.quality-chapter { margin-top:96px; }
.quality-index {
  background:linear-gradient(145deg,color-mix(in srgb,var(--accent-3) 7%,var(--panel)),var(--panel));
}
.quality-index::after { border-color:color-mix(in srgb,var(--accent-3) 30%,transparent); }

.quality-model-grid,
.bandwidth-grid,
.quality-compare-grid,
.quality-duality-grid {
  display:grid;
  grid-template-columns:repeat(3,minmax(0,1fr));
  gap:12px;
}
.quality-model-grid article,
.bandwidth-grid article,
.quality-compare-grid article,
.quality-duality-grid article {
  min-width:0;
  padding:24px;
  border:1px solid var(--line);
  border-radius:var(--radius-sm);
  background:var(--panel);
}
.quality-model-grid h3 { margin:14px 0 8px; }
.quality-model-grid p,
.bandwidth-grid p,
.quality-compare-grid p,
.quality-duality-grid p {
  margin:9px 0 0;
  color:var(--muted);
  font-size:.84rem;
}
.quality-primary {
  background:linear-gradient(145deg,color-mix(in srgb,var(--accent) 6%,var(--panel)),var(--panel)) !important;
}
.bandwidth-key {
  background:linear-gradient(145deg,color-mix(in srgb,var(--accent-3) 7%,var(--panel)),var(--panel)) !important;
}
.quality-warning {
  background:linear-gradient(145deg,color-mix(in srgb,var(--accent-2) 6%,var(--panel)),var(--panel)) !important;
}
.quality-equation {
  min-height:96px;
  overflow-x:auto;
  justify-content:flex-start;
  font-size:clamp(.96rem,1.5vw,1.16rem);
}

.quality-lab-section {
  background:
    radial-gradient(circle at 12% 18%,color-mix(in srgb,var(--accent-3) 7%,transparent),transparent 30%),
    linear-gradient(180deg,color-mix(in srgb,var(--accent) 3%,transparent),transparent 25%);
}
.quality-lab {
  display:grid;
  grid-template-columns:275px minmax(0,1fr);
  gap:12px;
  align-items:start;
}
.quality-controls {
  position:sticky;
  top:calc(var(--header-h) + 16px);
  display:grid;
  gap:21px;
  padding:22px;
  border:1px solid var(--line);
  border-radius:var(--radius-sm);
  background:var(--panel-solid);
}
.quality-main { min-width:0; display:grid; gap:12px; }
.quality-metrics {
  display:grid;
  grid-template-columns:repeat(5,minmax(0,1fr));
  overflow:hidden;
  border:1px solid var(--line);
  border-radius:var(--radius-sm);
  background:var(--panel);
}
.quality-metrics article {
  min-width:0;
  padding:15px 14px;
  border-right:1px solid var(--line);
}
.quality-metrics article:last-child { border-right:0; }
.quality-metrics span { display:block; color:var(--muted); font-size:.64rem; font-weight:760; }
.quality-metrics strong {
  display:inline-block;
  margin-top:5px;
  max-width:100%;
  overflow:hidden;
  text-overflow:ellipsis;
  font-size:1.02rem;
  font-variant-numeric:tabular-nums;
  white-space:nowrap;
}
.quality-metrics small { margin-left:4px; color:var(--muted); font-size:.56rem; }

.quality-plot { margin:0; }
.quality-plot figcaption {
  display:flex;
  justify-content:space-between;
  gap:18px;
  align-items:flex-end;
  padding:18px 20px;
  border-bottom:1px solid var(--line);
}
.quality-plot figcaption > div > span {
  display:block;
  color:var(--muted);
  font-size:.68rem;
  font-weight:750;
  letter-spacing:.06em;
  text-transform:uppercase;
}
.quality-plot figcaption strong { display:block; margin-top:3px; font-size:.92rem; }
.quality-plot figcaption p { margin:0; max-width:410px; color:var(--muted); font-size:.72rem; text-align:right; }
.quality-plot svg { display:block; width:100%; min-height:300px; }
.quality-curve,
.quality-decay-curve {
  fill:none;
  stroke:var(--accent-3);
  stroke-width:2.9;
  stroke-linecap:round;
  stroke-linejoin:round;
  vector-effect:non-scaling-stroke;
}
.quality-decay-curve { stroke:var(--accent); }
.quality-half-line {
  stroke:var(--line-strong);
  stroke-width:1.15;
  stroke-dasharray:5 6;
  vector-effect:non-scaling-stroke;
}
.quality-ref-line {
  stroke:var(--accent-3);
  stroke-width:1.2;
  stroke-dasharray:7 6;
  vector-effect:non-scaling-stroke;
}
.quality-band-line {
  stroke:var(--accent);
  stroke-width:1.25;
  stroke-dasharray:4 5;
  vector-effect:non-scaling-stroke;
}
.quality-current-line {
  stroke:var(--accent-2);
  stroke-width:1.35;
  stroke-dasharray:3 5;
  vector-effect:non-scaling-stroke;
}
.quality-marker {
  stroke:var(--bg);
  stroke-width:2.2;
  vector-effect:non-scaling-stroke;
}
.quality-marker.half { fill:var(--accent); }
.quality-marker.current { fill:var(--accent-2); }
.quality-bracket {
  fill:none;
  stroke:var(--accent);
  stroke-width:2;
  vector-effect:non-scaling-stroke;
}
.quality-label,
.quality-half-label {
  font-size:12px;
  font-weight:800;
}
.quality-label { fill:var(--accent); }
.quality-label.center { fill:var(--accent-3); }
.quality-half-label { fill:var(--muted); }
.quality-legend {
  display:flex;
  flex-wrap:wrap;
  gap:18px;
  padding:0 20px 18px;
  color:var(--muted);
  font-size:.7rem;
}
.quality-legend span { display:flex; align-items:center; gap:7px; }
.quality-legend i { display:inline-block; width:22px; height:3px; }
.quality-legend .power { background:var(--accent-3); }
.quality-legend .half { background:var(--accent); }
.quality-legend .current {
  background:repeating-linear-gradient(90deg,var(--accent-2) 0 5px,transparent 5px 9px);
}

