:root {
  --bg: #f6f1e6;
  --bg-soft: #ece4d4;
  --surface: #fffdf7;
  --ink: #1c1a17;
  --ink-soft: #5c5348;
  --line: #ddd2bd;
  --line-strong: #c8bba2;
  --accent: #b03a2e;
  --accent-wash: #f7e4de;
  --bamboo: #2f6b4f;
  --bamboo-wash: #e2efe6;
  --gold: #a9803a;
  --gold-wash: #f6ecd5;
  --indigo: #22384a;
  --radius: 14px;
  --radius-sm: 9px;
  --shadow: 0 1px 2px rgba(28, 26, 23, .06), 0 10px 26px rgba(28, 26, 23, .06);
  --shadow-tile: 0 2px 0 rgba(28, 26, 23, .12), 0 10px 22px rgba(28, 26, 23, .08);
  --wrap: 1120px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-display: "Iowan Old Style", "Palatino Linotype", Palatino, "Book Antiqua", Georgia, serif;
}

[data-theme="dark"] {
  --bg: #101d18;
  --bg-soft: #182822;
  --surface: #1b2b24;
  --ink: #f1ece1;
  --ink-soft: #b9b3a4;
  --line: #33463d;
  --line-strong: #4a5f54;
  --accent: #e2674f;
  --accent-wash: #33201b;
  --bamboo: #6fb08b;
  --bamboo-wash: #1d332a;
  --gold: #d8b263;
  --gold-wash: #2f2717;
  --indigo: #a9c4da;
  --shadow: 0 1px 2px rgba(0, 0, 0, .35), 0 10px 26px rgba(0, 0, 0, .3);
  --shadow-tile: 0 2px 0 rgba(0, 0, 0, .4), 0 10px 22px rgba(0, 0, 0, .3);
}

*, *::before, *::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font);
  font-size: 16.5px;
  line-height: 1.66;
  -webkit-font-smoothing: antialiased;
  background-image:
    radial-gradient(circle at 12% 0%, color-mix(in srgb, var(--gold) 9%, transparent), transparent 42%),
    radial-gradient(circle at 88% 12%, color-mix(in srgb, var(--bamboo) 7%, transparent), transparent 40%);
  background-attachment: fixed;
}

img, svg { max-width: 100%; }
a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { text-decoration-thickness: 2px; }

:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; border-radius: 4px; }

.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}

.skip-link {
  position: absolute; left: -9999px; top: 0; z-index: 100;
  background: var(--surface); color: var(--ink); padding: .6rem 1rem;
}
.skip-link:focus { left: 1rem; top: 1rem; }

.wrap { width: 100%; max-width: var(--wrap); margin: 0 auto; padding: 0 1.25rem; }

/* ---------- header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 60;
  background: color-mix(in srgb, var(--bg) 92%, transparent);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}
.header-inner { display: flex; align-items: center; gap: 1rem; min-height: 68px; }

.brand { display: inline-flex; align-items: center; gap: .65rem; color: var(--ink); text-decoration: none; flex-shrink: 0; }
.brand-mark {
  position: relative;
  display: grid; place-items: center;
  width: 38px; height: 46px;
  border-radius: 8px 8px 10px 10px;
  background: linear-gradient(160deg, var(--surface), var(--bg-soft));
  border: 1px solid var(--line-strong);
  box-shadow: var(--shadow-tile);
  color: var(--accent);
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 700;
  line-height: 1;
}
.brand-mark::after {
  content: ""; position: absolute; left: 4px; right: 4px; bottom: 4px; height: 4px;
  border-radius: 3px;
  background: repeating-linear-gradient(90deg, var(--bamboo) 0 3px, transparent 3px 6px);
  opacity: .55;
}
.brand-text { display: flex; flex-direction: column; line-height: 1.2; }
.brand-name { font-family: var(--font-display); font-weight: 700; font-size: 1.02rem; letter-spacing: .01em; }
.brand-sub { font-size: .7rem; color: var(--ink-soft); letter-spacing: .02em; }

