/* ============================================================
   Backtest Club — "The Ledger" design system
   Paper, serif, evidence. Every number in mono, every claim
   with a proof badge.
   ============================================================ */

:root {
  --paper: #fbfaf6;
  --ink: #1f2a27;
  --ink-soft: #55605c;
  --ink-faint: #8a8778;
  --line: #d8d6cc;
  --line-strong: #1f2a27;
  --pine: #1d5c4d;
  --pine-soft: #bcd3cc;
  --pine-wash: #eef4f1;
  --oxide: #a63a2b;
  --oxide-wash: #f6ece9;

  --serif: Charter, "Iowan Old Style", Georgia, "Times New Roman", serif;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, monospace;

  --measure: 65ch;
  --pad-x: clamp(1.25rem, 5vw, 2.5rem);
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}

body {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--serif);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; }
a:focus-visible {
  outline: 2px solid var(--pine);
  outline-offset: 3px;
}

img, svg { max-width: 100%; }

.container {
  max-width: 1040px;
  margin: 0 auto;
}

/* ---------- Masthead ---------- */

.masthead {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem 2rem;
  flex-wrap: wrap;
  padding: 1.15rem var(--pad-x);
  border-bottom: 2px solid var(--line-strong);
}

.brand {
  font-size: 1.3rem;
  font-weight: 700;
  letter-spacing: 0.01em;
  text-decoration: none;
}
.brand em {
  font-style: normal;
  color: var(--pine);
}

.brand-tagline {
  display: block;
  font-family: var(--sans);
  font-size: 0.68rem;
  font-weight: 400;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin-top: 0.15rem;
}

.masthead nav {
  display: flex;
  gap: 1.6rem;
  font-family: var(--sans);
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.masthead nav a {
  color: var(--ink-soft);
  text-decoration: none;
  padding-bottom: 2px;
}
.masthead nav a:hover { color: var(--pine); }
.masthead nav a[aria-current="page"] {
  color: var(--pine);
  border-bottom: 2px solid var(--pine);
}

/* ---------- Hero (homepage featured post) ---------- */

.hero {
  padding: 3.2rem var(--pad-x) 2.4rem;
  max-width: 780px;
}

.kicker {
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--pine);
  margin-bottom: 1rem;
}
.kicker .sep { color: var(--line); margin: 0 0.35rem; }

.hero h1 {
  font-size: clamp(1.8rem, 4.2vw, 2.7rem);
  line-height: 1.15;
  font-weight: 700;
  text-wrap: balance;
  margin-bottom: 1.1rem;
}
.hero h1 a { text-decoration: none; }
.hero h1 a:hover { color: var(--pine); }

.dek {
  font-size: 1.05rem;
  color: var(--ink-soft);
  line-height: 1.6;
  max-width: 58ch;
}

.read-link {
  display: inline-block;
  margin-top: 1.5rem;
  font-family: var(--sans);
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--pine);
  text-decoration: none;
  border-bottom: 2px solid var(--pine-soft);
  padding-bottom: 3px;
}
.read-link:hover { border-bottom-color: var(--pine); }

/* ---------- Evidence strip ---------- */

.evidence {
  display: flex;
  flex-wrap: wrap;
  margin: 0 var(--pad-x);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.evidence .stat {
  padding: 1.1rem 2rem 1.1rem 0;
  margin-right: 2rem;
}
.evidence .stat + .stat {
  border-left: 1px solid var(--line);
  padding-left: 2rem;
}

.stat .val {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: 1.4rem;
  font-weight: 600;
}
.stat .val.neg { color: var(--oxide); }
.stat .val.pos { color: var(--pine); }
.stat .lbl {
  font-family: var(--sans);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin-top: 0.25rem;
}

/* ---------- Article cards ---------- */

.section-label {
  font-family: var(--sans);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.13em;
  text-transform: uppercase;
  color: var(--ink-faint);
  padding: 2.4rem var(--pad-x) 0;
}

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(290px, 1fr));
  gap: 2.5rem;
  padding: 1.4rem var(--pad-x) 3rem;
}

.card .tag {
  font-family: var(--sans);
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--oxide);
}
.card .tag.basics { color: var(--pine); }
.card .tag.queued { color: var(--ink-faint); }

.card h3 {
  font-size: 1.18rem;
  line-height: 1.3;
  font-weight: 700;
  margin: 0.5rem 0;
  text-wrap: balance;
}
.card h3 a { text-decoration: none; }
.card h3 a:hover { color: var(--pine); }

.card p {
  font-family: var(--sans);
  font-size: 0.86rem;
  color: var(--ink-soft);
}

.proof {
  display: inline-block;
  margin-top: 0.85rem;
  font-family: var(--mono);
  font-size: 0.68rem;
  color: var(--pine);
  background: var(--pine-wash);
  border: 1px solid var(--pine-soft);
  border-radius: 3px;
  padding: 0.28rem 0.55rem;
}
.proof.pending {
  color: var(--ink-faint);
  background: transparent;
  border-color: var(--line);
}

/* ---------- Article page ---------- */

.post {
  padding: 3rem var(--pad-x) 1rem;
}

.post-header {
  max-width: 780px;
  margin-bottom: 2.2rem;
}
.post-header h1 {
  font-size: clamp(1.8rem, 4.2vw, 2.6rem);
  line-height: 1.15;
  font-weight: 700;
  text-wrap: balance;
  margin-bottom: 1.1rem;
}

.post-body {
  max-width: var(--measure);
  font-size: 1.02rem;
}

.post-body p { margin-bottom: 1.25rem; }

.post-body h2 {
  font-size: 1.45rem;
  line-height: 1.25;
  margin: 2.6rem 0 1rem;
  text-wrap: balance;
}
.post-body h3 {
  font-size: 1.1rem;
  margin: 2rem 0 0.8rem;
}

