/* Opus theme — refined fintech, cream paper + solid near-black slab + heavy mono numbers.
 * Mirrors the design vocabulary of app.opus.money: Swiss sans for prose, mono for figures,
 * one deep slab card per major numeric block, sparse accents in protocol-green / protocol-red.
 */

@import url("https://fonts.googleapis.com/css2?family=Geist:wght@300;400;500;600;700&family=Geist+Mono:wght@400;500;600&display=swap");

:root {
  /* Paper — warm cream sampled from app.opus.money */
  --paper: #f5f1ea;
  --paper-deep: #ece6da;
  --paper-line: rgba(20, 22, 26, 0.08);
  --paper-rule: rgba(20, 22, 26, 0.14);

  /* Slab — near-black with a hint of warm */
  --slab: #0f1012;
  --slab-soft: #181a1d;
  --slab-line: rgba(255, 255, 255, 0.08);

  /* Ink */
  --ink: #15171a;
  --ink-muted: #5e6166;
  --ink-faint: #8e8f92;

  /* On slab */
  --paper-on-slab: #ece6da;
  --mono-on-slab: #f4eedf;
  --muted-on-slab: #8e8f92;

  /* Protocol accents */
  --safe: #3db87c;
  --safe-soft: rgba(61, 184, 124, 0.14);
  --danger: #e0593a;
  --danger-soft: rgba(224, 89, 58, 0.14);
  --amber: #d6a142;

  /* Motion */
  --ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-out-quart: cubic-bezier(0.25, 1, 0.5, 1);
}

* { box-sizing: border-box; }

html, body {
  background: var(--paper);
  color: var(--ink);
  margin: 0;
  font-family: "Geist", system-ui, -apple-system, sans-serif;
  font-feature-settings: "ss01", "cv11";
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

.mono { font-family: "Geist Mono", "SF Mono", "Menlo", monospace; font-variant-numeric: tabular-nums; }

.page {
  max-width: 1180px;
  margin: 0 auto;
  padding: 28px clamp(20px, 4vw, 56px) 96px;
}

/* ─────────────── header bar ─────────────── */

.bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 4px 0 36px;
  border-bottom: 1px solid var(--paper-rule);
  margin-bottom: 36px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: "Geist Mono", monospace;
  font-weight: 600;
  font-size: 0.92rem;
  letter-spacing: -0.02em;
}

.brand-mark {
  width: 22px;
  height: 22px;
  display: inline-block;
  position: relative;
}

.brand-mark::before,
.brand-mark::after {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--ink);
  clip-path: polygon(0 100%, 50% 0, 100% 100%, 75% 100%, 50% 35%, 25% 100%);
}

.bar-meta {
  font-family: "Geist Mono", monospace;
  font-size: 0.72rem;
  letter-spacing: 0.04em;
  color: var(--ink-muted);
  text-transform: uppercase;
  display: flex;
  gap: 22px;
}

.bar-meta .dot {
  width: 6px;
  height: 6px;
  border-radius: 99px;
  background: var(--safe);
  display: inline-block;
  margin-right: 6px;
  vertical-align: 1px;
  box-shadow: 0 0 0 0 var(--safe-soft);
  animation: pulse 2.4s var(--ease-out-expo) infinite;
}

@keyframes pulse {
  0%   { box-shadow: 0 0 0 0 rgba(61, 184, 124, 0.45); }
  60%  { box-shadow: 0 0 0 9px rgba(61, 184, 124, 0); }
  100% { box-shadow: 0 0 0 0 rgba(61, 184, 124, 0); }
}

/* ─────────────── hero ─────────────── */

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.7fr) minmax(0, 1fr);
  gap: clamp(20px, 4vw, 56px);
  align-items: end;
  padding-bottom: 44px;
  border-bottom: 1px solid var(--paper-rule);
  margin-bottom: 44px;
}

.eyebrow {
  font-family: "Geist Mono", monospace;
  font-size: 0.74rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-muted);
  margin-bottom: 18px;
}

