/* ─── Variables ─────────────────────────────────────────────────────────────── */
:root {
  --bg: #000;
  --bg2: #161b22;
  --bg3: #1f2937;
  --border: #30363d;
  --text: #c9d1d9;
  --text-dim: #8b949e;
  --text-bright: #f0f6fc;
  --accent: #58a6ff;
  --green: #3fb950;
  --red: #f85149;
  --orange: #d29922;
  --purple: #bc8cff;

  --sync-color: #58a6ff;
  --async-color: #3fb950;
  --stress-color: #f85149;
  --partition-color: #ff6e6e;
  --cache-color: #2d9e9e;
  --node-color: #1f2937;
  --node-border: #374151;
}

/* ─── Reset ─────────────────────────────────────────────────────────────────── */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: "Monoid", "JetBrains Mono", "Fira Code", monospace;
  font-size: 13px;
  line-height: 1.6;
  min-height: 100vh;
}

/* ─── Intro screen ──────────────────────────────────────────────────────────── */
.intro-screen {
  position: fixed;
  inset: 0;
  background: var(--bg);
  z-index: 200;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
  overflow-y: auto;
  padding: 8vh 2rem 2rem;
  transition: opacity 0.3s ease;
}
.intro-screen.hidden {
  opacity: 0;
  pointer-events: none;
}
.intro-content {
  max-width: 400px;
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 0;
}
.intro-icon {
  width: 120px;
  height: 120px;
  border-radius: 24px;
  margin-bottom: 20px;
}
.intro-title {
  font-size: 22px;
  font-weight: 700;
  letter-spacing: 0.05em;
  margin-bottom: 4px;
}
.intro-subtitle {
  font-size: 11px;
  color: var(--text-dim);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-bottom: 4px;
}
.intro-version {
  font-size: 10px;
  color: var(--text-dim);
  opacity: 0.5;
  margin-bottom: 32px;
}
.intro-rules {
  list-style: none;
  padding: 0;
  margin: 0 0 32px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  text-align: left;
}
.intro-rules li {
  font-size: 12px;
  color: var(--text-dim);
  line-height: 1.6;
  padding-left: 16px;
  position: relative;
}
.intro-rules li::before {
  content: "·";
  position: absolute;
  left: 0;
  color: var(--accent);
}
.intro-begin-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 10px 28px;
  color: var(--text);
  font-family: inherit;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.1em;
  cursor: pointer;
  transition:
    border-color 0.15s,
    color 0.15s;
}
.intro-begin-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}
.intro-begin-btn .ph-light {
  font-size: 16px;
}

/* ─── Layout ────────────────────────────────────────────────────────────────── */
#app {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 16px 48px;
}

header {
  border-bottom: 1px solid var(--border);
  padding: 16px 0 12px;
  margin-bottom: 20px;
}

#header-icon {
  width: 3em;
  transform: translate(0, 1em); /* Should be 1em pretty much always */
}

.header-inner {
  display: flex;
  align-items: baseline;
  gap: 20px;
}
h1 {
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.05em;
}
.brand-wom {
  color: var(--accent);
}
.brand-bat {
  color: var(--text-dim);
}
.version-display {
  font-size: 10px;
  color: var(--text-dim);
}
.seed-display {
  font-size: 12px;
  color: var(--text-dim);
  letter-spacing: 0.08em;
  cursor: default;
  user-select: all;
  text-decoration: none;
}
.seed-display:hover {
  color: var(--text);
}
.quiz-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

/* ─── Panels ────────────────────────────────────────────────────────────────── */
.panel {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 20px 24px;
  margin-bottom: 16px;
}
.panel-title {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.15em;
  color: var(--text-dim);
  margin-bottom: 12px;
  text-transform: uppercase;
}
.panel-title .ph-light {
  font-size: 14px;
  letter-spacing: 0;
}

/* ─── Incident panel ────────────────────────────────────────────────────────── */
.stressor-text {
  color: var(--orange);
  font-size: 13px;
  margin-bottom: 6px;
}
.arrival-rate {
  color: var(--text-dim);
  font-size: 12px;
}
.system-policy {
  color: var(--text-dim);
  font-size: 11px;
  opacity: 0.6;
  margin-top: 4px;
}

/* ─── Help button (graph panel title) ──────────────────────────────────────── */
.help-btn {
  background: none;
  border: none;
  color: var(--text-dim);
  cursor: pointer;
  font-size: 16px;
  padding: 0;
  line-height: 1;
  margin-left: auto;
  transition: color 0.15s;
}
.help-btn:hover {
  color: var(--accent);
}

