/* ============================================================
   StrikeAndYield — original stylesheet. Dark, glassy, glow-forward.
   Typeface: Inter Variable (OFL, self-hosted).
   ============================================================ */

@font-face {
  font-family: "Inter Var";
  src: url("../vendor/inter/inter-latin-wght-normal.woff2") format("woff2");
  font-weight: 100 900;
  font-style: normal;
  font-display: swap;
  unicode-range: U+0000-00FF, U+2010-2027, U+2030-205E, U+20A0-20BF, U+2190-2199;
}
@font-face {
  font-family: "Inter Var";
  src: url("../vendor/inter/inter-latin-ext-wght-normal.woff2") format("woff2");
  font-weight: 100 900;
  font-style: normal;
  font-display: swap;
  unicode-range: U+0100-024F, U+1E00-1EFF, U+2C60-2C7F;
}
@font-face {
  font-family: "Space Grotesk Var";
  src: url("../vendor/space-grotesk/space-grotesk-latin-wght-normal.woff2") format("woff2");
  font-weight: 300 700;
  font-style: normal;
  font-display: swap;
}

:root {
  color-scheme: dark;
  --bg: #070a14;
  --bg-raise: rgba(255, 255, 255, 0.035);
  --bg-raise-2: rgba(255, 255, 255, 0.06);
  --line: rgba(255, 255, 255, 0.09);
  --line-soft: rgba(255, 255, 255, 0.055);
  --ink: #eef2fb;
  --ink-2: #aab3c8;
  --ink-3: #737e96;
  --accent: #4d9fff;               /* per-card override via inline style */
  --brand-1: #4d9fff;
  --brand-2: #9d7bff;
  --brand-3: #2fd4bf;
  --radius: 18px;
  --font: "Inter Var", "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-display: "Space Grotesk Var", "Space Grotesk", "Inter Var", system-ui, sans-serif;
  --maxw: 1180px;
  /* payoff diagram series (validated for dark surfaces) */
  --pf-s1: #3987e5;
  --pf-s2: #d95926;
  --pf-s3: #8a94ab;
}

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

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

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--ink);
  line-height: 1.65;
  font-size: 16.5px;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

#bg {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  display: block;
}

.page {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  /* readability scrim: dims the animated canvas behind all content */
  background:
    radial-gradient(120% 60% at 50% 0%, rgba(7, 10, 20, 0.38), rgba(7, 10, 20, 0.52) 70%),
    rgba(7, 10, 20, 0.28);
}

main {
  width: min(var(--maxw), 100% - 2.5rem);
  margin-inline: auto;
  flex: 1;
}

::selection { background: rgba(77, 159, 255, 0.35); }

a { color: inherit; }

/* ---------------- header ---------------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.8rem clamp(1rem, 4vw, 2.2rem);
  background: rgba(7, 10, 20, 0.72);
  backdrop-filter: blur(14px) saturate(1.3);
  -webkit-backdrop-filter: blur(14px) saturate(1.3);
  border-bottom: 1px solid var(--line-soft);
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  text-decoration: none;
}
.logo-mark { width: 28px; height: 28px; }
.lm { opacity: 0.95; }
.lm1 { fill: var(--brand-1); }
.lm2 { fill: var(--brand-2); }
.lm3 { fill: var(--brand-3); }
.lm4 { fill: #ffc94d; }
.logo:hover .lm { filter: drop-shadow(0 0 6px currentColor); }
.logo-text {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.18rem;
  letter-spacing: -0.02em;
}
.logo-text em {
  font-style: normal;
  background: linear-gradient(92deg, var(--brand-1), var(--brand-2));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.site-nav { display: flex; gap: 0.25rem; }
.site-nav a {
  text-decoration: none;
  color: var(--ink-2);
  font-size: 0.92rem;
  font-weight: 550;
  padding: 0.45rem 0.85rem;
  border-radius: 999px;
  transition: color 0.2s, background 0.2s;
}
.site-nav a:hover { color: var(--ink); background: var(--bg-raise-2); }