.eyebrow .sep { color: var(--paper-rule); margin: 0 8px; }

h1 {
  font-family: "Geist", sans-serif;
  font-weight: 500;
  font-size: clamp(1.85rem, 3.2vw, 2.9rem);
  line-height: 1.06;
  letter-spacing: -0.025em;
  margin: 0 0 18px;
  max-width: 22ch;
}

h1 em {
  font-style: normal;
  font-family: "Geist Mono", monospace;
  font-weight: 500;
  letter-spacing: -0.02em;
}

.lede {
  color: var(--ink-muted);
  font-size: 1.02rem;
  max-width: 52ch;
  margin: 0;
}

.lede code {
  font-family: "Geist Mono", monospace;
  font-size: 0.9em;
  color: var(--ink);
  background: none;
  padding: 0;
}

.hero-side {
  display: flex;
  flex-direction: column;
  gap: 14px;
  align-items: flex-end;
  text-align: right;
  font-family: "Geist Mono", monospace;
  font-size: 0.78rem;
  color: var(--ink-muted);
  letter-spacing: 0.02em;
}

.hero-side .scope {
  color: var(--ink);
  font-size: 0.92rem;
}

/* ─────────────── slab (the dark hero stats card, mirrors prod) ─────────────── */

.slab {
  background: var(--slab);
  color: var(--paper-on-slab);
  border-radius: 18px;
  padding: clamp(28px, 4vw, 44px) clamp(28px, 4vw, 56px);
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 28px 36px;
  margin-bottom: 56px;
  position: relative;
  overflow: hidden;
}

.slab::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: 18px;
  pointer-events: none;
  background: radial-gradient(120% 80% at 0% 0%, rgba(244, 238, 223, 0.05), transparent 50%);
}

.stat {
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 0;
}

.stat .label {
  font-family: "Geist", sans-serif;
  font-size: 0.82rem;
  color: var(--muted-on-slab);
  letter-spacing: 0;
}

.stat .figure {
  font-family: "Geist Mono", monospace;
  font-variant-numeric: tabular-nums;
  font-weight: 500;
  font-size: clamp(1.8rem, 3.5vw, 2.7rem);
  letter-spacing: -0.03em;
  color: var(--mono-on-slab);
  line-height: 1;
  display: flex;
  align-items: baseline;
  gap: 4px;
}

.stat .unit {
  font-family: "Geist Mono", monospace;
  font-size: 0.72rem;
  color: var(--muted-on-slab);
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin-left: 4px;
  align-self: center;
}

.stat .sub {
  font-family: "Geist Mono", monospace;
  font-size: 0.72rem;
  color: var(--muted-on-slab);
  letter-spacing: 0.02em;
  margin-top: 2px;
}

.stat .sub .safe { color: var(--safe); }
.stat .sub .danger { color: var(--danger); }

/* ─────────────── section heads ─────────────── */

.sec {
  margin: 0 0 56px;
}

.sec-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 22px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--paper-rule);
  gap: 22px;
}

.sec-head h2 {
  margin: 0;
  font-family: "Geist", sans-serif;
  font-weight: 500;
  font-size: 1.2rem;
  letter-spacing: -0.01em;
}

.sec-head .tag {
  font-family: "Geist Mono", monospace;
  font-size: 0.7rem;
  color: var(--ink-muted);
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

/* ─────────────── why-this-matters paired block ─────────────── */

.pair {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr);
  gap: 36px;
  align-items: start;
}

.pair-main h3 {
  font-family: "Geist Mono", monospace;
  font-weight: 500;
  font-size: 0.78rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--danger);
  margin: 0 0 14px;
}

.pair-main p {
  margin: 0;
  font-size: 1.02rem;
  color: var(--ink);
  max-width: 56ch;
}

.pair-main p code {
  font-family: "Geist Mono", monospace;
  background: var(--paper-deep);
  padding: 1px 6px;
  border-radius: 4px;
  font-size: 0.9em;
}

.pair-side {
  padding-left: 28px;
  border-left: 2px solid var(--safe);
}

.pair-side h3 {
  font-family: "Geist Mono", monospace;
  font-weight: 500;
  font-size: 0.78rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--safe);
  margin: 0 0 14px;
}

.pair-side ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

.pair-side li {
  font-size: 0.95rem;
  color: var(--ink);
  padding: 6px 0;
}

.pair-side li strong {
  font-family: "Geist Mono", monospace;
  font-weight: 500;
  color: var(--ink);
}

