.heart-data-article {
  --chart-below: #c8d0cb;
  --chart-inside: #18a957;
  --chart-above: #e34850;
  --chart-blue: #2266d8;
  --chart-purple: #7450cc;
  max-width: 76rem;
}

.heart-data-article .reading-width { max-width: 48rem; }
.heart-data-article .lede { max-width: 48rem; }
.heart-data-article .answer-box {
  max-width: 52rem;
  margin: 2rem 0 3rem;
  padding: 1.35rem 1.5rem;
  border-top: 1px solid #bfe6cd;
  border-right: 1px solid #bfe6cd;
  border-bottom: 1px solid #bfe6cd;
  border-left: 4px solid var(--ramp-green);
  background: #f2f8f4;
}
.heart-data-article .answer-box::before { display: none; }
.heart-data-article .answer-box p { margin: 0; }
.heart-data-article .metric-strip {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1px;
  margin: 2rem 0 3.5rem;
  background: #d8dfdb;
  border: 1px solid #d8dfdb;
}
.heart-data-article .metric {
  min-height: 8.5rem;
  padding: 1.2rem;
  background: #fff;
}
.heart-data-article .metric strong { display: block; color: var(--ink); font-size: clamp(1.8rem, 4vw, 2.65rem); line-height: 1; }
.heart-data-article .metric span { display: block; margin-top: 0.55rem; color: var(--muted); line-height: 1.35; }
.heart-data-article .metric small { display: block; margin-top: 0.35rem; color: #65706a; }

.chart-card {
  margin: 2rem 0 4rem;
  padding: clamp(1rem, 3vw, 1.75rem);
  border: 1px solid #ccd5d0;
  border-radius: 10px;
  background: #fff;
}
.chart-card h3 { margin: 0 0 0.45rem; font-size: clamp(1.35rem, 3vw, 1.85rem); }
.chart-card > p { max-width: 48rem; color: var(--muted); }
.chart-shell { width: 100%; min-height: 21rem; margin-top: 1rem; overflow-x: auto; }
.chart-shell svg { display: block; width: 100%; min-width: 42rem; height: auto; font-family: inherit; }
.chart-shell text { fill: #27302b; font-size: 13px; }
.chart-shell .axis { stroke: #59635e; stroke-width: 1; }
.chart-shell .grid { stroke: #e1e6e3; stroke-width: 1; }
.chart-shell .miss { fill: #fff; stroke: #252b28; stroke-width: 2; }
.chart-legend { display: flex; flex-wrap: wrap; gap: 0.6rem 1.2rem; margin: 1rem 0 0; padding: 0; list-style: none; }
.chart-legend li { display: flex; align-items: center; gap: 0.45rem; color: #35403a; font-size: 0.9rem; }
.legend-swatch { width: 0.85rem; height: 0.85rem; border: 1px solid rgba(0,0,0,.25); }
.chart-card details { margin-top: 1.25rem; border-top: 1px solid #dce2de; }
.chart-card summary { padding: 1rem 0 0.25rem; color: var(--green-dark); font-weight: 750; cursor: pointer; }
.chart-card .table-wrap { margin: 0.8rem 0 0; }
.chart-note { margin-top: 0.8rem; font-size: 0.88rem; color: #59635e; }

.method-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1.25rem; margin: 1.5rem 0 2.5rem; }
.method-grid section { padding: 1.25rem; border-top: 3px solid var(--ink); background: #f7f9f8; }
.method-grid h3 { margin: 0 0 0.55rem; font-size: 1.05rem; }
.method-grid p { margin: 0; color: var(--muted); }
.download-list { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 0.75rem; margin: 1.25rem 0; }
.download-list a { padding: 1rem; border: 1px solid #cbd4cf; border-radius: 6px; font-weight: 750; }
.download-list small { display: block; margin-top: 0.3rem; color: var(--muted); font-weight: 400; }

.research-conversion {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 12rem;
  gap: clamp(1.5rem, 5vw, 3rem);
  align-items: center;
  margin: 4rem 0 2rem;
  padding: clamp(1.5rem, 4vw, 2.75rem);
  color: #fff;
  background: linear-gradient(135deg, #0c1410, #101b17);
  border-top: 4px solid var(--ramp-green);
  border-radius: 10px;
}
.heart-data-article .research-conversion h2 { margin: 0 0 0.75rem; color: #fff; }
.heart-data-article .research-conversion p { color: #cbd5cf; }
.research-conversion .cta-row { margin-bottom: 0; }
.qr-link { display: block; padding: 0.7rem; color: #111; background: #fff; border-radius: 8px; text-align: center; }
.qr-link img { display: block; width: 100%; height: auto; }
.qr-link span { display: block; margin-top: 0.45rem; font-size: 0.78rem; font-weight: 750; }
.mobile-primary { display: none; }

@media (max-width: 760px) {
  .heart-data-article h1 { font-size: clamp(2.65rem, 10vw, 3.35rem); }
  .heart-data-article .metric-strip { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .heart-data-article .metric { min-height: 7rem; }
  .chart-card { padding-inline: 0.8rem; }
  .chart-shell { min-height: 18rem; }
  .chart-shell svg { min-width: 38rem; }
  .method-grid, .download-list { grid-template-columns: 1fr; }
  .research-conversion { grid-template-columns: 1fr; }
  .research-conversion .qr-link { display: none; }
  .desktop-app-store { display: none; }
  .mobile-primary { display: inline-flex; }
}

@media (prefers-reduced-motion: reduce) {
  .chart-shell { scroll-behavior: auto; }
}