.main-nav { display: flex; align-items: center; gap: .15rem; margin-left: auto; }
.nav-item { position: relative; }
.nav-item > a, .nav-item > button {
  display: inline-flex; align-items: center; gap: .25rem;
  border: 0; background: none; cursor: pointer;
  color: var(--ink-soft); text-decoration: none; font: inherit; font-size: .86rem;
  padding: .45rem .6rem; border-radius: 8px; white-space: nowrap;
}
.nav-item > a:hover, .nav-item > button:hover { background: var(--bg-soft); color: var(--ink); }
.nav-item > a[aria-current="page"], .nav-item > button[aria-current="page"] { background: var(--accent-wash); color: var(--accent); font-weight: 600; }

.subnav {
  position: absolute; top: calc(100% + 8px); left: 0; min-width: 236px;
  padding: .45rem; border: 1px solid var(--line); border-radius: 12px;
  background: var(--surface); box-shadow: var(--shadow);
  display: none; z-index: 70;
}
/* invisible bridge over the 8px gap, so the pointer can travel from the
   parent link into the panel without the hover state dropping */
.subnav::before {
  content: ""; position: absolute; left: 0; right: 0; top: -10px; height: 10px;
}
.nav-item:hover .subnav, .nav-item:focus-within .subnav { display: block; }
.subnav a { display: block; padding: .42rem .6rem; border-radius: 7px; color: var(--ink-soft); text-decoration: none; font-size: .85rem; }
.subnav a:hover { background: var(--bg-soft); color: var(--ink); }
.subnav a span { display: block; font-size: .72rem; color: var(--ink-soft); opacity: .85; }

.header-actions { display: flex; align-items: center; gap: .4rem; }
.icon-btn {
  display: grid; place-items: center; width: 38px; height: 38px;
  border: 1px solid var(--line); border-radius: 10px;
  background: var(--surface); color: var(--ink); cursor: pointer;
}
.icon-btn svg { width: 18px; height: 18px; }
.icon-btn:hover { border-color: var(--accent); color: var(--accent); }
.menu-btn { display: none; }

.btn-subscribe {
  display: inline-flex; align-items: center; gap: .4rem;
  padding: .48rem .9rem; border-radius: 999px;
  border: 1.5px solid var(--accent); color: var(--accent);
  background: transparent; text-decoration: none;
  font-size: .82rem; font-weight: 700; white-space: nowrap;
}
.btn-subscribe:hover { background: var(--accent); color: #fff; }

/* ---------- hero ---------- */
.hero { padding: 3.4rem 0 1.6rem; max-width: 820px; }
.eyebrow {
  display: inline-block; margin: 0 0 .85rem; padding: .22rem .65rem;
  border: 1px solid var(--line-strong); border-radius: 999px;
  background: var(--gold-wash); color: var(--gold);
  font-size: .72rem; font-weight: 700; letter-spacing: .08em; text-transform: uppercase;
}
h1, h2, h3 { line-height: 1.24; letter-spacing: -.012em; }
h1 { font-family: var(--font-display); font-size: clamp(1.95rem, 4.2vw, 2.85rem); margin: 0 0 .9rem; font-weight: 700; }
h2 { font-family: var(--font-display); font-size: 1.4rem; margin: 0 0 1rem; }
h3 { font-size: 1.04rem; margin: 0 0 .35rem; }
.lede { font-size: 1.1rem; color: var(--ink-soft); margin: 0 0 1.2rem; }

.hero-answer {
  margin: 1.4rem 0 0; padding: 1rem 1.15rem;
  border: 1px solid var(--line); border-left: 4px solid var(--bamboo);
  border-radius: var(--radius); background: var(--surface);
  font-size: .96rem;
}
.hero-answer strong { color: var(--bamboo); }