.pair-side code {
  font-family: "Geist Mono", monospace;
  font-size: 0.88em;
  color: var(--ink-muted);
}

/* ─────────────── changelog two-column ─────────────── */

.changelog {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0;
  border-top: 1px solid var(--paper-rule);
}

.changelog-col {
  padding: 24px 28px 8px;
  border-bottom: 1px solid var(--paper-rule);
}

.changelog-col:first-child {
  border-right: 1px solid var(--paper-rule);
  padding-left: 0;
}

.changelog-col:last-child {
  padding-right: 0;
}

.changelog-col h3 {
  font-family: "Geist", sans-serif;
  font-weight: 500;
  font-size: 0.78rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-muted);
  margin: 0 0 18px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.changelog-col h3 .dot {
  width: 6px;
  height: 6px;
  border-radius: 99px;
  display: inline-block;
}

.changelog-col.bugs h3 .dot { background: var(--danger); }
.changelog-col.improvements h3 .dot { background: var(--safe); }

.entry {
  padding: 12px 0;
  border-bottom: 1px solid var(--paper-line);
  display: grid;
  grid-template-columns: 60px 1fr;
  gap: 14px;
  align-items: baseline;
}

.entry:last-child { border-bottom: none; }

.entry .ref {
  font-family: "Geist Mono", monospace;
  font-size: 0.7rem;
  color: var(--ink-faint);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  padding-top: 2px;
}

.entry .what {
  font-size: 0.95rem;
  color: var(--ink);
}

.entry .what strong {
  font-weight: 500;
  color: var(--ink);
}

.entry .what .why {
  display: block;
  font-size: 0.84rem;
  color: var(--ink-muted);
  margin-top: 3px;
  max-width: 60ch;
}

.entry code {
  font-family: "Geist Mono", monospace;
  font-size: 0.88em;
  color: var(--ink-muted);
}

/* ─────────────── delta strip (headline before→after) ─────────────── */

.delta-strip {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
  margin-bottom: 28px;
}

.delta {
  background: var(--paper-deep);
  border: 1px solid var(--paper-rule);
  border-radius: 12px;
  padding: 18px 22px 16px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.delta-label {
  font-family: "Geist Mono", monospace;
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-muted);
}

.delta-row {
  display: flex;
  align-items: baseline;
  gap: 10px;
  font-family: "Geist Mono", monospace;
  font-variant-numeric: tabular-nums;
  font-weight: 500;
  font-size: clamp(1.3rem, 2.4vw, 1.85rem);
  letter-spacing: -0.02em;
  line-height: 1;
}

.delta-before-num {
  color: var(--danger);
  text-decoration: line-through;
  text-decoration-thickness: 1.5px;
  text-decoration-color: rgba(224, 89, 58, 0.55);
}

.delta-arrow {
  font-family: "Geist", sans-serif;
  font-weight: 400;
  color: var(--ink-faint);
  font-size: 0.85em;
}

.delta-after-num {
  color: var(--safe);
  font-weight: 600;
}

.delta-pct {
  font-family: "Geist Mono", monospace;
  font-size: 0.78rem;
  color: var(--safe);
  letter-spacing: 0.02em;
  margin-top: 4px;
}

.parity-lede {
  margin: 0 0 22px;
  font-size: 0.94rem;
  color: var(--ink-muted);
  max-width: 78ch;
}

.parity-lede strong {
  color: var(--ink);
  font-weight: 600;
}

.parity-lede code {
  font-family: "Geist Mono", monospace;
  font-size: 0.9em;
  background: var(--paper-deep);
  padding: 1px 5px;
  border-radius: 4px;
}

/* slab num emphasis */
.stat .figure .danger-num {
  color: var(--danger);
  margin-right: 2px;
}

/* ─────────────── side-by-side ─────────────── */

.parity {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.parity-card-before {
  position: relative;
}

.parity-card-after {
  position: relative;
}

.parity-card-after .parity-shot {
  box-shadow: 0 0 0 1px rgba(61, 184, 124, 0.35), 0 12px 30px rgba(61, 184, 124, 0.08);
}

.parity-card-before .parity-shot {
  box-shadow: 0 0 0 1px rgba(224, 89, 58, 0.35), 0 12px 30px rgba(224, 89, 58, 0.06);
}