/* ---------------- hero ---------------- */

.hero {
  text-align: center;
  padding: clamp(4rem, 10vh, 7.5rem) 0 3.5rem;
}
.hero-kicker {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 650;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--ink-3);
  border: 1px solid var(--line);
  padding: 0.35rem 1rem;
  border-radius: 999px;
  background: var(--bg-raise);
  margin-bottom: 1.6rem;
}
.hero h1 {
  font-family: var(--font-display);
  font-size: clamp(2.3rem, 6vw, 4.2rem);
  font-weight: 700;
  letter-spacing: -0.035em;
  line-height: 1.08;
}
.grad {
  background: linear-gradient(92deg, var(--brand-1) 0%, var(--brand-2) 55%, var(--brand-3) 110%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero-sub {
  max-width: 46rem;
  margin: 1.4rem auto 0;
  color: var(--ink-2);
  font-size: 1.08rem;
}
.hero-stats {
  display: flex;
  justify-content: center;
  gap: clamp(1.5rem, 6vw, 4rem);
  margin-top: 2.6rem;
}
.hero-stats div { display: grid; gap: 0.1rem; }
.hero-stats strong {
  font-family: var(--font-display);
  font-size: 1.9rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  background: linear-gradient(180deg, #fff, #b9c6e4);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero-stats span {
  font-size: 0.8rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-3);
}

/* ---------------- toolbar: search + chips ---------------- */

.toolbar {
  position: sticky;
  top: 3.6rem;
  z-index: 40;
  display: grid;
  gap: 0.8rem;
  padding: 0.9rem 0 1.1rem;
  background: linear-gradient(180deg, var(--bg) 78%, transparent);
}
.search-wrap {
  position: relative;
  max-width: 34rem;
  margin-inline: auto;
  width: 100%;
}
.search-wrap svg {
  position: absolute;
  left: 1rem;
  top: 50%;
  translate: 0 -50%;
  width: 18px;
  height: 18px;
  color: var(--ink-3);
  pointer-events: none;
}
#search {
  width: 100%;
  font: inherit;
  color: var(--ink);
  background: var(--bg-raise);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 0.78rem 1.2rem 0.78rem 2.7rem;
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s, background 0.2s;
}
#search::placeholder { color: var(--ink-3); }
#search:focus {
  border-color: rgba(77, 159, 255, 0.55);
  box-shadow: 0 0 0 4px rgba(77, 159, 255, 0.14), 0 0 24px rgba(77, 159, 255, 0.12);
  background: var(--bg-raise-2);
}

.chips {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.45rem;
}
.chip {
  font: inherit;
  font-size: 0.82rem;
  font-weight: 570;
  color: var(--ink-2);
  background: var(--bg-raise);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 0.34rem 0.9rem;
  cursor: pointer;
  transition: all 0.2s;
}
.chip:hover { color: var(--ink); border-color: color-mix(in srgb, var(--accent, #fff) 45%, transparent); }
.chip.is-active {
  color: #0a0e1a;
  background: var(--accent, var(--ink));
  border-color: transparent;
  font-weight: 680;
  box-shadow: 0 0 16px color-mix(in srgb, var(--accent, #fff) 45%, transparent);
}
.chip[data-cat="all"].is-active { background: var(--ink); }

/* ---------------- category sections & tile grid ---------------- */

.cat-section { margin: 3.2rem 0; scroll-margin-top: 8rem; }

.cat-head {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1.3rem;
}
.cat-icon {
  flex: none;
  display: grid;
  place-items: center;
  width: 46px;
  height: 46px;
  border-radius: 14px;
  color: var(--accent);
  background: color-mix(in srgb, var(--accent) 12%, transparent);
  border: 1px solid color-mix(in srgb, var(--accent) 30%, transparent);
  box-shadow: 0 0 22px color-mix(in srgb, var(--accent) 18%, transparent);
}
.cat-icon svg { width: 24px; height: 24px; }
.cat-head h2 {
  font-family: var(--font-display);
  font-size: 1.45rem;
  font-weight: 600;
  letter-spacing: -0.02em;
}
.cat-head p { color: var(--ink-3); font-size: 0.92rem; max-width: 44rem; }
.cat-count {
  margin-left: auto;
  font-size: 0.8rem;
  font-weight: 650;
  color: var(--ink-3);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 0.15rem 0.7rem;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(255px, 1fr));
  gap: 0.9rem;
}