.btn {
  display: inline-block; padding: .62rem 1.15rem; border-radius: 10px;
  background: var(--accent); color: #fff; text-decoration: none; font-weight: 700; font-size: .92rem;
}
.btn:hover { background: color-mix(in srgb, var(--accent) 86%, #000); }
.btn-ghost {
  background: transparent; color: var(--ink); border: 1.5px solid var(--line-strong);
}
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); background: transparent; }

/* ---------- cards ---------- */
.card-group { padding: 1.9rem 0; border-top: 1px solid var(--line); }
.card-group > h2 { display: flex; align-items: center; gap: .5rem; }
.card-group > h2::before {
  content: ""; width: 8px; height: 8px; border-radius: 2px;
  background: var(--accent); transform: rotate(45deg);
}
.card-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(248px, 1fr)); gap: 1rem; }
.card {
  position: relative; display: flex; flex-direction: column;
  padding: 1.15rem 1.2rem 1.05rem;
  border: 1px solid var(--line); border-radius: var(--radius);
  background: var(--surface); color: var(--ink); text-decoration: none;
  box-shadow: var(--shadow); transition: transform .16s ease, border-color .16s ease, box-shadow .16s ease;
}
.card::after {
  content: ""; position: absolute; left: 14px; right: 14px; bottom: 0; height: 3px;
  border-radius: 3px 3px 0 0;
  background: repeating-linear-gradient(90deg, var(--bamboo) 0 4px, transparent 4px 8px);
  opacity: 0; transition: opacity .16s ease;
}
.card:hover { transform: translateY(-3px); border-color: var(--accent); box-shadow: var(--shadow-tile); }
.card:hover::after { opacity: .5; }
.card p { margin: 0; color: var(--ink-soft); font-size: .9rem; }
.card-tag {
  align-self: flex-start; margin-bottom: .55rem; padding: .12rem .5rem;
  border-radius: 999px; background: var(--bamboo-wash); color: var(--bamboo);
  font-size: .69rem; font-weight: 700; letter-spacing: .05em; text-transform: uppercase;
}
.card.featured { border-color: var(--accent); }
.card.featured .card-tag { background: var(--accent-wash); color: var(--accent); }

/* ---------- article layout ---------- */
.breadcrumb { padding: 1.1rem 0 0; font-size: .8rem; color: var(--ink-soft); }
.breadcrumb ol { display: flex; flex-wrap: wrap; gap: .35rem; list-style: none; margin: 0; padding: 0; }
.breadcrumb li + li::before { content: "/"; margin-right: .35rem; color: var(--line-strong); }
.breadcrumb a { color: var(--ink-soft); }

.layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 292px;
  gap: 3rem;
  align-items: start;
  padding-bottom: 2rem;
}
.doc-main { min-width: 0; }
.side { position: sticky; top: 84px; display: grid; gap: 1.1rem; }

.article-head { padding: 1.6rem 0 1rem; }
.meta-row { display: flex; flex-wrap: wrap; align-items: center; gap: .45rem; color: var(--ink-soft); font-size: .8rem; }
.badge {
  padding: .12rem .5rem; border: 1px solid var(--line-strong); border-radius: 999px;
  background: var(--bg-soft); font-size: .7rem; font-weight: 700; letter-spacing: .03em;
}
.badge--accent { background: var(--accent-wash); color: var(--accent); border-color: transparent; }

.keybox {
  margin: 1.25rem 0 1.5rem; padding: 1.1rem 1.25rem;
  border: 1px solid var(--line); border-top: 4px solid var(--accent);
  border-radius: var(--radius); background: var(--surface); box-shadow: var(--shadow);
}
.keybox h2 {
  font-family: var(--font); font-size: .8rem; margin: 0 0 .65rem;
  text-transform: uppercase; letter-spacing: .1em; color: var(--ink-soft);
}
.keybox dl { display: grid; grid-template-columns: max-content 1fr; gap: .5rem 1.1rem; margin: 0; font-size: .92rem; }
.keybox dt { color: var(--ink-soft); font-weight: 600; }
.keybox dd { margin: 0; }

