/* About page — Modern Editorial Dark
   d3a-* prefix. Inherits .d3 root variables (palette, type).
   The page is a long single column: hero, prose intro, then a stack
   of "spec sheet" panels rendered as low-chrome data blocks. */

.d3a-hero {
  max-width: 880px;
  margin: 0 auto;
  padding: 72px 56px 36px;
}
.d3a-hero-row {
  display: grid;
  grid-template-columns: 96px 1fr;
  gap: 28px;
  align-items: center;
}
.d3a-hero-portrait {
  width: 96px; height: 96px; border-radius: 50%;
  background-size: cover; background-position: center;
  border: 1px solid var(--rule-bright);
  box-shadow: inset 0 0 0 2px var(--bg);
  position: relative;
}
.d3a-hero-portrait::before {
  content: ''; position: absolute; inset: -3px; border-radius: 50%;
  box-shadow:
    0 0 0 2px var(--bg),
    0 0 0 3px var(--rule-bright),
    0 0 50px -2px var(--accent),
    0 0 90px -16px var(--accent);
  z-index: -1;
  animation: d3-halo-pulse 6.4s ease-in-out infinite;
}
@media (prefers-reduced-motion: reduce) {
  .d3a-hero-portrait::before { animation: none; }
}
.d3a-hero-kicker {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 10px;
}
.d3a-hero-title {
  font-family: 'Source Serif 4', serif;
  font-weight: 400;
  font-size: 44px;
  line-height: 1.05;
  letter-spacing: -0.02em;
  margin: 0;
  color: var(--text);
  text-wrap: balance;
}

/* Prose intro — same width and feel as an article body. */
.d3a-intro {
  max-width: 660px;
  margin: 0 auto;
  padding: 28px 24px 36px;
  font-family: 'Source Serif 4', serif;
  font-size: 18px;
  line-height: 1.65;
  color: var(--text);
}
.d3a-intro p { margin: 0 0 1em; text-wrap: pretty; }
.d3a-intro p:first-child { font-size: 21px; line-height: 1.5; }
.d3a-intro em { font-style: italic; color: var(--text); }

/* ── Spec sheet ─────────────────────────────────────── */
.d3a-spec {
  max-width: 880px;
  margin: 0 auto;
  padding: 0 56px;
}
.d3a-spec-banner {
  display: flex; align-items: baseline; gap: 14px;
  padding: 14px 0;
  margin-top: 16px;
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--text-faint);
}
.d3a-spec-banner-title {
  color: var(--accent);
  font-weight: 500;
}
.d3a-spec-banner-spacer { flex: 1; }
.d3a-spec-banner-stamp { color: var(--text-faint); }

/* A "panel" is one numbered section of the spec sheet. */
.d3a-panel {
  padding: 36px 0 8px;
  border-bottom: 1px solid var(--rule);
}
.d3a-panel:last-child { border-bottom: none; }

.d3a-panel-head {
  display: flex; align-items: baseline; gap: 14px;
  margin-bottom: 18px;
}
.d3a-panel-num {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--text-faint);
}
.d3a-panel-title {
  font-family: 'Source Serif 4', serif;
  font-weight: 400;
  font-size: 26px;
  line-height: 1.15;
  letter-spacing: -0.01em;
  color: var(--text);
  margin: 0;
}
.d3a-panel-note {
  margin-left: auto;
  font-family: 'JetBrains Mono', monospace;
  font-size: 10.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-faint);
}

/* Definition list rendered as aligned rows. */
.d3a-dl {
  display: grid;
  grid-template-columns: 160px 1fr;
  gap: 0;
  margin: 0 0 14px;
  font-size: 14.5px;
}
.d3a-dl-key {
  padding: 11px 0;
  font-family: 'JetBrains Mono', monospace;
  font-size: 11.5px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-faint);
  border-top: 1px dashed var(--rule);
}
.d3a-dl-val {
  padding: 11px 0;
  font-family: 'Inter', sans-serif;
  color: var(--text);
  border-top: 1px dashed var(--rule);
}
.d3a-dl-val .d3a-dl-aside {
  display: block;
  font-family: 'Source Serif 4', serif;
  font-style: italic;
  font-size: 14px;
  color: var(--text-soft);
  margin-top: 4px;
}
.d3a-dl-val code {
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px;
  color: var(--accent);
}

/* The Pi callout — a small inline note bound to the Hardware panel. */
.d3a-callout {
  margin: 14px 0 8px;
  padding: 14px 18px;
  background: var(--bg-card);
  border: 1px solid var(--rule);
  border-left: 2px solid var(--accent);
  font-family: 'Source Serif 4', serif;
  font-size: 15px;
  line-height: 1.55;
  color: var(--text-soft);
  font-style: italic;
}
.d3a-callout strong {
  font-style: normal;
  color: var(--text);
  font-weight: 500;
}