.parity-badge {
  font-family: "Geist Mono", monospace;
  font-size: 0.66rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 3px 8px;
  border-radius: 99px;
  font-weight: 500;
}

.parity-badge-good {
  background: var(--safe-soft);
  color: var(--safe);
}

.parity-badge-bad {
  background: var(--danger-soft);
  color: var(--danger);
}

.parity-meta dd.meta-bad {
  color: var(--danger);
  font-weight: 600;
}

.parity-meta dd.meta-good {
  color: var(--safe);
  font-weight: 600;
}

/* ─────────────── alchemy cost savings ─────────────── */

.cost-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  margin-bottom: 22px;
}

.cost-card {
  background: var(--paper-deep);
  border: 1px solid var(--paper-rule);
  border-radius: 12px;
  padding: 18px 20px 16px;
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-width: 0;
}

.cost-card-headline {
  background: var(--slab);
  border-color: var(--slab);
  color: var(--paper-on-slab);
}

.cost-card-headline .cost-label,
.cost-card-headline .cost-money,
.cost-card-headline .cost-sub {
  color: var(--muted-on-slab);
}

.cost-card-headline .cost-fig {
  color: var(--safe);
}

.cost-card-projection {
  border-color: var(--safe);
  background: var(--safe-soft);
}

.cost-card-projection .cost-fig {
  color: var(--safe);
}

.cost-label {
  font-family: "Geist Mono", monospace;
  font-size: 0.68rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-muted);
}

.cost-fig {
  font-family: "Geist Mono", monospace;
  font-variant-numeric: tabular-nums;
  font-weight: 600;
  font-size: clamp(1.3rem, 2.4vw, 1.85rem);
  letter-spacing: -0.025em;
  line-height: 1.05;
  color: var(--ink);
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin-top: 2px;
}

.cost-unit {
  font-size: 0.55em;
  color: var(--ink-faint);
  letter-spacing: 0.04em;
  margin-left: 2px;
}

.cost-card-headline .cost-unit,
.cost-card-projection .cost-unit {
  color: inherit;
  opacity: 0.7;
}

.cost-money {
  font-family: "Geist Mono", monospace;
  font-size: 0.78rem;
  color: var(--ink-muted);
  margin-top: 2px;
}

.cost-sub {
  font-family: "Geist Mono", monospace;
  font-size: 0.7rem;
  color: var(--ink-faint);
  letter-spacing: 0.02em;
  margin-top: 4px;
}

.cost-note {
  font-size: 0.94rem;
  color: var(--ink-muted);
  max-width: 78ch;
  margin: 0 0 18px;
}

.cost-note strong {
  color: var(--ink);
  font-weight: 600;
}

.cost-note code {
  font-family: "Geist Mono", monospace;
  font-size: 0.9em;
  background: var(--paper-deep);
  padding: 1px 5px;
  border-radius: 4px;
}

.cost-note em {
  font-style: italic;
  color: var(--ink);
}

.cost-assumptions {
  font-size: 0.86rem;
  color: var(--ink-muted);
}

.cost-assumptions summary {
  cursor: pointer;
  font-family: "Geist Mono", monospace;
  font-size: 0.74rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink-muted);
  padding: 6px 0;
  border-bottom: 1px dashed var(--paper-rule);
  user-select: none;
}

.cost-assumptions[open] summary {
  color: var(--ink);
}

.cost-assumptions ul {
  margin: 12px 0 0;
  padding-left: 18px;
}

.cost-assumptions li {
  margin: 6px 0;
}

.cost-assumptions code {
  font-family: "Geist Mono", monospace;
  font-size: 0.9em;
  background: var(--paper-deep);
  padding: 1px 5px;
  border-radius: 4px;
}

.cost-assumptions a {
  color: var(--ink);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 2px;
}

.cost-assumptions a:hover {
  color: var(--safe);
}

.timing-note .emph {
  font-family: "Geist Mono", monospace;
  color: var(--safe);
  font-weight: 600;
}

.parity-card {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.parity-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
}

.parity-head h3 {
  font-family: "Geist Mono", monospace;
  font-weight: 500;
  font-size: 0.92rem;
  letter-spacing: 0;
  margin: 0;
}