/* ─── Help modal ────────────────────────────────────────────────────────────── */
.modal-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  align-items: center;
  justify-content: center;
  z-index: 100;
}
.modal-overlay.is-open {
  display: flex;
}
.modal {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: 8px;
  max-width: 520px;
  width: calc(100% - 32px);
  max-height: 80vh;
  overflow-y: auto;
}
.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 20px 12px;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  background: var(--bg2);
}
.modal-title {
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.15em;
  color: var(--text-dim);
}
.modal-close {
  background: none;
  border: none;
  color: var(--text-dim);
  cursor: pointer;
  font-size: 18px;
  padding: 0;
  line-height: 1;
  transition: color 0.15s;
}
.modal-close:hover {
  color: var(--text);
}
.modal-body {
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}
.modal-section-title {
  font-size: 9px;
  font-weight: 700;
  letter-spacing: 0.15em;
  color: var(--text-dim);
  margin-bottom: 10px;
}
.modal-dl {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 6px 16px;
  align-items: baseline;
}
.modal-dl dt {
  color: var(--accent);
  font-size: 11px;
  font-weight: 700;
  white-space: nowrap;
}
.modal-dl dd {
  color: var(--text-dim);
  font-size: 11px;
  line-height: 1.6;
}
.modal-dl strong {
  color: var(--text);
  font-weight: 700;
}

/* ─── Graph panel ───────────────────────────────────────────────────────────── */
.legend {
  display: flex;
  gap: 20px;
  font-size: 11px;
  color: var(--text-dim);
  margin-bottom: 12px;
}
.legend-sync {
  color: var(--sync-color);
}
.legend-async {
  color: var(--async-color);
}
.legend-stress {
  color: var(--stress-color);
}
.legend-partition {
  color: var(--partition-color);
}
.legend-cache {
  color: var(--cache-color);
}

#graph-container {
  overflow-x: auto;
}
.graph-svg {
  display: block;
  max-width: 100%;
}

/* ─── SVG Node styles ───────────────────────────────────────────────────────── */
.node-rect {
  fill: var(--node-color);
  stroke: var(--node-border);
  stroke-width: 1.5;
  transition:
    stroke 0.15s,
    stroke-width 0.15s;
}
.node-ellipse {
  fill: var(--node-color);
  stroke: var(--node-border);
  stroke-width: 1.5;
  transition:
    stroke 0.15s,
    stroke-width 0.15s;
}
.node:hover .node-rect,
.node:hover .node-ellipse {
  stroke: var(--accent);
  stroke-width: 2;
}
.node--stressed .node-rect,
.node--stressed .node-ellipse {
  stroke: var(--stress-color);
  stroke-width: 2;
}
.node--selected .node-rect,
.node--selected .node-ellipse {
  stroke: var(--accent);
  stroke-width: 2.5;
  filter: drop-shadow(0 0 6px rgba(88, 166, 255, 0.4));
}
.node--correct .node-rect,
.node--correct .node-ellipse {
  stroke: var(--green);
  stroke-width: 2.5;
  filter: drop-shadow(0 0 8px rgba(63, 185, 80, 0.5));
}
.node--wrong .node-rect,
.node--wrong .node-ellipse {
  stroke: var(--red);
  stroke-width: 2.5;
  opacity: 0.6;
}
.node--cache .node-rect,
.node--cache .node-ellipse {
  stroke: var(--cache-color);
}
.node--cache.node--stressed .node-rect,
.node--cache.node--stressed .node-ellipse {
  stroke: var(--stress-color);
}

.node-name {
  fill: var(--text-bright);
  font-size: 11px;
  font-weight: 700;
  font-family: inherit;
}
.node-stat {
  fill: var(--text-dim);
  font-size: 10px;
  font-family: inherit;
}
.node-quota {
  fill: var(--purple);
  font-size: 10px;
  font-family: inherit;
}
.node-stress-label {
  fill: var(--stress-color);
  font-size: 9px;
  font-weight: 700;
  font-family: inherit;
}
.node-cache-stat {
  fill: var(--cache-color);
  font-size: 10px;
  font-family: inherit;
}
.node-cb-stat {
  fill: var(--orange);
  font-size: 10px;
  font-family: inherit;
}

