:root {
  --ink: #16130f;
  --ink-soft: #3a3228;
  --paper: #f4efe6;
  --paper-2: #ebe4d6;
  --card: #fffaf3;
  --amber: #e8a317;
  --amber-hot: #ffc44d;
  --amber-deep: #8a4f00;
  --cream: #f4efe6;
  --muted: #5e564c;
  --muted-on-dark: #d4c8b6;
  --line: #ddd4c4;
  --line-dark: #3a3228;
  --ok: #1d5c34;
  --danger: #8e2a22;
  --shadow: 0 22px 50px rgba(22, 19, 15, 0.28);
  --serif: "Fraunces", Georgia, "Times New Roman", serif;
  --sans: "Figtree", "Avenir Next", "Segoe UI", sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, Menlo, monospace;
  --wrap: min(1080px, calc(100% - 2.75rem));
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 5.25rem;
}

body {
  font-family: var(--sans);
  background: var(--paper);
  color: var(--ink);
  line-height: 1.6;
  font-size: 1.05rem;
  -webkit-font-smoothing: antialiased;
  overflow-x: clip;
}

img { max-width: 100%; }

a { color: var(--amber-deep); text-underline-offset: 3px; }
a:hover { color: var(--ink); }

:focus-visible {
  outline: 3px solid var(--amber);
  outline-offset: 3px;
}

.wrap {
  width: var(--wrap);
  margin: 0 auto;
}

.skip {
  position: absolute;
  left: 1rem;
  top: 0;
  transform: translateY(-120%);
  background: var(--amber);
  color: var(--ink);
  padding: 0.7rem 1rem;
  z-index: 80;
  font-weight: 700;
  text-decoration: none;
}
.skip:focus { transform: none; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background: var(--ink);
  color: var(--cream);
  border-bottom: 3px solid var(--amber);
}

.nav {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.85rem 1.5rem;
  padding: 0.95rem 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  color: var(--cream);
  text-decoration: none;
  min-width: 0;
}

.brand-mark {
  width: 42px;
  height: 42px;
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  background: var(--amber);
  color: var(--ink);
  font-family: var(--serif);
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: -0.04em;
}

.brand-name {
  font-family: var(--serif);
  font-weight: 650;
  font-size: 1.35rem;
  letter-spacing: -0.03em;
  line-height: 1;
}

.brand-name span {
  font-family: var(--mono);
  font-weight: 600;
  font-size: 0.95rem;
  letter-spacing: 0.08em;
  color: var(--amber);
  margin-left: 0.35rem;
  text-transform: uppercase;
}

.nav-links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.35rem 1.15rem;
}

.nav-links a:not(.btn) {
  color: var(--muted-on-dark);
  text-decoration: none;
  font-weight: 650;
  font-size: 0.98rem;
}

.nav-links a:not(.btn):hover {
  color: var(--cream);
  text-decoration: underline;
  text-decoration-thickness: 2px;
  text-underline-offset: 4px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  border: 2px solid transparent;
  cursor: pointer;
  border-radius: 2px;
  padding: 0.9rem 1.15rem;
  font: 700 0.98rem/1 var(--sans);
  text-decoration: none;
  transition: background 0.15s ease, color 0.15s ease, border-color 0.15s ease, transform 0.15s ease;
}

.btn:hover { transform: translateY(-1px); }
.btn:active { transform: translateY(0); }

.btn-amber {
  background: var(--amber);
  color: var(--ink);
  border-color: var(--amber);
}
.btn-amber:hover {
  background: var(--amber-hot);
  border-color: var(--amber-hot);
  color: var(--ink);
}

.btn-line {
  background: transparent;
  color: var(--cream);
  border-color: #8d7d68;
}
.btn-line:hover {
  background: var(--amber);
  border-color: var(--amber);
  color: var(--ink);
}

.btn-ink {
  background: var(--ink);
  color: var(--cream);
  border-color: var(--ink);
}
.btn-ink:hover {
  background: #3d3428;
  border-color: #3d3428;
  color: var(--cream);
}

.btn-ghost {
  background: transparent;
  color: var(--ink);
  border-color: var(--ink);
}
.btn-ghost:hover {
  background: var(--ink);
  color: var(--cream);
}

.btn[data-state="copied"] {
  background: var(--ok);
  border-color: var(--ok);
  color: #f4efe6;
}
.btn[data-state="error"] {
  background: var(--danger);
  border-color: var(--danger);
  color: #fff;
}