.prose { max-width: 760px; padding-bottom: 1.5rem; }
.prose h2 { margin-top: 2.3rem; padding-top: .3rem; scroll-margin-top: 90px; }
.prose h2 + p { margin-top: .35rem; }
.prose h3 { margin-top: 1.7rem; }
.prose p { margin: .85rem 0; }
.prose ul, .prose ol { padding-left: 1.25rem; margin: .8rem 0; }
.prose li { margin: .35rem 0; }
.prose table { width: 100%; border-collapse: collapse; margin: 1.1rem 0; font-size: .88rem; }
.prose th, .prose td { border: 1px solid var(--line); padding: .5rem .62rem; text-align: left; vertical-align: top; }
.prose th { background: var(--bg-soft); font-size: .82rem; letter-spacing: .02em; }
.prose tbody tr:nth-child(even) td { background: color-mix(in srgb, var(--bg-soft) 40%, transparent); }
.prose code { padding: .1rem .32rem; border-radius: 4px; background: var(--bg-soft); font-size: .88em; }
.prose strong { color: color-mix(in srgb, var(--ink) 88%, var(--accent)); }

.note {
  margin: 1.4rem 0; padding: .9rem 1.1rem; border-radius: var(--radius-sm);
  border: 1px solid var(--line); background: var(--bg-soft); font-size: .91rem;
}
.note--bamboo { border-left: 4px solid var(--bamboo); background: var(--bamboo-wash); }
.note--gold { border-left: 4px solid var(--gold); background: var(--gold-wash); }
.note p { margin: .3rem 0; }

/* tile chips in text */
.tile {
  display: inline-block; min-width: 1.6em; padding: .05em .35em; margin: 0 .08em;
  border: 1px solid var(--line-strong); border-radius: 5px;
  background: var(--surface); box-shadow: 0 1px 0 var(--line);
  font-family: var(--font-display); font-size: .88em; text-align: center; line-height: 1.35;
  white-space: nowrap;
}
.tile--red { color: var(--accent); }
.tile--green { color: var(--bamboo); }
.tile--blue { color: var(--indigo); }

/* figures */
.page-figure { margin: 1.6rem 0; }
.page-figure img {
  display: block; width: 100%; height: auto;
  border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface);
}
.page-figure figcaption { margin-top: .5rem; font-size: .78rem; color: var(--ink-soft); line-height: 1.5; }

/* details / faq */
details.faq-item {
  margin: .55rem 0; padding: .85rem 1.05rem;
  border: 1px solid var(--line); border-radius: var(--radius-sm); background: var(--surface);
}
details.faq-item summary {
  cursor: pointer; font-weight: 700; font-size: .95rem; color: var(--ink);
  list-style: none; display: flex; gap: .6rem; align-items: flex-start;
}
details.faq-item summary::-webkit-details-marker { display: none; }
details.faq-item summary::before {
  content: "+"; flex-shrink: 0; width: 1.1rem; height: 1.1rem; margin-top: .12rem;
  border-radius: 4px; background: var(--accent-wash); color: var(--accent);
  font-size: .8rem; line-height: 1.1rem; text-align: center; font-weight: 700;
}
details.faq-item[open] summary::before { content: "−"; }
details.faq-item p { margin: .6rem 0 0; font-size: .92rem; color: var(--ink-soft); }

/* ---------- sidebar ---------- */
.side-card {
  padding: 1.1rem 1.15rem; border: 1px solid var(--line); border-radius: var(--radius);
  background: var(--surface); box-shadow: var(--shadow);
}
.side-card h2, .side-card h3 {
  font-family: var(--font); font-size: .78rem; margin: 0 0 .6rem;
  letter-spacing: .1em; text-transform: uppercase; color: var(--ink-soft);
}
.side-card ul { list-style: none; margin: 0; padding: 0; }
.side-card li { margin: .32rem 0; }
.side-card a { color: var(--ink-soft); text-decoration: none; font-size: .87rem; display: block; }
.side-card a:hover { color: var(--accent); }
.side-cta { border-top: 4px solid var(--bamboo); }
.side-cta p { margin: .35rem 0 .7rem; font-size: .88rem; color: var(--ink-soft); }
.side-cta .btn { width: 100%; text-align: center; }