/* ─── SVG Edge styles ───────────────────────────────────────────────────────── */
.edge--sync {
  stroke: var(--sync-color);
  stroke-width: 1.5;
  opacity: 0.7;
}
.edge--async {
  stroke: var(--async-color);
  stroke-width: 1.5;
  stroke-dasharray: 5 4;
  opacity: 0.7;
}
.edge--stress {
  stroke: var(--stress-color);
  stroke-width: 2;
  opacity: 0.9;
}
.edge--partition {
  stroke: var(--partition-color);
  stroke-width: 2;
  stroke-dasharray: 8 4;
  opacity: 0.9;
}

.edge-label-bg {
  fill: var(--bg2);
  stroke: var(--border);
  stroke-width: 0.5;
}

.edge-label {
  font-size: 9px;
  font-family: inherit;
  fill: var(--text-dim);
}
.edge-label--sync {
  fill: var(--sync-color);
  opacity: 0.9;
}
.edge-label--async {
  fill: var(--async-color);
  opacity: 0.9;
}
.edge-label--stress {
  fill: var(--stress-color);
  opacity: 1;
}
.edge-label--partition {
  fill: var(--partition-color);
  opacity: 1;
}

/* ─── Quiz panel ────────────────────────────────────────────────────────────── */
.quiz-prompt {
  color: var(--text-dim);
  font-size: 12px;
  margin-bottom: 16px;
}
.quiz-row {
  display: flex;
  gap: 32px;
  flex-wrap: wrap;
  margin-bottom: 20px;
}
.quiz-col {
  flex: 1;
  min-width: 200px;
}
.quiz-label {
  display: block;
  font-size: 10px;
  color: var(--text-dim);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 8px;
}

.selected-node {
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-radius: 4px;
  color: var(--text-dim);
  min-height: 38px;
  background: var(--bg3);
  font-size: 12px;
}
.selected-node.has-selection {
  color: var(--accent);
  border-color: var(--accent);
}

.failure-btns {
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.failure-btn {
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: 10px;
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 8px 12px;
  cursor: pointer;
  color: var(--text);
  font-family: inherit;
  text-align: left;
  transition:
    border-color 0.15s,
    background 0.15s;
}
.failure-btn:hover {
  border-color: var(--accent);
  background: #1a2233;
}
.failure-btn.active {
  border-color: var(--accent);
  background: #162032;
}
.btn-icon {
  font-size: 20px;
  color: var(--text-dim);
  flex-shrink: 0;
  transition: color 0.15s;
}
.failure-btn.active .btn-icon {
  color: var(--accent);
}
.btn-text {
  display: flex;
  flex-direction: column;
}
.btn-title {
  font-size: 12px;
  font-weight: 700;
  color: var(--text-bright);
}
.failure-btn.active .btn-title {
  color: var(--accent);
}
.btn-sub {
  font-size: 10px;
  color: var(--text-dim);
}

.submit-btn {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  background: var(--accent);
  color: #0d1117;
  border: none;
  border-radius: 4px;
  padding: 10px 24px;
  font-family: inherit;
  font-size: 13px;
  font-weight: 700;
  cursor: pointer;
  transition: opacity 0.15s;
}
.submit-btn:disabled {
  opacity: 0.3;
  cursor: not-allowed;
}
.submit-btn:not(:disabled):hover {
  opacity: 0.85;
}

/* ─── Result panel ──────────────────────────────────────────────────────────── */
.verdict {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  font-weight: 700;
  margin-bottom: 12px;
}
.verdict .ph-light {
  font-size: 20px;
  flex-shrink: 0;
}
.verdict--correct {
  color: var(--green);
}
.verdict--partial {
  color: var(--orange);
}
.verdict--wrong {
  color: var(--red);
}
.verdict--stable {
  color: var(--text-dim);
}

.explanation {
  color: var(--text-dim);
  font-size: 12px;
  margin-bottom: 16px;
  line-height: 1.7;
  max-width: 72ch;
}

.peaks {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 12px 16px;
  font-size: 11px;
  color: var(--text-dim);
  margin-bottom: 16px;
  overflow-x: auto;
  white-space: pre;
}

.next-btn {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 8px 20px;
  color: var(--text);
  font-family: inherit;
  font-size: 12px;
  cursor: pointer;
  transition:
    border-color 0.15s,
    color 0.15s;
}
.next-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* ─── Responsive ────────────────────────────────────────────────────────────── */
@media (max-width: 640px) {
  .quiz-row {
    flex-direction: column;
  }
  .panel {
    padding: 14px 16px;
  }
}