.post-body ul, .post-body ol {
  margin: 0 0 1.25rem 1.4rem;
}
.post-body li { margin-bottom: 0.5rem; }

.post-body strong { font-weight: 700; }

.post-body .lede::first-letter {
  font-size: 3.1em;
  float: left;
  line-height: 0.85;
  padding: 0.04em 0.08em 0 0;
  color: var(--pine);
  font-weight: 700;
}

/* Myth callout */
.callout {
  border-left: 3px solid var(--oxide);
  background: var(--oxide-wash);
  padding: 1rem 1.25rem;
  margin: 1.8rem 0;
  font-size: 0.95rem;
}
.callout .callout-label {
  display: block;
  font-family: var(--sans);
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--oxide);
  margin-bottom: 0.4rem;
}
.callout.finding {
  border-left-color: var(--pine);
  background: var(--pine-wash);
}
.callout.finding .callout-label { color: var(--pine); }
.callout p:last-child { margin-bottom: 0; }

/* Data tables */
.table-wrap { overflow-x: auto; margin: 1.8rem 0; }
.post-body table {
  border-collapse: collapse;
  width: 100%;
  font-family: var(--sans);
  font-size: 0.88rem;
}
.post-body caption {
  caption-side: top;
  text-align: left;
  font-family: var(--sans);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-faint);
  padding-bottom: 0.6rem;
}
.post-body th {
  text-align: left;
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-faint);
  font-weight: 600;
  border-bottom: 2px solid var(--line-strong);
  padding: 0.5rem 1.5rem 0.5rem 0;
}
.post-body td {
  border-bottom: 1px solid var(--line);
  padding: 0.55rem 1.5rem 0.55rem 0;
}
.post-body td.num, .post-body th.num {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  text-align: right;
}
td .neg { color: var(--oxide); }
td .pos { color: var(--pine); }

/* Histogram (CSS bars) */
.chart { margin: 2rem 0; }
.chart-title {
  font-family: var(--sans);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin-bottom: 1rem;
}
.chart-scroll { overflow-x: auto; }
.bars {
  display: flex;
  align-items: flex-end;
  gap: 6px;
  height: 200px;
  min-width: 520px;
  border-bottom: 2px solid var(--line-strong);
  padding: 0 0.25rem;
}
.bar-col {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-end;
  height: 100%;
}
.bar-count {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: 0.62rem;
  color: var(--ink-faint);
  margin-bottom: 3px;
}
.bar {
  width: 100%;
  min-height: 3px;
  background: #c9cfc3;
}
.bar-col.lucky .bar { background: var(--pine); }
.bar-col.lucky .bar-count { color: var(--pine); font-weight: 600; }
.bar-labels {
  display: flex;
  gap: 6px;
  min-width: 520px;
  padding: 0.35rem 0.25rem 0;
}
.bar-labels span {
  flex: 1;
  text-align: center;
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: 0.62rem;
  color: var(--ink-faint);
}
.chart-caption {
  font-family: var(--sans);
  font-size: 0.8rem;
  color: var(--ink-soft);
  margin-top: 0.8rem;
  max-width: 60ch;
}

/* Methodology box */
.methodology {
  border: 1px solid var(--line);
  border-top: 3px solid var(--pine);
  padding: 1.4rem 1.5rem;
  margin: 2.5rem 0;
  font-family: var(--sans);
  font-size: 0.88rem;
}
.methodology h2 {
  font-family: var(--sans);
  font-size: 0.75rem !important;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--pine);
  margin: 0 0 0.9rem !important;
}
.methodology dl {
  display: grid;
  grid-template-columns: max-content 1fr;
  gap: 0.4rem 1.5rem;
}
.methodology dt { color: var(--ink-faint); }
.methodology dd { font-family: var(--mono); font-size: 0.8rem; font-variant-numeric: tabular-nums; }
.methodology p { margin: 0.9rem 0 0; font-size: 0.85rem; color: var(--ink-soft); }
.methodology a { color: var(--pine); }

/* Post footer / next */
.post-footer {
  max-width: var(--measure);
  margin-top: 2.5rem;
  padding: 1.4rem 0 0;
  border-top: 1px solid var(--line);
  font-family: var(--sans);
  font-size: 0.85rem;
  color: var(--ink-soft);
}
.post-footer a { color: var(--pine); }

/* ---------- About page ---------- */

.page {
  padding: 3rem var(--pad-x) 2rem;
}
.page .post-body h2:first-child { margin-top: 0; }

.rules {
  counter-reset: rule;
  list-style: none;
  margin-left: 0 !important;
}
.rules li {
  counter-increment: rule;
  position: relative;
  padding-left: 2.6rem;
  margin-bottom: 1rem;
}
.rules li::before {
  content: counter(rule, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 0.15em;
  font-family: var(--mono);
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--pine);
}

/* ---------- Site footer ---------- */

.site-footer {
  border-top: 2px solid var(--line-strong);
  margin-top: 2rem;
  padding: 1.8rem var(--pad-x) 2.4rem;
  font-family: var(--sans);
  font-size: 0.78rem;
  color: var(--ink-soft);
}
.site-footer .disclaimer {
  max-width: 72ch;
  margin-bottom: 1rem;
}
.site-footer .meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
  color: var(--ink-faint);
}
.site-footer a { color: var(--pine); text-decoration: none; }
.site-footer a:hover { text-decoration: underline; }

/* ---------- Small screens ---------- */

@media (max-width: 560px) {
  .masthead { flex-direction: column; align-items: flex-start; }
  .evidence .stat { padding-right: 1.25rem; margin-right: 1.25rem; }
  .evidence .stat + .stat { padding-left: 1.25rem; }
}