.nav .btn {
  padding: 0.62rem 0.85rem;
  font-size: 0.92rem;
}

.hero {
  background: var(--ink);
  color: var(--cream);
  padding: clamp(2.2rem, 5vw, 4rem) 0 clamp(2.6rem, 6vw, 4.4rem);
}

.hero-grid {
  display: grid;
  gap: 2rem;
  align-items: start;
}
.hero-grid > * { min-width: 0; }

@media (min-width: 900px) {
  .hero-grid { grid-template-columns: 1.15fr 0.85fr; gap: 3rem; }
}

.kicker {
  font-family: var(--mono);
  font-size: 0.78rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--amber);
  font-weight: 600;
}

h1 {
  margin-top: 0.85rem;
  font-family: var(--serif);
  font-weight: 650;
  font-size: clamp(2.35rem, 5vw, 4rem);
  line-height: 1.02;
  letter-spacing: -0.035em;
  text-wrap: balance;
}

h1 em {
  font-style: normal;
  color: var(--amber);
}

.quick-answer {
  margin-top: 1.15rem;
  max-width: 38rem;
  color: var(--muted-on-dark);
  font-size: 1.12rem;
}

.quick-answer strong { color: var(--cream); font-weight: 700; }

.hero-actions {
  margin-top: 1.5rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
}

.checked {
  margin-top: 1.35rem;
  color: #b7aa9a;
  font-size: 0.92rem;
  max-width: 38rem;
}

.board {
  background: #0e0c0a;
  border: 1px solid #3a3228;
  border-top: 8px solid var(--amber);
  box-shadow: var(--shadow);
  padding: 1.35rem 1.35rem 1.2rem;
}

.board-kicker {
  font-family: var(--mono);
  font-size: 0.75rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--amber);
}

.board-code {
  font-family: var(--mono);
  font-weight: 600;
  font-size: clamp(2.6rem, 6vw, 3.5rem);
  letter-spacing: 0.08em;
  color: var(--amber-hot);
  line-height: 1.1;
  margin: 0.35rem 0 1rem;
}

.board-rows { list-style: none; }
.board-rows li {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.55rem 0;
  border-top: 1px dashed #4a4034;
  font-size: 0.98rem;
}
.board-rows span { color: #cbbfae; }
.board-rows strong {
  font-family: var(--mono);
  font-weight: 600;
  color: var(--cream);
  text-align: right;
}

.board .btn { width: 100%; margin-top: 0.85rem; }
.board .btn + .btn { margin-top: 0.55rem; }

.copied-note {
  min-height: 1.3em;
  margin-top: 0.7rem;
  text-align: center;
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--amber-hot);
  opacity: 0;
}
.copied-note.show { opacity: 1; }
.copied-note.error { color: #ffb4ae; }

.board-foot {
  margin-top: 0.85rem;
  color: #b7aa9a;
  font-size: 0.88rem;
  text-align: center;
}

section { padding: clamp(2.6rem, 5vw, 4.4rem) 0; }

.band { background: var(--paper-2); }

.section-kicker {
  font-family: var(--mono);
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--amber-deep);
  font-weight: 600;
}

h2 {
  margin-top: 0.4rem;
  font-family: var(--serif);
  font-weight: 650;
  font-size: clamp(1.8rem, 3.4vw, 2.7rem);
  letter-spacing: -0.03em;
  line-height: 1.12;
  text-wrap: balance;
  max-width: 18em;
}

.lede {
  margin-top: 0.9rem;
  max-width: 40rem;
  color: var(--muted);
  font-size: 1.08rem;
}
.lede strong { color: var(--ink); }

.order {
  list-style: none;
  counter-reset: step;
  margin-top: 1.8rem;
  max-width: 46rem;
}

.order li {
  counter-increment: step;
  display: grid;
  grid-template-columns: 3.2rem 1fr;
  gap: 0.35rem 1rem;
  padding: 1.2rem 0;
  border-top: 1px solid var(--line);
}

.order li::before {
  content: counter(step);
  grid-row: span 2;
  font-family: var(--serif);
  font-size: 2rem;
  font-weight: 650;
  color: var(--amber-deep);
  line-height: 1;
}

.order h3 {
  font-family: var(--serif);
  font-size: 1.35rem;
  font-weight: 650;
  letter-spacing: -0.02em;
}

