink: #24231f;
  --muted: #6b665d;
  --line: #d9d1c0;
  --panel: #fffdf7;
  --accent: #287a78;
  --accent-strong: #175f60;
  --coral: #c45c43;
  --gold: #c89a31;
  --green: #5b8d47;
  --shadow: 0 18px 48px rgba(42, 35, 20, 0.12);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  background:
    linear-gradient(rgba(248, 245, 236, 0.86), rgba(248, 245, 236, 0.92)),
    repeating-linear-gradient(0deg, transparent 0 31px, rgba(86, 123, 143, 0.18) 32px 33px),
    var(--paper);
}

button,
.button-link,
input {
  font: inherit;
}

button,
.button-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 38px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 0 14px;
  color: var(--ink);
  background: #fffaf0;
  cursor: pointer;
  text-decoration: none;
  transition: transform 140ms ease, border-color 140ms ease, background 140ms ease;
}

button:hover,
.button-link:hover {
  border-color: var(--accent);
  transform: translateY(-1px);
}

.primary-button {
  color: #fff;
  border-color: var(--accent-strong);
  background: var(--accent);
}

.app-shell {
  display: grid;
  grid-template-rows: auto auto 1fr;
  gap: 16px;
  width: min(1520px, 100%);
  min-height: 100vh;
  margin: 0 auto;
  padding: 18px;
}

.toolbar,
.model-intro,
.control-panel,
.insight-panel {
  border: 1px solid var(--line);
  background: rgba(255, 253, 247, 0.92);
  box-shadow: var(--shadow);
}

.toolbar {
  display: grid;
  grid-template-columns: minmax(220px, 1fr) auto minmax(420px, 1.2fr);
  align-items: center;
  gap: 20px;
  min-height: 86px;
  border-radius: 8px;
  padding: 14px 18px;
}

.identity h1,
.panel-section h2 {
  margin: 0;
  letter-spacing: 0;
}

.identity h1 {
  font-size: clamp(1.45rem, 2.4vw, 2.25rem);
  line-height: 1;
}

.identity p,
.microcopy,
.model-intro p {
  margin: 7px 0 0;
  color: var(--muted);
  line-height: 1.4;
}

.model-intro {
  display: grid;
  grid-template-columns: minmax(280px, 0.8fr) minmax(480px, 1.2fr);
  gap: 18px;
  align-items: center;
  border-radius: 8px;
  padding: 16px 18px;
}

.model-intro h2 {
  margin: 0;
  font-size: 1rem;
}

.formula-card {
  border-left: 3px solid var(--accent);
  padding-left: 14px;
}

.formula-card span {
  display: block;
  color: var(--muted);
  font-size: 0.78rem;
  text-transform: uppercase;
}

.math-formula {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin-top: 8px;
  font-family: ui-serif, Georgia, "Times New Roman", serif;
  font-size: 1.05rem;
  line-height: 1.55;
  overflow-wrap: anywhere;
}

.math-integral,
.math-sum {
  display: inline-flex;
  align-items: center;
  font-size: 1.45em;
}

.simulation-formula {
  display: grid;
  gap: 5px;
  margin-top: 12px;
  border-top: 1px solid rgba(217, 209, 192, 0.85);
  padding-top: 10px;
}

.simulation-formula span {
  color: var(--muted);
  font-size: 0.78rem;
  text-transform: uppercase;
}

.simulation-formula strong {
  font-family: ui-serif, Georgia, "Times New Roman", serif;
  font-size: 0.94rem;
  line-height: 1.4;
  overflow-wrap: anywhere;
}

.formula-terms {
  display: grid;
  grid-template-columns: repeat(2, minmax(180px, 1fr));
  gap: 8px 14px;
  margin: 12px 0 0;
}

.formula-terms div {
  display: grid;
  grid-template-columns: minmax(72px, auto) 1fr;
  gap: 8px;
  align-items: baseline;
}

.formula-terms dt {
  color: var(--ink);
  font-family: ui-serif, Georgia, "Times New Roman", serif;
  font-weight: 700;
}

.formula-terms dd {
  margin: 0;
  color: var(--muted);
  font-size: 0.84rem;
  line-height: 1.35;
}

.help-term {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  border-radius: 4px;
  outline: 0;
  cursor: help;
  text-decoration: underline;
  text-decoration-style: dotted;
  text-underline-offset: 3px;
}

.help-term::after {
  content: attr(data-help);
  position: absolute;
  left: 0;
  top: calc(100% + 8px);
  z-index: 20;
  width: min(280px, 78vw);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px;
  color: var(--ink);
  background: rgba(255, 253, 247, 0.99);
  box-shadow: var(--shadow);
  font-size: 0.84rem;
  font-weight: 500;
  line-height: 1.35;
  text-transform: none;
  pointer-events: none;
  opacity: 0;
  transform: translateY(-4px);
  transition: opacity 120ms ease, transform 120ms ease;
}

