/* Sub-navigation */
.subnav {
  position: sticky;
  top: var(--header-h, 57px);
  z-index: 15;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  margin: 0 -20px 32px;
  padding: 10px 20px;
  overflow-x: auto;
  white-space: nowrap;
  -webkit-overflow-scrolling: touch;
}

.subnav a {
  display: inline-block;
  text-decoration: none;
  color: var(--text-muted);
  font-size: 0.85rem;
  padding: 6px 12px;
  border-radius: 999px;
  margin-right: 4px;
}

.subnav a:hover {
  background: var(--bg-elevated);
  color: var(--text);
}

/* Section structure */
.hw-section {
  margin-top: 56px;
  scroll-margin-top: 110px;
}

.hw-section:first-of-type {
  margin-top: 0;
}

.hw-section h2 {
  font-size: 1.5rem;
  margin: 0 0 6px;
}

.hw-section > .hw-section-intro {
  color: var(--text-muted);
  max-width: 70ch;
  margin: 0 0 28px;
}

.hw-subsection {
  margin-top: 36px;
  padding-top: 28px;
  border-top: 1px solid var(--border);
}

.hw-subsection:first-of-type {
  margin-top: 24px;
  padding-top: 0;
  border-top: none;
}

.hw-subsection h3 {
  font-size: 1.15rem;
  margin: 0 0 12px;
}

/* Definition blocks */
.definition p {
  margin: 0 0 10px;
  max-width: 68ch;
}

.definition p.lead {
  font-weight: 600;
  font-size: 1.02rem;
}

.definition p.muted {
  color: var(--text-muted);
  font-size: 0.93rem;
}

/* Figures */
.hw-figure {
  margin: 20px 0;
}

.hw-figure img {
  width: 100%;
  border-radius: 12px;
  border: 1px solid var(--border);
  display: block;
  background: var(--bg-elevated);
}

.hw-figure figcaption {
  margin-top: 8px;
  font-size: 0.82rem;
  color: var(--text-muted);
}

.hw-figure-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
  margin: 20px 0;
}

.hw-figure-row .hw-figure {
  margin: 0;
}

.hw-figure--diagram img {
  background: #ffffff;
  object-fit: contain;
  padding: 10px;
}

@media (prefers-color-scheme: dark) {
  .hw-figure--diagram img {
    background: #ffffff;
  }
}

/* Advantages / disadvantages */
.adv-disadv {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px;
  margin: 20px 0;
}

.adv-disadv > div {
  border-radius: 12px;
  padding: 18px 20px;
  border: 1px solid var(--border);
}

.adv-disadv .advantages {
  background: color-mix(in srgb, var(--cat-research) 8%, var(--bg-elevated));
  border-color: color-mix(in srgb, var(--cat-research) 35%, var(--border));
}

.adv-disadv .disadvantages {
  background: color-mix(in srgb, var(--cat-input) 8%, var(--bg-elevated));
  border-color: color-mix(in srgb, var(--cat-input) 35%, var(--border));
}

.adv-disadv h4 {
  margin: 0 0 10px;
  font-size: 0.95rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.adv-disadv .advantages h4 {
  color: var(--cat-research);
}

.adv-disadv .disadvantages h4 {
  color: var(--cat-input);
}

.adv-disadv ul {
  margin: 0;
  padding-left: 18px;
  font-size: 0.9rem;
  color: var(--text);
}

.adv-disadv li {
  margin-bottom: 6px;
}

/* Formula callouts */
.formula {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  border-radius: 8px;
  padding: 16px 20px;
  margin: 16px 0;
  font-family: "Cambria", Georgia, serif;
  font-size: 1.1rem;
}

.formula .formula-note {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  color: var(--text-muted);
  font-size: 0.85rem;
  margin-top: 8px;
}

/* Terminology grid */
.term-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 16px;
  margin: 20px 0;
}

.term-grid h4 {
  margin: 0 0 6px;
  font-size: 0.95rem;
}

.term-grid p {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.88rem;
}

/* Data table */
.hw-table-wrap {
  overflow-x: auto;
  margin: 16px 0;
}

table.hw-table {
  border-collapse: collapse;
  width: 100%;
  font-size: 0.85rem;
  min-width: 480px;
}

table.hw-table caption {
  text-align: left;
  font-weight: 600;
  margin-bottom: 8px;
}

table.hw-table th,
table.hw-table td {
  border: 1px solid var(--border);
  padding: 6px 10px;
  text-align: center;
}

table.hw-table th {
  background: var(--bg-elevated);
}

table.hw-table td:first-child,
table.hw-table th:first-child {
  text-align: left;
}

/* Type gallery cards (display types) */
.type-card {
  margin-top: 20px;
}

.type-card__media {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 10px;
  margin-bottom: 16px;
}

.type-card__media img {
  width: 100%;
  height: 180px;
  object-fit: cover;
  border-radius: 10px;
  border: 1px solid var(--border);
  display: block;
}

/* Interactive demo */
.demo-panel {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 24px;
  margin: 20px 0;
}

.demo-controls {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px;
  margin-bottom: 20px;
}

.demo-control label {
  display: flex;
  justify-content: space-between;
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 6px;
}

.demo-control label span.val {
  font-weight: 700;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
}

.demo-control input[type="range"] {
  width: 100%;
}

.demo-stage {
  background: var(--bg);
  border-radius: 12px;
  border: 1px solid var(--border);
  overflow: hidden;
}

.demo-stage canvas {
  display: block;
  width: 100%;
  height: auto;
}

.demo-readouts {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 12px;
  margin-top: 16px;
}

.demo-readout {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 10px 14px;
  text-align: center;
}

.demo-readout .demo-readout__label {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-muted);
}

.demo-readout .demo-readout__value {
  font-size: 1.2rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

/* Variant cross-link banner */
.variant-banner {
  background: color-mix(in srgb, var(--accent) 10%, var(--bg-elevated));
  border: 1px solid color-mix(in srgb, var(--accent) 35%, var(--border));
  border-radius: 12px;
  padding: 12px 16px;
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 28px;
}

.variant-banner strong {
  color: var(--text);
}