/* ---- the glow tiles ---- */

.tile {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  min-height: 172px;
  padding: 1.15rem 1.2rem 1.05rem;
  text-decoration: none;
  border-radius: var(--radius);
  background:
    radial-gradient(120% 90% at var(--mx, 20%) var(--my, 0%),
      color-mix(in srgb, var(--accent) 10%, transparent), transparent 55%),
    var(--bg-raise);
  border: 1px solid var(--line);
  overflow: hidden;
  isolation: isolate;
  transition: transform 0.25s cubic-bezier(0.2, 0.7, 0.3, 1),
              border-color 0.25s, box-shadow 0.25s;
}
.tile::after {                     /* top rim light */
  content: "";
  position: absolute;
  inset: 0 0 auto;
  height: 1px;
  background: linear-gradient(90deg, transparent 5%,
    color-mix(in srgb, var(--accent) 65%, transparent) 50%, transparent 95%);
  opacity: 0.55;
  transition: opacity 0.25s;
}
.tile:hover, .tile:focus-visible {
  transform: translateY(-4px);
  border-color: color-mix(in srgb, var(--accent) 45%, var(--line));
  box-shadow:
    0 14px 34px -12px color-mix(in srgb, var(--accent) 38%, transparent),
    0 0 0 1px color-mix(in srgb, var(--accent) 22%, transparent),
    0 0 42px -6px color-mix(in srgb, var(--accent) 30%, transparent);
}
.tile:hover::after { opacity: 1; }
.tile:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }

.tile-top {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.6rem;
}
.tile-cat {
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
}
.tile-aka {
  font-size: 0.72rem;
  color: var(--ink-3);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.tile-name {
  font-family: var(--font-display);
  font-size: 1.14rem;
  font-weight: 600;
  letter-spacing: -0.015em;
  color: var(--ink);
  line-height: 1.25;
}
.tile-tag {
  font-size: 0.86rem;
  color: var(--ink-2);
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.tile-go {
  margin-top: auto;
  padding-top: 0.5rem;
  font-size: 0.8rem;
  font-weight: 640;
  color: var(--accent);
  opacity: 0;
  translate: -6px 0;
  transition: opacity 0.25s, translate 0.25s;
}
.tile:hover .tile-go, .tile:focus-visible .tile-go { opacity: 1; translate: 0 0; }

.no-results {
  text-align: center;
  color: var(--ink-3);
  padding: 3rem 0 1rem;
}

/* ---------------- product page ---------------- */

.product { padding: 2.2rem 0 3rem; max-width: 860px; margin-inline: auto; }

.crumbs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  font-size: 0.84rem;
  color: var(--ink-3);
  margin-bottom: 2rem;
}
.crumbs a { color: var(--ink-3); text-decoration: none; }
.crumbs a:hover { color: var(--ink); }

.product-head { margin-bottom: 1.8rem; }
.cat-chip {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  background: color-mix(in srgb, var(--accent) 11%, transparent);
  border: 1px solid color-mix(in srgb, var(--accent) 32%, transparent);
  border-radius: 999px;
  padding: 0.3rem 0.85rem;
  margin-bottom: 1rem;
  box-shadow: 0 0 18px color-mix(in srgb, var(--accent) 16%, transparent);
}
.product-head h1 {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.1;
}
.aka { color: var(--ink-3); font-size: 0.92rem; margin-top: 0.5rem; }
.lede {
  margin-top: 0.9rem;
  font-size: 1.15rem;
  color: var(--ink-2);
  max-width: 44rem;
}

.facts {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(170px, 1fr));
  gap: 0.7rem;
  margin: 1.6rem 0;
}
.fact {
  background: var(--bg-raise);
  border: 1px solid var(--line-soft);
  border-radius: 14px;
  padding: 0.75rem 0.95rem;
}
.fact dt {
  font-size: 0.7rem;
  font-weight: 680;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-3);
}
.fact dd { font-size: 0.92rem; font-weight: 560; margin-top: 0.15rem; }