.quality-bottom-grid {
  display:grid;
  grid-template-columns:minmax(0,1.15fr) minmax(310px,.85fr);
  gap:12px;
}
.quality-readout { min-width:0; }
.quality-state-grid { display:grid; grid-template-columns:1fr 1fr; }
.quality-state-grid > div {
  display:grid;
  grid-template-columns:auto 1fr auto;
  gap:7px;
  align-items:baseline;
  min-width:0;
  padding:14px;
  border-right:1px solid var(--line);
  border-bottom:1px solid var(--line);
}
.quality-state-grid > div:nth-child(2n) { border-right:0; }
.quality-state-grid > div:nth-last-child(-n+2) { border-bottom:0; }
.quality-state-grid span { color:var(--accent-2); font-size:.67rem; font-weight:850; }
.quality-state-grid strong { justify-self:end; font-size:.82rem; font-variant-numeric:tabular-nums; }
.quality-state-grid small { color:var(--muted); font-size:.56rem; }
.quality-interpretation { padding:18px 20px 20px; border-top:1px solid var(--line); }
.quality-interpretation > span {
  color:var(--muted);
  font-size:.66rem;
  font-weight:760;
  letter-spacing:.06em;
  text-transform:uppercase;
}
.quality-interpretation strong { display:block; margin-top:8px; font-size:1.02rem; }
.quality-interpretation p { margin:8px 0 0; color:var(--muted); font-size:.78rem; }

.quality-duality-grid article > span {
  color:var(--accent-2);
  font-size:.67rem;
  font-weight:850;
  letter-spacing:.06em;
  text-transform:uppercase;
}
.quality-duality-grid strong { display:block; margin-top:8px; font-size:1.04rem; }

@media (max-width:1120px) {
  .quality-metrics { grid-template-columns:repeat(3,1fr); }
  .quality-metrics article:nth-child(3) { border-right:0; }
  .quality-metrics article:nth-child(-n+3) { border-bottom:1px solid var(--line); }
}
@media (max-width:980px) {
  .quality-model-grid,
  .bandwidth-grid,
  .quality-compare-grid,
  .quality-duality-grid { grid-template-columns:1fr 1fr; }
  .quality-model-grid > :last-child,
  .bandwidth-grid > :last-child,
  .quality-compare-grid > :last-child,
  .quality-duality-grid > :last-child { grid-column:1/-1; }
  .quality-lab { grid-template-columns:1fr; }
  .quality-controls { position:static; grid-template-columns:1fr 1fr; }
  .quality-bottom-grid { grid-template-columns:1fr; }
}
@media (max-width:760px) {
  .quality-chapter { margin-top:58px; }
  .quality-model-grid,
  .bandwidth-grid,
  .quality-compare-grid,
  .quality-duality-grid,
  .quality-controls { grid-template-columns:1fr; }
  .quality-model-grid > :last-child,
  .bandwidth-grid > :last-child,
  .quality-compare-grid > :last-child,
  .quality-duality-grid > :last-child { grid-column:auto; }
  .quality-metrics { grid-template-columns:1fr 1fr; }
  .quality-metrics article { border-right:1px solid var(--line); border-bottom:1px solid var(--line); }
  .quality-metrics article:nth-child(2n) { border-right:0; }
  .quality-metrics article:nth-child(3) { border-right:1px solid var(--line); }
  .quality-metrics article:last-child { border-right:0; border-bottom:0; grid-column:1/-1; }
  .quality-plot figcaption { display:block; }
  .quality-plot figcaption p { margin-top:8px; text-align:left; }
  .quality-plot svg { min-height:250px; }
  .quality-state-grid { grid-template-columns:1fr; }
  .quality-state-grid > div { border-right:0; border-bottom:1px solid var(--line); }
  .quality-state-grid > div:last-child { border-bottom:0; }
}