.order p { color: var(--muted); margin-top: 0.25rem; }

.math-grid {
  margin-top: 1.8rem;
  display: grid;
  gap: 1.25rem;
}

@media (min-width: 860px) {
  .math-grid { grid-template-columns: 1.15fr 0.85fr; align-items: start; }
}

.table-wrap {
  background: var(--card);
  border: 1px solid var(--line);
  overflow-x: auto;
}

table {
  width: 100%;
  border-collapse: collapse;
  min-width: 18rem;
}

th, td {
  text-align: left;
  padding: 0.8rem 1rem;
  border-bottom: 1px solid var(--line);
}

th {
  font-family: var(--mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  background: var(--ink);
  color: var(--cream);
  font-weight: 600;
}

td:last-child, th:last-child { text-align: right; }

td.num, th.num {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
}

tbody tr:last-child td { border-bottom: 0; }

.calc {
  background: var(--ink);
  color: var(--cream);
  padding: 1.3rem 1.25rem 1.25rem;
}

.calc h3 {
  font-family: var(--serif);
  font-size: 1.55rem;
  font-weight: 650;
  letter-spacing: -0.02em;
}

.calc p.hint {
  margin-top: 0.4rem;
  color: var(--muted-on-dark);
  font-size: 0.95rem;
}

.calc label {
  display: block;
  margin-top: 1rem;
  font-size: 0.82rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  font-weight: 700;
  color: #cbbfae;
}

.calc input {
  display: block;
  width: 100%;
  margin-top: 0.4rem;
  background: #0e0c0a;
  color: var(--amber-hot);
  border: 2px solid #4a4034;
  border-radius: 2px;
  padding: 0.75rem 0.8rem;
  font: 600 1.6rem/1 var(--mono);
}

.calc input:focus {
  border-color: var(--amber);
  outline: none;
}

.presets {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-top: 0.75rem;
}

.presets button {
  background: transparent;
  color: var(--cream);
  border: 1px solid #6d5e4c;
  padding: 0.4rem 0.6rem;
  font: 700 0.85rem/1 var(--sans);
  cursor: pointer;
}

.presets button[aria-pressed="true"],
.presets button:hover {
  background: var(--amber);
  border-color: var(--amber);
  color: var(--ink);
}

.calc-out {
  margin-top: 1rem;
  padding-top: 0.9rem;
  border-top: 1px solid #3a3228;
  font-size: 1.05rem;
}

.calc-out strong {
  display: block;
  margin-top: 0.15rem;
  font-family: var(--mono);
  font-size: clamp(2rem, 4vw, 2.5rem);
  color: var(--amber-hot);
  font-weight: 600;
}

.fine {
  margin-top: 0.85rem;
  color: var(--muted);
  font-size: 0.92rem;
  max-width: 42rem;
}

.split {
  margin-top: 1.6rem;
  display: grid;
  gap: 1rem;
}

@media (min-width: 800px) {
  .split { grid-template-columns: 1fr 1fr; }
}

.panel {
  background: var(--card);
  border: 1px solid var(--line);
  padding: 1.25rem 1.2rem 1.3rem;
}

.panel h3 {
  font-family: var(--serif);
  font-size: 1.45rem;
  font-weight: 650;
  letter-spacing: -0.02em;
}

.panel p { margin-top: 0.55rem; color: var(--muted); }
.panel .figure {
  margin-top: 0.8rem;
  font-family: var(--mono);
  font-size: 1.8rem;
  font-weight: 600;
  color: var(--amber-deep);
}

.miss {
  list-style: none;
  margin-top: 1.5rem;
  display: grid;
  gap: 0.75rem;
}

@media (min-width: 800px) {
  .miss { grid-template-columns: 1fr 1fr; }
}

.miss li {
  background: var(--card);
  border-left: 6px solid var(--amber);
  padding: 1rem 1rem 1.05rem 1.05rem;
}

.miss strong {
  display: block;
  font-family: var(--serif);
  font-size: 1.2rem;
  font-weight: 650;
  margin-bottom: 0.3rem;
}

.miss span { color: var(--muted); }

.faq { margin-top: 1.4rem; max-width: 46rem; }

.faq details {
  border-bottom: 1px solid var(--line);
  padding: 0.35rem 0;
}

.faq summary {
  cursor: pointer;
  list-style: none;
  padding: 0.9rem 0;
  font-family: var(--serif);
  font-size: 1.28rem;
  font-weight: 650;
  letter-spacing: -0.02em;
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: baseline;
}