/* payoff figure */
.payoff-fig {
  margin: 1.8rem 0;
  background: var(--bg-raise);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  padding: 1.1rem 1.1rem 0.5rem;
}
.payoff-fig figcaption {
  font-size: 0.8rem;
  color: var(--ink-3);
  margin-bottom: 0.3rem;
}
.payoff { width: 100%; height: auto; display: block; }
.pf-grid { stroke: rgba(255, 255, 255, 0.05); stroke-width: 1; }
.pf-zero { stroke: rgba(255, 255, 255, 0.28); stroke-width: 1.2; }
.pf-vline { stroke: rgba(255, 255, 255, 0.2); stroke-width: 1; stroke-dasharray: 4 5; }
.pf-line { fill: none; stroke-width: 2.4; stroke-linejoin: round; stroke-linecap: round; }
.pf-line.pf-s1 { stroke: var(--pf-s1); filter: drop-shadow(0 0 5px rgba(57, 135, 229, 0.55)); }
.pf-line.pf-s2 { stroke: var(--pf-s2); }
.pf-line.pf-s3 { stroke: var(--pf-s3); stroke-dasharray: 5 5; }
.pf-label { font: 600 12px var(--font); }
.pf-label.pf-s1 { fill: var(--pf-s1); }
.pf-label.pf-s2 { fill: var(--pf-s2); }
.pf-label.pf-s3 { fill: var(--pf-s3); }
.pf-tick, .pf-axis { font: 500 11px var(--font); fill: var(--ink-3); }

/* ---- knowledge levels (accordions) ---- */

.levels { display: grid; gap: 0.8rem; margin: 2.2rem 0; }

.level {
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background: var(--bg-raise);
  overflow: hidden;
  transition: border-color 0.25s, box-shadow 0.25s;
}
.level[open] {
  border-color: color-mix(in srgb, var(--lv, var(--accent)) 38%, var(--line));
  box-shadow: 0 0 32px -8px color-mix(in srgb, var(--lv, var(--accent)) 25%, transparent);
}
.lv-1 { --lv: #2fd4bf; }
.lv-2 { --lv: #4d9fff; }
.lv-3 { --lv: #9d7bff; }

.level summary {
  display: flex;
  align-items: center;
  gap: 0.9rem;
  padding: 1.05rem 1.25rem;
  cursor: pointer;
  list-style: none;
  user-select: none;
}
.level summary::-webkit-details-marker { display: none; }
.level summary:hover { background: var(--bg-raise); }

.lv-badge {
  flex: none;
  font-size: 0.7rem;
  font-weight: 720;
  letter-spacing: 0.13em;
  text-transform: uppercase;
  color: var(--lv);
  background: color-mix(in srgb, var(--lv) 12%, transparent);
  border: 1px solid color-mix(in srgb, var(--lv) 34%, transparent);
  border-radius: 999px;
  padding: 0.28rem 0.8rem;
  box-shadow: 0 0 14px color-mix(in srgb, var(--lv) 15%, transparent);
}
.lv-title { font-weight: 640; font-size: 1.02rem; }
.lv-chev {
  width: 20px;
  height: 20px;
  margin-left: auto;
  color: var(--ink-3);
  transition: transform 0.3s;
}
.level[open] .lv-chev { transform: rotate(180deg); }

.level-body {
  padding: 0.4rem 1.4rem 1.5rem;
  border-top: 1px solid var(--line-soft);
}
.level-body > * + * { margin-top: 0.9rem; }
.level-body p, .level-body li { color: var(--ink-2); }
.level-body strong { color: var(--ink); font-weight: 650; }
.level-body h3 {
  color: var(--ink);
  font-size: 1.02rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin-top: 1.5rem;
}
.level-body ul, .level-body ol { padding-left: 1.3rem; }
.level-body li + li { margin-top: 0.35rem; }
.level-body .formula {
  overflow-x: auto;
  padding: 0.9rem 1rem;
  background: rgba(0, 0, 0, 0.28);
  border: 1px solid var(--line-soft);
  border-radius: 12px;
  font-size: 1.02rem;
}
.level-body .callout {
  border-left: 3px solid var(--lv, var(--accent));
  background: color-mix(in srgb, var(--lv, var(--accent)) 7%, transparent);
  border-radius: 0 12px 12px 0;
  padding: 0.8rem 1.05rem;
  font-size: 0.94rem;
}
.level-body table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
}
.level-body th, .level-body td {
  text-align: left;
  padding: 0.5rem 0.7rem;
  border-bottom: 1px solid var(--line-soft);
  color: var(--ink-2);
}
.level-body th { color: var(--ink-3); font-weight: 650; font-size: 0.78rem;
  text-transform: uppercase; letter-spacing: 0.1em; }

/* ---- promo / affiliate + ad slots ---- */

.promo {
  margin: 2rem 0;
  padding: 1.3rem 1.5rem;
  border-radius: var(--radius);
  border: 1px dashed color-mix(in srgb, var(--accent) 35%, var(--line));
  background: color-mix(in srgb, var(--accent) 5%, transparent);
}
.promo h2 { font-size: 1.05rem; font-weight: 700; margin-bottom: 0.35rem; }
.promo p { font-size: 0.9rem; color: var(--ink-2); }