.help-term:hover::after,
.help-term:focus::after,
.help-term:focus-visible::after {
  opacity: 1;
  transform: translateY(0);
}

.run-controls,
.event-actions,
.mode-tabs {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.metric-strip {
  display: grid;
  grid-template-columns: repeat(6, minmax(90px, 1fr));
  gap: 8px;
}

.metric-strip div {
  min-width: 0;
  border-left: 3px solid var(--accent);
  padding: 3px 0 3px 10px;
}

.metric-strip span {
  display: block;
  color: var(--muted);
  font-size: 0.76rem;
}

.metric-strip strong {
  display: block;
  margin-top: 3px;
  font-size: 1.15rem;
}

.workspace {
  display: grid;
  grid-template-columns: 290px minmax(420px, 1fr) 330px;
  gap: 16px;
  min-height: 0;
}

.control-panel,
.insight-panel {
  overflow: auto;
  border-radius: 8px;
}

.panel-section {
  padding: 16px;
  border-bottom: 1px solid var(--line);
}

.panel-section:last-child {
  border-bottom: 0;
}

.panel-section h2 {
  margin-bottom: 14px;
  font-size: 0.92rem;
  text-transform: uppercase;
  color: #48443d;
}

label {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 8px 12px;
  align-items: center;
  margin-top: 13px;
  color: var(--muted);
}

input[type="range"] {
  grid-column: 1 / -1;
  width: 100%;
  accent-color: var(--accent);
}

output {
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}

.mode-tabs {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  padding: 3px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #f2ecdc;
}

.mode-tabs button {
  border: 0;
  background: transparent;
}

.mode-tabs button.active {
  color: #fff;
  background: var(--accent);
}

.selected-list,
.event-log {
  color: var(--muted);
  font-size: 0.9rem;
  line-height: 1.45;
}

.selected-chip {
  display: inline-block;
  margin: 0 5px 6px 0;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 4px 8px;
  color: var(--ink);
  background: #fff8e8;
}

.stage {
  position: relative;
  min-height: calc(100vh - 138px);
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background:
    radial-gradient(circle at 18% 12%, rgba(200, 154, 49, 0.13), transparent 28%),
    linear-gradient(135deg, rgba(255, 253, 247, 0.96), rgba(241, 248, 244, 0.92));
  box-shadow: var(--shadow);
}

#network {
  display: block;
  width: 100%;
  height: 100%;
  min-height: calc(100vh - 138px);
}

.edge {
  stroke: rgba(92, 86, 75, 0.22);
  stroke-linecap: round;
}

.cow-node {
  cursor: pointer;
}

.cow-node circle {
  stroke: rgba(36, 35, 31, 0.42);
  stroke-width: 1.4;
  transition: stroke-width 140ms ease, filter 140ms ease;
}

.cow-node.selected circle {
  stroke: var(--coral);
  stroke-width: 4;
  filter: drop-shadow(0 4px 8px rgba(196, 92, 67, 0.35));
}

.cow-node text {
  fill: #2f2c27;
  font-size: 11px;
  font-weight: 700;
  text-anchor: middle;
  pointer-events: none;
}

.tooltip {
  position: absolute;
  z-index: 5;
  width: 190px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px;
  color: var(--ink);
  background: rgba(255, 253, 247, 0.98);
  box-shadow: var(--shadow);
  pointer-events: none;
  font-size: 0.88rem;
}

.ranking-list {
  display: grid;
  gap: 8px;
  margin: 0;
  padding-left: 24px;
}

.ranking-list li {
  padding: 8px 0;
  border-bottom: 1px solid rgba(217, 209, 192, 0.7);
}

.ranking-list strong {
  display: block;
}

.ranking-list span {
  display: block;
  margin-top: 2px;
  color: var(--muted);
  font-size: 0.84rem;
}

#distributionChart {
  width: 100%;
  height: auto;
}

.event-entry {
  margin-bottom: 10px;
  padding-bottom: 10px;
  border-bottom: 1px solid rgba(217, 209, 192, 0.7);
}

.event-entry strong {
  display: block;
  color: var(--ink);
}

@media (max-width: 1100px) {
  .toolbar,
  .model-intro,
  .workspace {
    grid-template-columns: 1fr;
  }

  .metric-strip {
    grid-template-columns: repeat(2, minmax(120px, 1fr));
  }

  .stage,
  #network {
    min-height: 620px;
  }
}

@media (max-width: 620px) {
  .app-shell {
    padding: 10px;
  }

  .toolbar {
    padding: 14px;
  }

  .model-intro {
    padding: 14px;
  }

  .math-formula,
  .simulation-formula strong {
    font-size: 0.82rem;
  }

  .formula-terms {
    grid-template-columns: 1fr;
  }

  .metric-strip {
    grid-template-columns: 1fr;
  }

  .run-controls {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
  }

  button {
    padding: 0 10px;
  }
}