.faq summary::-webkit-details-marker { display: none; }

.faq summary::after {
  content: "+";
  font-family: var(--mono);
  color: var(--amber-deep);
  font-size: 1.4rem;
  line-height: 1;
}

.faq details[open] summary::after { content: "–"; }

.faq details p {
  color: var(--muted);
  padding: 0 0 1rem;
  max-width: 42rem;
}

.page-hero { padding: clamp(2.2rem, 5vw, 3.4rem) 0 0.5rem; }

.page-hero h1 { max-width: 14em; }

.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;
}

.crumb {
  font-size: 0.92rem;
  color: var(--muted);
  margin-bottom: 0.8rem;
}
.crumb a { color: var(--muted); }

.prose { max-width: 42rem; }
.prose p + p { margin-top: 0.85rem; }
.prose h2 { margin-top: 2rem; max-width: none; font-size: 1.7rem; }
.prose ul { margin: 0.75rem 0 0 1.2rem; color: var(--muted); }
.prose li + li { margin-top: 0.4rem; }

.site-footer {
  background: var(--ink);
  color: #cbbfae;
  padding: 2.8rem 0 1.6rem;
  margin-top: 1rem;
}

.foot-grid {
  display: grid;
  gap: 1.8rem;
}

@media (min-width: 800px) {
  .foot-grid { grid-template-columns: 1.4fr 0.8fr; }
}

.foot-brand {
  color: var(--cream);
  font-family: var(--serif);
  font-size: 1.6rem;
  font-weight: 650;
}

.foot-brand span {
  font-family: var(--mono);
  color: var(--amber);
  font-size: 0.95rem;
  letter-spacing: 0.08em;
  margin-left: 0.35rem;
}

.site-footer p { margin-top: 0.75rem; max-width: 36rem; }
.site-footer a { color: var(--amber-hot); }
.site-footer a:hover { color: var(--cream); }

.site-footer nav {
  display: grid;
  gap: 0.45rem;
  align-content: start;
}

.site-footer nav a {
  color: #d4c8b6;
  text-decoration: none;
  font-weight: 650;
}
.site-footer nav a:hover {
  color: var(--amber-hot);
  text-decoration: underline;
}

.foot-bottom {
  margin-top: 2rem;
  padding-top: 1rem;
  border-top: 1px solid #3a3228;
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 1.4rem;
  justify-content: space-between;
  font-size: 0.85rem;
  color: #9c9080;
}

.copy-modal {
  position: fixed;
  inset: 0;
  z-index: 90;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.25rem;
  background: rgba(14, 12, 10, 0.72);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity 0.2s ease, visibility 0.2s;
}

.copy-modal.is-open {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
}

.copy-modal-panel {
  position: relative;
  width: min(100%, 28rem);
  background: var(--card);
  color: var(--ink);
  padding: 1.6rem 1.4rem 1.4rem;
  border-top: 8px solid var(--amber);
  box-shadow: var(--shadow);
}

.copy-modal-close {
  position: absolute;
  top: 0.55rem;
  right: 0.55rem;
  width: 2.4rem;
  height: 2.4rem;
  border: 0;
  background: transparent;
  cursor: pointer;
  font-size: 1.5rem;
  line-height: 1;
  color: var(--muted);
}

.copy-modal-close:hover { color: var(--ink); background: var(--paper-2); }

.copy-modal-kicker {
  font-family: var(--mono);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--amber-deep);
  font-weight: 600;
}

.copy-modal-title {
  margin-top: 0.45rem;
  font-family: var(--serif);
  font-size: 1.7rem;
  font-weight: 650;
  letter-spacing: -0.03em;
  line-height: 1.15;
  max-width: none;
}

.copy-modal-body {
  margin-top: 0.7rem;
  color: var(--muted);
}

.copy-modal-actions { margin-top: 1.2rem; }
.copy-modal-actions .btn { width: 100%; }

body.modal-open { overflow: hidden; }

@media (max-width: 640px) {
  :root { --wrap: min(1080px, calc(100% - 2rem)); }
  .hero-actions { flex-direction: column; align-items: stretch; }
  .hero-actions .btn { width: 100%; }
  .nav-links { width: 100%; }
  h2 { max-width: none; }
}

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