/* Two-column tool listing for "mine" vs "borrowed". */
.d3a-tools {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 36px;
  margin-top: 4px;
}
@media (max-width: 720px) {
  .d3a-tools { grid-template-columns: 1fr; gap: 24px; }
}
.d3a-tools-col-label {
  font-family: 'JetBrains Mono', monospace;
  font-size: 10.5px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 10px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--rule);
}
.d3a-tools-col-blurb {
  font-family: 'Source Serif 4', serif;
  font-size: 14px;
  line-height: 1.55;
  color: var(--text-soft);
  font-style: italic;
  margin: 0 0 12px;
}
.d3a-tools-row {
  display: grid;
  grid-template-columns: 110px 1fr;
  gap: 12px;
  padding: 9px 0;
  font-size: 14px;
  border-top: 1px dashed var(--rule);
  align-items: baseline;
}
.d3a-tools-row:last-child { border-bottom: 1px dashed var(--rule); }
.d3a-tools-name {
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px;
  color: var(--accent);
}
.d3a-tools-desc {
  color: var(--text);
  line-height: 1.5;
}

/* Model routing table. */
.d3a-models {
  display: grid;
  grid-template-columns: 1fr 1.1fr 1.4fr;
  gap: 0;
  font-size: 14px;
}
.d3a-models-h {
  font-family: 'JetBrains Mono', monospace;
  font-size: 10.5px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--text-faint);
  padding: 10px 14px 10px 0;
  border-bottom: 1px solid var(--rule);
}
.d3a-models-h:not(:last-child) { padding-right: 18px; }
.d3a-models-job,
.d3a-models-model,
.d3a-models-why {
  padding: 13px 14px 13px 0;
  border-top: 1px dashed var(--rule);
}
.d3a-models-job {
  font-family: 'Inter', sans-serif;
  font-weight: 500;
  color: var(--text);
}
.d3a-models-model {
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px;
  color: var(--accent);
  padding-right: 18px;
}
.d3a-models-why {
  font-family: 'Source Serif 4', serif;
  font-style: italic;
  color: var(--text-soft);
  line-height: 1.5;
}
@media (max-width: 720px) {
  .d3a-models { grid-template-columns: 1fr; }
  .d3a-models-h:not(:first-child) { display: none; }
  .d3a-models-job { padding-bottom: 4px; border-top: 1px solid var(--rule); padding-top: 14px; }
  .d3a-models-model { padding-top: 0; padding-bottom: 4px; border-top: none; }
  .d3a-models-why { padding-top: 0; border-top: none; }
}

/* Last 30 days — stat blocks + sparkline. */
.d3a-usage-stamp {
  display: flex; align-items: baseline; gap: 10px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 10.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-faint);
  margin-bottom: 18px;
}
.d3a-usage-stamp .d3a-usage-window {
  color: var(--text);
}
.d3a-usage-stamp .d3a-usage-next {
  margin-left: auto;
  color: var(--accent);
}

.d3a-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0;
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
}
@media (max-width: 720px) {
  .d3a-stats { grid-template-columns: repeat(2, 1fr); }
}
.d3a-stat {
  padding: 18px 18px;
  border-right: 1px dashed var(--rule);
}
.d3a-stat:first-child { padding-left: 0; }
.d3a-stat:last-child { border-right: none; }
@media (max-width: 720px) {
  .d3a-stat:nth-child(odd) { padding-left: 0; }
  .d3a-stat:nth-child(2n) { border-right: none; }
  .d3a-stat:nth-child(n+3) { border-top: 1px dashed var(--rule); }
}
.d3a-stat-label {
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--text-faint);
  margin-bottom: 8px;
}
.d3a-stat-value {
  font-family: 'Source Serif 4', serif;
  font-weight: 400;
  font-size: 30px;
  line-height: 1;
  color: var(--text);
  letter-spacing: -0.01em;
}
.d3a-stat-sub {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  color: var(--text-faint);
  margin-top: 6px;
  letter-spacing: 0.04em;
}
.d3a-stat-sub-pos { color: oklch(72% 0.13 145); }
.d3a-stat-sub-neg { color: oklch(68% 0.14 30); }

/* Sparkline panel. */
.d3a-spark-wrap {
  margin-top: 28px;
  padding: 18px 0 4px;
}
.d3a-spark-head {
  display: flex; align-items: baseline; gap: 10px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 10.5px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--text-faint);
  margin-bottom: 12px;
}
.d3a-spark-head-title { color: var(--text); }
.d3a-spark-head-peak { margin-left: auto; color: var(--accent); }
.d3a-spark-svg {
  display: block;
  width: 100%;
  height: 88px;
}
.d3a-spark-svg path.line {
  fill: none; stroke: var(--accent); stroke-width: 1.4;
}
.d3a-spark-svg path.fill {
  fill: var(--accent);
  opacity: 0.10;
}
.d3a-spark-svg circle.peak {
  fill: var(--accent);
  filter: drop-shadow(0 0 6px var(--accent));
}
.d3a-spark-axis {
  display: flex; justify-content: space-between;
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  letter-spacing: 0.04em;
  color: var(--text-faint);
  margin-top: 6px;
}