.ad-slot { margin: 1.6rem 0; }
.ad-slot:not(.has-ad) { display: none; }
.ad-slot.has-ad {
  border: 1px solid var(--line-soft);
  border-radius: 14px;
  padding: 0.6rem;
  text-align: center;
}
.ad-slot.has-ad::before {
  content: "Advertisement";
  display: block;
  font-size: 0.65rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink-3);
  margin-bottom: 0.4rem;
}

/* ---- related + pager ---- */

.related { margin: 2.6rem 0 0; }
.related h2 { font-family: var(--font-display); font-size: 1.2rem; font-weight: 600; margin-bottom: 1rem; letter-spacing: -0.015em; }
.grid-related { grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); }

.pager {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.9rem;
  margin-top: 2.4rem;
}
.pager a {
  display: grid;
  gap: 0.15rem;
  padding: 1rem 1.2rem;
  text-decoration: none;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg-raise);
  transition: border-color 0.2s, background 0.2s;
}
.pager a:hover { border-color: color-mix(in srgb, var(--accent) 40%, var(--line)); background: var(--bg-raise-2); }
.pager a[rel="next"] { text-align: right; }
.pager span { font-size: 0.75rem; letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-3); }
.pager strong { font-weight: 660; font-size: 0.98rem; }

/* ---------------- static / prose pages ---------------- */

.prose {
  max-width: 760px;
  margin-inline: auto;
  padding: 3rem 0 4rem;
}
.prose h1 {
  font-family: var(--font-display);
  font-size: clamp(1.9rem, 4.5vw, 2.7rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: 1.4rem;
}
.prose h2 { font-family: var(--font-display); font-size: 1.35rem; font-weight: 600; letter-spacing: -0.015em; margin: 2.2rem 0 0.7rem; }
.prose h3 { font-size: 1.05rem; font-weight: 700; margin: 1.6rem 0 0.5rem; }
.prose p, .prose li { color: var(--ink-2); }
.prose p + p { margin-top: 0.9rem; }
.prose ul, .prose ol { padding-left: 1.3rem; margin: 0.8rem 0; }
.prose li + li { margin-top: 0.4rem; }
.prose a { color: var(--brand-1); }
.prose .callout {
  border-left: 3px solid var(--brand-1);
  background: rgba(77, 159, 255, 0.07);
  border-radius: 0 12px 12px 0;
  padding: 0.9rem 1.1rem;
  margin: 1.2rem 0;
  font-size: 0.95rem;
}
.prose table { width: 100%; border-collapse: collapse; font-size: 0.92rem; margin: 1rem 0; }
.prose th, .prose td { text-align: left; padding: 0.55rem 0.7rem; border-bottom: 1px solid var(--line-soft); color: var(--ink-2); }
.prose th { color: var(--ink-3); font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.1em; }

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

.site-footer {
  margin-top: 4rem;
  border-top: 1px solid var(--line-soft);
  background: rgba(4, 6, 12, 0.6);
  padding: 2.6rem clamp(1rem, 4vw, 2.2rem) 2rem;
}
.foot-grid {
  width: min(var(--maxw), 100%);
  margin-inline: auto;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 2rem;
}
.foot-brand { max-width: 30rem; display: grid; gap: 0.5rem; }
.foot-brand p { color: var(--ink-2); font-size: 0.92rem; }
.foot-note { color: var(--ink-3) !important; font-size: 0.8rem !important; }
.foot-delisoria {
  font-size: 0.78rem !important;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink-3) !important;
}
.foot-delisoria strong {
  font-family: var(--font-display);
  color: var(--ink-2);
  letter-spacing: 0.22em;
}
.foot-nav { display: grid; gap: 0.45rem; align-content: start; }
.foot-nav a {
  color: var(--ink-2);
  text-decoration: none;
  font-size: 0.9rem;
}
.foot-nav a:hover { color: var(--ink); }
.foot-copy {
  width: min(var(--maxw), 100%);
  margin: 2rem auto 0;
  padding-top: 1.2rem;
  border-top: 1px solid var(--line-soft);
  color: var(--ink-3);
  font-size: 0.8rem;
}

