/* ========================================
   HiPPO interactive essay — page styles
   ======================================== */

:root {
  --demo-width: 1140px;
  --panel-bg: #101010;
  --panel-border: #2a2a2a;
  --viz-surface: #141414;
  --ctl-bg: #1c1c1c;
  --ctl-border: #333333;
}

/* --- Article typography --- */

.article-header {
  text-align: center;
  padding: 4rem 0 1rem;
}

.kicker {
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 1rem;
}

.article-header h1 {
  font-size: 2.4rem;
  line-height: 1.2;
  margin: 0 0 1.4rem;
}

.article-header .lead {
  font-size: 1.1rem;
  color: var(--text-secondary);
  text-align: left;
  margin: 0 auto;
  max-width: 46rem;
}

.paper-cite {
  margin: 2rem auto 0;
  max-width: 46rem;
  text-align: left;
  border: 1px solid var(--border-color);
  border-left: 3px solid var(--accent);
  border-radius: 10px;
  background: var(--bg-chrome);
  padding: 0.9rem 1.25rem;
}

.paper-cite-label {
  display: block;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 0.3rem;
}

.paper-cite p {
  margin: 0;
  font-size: 0.9375rem;
  color: var(--text-secondary);
}

.article-body {
  max-width: 780px;
}

.article-body h2 {
  font-size: 1.55rem;
  margin: 3rem 0 1rem;
  line-height: 1.3;
}

.article-body p {
  color: var(--text-secondary);
  margin: 0 0 1.1rem;
}

.article-body strong {
  color: var(--text-primary);
}

.article-body .katex-display {
  overflow-x: auto;
  overflow-y: hidden;
  padding: 0.4rem 0;
  color: var(--text-primary);
}

.article-body .katex {
  font-size: 1.04em;
}

.howto {
  color: var(--text-secondary);
  padding-left: 1.25rem;
  margin: 0 0 1.5rem;
}

.howto li {
  margin-bottom: 0.45rem;
}

.ink-recon {
  color: var(--accent);
  font-weight: 600;
}

.ink-measure {
  color: var(--accent-pale);
  font-weight: 600;
}

.mut {
  color: var(--text-muted);
  font-size: 0.85em;
}

/* --- Measure comparison table --- */

.measure-table-wrap {
  overflow-x: auto;
  margin: 1.4rem 0;
  border: 1px solid var(--border-color);
  border-radius: 10px;
}

.measure-table {
  width: 100%;
  min-width: 620px;
  border-collapse: collapse;
  font-size: 0.9rem;
  background: var(--panel-bg);
}

.measure-table th,
.measure-table td {
  text-align: left;
  vertical-align: top;
  padding: 0.75rem 0.9rem;
  border-bottom: 1px solid var(--border-color);
}

.measure-table thead th {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
}

.measure-table tbody tr:last-child td {
  border-bottom: 0;
}

.measure-table td {
  color: var(--text-secondary);
}

.measure-table td strong {
  color: var(--text-primary);
}

/* --- References / colophon --- */

.refs {
  color: var(--text-secondary);
  font-size: 0.9375rem;
  padding-left: 1.35rem;
}

.refs li {
  margin-bottom: 0.55rem;
}

.colophon {
  margin-top: 2.5rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--border-color);
  font-size: 0.875rem;
  color: var(--text-muted);
}

/* ========================================
   Demo
   ======================================== */

.demo-breakout {
  width: min(var(--demo-width), 100% - 2rem);
  margin: 2rem auto 3rem;
}

.demo-panel {
  position: relative;
  background: var(--panel-bg);
  border: 1px solid var(--panel-border);
  border-radius: 14px;
  padding: 1.25rem 1.25rem 1.4rem;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.35);
}

/* --- Controls --- */

.demo-controls {
  display: grid;
  grid-template-columns: minmax(300px, 1.6fr) 1fr 1fr 1fr;
  gap: 1.25rem;
  align-items: start;
  padding-bottom: 1.1rem;
  margin-bottom: 1.1rem;
  border-bottom: 1px solid var(--panel-border);
}

.control-label {
  display: block;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
}

.control-label #nVal {
  color: var(--text-primary);
  text-transform: none;
  letter-spacing: normal;
}

.seg {
  display: inline-flex;
  border: 1px solid var(--ctl-border);
  border-radius: 8px;
  overflow: hidden;
  background: var(--ctl-bg);
}

.seg button {
  appearance: none;
  border: 0;
  background: transparent;
  color: var(--text-secondary);
  font: inherit;
  font-size: 0.85rem;
  font-weight: 600;
  line-height: 1.15;
  padding: 0.45rem 0.9rem;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.1rem;
  border-right: 1px solid var(--ctl-border);
  transition: background 0.15s ease, color 0.15s ease;
}

.seg button:last-child {
  border-right: 0;
}

.seg button small {
  font-size: 0.66rem;
  font-weight: 500;
  color: var(--text-muted);
  text-transform: none;
  letter-spacing: 0.01em;
}

.seg button:hover {
  color: var(--text-primary);
}

.seg button.on {
  background: var(--accent-dim);
  color: var(--accent);
}

.seg button.on small {
  color: var(--accent-pale);
}

.measure-desc {
  margin: 0.6rem 0 0;
  font-size: 0.8125rem;
  line-height: 1.5;
  color: var(--text-secondary);
  max-width: 34rem;
}