/* Top lists — tools and models side by side. */
.d3a-tops {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 36px;
  margin-top: 28px;
}
@media (max-width: 720px) {
  .d3a-tops { grid-template-columns: 1fr; gap: 24px; }
}
.d3a-tops-h {
  font-family: 'JetBrains Mono', monospace;
  font-size: 10.5px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent);
  padding-bottom: 8px;
  border-bottom: 1px solid var(--rule);
  margin-bottom: 0;
}
.d3a-tops-row {
  display: grid;
  grid-template-columns: 1fr auto auto;
  gap: 16px;
  align-items: center;
  padding: 9px 0;
  border-top: 1px dashed var(--rule);
  font-size: 13.5px;
}
.d3a-tops-row:first-of-type { border-top: none; }
.d3a-tops-name {
  font-family: 'JetBrains Mono', monospace;
  color: var(--text);
}
.d3a-tops-bar {
  width: 80px; height: 4px;
  background: var(--bg-elev);
  border-radius: 2px;
  overflow: hidden;
}
.d3a-tops-bar-fill {
  height: 100%;
  background: var(--accent);
  opacity: 0.7;
}
.d3a-tops-num {
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  color: var(--text-faint);
  letter-spacing: 0.04em;
  min-width: 64px;
  text-align: right;
}

/* Diff line — "what changed since last update" */
.d3a-diff {
  margin-top: 32px;
  padding: 16px 18px;
  background: var(--bg-card);
  border: 1px solid var(--rule);
  border-radius: 4px;
}
.d3a-diff-title {
  font-family: 'JetBrains Mono', monospace;
  font-size: 10.5px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--text-faint);
  margin-bottom: 10px;
}
.d3a-diff-row {
  display: grid;
  grid-template-columns: 18px 1fr;
  gap: 10px;
  padding: 4px 0;
  font-family: 'Source Serif 4', serif;
  font-size: 14.5px;
  line-height: 1.5;
  color: var(--text);
}
.d3a-diff-mark {
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  color: var(--text-faint);
}
.d3a-diff-mark.up { color: oklch(72% 0.13 145); }
.d3a-diff-mark.down { color: oklch(68% 0.14 30); }
.d3a-diff-mark.same { color: var(--text-faint); }

/* Closing colophon for the page itself. */
.d3a-colophon {
  max-width: 660px;
  margin: 32px auto 0;
  padding: 28px 24px;
  font-family: 'Source Serif 4', serif;
  font-size: 14.5px;
  line-height: 1.6;
  color: var(--text-soft);
  font-style: italic;
  text-align: center;
}
.d3a-foot {
  max-width: 1140px; margin: 0 auto;
  padding: 28px 56px 48px;
  border-top: 1px solid var(--rule);
  display: flex; justify-content: space-between; align-items: center;
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-faint);
}
.d3a-foot a { color: var(--text); text-decoration: none; }
.d3a-foot a:hover { color: var(--accent); }

/* ---------- Responsive ---------- */

@media (max-width: 1000px) {
  .d3a-hero { padding: 56px 28px 32px; }
  .d3a-hero-title { font-size: 36px; }
  .d3a-spec { padding: 0 28px; }
  .d3a-foot { padding: 24px 28px 40px; }
}

@media (max-width: 700px) {
  .d3a-hero { padding: 36px 20px 24px; }
  .d3a-hero-row { grid-template-columns: 72px 1fr; gap: 18px; }
  .d3a-hero-portrait { width: 72px; height: 72px; }
  .d3a-hero-kicker { font-size: 10.5px; margin-bottom: 8px; }
  .d3a-hero-title { font-size: 28px; line-height: 1.08; }

  .d3a-intro { padding: 22px 20px 28px; font-size: 17px; }
  .d3a-intro p:first-child { font-size: 19px; }

  .d3a-spec { padding: 0 20px; }
  .d3a-panel { padding: 28px 0 6px; }
  .d3a-panel-title { font-size: 22px; }

  .d3a-dl { grid-template-columns: 1fr; }
  .d3a-dl-key { padding: 10px 0 2px; border-top: 1px dashed var(--rule); }
  .d3a-dl-val { padding: 0 0 12px; border-top: none; }

  .d3a-tools-row { grid-template-columns: 1fr; gap: 4px; }

  .d3a-stat { padding: 14px 14px; }
  .d3a-stat-value { font-size: 26px; }

  .d3a-colophon { padding: 24px 20px; }
  .d3a-foot {
    flex-direction: column;
    gap: 10px;
    text-align: center;
    padding: 22px 20px 40px;
  }
}