/* ---------- ads ---------- */
.ad-slot {
  position: relative; display: grid; place-items: center;
  margin: 1.5rem auto; width: 100%; max-width: 970px;
  min-height: 90px; padding: 1rem;
  border: 1px dashed var(--line-strong); border-radius: var(--radius-sm);
  background: color-mix(in srgb, var(--bg-soft) 55%, transparent);
  color: var(--ink-soft); font-size: .68rem; letter-spacing: .14em; text-transform: uppercase;
  text-align: center; overflow: hidden;
}
.ad-slot::before {
  content: "Advertisement"; position: absolute; top: 0; left: 0;
  padding: .1rem .45rem; border-radius: 0 0 6px 0;
  background: var(--bg-soft); color: var(--ink-soft); font-size: .6rem; letter-spacing: .1em;
}
.ad-slot--rectangle { max-width: 336px; min-height: 280px; }
.ad-slot.is-filled { border-style: solid; background: transparent; padding: 0; }
.ad-slot.is-filled::before { content: "Advertisement"; }

/* ---------- subscribe ---------- */
.subscribe {
  margin: 2.6rem 0 0; padding: 2.2rem 1.25rem;
  background:
    linear-gradient(140deg, color-mix(in srgb, var(--bamboo) 92%, #000), var(--bamboo));
  color: #f3efe4;
  border-top: 4px solid var(--gold);
}
.subscribe-inner { max-width: 720px; margin: 0 auto; text-align: center; }
.subscribe .eyebrow {
  background: rgba(255,255,255,.12); border-color: rgba(255,255,255,.3); color: #f6ecd5;
}
.subscribe h2 { font-family: var(--font-display); color: #fff; font-size: 1.55rem; margin: 0 0 .7rem; }
.subscribe p { color: rgba(243, 239, 228, .88); margin: 0 0 1.1rem; font-size: .95rem; }
.subscribe-form { display: flex; gap: .5rem; max-width: 460px; margin: 0 auto; }
.subscribe-form input {
  flex: 1; min-width: 0; padding: .7rem .9rem; border-radius: 10px;
  border: 1px solid rgba(255,255,255,.35); background: rgba(255,255,255,.95); color: #1c1a17;
  font: inherit; font-size: .92rem;
}
.subscribe-form button {
  padding: .7rem 1.15rem; border: 0; border-radius: 10px;
  background: var(--accent); color: #fff; font: inherit; font-weight: 700; font-size: .9rem; cursor: pointer;
  white-space: nowrap;
}
.subscribe-form button:hover { background: #8f2d24; }
.subscribe-note { font-size: .76rem; opacity: .75; margin: .8rem 0 0; }
.subscribe-status { min-height: 1.2em; margin: .6rem 0 0; font-size: .85rem; font-weight: 600; color: #f6ecd5; }

/* ---------- quiz ---------- */
.quiz { counter-reset: q; }
.quiz-item {
  margin: 1rem 0; padding: 1rem 1.1rem; border: 1px solid var(--line);
  border-radius: var(--radius-sm); background: var(--surface);
}
.quiz-item .q-num {
  display: inline-block; margin-right: .45rem; padding: .05rem .42rem;
  border-radius: 4px; background: var(--gold-wash); color: var(--gold);
  font-size: .72rem; font-weight: 700; letter-spacing: .05em;
}
.quiz-item h3 { display: inline; font-size: .96rem; }
.quiz-item details { margin-top: .6rem; }
.quiz-item summary { cursor: pointer; font-size: .84rem; font-weight: 700; color: var(--accent); }
.quiz-item p { margin: .5rem 0 0; font-size: .9rem; color: var(--ink-soft); }