.signal-row {
  display: flex;
  gap: 0.5rem;
  align-items: center;
}

select,
.btn {
  appearance: none;
  font: inherit;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-primary);
  background: var(--ctl-bg);
  border: 1px solid var(--ctl-border);
  border-radius: 8px;
  padding: 0.42rem 0.7rem;
  cursor: pointer;
  transition: border-color 0.15s ease, background 0.15s ease, color 0.15s ease;
}

select:hover,
.btn:hover {
  border-color: #4a4a4a;
}

select {
  padding-right: 1.6rem;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='6'%3E%3Cpath d='M1 1l4 4 4-4' stroke='%23a3a3a3' fill='none' stroke-width='1.5'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0.6rem center;
}

.btn[aria-pressed="true"] {
  background: var(--accent-dim);
  border-color: rgba(16, 185, 129, 0.5);
  color: var(--accent);
}

.btn-play {
  min-width: 2.6rem;
  font-size: 0.8rem;
}

input[type="range"] {
  width: 100%;
  accent-color: var(--accent);
  cursor: pointer;
  margin: 0.35rem 0 0;
}

/* --- Chart header --- */

.chart-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem 1rem;
  margin-bottom: 0.5rem;
}

.chart-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 1.1rem;
  align-items: center;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 0.42rem;
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.chip-toggle {
  cursor: pointer;
  user-select: none;
}

.chip-toggle input {
  accent-color: #e66767;
  cursor: pointer;
}

.swatch {
  display: inline-block;
  width: 14px;
  height: 3px;
  border-radius: 2px;
}

.swatch-sig    { background: #8f8f8f; }
.swatch-recon  { background: var(--accent); height: 4px; }
.swatch-measure {
  width: 14px;
  height: 10px;
  border-radius: 2px;
  background: rgba(16, 185, 129, 0.18);
  border: 1px solid rgba(16, 185, 129, 0.35);
}

.chart-readout {
  display: flex;
  gap: 1.1rem;
  font-size: 0.8rem;
  color: var(--text-secondary);
  font-variant-numeric: tabular-nums;
}

.chart-readout #errVal {
  color: var(--text-muted);
}

/* --- Canvases --- */

.canvas-wrap {
  position: relative;
}

.canvas-wrap canvas {
  display: block;
  width: 100%;
  border-radius: 8px;
  background: var(--viz-surface);
  border: 1px solid var(--panel-border);
}

.canvas-main canvas {
  height: 340px;
  touch-action: none;
}

.canvas-main.drawing canvas {
  cursor: crosshair;
  border-color: rgba(16, 185, 129, 0.55);
}

.draw-hint {
  display: none;
  position: absolute;
  top: 0.6rem;
  left: 50%;
  transform: translateX(-50%);
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--accent);
  background: rgba(16, 24, 20, 0.85);
  border: 1px solid rgba(16, 185, 129, 0.4);
  border-radius: 999px;
  padding: 0.25rem 0.8rem;
  pointer-events: none;
  white-space: nowrap;
}

.canvas-main.drawing .draw-hint {
  display: block;
}

/* --- Transport --- */

.transport {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  margin-top: 0.75rem;
}

.transport input[type="range"] {
  flex: 1;
  margin: 0;
}

/* --- Sub panels --- */

.sub-panels {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 1rem;
  margin-top: 1.25rem;
}

.panel h3 {
  font-family: var(--body-font);
  font-size: 0.9rem;
  font-weight: 600;
  margin: 0 0 0.15rem;
  color: var(--text-primary);
}

.panel h3 .katex {
  font-size: 0.95em;
}

.panel-sub {
  margin: 0 0 0.55rem;
  font-size: 0.78rem;
  line-height: 1.45;
  color: var(--text-muted);
  min-height: 2.3em;
}

.panel canvas {
  height: 230px;
}

/* --- Tooltip --- */

.tooltip {
  position: absolute;
  display: none;
  pointer-events: none;
  z-index: 10;
  background: #222220;
  border: 1px solid #3a3a38;
  border-radius: 6px;
  padding: 0.35rem 0.6rem;
  font-size: 0.78rem;
  line-height: 1.45;
  color: var(--text-primary);
  white-space: nowrap;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.45);
  font-variant-numeric: tabular-nums;
}

.tooltip .tt-mut {
  color: var(--text-muted);
}

/* --- Experiments --- */

.exp-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin: 1.5rem 0 1rem;
}

.exp-card {
  border: 1px solid var(--border-color);
  border-radius: 10px;
  background: var(--panel-bg);
  padding: 1.1rem 1.2rem;
  display: flex;
  flex-direction: column;
}

.exp-card h3 {
  font-family: var(--body-font);
  font-size: 0.95rem;
  font-weight: 600;
  margin: 0 0 0.4rem;
}

.exp-card p {
  font-size: 0.85rem;
  line-height: 1.55;
  margin: 0 0 0.8rem;
  flex: 1;
}

.exp-card .btn {
  align-self: flex-start;
  color: var(--accent);
  border-color: rgba(16, 185, 129, 0.35);
}

.exp-card .btn:hover {
  background: var(--accent-dim);
}

/* --- Responsive --- */

@media (max-width: 1000px) {
  .demo-controls {
    grid-template-columns: 1fr 1fr;
  }

  .sub-panels {
    grid-template-columns: 1fr;
  }

  .panel canvas {
    height: 200px;
  }
}

@media (max-width: 640px) {
  .article-header h1 {
    font-size: 1.7rem;
  }

  .demo-controls {
    grid-template-columns: 1fr;
    gap: 1rem;
  }

  .canvas-main canvas {
    height: 260px;
  }

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