.parity-head .url {
  font-family: "Geist Mono", monospace;
  font-size: 0.7rem;
  color: var(--ink-faint);
}

.parity-shot {
  border: 1px solid var(--paper-rule);
  border-radius: 10px;
  overflow: hidden;
  background: var(--paper-deep);
}

.parity-shot img {
  display: block;
  width: 100%;
  height: auto;
}

.parity-meta {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 4px 16px;
  font-family: "Geist Mono", monospace;
  font-size: 0.76rem;
  padding-top: 4px;
}

.parity-meta dt {
  color: var(--ink-faint);
  font-size: 0.66rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.parity-meta dd {
  margin: 0 0 6px;
  font-variant-numeric: tabular-nums;
  color: var(--ink);
}

/* ─────────────── timing table ─────────────── */

.timing {
  width: 100%;
  border-collapse: collapse;
  font-family: "Geist Mono", monospace;
  font-size: 0.86rem;
}

.timing th, .timing td {
  text-align: right;
  padding: 12px 14px;
  border-bottom: 1px solid var(--paper-line);
  font-variant-numeric: tabular-nums;
}

.timing th:first-child, .timing td:first-child {
  text-align: left;
  font-family: "Geist", sans-serif;
}

.timing th:nth-child(2), .timing td:nth-child(2) {
  text-align: left;
}

.timing thead th {
  font-family: "Geist Mono", monospace;
  font-weight: 500;
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--ink-faint);
  border-bottom-color: var(--paper-rule);
}

.timing tbody tr:last-child td {
  border-bottom: none;
}

.timing-note {
  margin-top: 16px;
  font-size: 0.86rem;
  color: var(--ink-muted);
  max-width: 78ch;
}

/* ─────────────── architecture (three plain columns, no cards) ─────────────── */

.arch {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 48px;
}

.arch-col h3 {
  font-family: "Geist Mono", monospace;
  font-weight: 500;
  font-size: 0.74rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-muted);
  margin: 0 0 12px;
}

.arch-col p {
  margin: 0;
  font-size: 0.95rem;
  color: var(--ink);
}

.arch-col code {
  font-family: "Geist Mono", monospace;
  font-size: 0.88em;
  color: var(--ink-muted);
}

/* ─────────────── footer ─────────────── */

footer.page-foot {
  margin-top: 72px;
  padding-top: 18px;
  border-top: 1px solid var(--paper-rule);
  display: flex;
  justify-content: space-between;
  font-family: "Geist Mono", monospace;
  font-size: 0.72rem;
  color: var(--ink-faint);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

/* ─────────────── entrance animations ─────────────── */

.reveal {
  opacity: 0;
  transform: translateY(14px);
  transition:
    opacity 900ms var(--ease-out-expo),
    transform 1100ms var(--ease-out-expo);
}

.reveal.is-in {
  opacity: 1;
  transform: translateY(0);
}

.stagger > * {
  opacity: 0;
  transform: translateY(10px);
  transition:
    opacity 700ms var(--ease-out-expo),
    transform 800ms var(--ease-out-expo);
  transition-delay: var(--d, 0ms);
}

.stagger.is-in > * {
  opacity: 1;
  transform: translateY(0);
}

/* the slab's figures count up — start invisible until in view */
.stat .figure {
  opacity: 0;
  transition: opacity 600ms var(--ease-out-quart) 200ms;
}

.slab.is-in .stat .figure { opacity: 1; }

/* ─────────────── responsive ─────────────── */

@media (max-width: 880px) {
  .hero { grid-template-columns: 1fr; }
  .hero-side { align-items: flex-start; text-align: left; }
  .slab { grid-template-columns: repeat(2, 1fr); }
  .pair { grid-template-columns: 1fr; }
  .pair-side { padding-left: 18px; }
  .changelog { grid-template-columns: 1fr; }
  .changelog-col:first-child { border-right: none; padding-left: 0; padding-right: 0; }
  .parity { grid-template-columns: 1fr; }
  .delta-strip { grid-template-columns: 1fr; }
  .cost-grid { grid-template-columns: 1fr 1fr; }
  .arch { grid-template-columns: 1fr; gap: 28px; }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  .reveal, .stagger > *, .stat .figure { opacity: 1 !important; transform: none !important; }
}