.hand {
  font-family: ui-monospace, "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  font-size: .95rem;
  letter-spacing: .01em;
  background: var(--bamboo-wash);
  border-left: 3px solid var(--bamboo);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: .7rem .95rem;
  margin: 1rem 0;
}

.formula {
  text-align: center;
  font-size: 1.12rem;
  background: var(--gold-wash);
  border-radius: var(--radius-sm);
  padding: .85rem;
  margin: 1rem 0;
}

/* ---------- footer ---------- */
.site-footer { margin-top: 3rem; border-top: 1px solid var(--line); background: var(--bg-soft); }
.footer-inner { display: flex; flex-wrap: wrap; gap: 2rem; justify-content: space-between; padding-top: 2.2rem; padding-bottom: 1.5rem; }
.footer-brand { max-width: 350px; }
.footer-brand .brand-name { font-family: var(--font-display); font-size: 1rem; }
.footer-note { color: var(--ink-soft); font-size: .8rem; margin: .45rem 0 0; }
.footer-cols { display: flex; flex-wrap: wrap; gap: 2.2rem; }
.footer-cols a { display: block; color: var(--ink-soft); text-decoration: none; font-size: .84rem; padding: .13rem 0; }
.footer-cols a:hover { color: var(--accent); }
.footer-head { margin: 0 0 .45rem; font-size: .73rem; font-weight: 700; letter-spacing: .07em; text-transform: uppercase; color: var(--ink); }
.footer-base { padding-top: 1rem; padding-bottom: 1.6rem; border-top: 1px solid var(--line); color: var(--ink-soft); font-size: .76rem; }
.footer-base p { margin: 0; }

/* ---------- 404 ---------- */
.notfound { padding: 4rem 0 5rem; max-width: 640px; }
.notfound h1 { font-size: 3rem; margin-bottom: .4rem; }

/* ---------- responsive ---------- */
@media (max-width: 980px) {
  .layout { grid-template-columns: minmax(0, 1fr); gap: 1.5rem; }
  .side { position: static; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
}
@media (max-width: 900px) {
  .menu-btn { display: grid; }
  .main-nav {
    display: none; position: absolute; left: 1rem; right: 1rem; top: calc(100% + .45rem);
    padding: .55rem; border: 1px solid var(--line); border-radius: var(--radius);
    background: var(--surface); box-shadow: var(--shadow);
    flex-direction: column; align-items: stretch; gap: .1rem;
    max-height: 70vh; overflow-y: auto;
  }
  .main-nav.is-open { display: flex; }
  .header-inner { position: relative; }
  .nav-item > a, .nav-item > button { width: 100%; justify-content: space-between; }
  .subnav {
    position: static; display: block; min-width: 0; box-shadow: none;
    border: 0; border-radius: 0; padding: 0 0 0 .75rem; background: transparent;
  }
  .subnav::before { display: none; }
  .nav-item:hover .subnav { display: block; }
  .keybox dl { grid-template-columns: 1fr; gap: .12rem; }
  .keybox dd { margin-bottom: .6rem; }
  .prose table { display: block; overflow-x: auto; -webkit-overflow-scrolling: touch; }
  .btn-subscribe span { display: none; }
  .subscribe-form { flex-direction: column; }
}
@media (max-width: 640px) {
  /* diagrams lose their labels if they scale to a phone width, so let them scroll */
  .page-figure { overflow-x: auto; }
  .page-figure img { min-width: 680px; }
  .page-figure figcaption { position: sticky; left: 0; }
}
@media (max-width: 520px) {
  body { font-size: 16px; }
  .brand-sub { display: none; }
  .hero { padding-top: 2.4rem; }
  .ad-slot { min-height: 100px; }
  .ad-slot--rectangle { min-height: 250px; }
  .footer-cols { gap: 1.6rem; }
}

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; scroll-behavior: auto !important; }
}

@media print {
  .site-header, .side, .subscribe, .site-footer, .ad-slot, .breadcrumb { display: none !important; }
  body { background: #fff; color: #000; }
  .layout { display: block; }
  .prose h2 { page-break-after: avoid; }
}