:root {
  --serif: 'Source Serif 4', Georgia, serif;
  --sans: 'Manrope', -apple-system, BlinkMacSystemFont, sans-serif;
  --mono: 'IBM Plex Mono', monospace;

  --bg: #fdfcf9;
  --paper: #ffffff;
  --text: #2f2a22;
  --muted: #6e665b;
  --border: #e2d8c6;
  --accent: #2c6fb7;
  --accent-hover: #1e528a;
  --q-color: #d9622b;
  --k-color: #2c6fb7;
  --v-color: #1e7770;
  --warm: #d9622b;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; font-family: var(--serif); color: var(--text); background: var(--bg); line-height: 1.65; }

.article { max-width: 980px; margin: 0 auto; padding: 2.5rem 1.5rem 5rem; }
.back-link { display: inline-block; margin-bottom: 1.5rem; color: var(--muted); text-decoration: none; font-family: var(--sans); font-size: 0.9rem; transition: color 0.2s; }
.back-link:hover { color: var(--text); }
.article-header { margin-bottom: 3rem; text-align: center; }
.kicker { margin: 0 0 0.75rem; font-family: var(--sans); font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.14em; color: var(--muted); }
h1 { margin: 0 auto 1rem; font-size: clamp(2.4rem, 5vw, 3.5rem); line-height: 1.1; letter-spacing: -0.02em; color: #1a1815; max-width: 16ch; }
.abstract { margin: 0 auto 1rem; max-width: 62ch; font-size: 1.15rem; color: #4d463d; }
.byline { display: flex; gap: 1rem; justify-content: center; flex-wrap: wrap; margin-top: 1.4rem; padding-top: 1rem; border-top: 1px solid var(--border); color: var(--muted); font-family: var(--sans); font-size: 0.92rem; }

.step-section {
  position: relative;
  margin-top: 4rem;
  padding: 3rem 2.5rem;
  background: var(--paper);
  border: 1px solid var(--border);
  border-radius: 24px;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.03);
}

.step-badge {
  position: absolute;
  top: -16px;
  left: 32px;
  background: var(--accent);
  color: white;
  font-family: var(--sans);
  font-weight: 700;
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 0.4rem 1.2rem;
  border-radius: 999px;
  box-shadow: 0 4px 12px rgba(44, 111, 183, 0.25);
}

h2 { margin: 0 0 1rem; font-size: clamp(1.6rem, 3.5vw, 2.2rem); line-height: 1.15; color: #1a1815; }
h3 { margin-top: 2rem; margin-bottom: 0.8rem; font-size: 1.25rem; color: #1a1815; }
p { max-width: 68ch; font-size: 1.1rem; }
ul { max-width: 68ch; font-size: 1.1rem; }
li { margin-bottom: 0.5rem; }

.explanation-list {
  max-width: 68ch;
  font-size: 1.1rem;
  margin: 1rem 0;
  padding-left: 1.5rem;
}
.explanation-list li {
  margin-bottom: 0.7rem;
}

.button-row {
  display: flex;
  gap: 0.6rem;
  flex-wrap: wrap;
  margin: 1.25rem 0 0.5rem;
}
.mode-button {
  border: 1px solid var(--border);
  background: white;
  color: var(--text);
  padding: 0.6rem 1.1rem;
  border-radius: 999px;
  font: 600 0.9rem var(--sans);
  cursor: pointer;
  transition: all 150ms ease;
  box-shadow: 0 2px 8px rgba(0,0,0,0.02);
}
.mode-button:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0,0,0,0.06);
  border-color: var(--accent);
}
.mode-button.is-active {
  background: var(--text);
  color: white;
  border-color: var(--text);
}

.scenario-caption {
  font-family: var(--sans);
  color: var(--muted);
  font-style: italic;
  font-size: 0.98rem;
  margin: 0.5rem 0 0;
}

.interactive-figure {
  margin: 2.5rem 0;
  padding: 1.5rem;
  background: white;
  border: 1px solid var(--border);
  border-radius: 20px;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.04);
}
canvas { width: 100%; height: auto; display: block; border: 1px solid #f0ebe1; border-radius: 12px; cursor: crosshair; }
figcaption { margin-top: 1rem; color: var(--muted); font-size: 0.95rem; text-align: center; font-family: var(--sans); }

.math-block { margin: 1.5rem 0; padding: 0.8rem; overflow-x: auto; background: rgba(0,0,0,0.02); border-radius: 12px; text-align: center; }

.table-wrap { overflow-x: auto; margin: 2rem 0; }
.data-table { width: 100%; border-collapse: collapse; font-family: var(--sans); font-size: 0.95rem; }
.data-table th, .data-table td { padding: 0.8rem 1rem; text-align: left; border-bottom: 1px solid var(--border); }
.data-table th { background: rgba(0,0,0,0.02); color: var(--muted); font-weight: 700; text-transform: uppercase; letter-spacing: 0.05em; font-size: 0.8rem; }
.data-table tfoot td { background: rgba(44, 111, 183, 0.04); font-weight: 700; color: var(--accent); }

.examples-table-wrap { overflow-x: auto; margin: 1.5rem 0; }
.examples-table {
  width: 100%;
  border-collapse: collapse;
  font-family: var(--sans);
  font-size: 0.95rem;
}
.examples-table th,
.examples-table td {
  padding: 0.8rem 1rem;
  text-align: left;
  border-bottom: 1px solid var(--border);
}
.examples-table th {
  background: rgba(0,0,0,0.02);
  color: var(--muted);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-size: 0.82rem;
}

.weight-bar-cell {
  width: 180px;
}
.weight-bar {
  background: var(--accent);
  height: 12px;
  border-radius: 6px;
  transition: width 180ms ease;
}

.callout {
  margin: 2rem 0; padding: 1.2rem 1.4rem;
  border-left: 4px solid var(--accent); background: rgba(44, 111, 183, 0.04);
  border-radius: 0 12px 12px 0; font-size: 1rem;
}
.callout strong {
  font-family: var(--sans);
  font-size: 0.9rem;
}
.callout--think { border-left-color: var(--q-color); background: rgba(217, 98, 43, 0.04); }

.misconception-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1rem;
  margin: 1.5rem 0;
}
.misconception-card {
  padding: 1.2rem;
  border: 1px solid rgba(200, 50, 50, 0.15);
  border-radius: 14px;
  background: rgba(200, 50, 50, 0.03);
}
.misconception-card p { margin: 0; font-size: 0.95rem; line-height: 1.55; }
.misconception-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.2rem 0.8rem;
  border-radius: 16px;
  background: rgba(200, 50, 50, 0.1);
  color: #c03030;
  font-family: var(--sans);
  font-size: 0.82rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.5rem;
}

@media (max-width: 640px) {
  .article { padding-inline: 1rem; }
  .step-section { padding: 2rem 1.5rem; }
}