/* ---------------- responsive ---------------- */

@media (max-width: 720px) {
  body { font-size: 15.5px; }
  .site-nav a { padding: 0.4rem 0.6rem; font-size: 0.85rem; }
  .toolbar { top: 3.3rem; }
  .hero-stats { gap: 1.6rem; }
  .pager { grid-template-columns: 1fr; }
  .level summary { padding: 0.9rem 1rem; gap: 0.6rem; flex-wrap: wrap; }
  .lv-title { font-size: 0.95rem; }
  .level-body { padding: 0.3rem 1rem 1.2rem; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition-duration: 0.01ms !important; animation-duration: 0.01ms !important; }
}

/* ---------------- category deep-dive pages & tools ---------------- */

.cat-link { color: inherit; text-decoration: none; }
.cat-link:hover { color: var(--accent); }
.cat-deep {
  margin-left: auto;
  flex: none;
  font-size: 0.8rem;
  font-weight: 640;
  color: var(--accent);
  text-decoration: none;
  border: 1px solid color-mix(in srgb, var(--accent) 35%, transparent);
  border-radius: 999px;
  padding: 0.3rem 0.85rem;
  transition: background 0.2s, box-shadow 0.2s;
  white-space: nowrap;
}
.cat-deep:hover {
  background: color-mix(in srgb, var(--accent) 12%, transparent);
  box-shadow: 0 0 16px color-mix(in srgb, var(--accent) 25%, transparent);
}
.cat-head .cat-count { margin-left: 0; }

.category-page { padding: 2.2rem 0 3rem; max-width: 980px; margin-inline: auto; }
.prose-embed { padding: 0; max-width: none; }
.prose-embed h2 { margin-top: 2rem; }
.cat-products { margin: 2.6rem 0; }
.cat-products h2 {
  font-family: var(--font-display);
  font-size: 1.3rem;
  font-weight: 600;
  letter-spacing: -0.015em;
  margin-bottom: 1rem;
}

/* interactive calculators */
.tool {
  margin: 1.8rem 0;
  border-radius: var(--radius);
  border: 1px solid color-mix(in srgb, var(--accent) 30%, var(--line));
  background:
    radial-gradient(120% 100% at 15% 0%, color-mix(in srgb, var(--accent) 8%, transparent), transparent 60%),
    var(--bg-raise);
  box-shadow: 0 0 34px -12px color-mix(in srgb, var(--accent) 30%, transparent);
  padding: 1.4rem 1.5rem 1.5rem;
}
.tool h3 {
  font-family: var(--font-display);
  font-size: 1.08rem;
  font-weight: 600;
  margin-bottom: 0.2rem;
}
.tool > p { font-size: 0.88rem; color: var(--ink-3); margin-bottom: 1rem; }
.tool-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 0.8rem;
  margin-bottom: 1.1rem;
}
.tool label {
  display: grid;
  gap: 0.25rem;
  font-size: 0.72rem;
  font-weight: 660;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--ink-3);
}
.tool input, .tool select {
  font: inherit;
  font-size: 0.95rem;
  color: var(--ink);
  background: rgba(0, 0, 0, 0.3);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 0.5rem 0.7rem;
  outline: none;
  width: 100%;
  transition: border-color 0.2s, box-shadow 0.2s;
}
.tool input:focus, .tool select:focus {
  border-color: color-mix(in srgb, var(--accent) 55%, transparent);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 15%, transparent);
}
.tool-out {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 0.7rem;
}
.tool-out .out {
  background: rgba(0, 0, 0, 0.28);
  border: 1px solid var(--line-soft);
  border-radius: 12px;
  padding: 0.7rem 0.9rem;
}
.tool-out .out dt {
  font-size: 0.68rem;
  font-weight: 680;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-3);
}
.tool-out .out dd {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 600;
  margin-top: 0.1rem;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
}
.tool-note { font-size: 0.78rem; color: var(--ink-3); margin-top: 0.9rem; }

/* very small phones: keep the header on one line without clipping the nav */
@media (max-width: 480px) {
  .site-header { padding: 0.6rem 0.85rem; gap: 0.4rem; }
  .logo-mark { width: 24px; height: 24px; }
  .logo-text { font-size: 1rem; }
  .logo { gap: 0.45rem; }
  .site-nav { gap: 0; }
  .site-nav a { padding: 0.35rem 0.4rem; font-size: 0.76rem; }
}