:root {
  --paper: #f8fafb;
  --paper-2: #e9edf2;
  --ink: #242e38;
  --slate: #46525e;
  --slate-mute: #55616d;
  --gall: #2b4a6f;
  --oxide: #7a5636;
  --rule: #b9c3cc;
  --serif: "Iowan Old Style", "Palatino Linotype", Palatino, "Book Antiqua", Georgia, serif;
  --sans: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
  --seam: clamp(56px, 9vw, 116px);
}

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

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 400 17px/1.62 var(--serif);
  -webkit-text-size-adjust: 100%;
}

h1, h2, h3 { font-weight: 400; margin: 0; letter-spacing: -0.005em; }
p, ul, ol, table { margin: 0; }
a { color: var(--gall); text-underline-offset: 3px; text-decoration-thickness: 1px; }
a:hover { color: var(--ink); }
em { font-style: italic; }
cite { font-style: italic; }

:focus-visible { outline: 2px solid var(--gall); outline-offset: 2px; }

.wrap { max-width: 1180px; margin-inline: auto; padding-inline: clamp(20px, 4vw, 48px); }
.vh {
  position: absolute; width: 1px; height: 1px; overflow: hidden;
  clip-path: inset(50%); white-space: nowrap;
}

.skip {
  position: absolute; left: 12px; top: -60px; z-index: 9;
  background: var(--ink); color: var(--paper); padding: 10px 16px; text-decoration: none;
  font: 600 13px/1 var(--sans); letter-spacing: 0.1em; text-transform: uppercase;
}
.skip:focus { top: 12px; color: var(--paper); }

.label, .cap, .folio, .sum-meta, .masthead-note, .plate-cap, .nav, .navtoggle, .foot-note {
  font-family: var(--sans);
}

.masthead { background: var(--paper-2); border-bottom: 2px solid var(--ink); }
.masthead-in {
  display: grid; align-items: baseline; gap: 4px 24px;
  grid-template-columns: auto minmax(0, 1fr) auto; padding-block: 14px 12px;
}
.wordmark { font: 400 1.22rem/1.2 var(--serif); letter-spacing: 0.02em; }
.wordmark a { color: var(--ink); text-decoration: none; }
.masthead-note {
  font-size: 0.7rem; letter-spacing: 0.14em; text-transform: uppercase; color: var(--slate-mute);
  text-align: right; text-wrap: balance;
}
.navtoggle {
  display: none; font: 600 0.72rem/1 var(--sans); letter-spacing: 0.12em; text-transform: uppercase;
  background: none; border: 1px solid var(--ink); color: var(--ink); padding: 9px 13px; cursor: pointer;
}
.nav { grid-column: 1 / -1; border-top: 1px solid var(--rule); margin-top: 10px; padding-top: 9px; }
.nav ul { list-style: none; padding: 0; display: flex; flex-wrap: wrap; gap: 4px 30px; }
.nav a {
  font-size: 0.74rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--slate);
  text-decoration: none; display: inline-block; padding: 3px 0; border-bottom: 1px solid transparent;
}
.nav a:hover { color: var(--ink); border-bottom-color: var(--ink); }

.hero {
  display: grid; gap: clamp(28px, 4vw, 56px); align-items: end;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr);
  padding-block: clamp(36px, 5vw, 68px) clamp(30px, 4vw, 52px);
}
h1 { font-size: clamp(1.95rem, 3.6vw, 2.95rem); line-height: 1.12; max-width: 24ch; text-wrap: balance; }
.standfirst {
  margin-top: 18px; font-size: clamp(1.02rem, 1.25vw, 1.16rem); color: var(--slate); max-width: 46ch;
}
.keylines {
  list-style: none; padding: 0; margin-top: 26px; display: flex; gap: 0;
  border-top: 1px solid var(--rule); border-bottom: 1px solid var(--rule);
}
.keylines li { flex: 1; padding: 12px 14px 12px 0; }
.keylines li + li { border-left: 1px solid var(--rule); padding-left: 18px; }
.fig { display: block; font: 400 1.6rem/1 var(--serif); color: var(--gall); }
.cap {
  display: block; margin-top: 6px; font-size: 0.68rem; letter-spacing: 0.1em;
  text-transform: uppercase; color: var(--slate-mute); text-wrap: balance;
}
.nw { white-space: nowrap; }

.plate-svg {
  display: block; width: 100%; height: auto; background: var(--paper);
  background-image: repeating-linear-gradient(to bottom, transparent 0 23px, rgba(43, 74, 111, .06) 23px 24px);
  border: 1px solid var(--rule);
}
.rule-line line { stroke: var(--rule); stroke-width: 1; }
.mark { fill: var(--ink); stroke: var(--ink); stroke-width: 0.8; stroke-linejoin: round; }
.hair { stroke-width: 1.4; }
.counter { fill: rgba(43, 74, 111, .13); }
.nib-edge line { stroke: var(--oxide); stroke-width: 6; stroke-linecap: butt; }
.plate-cap text {
  fill: var(--slate-mute); font-family: var(--sans); font-size: 9px; letter-spacing: 0.08em;
  text-transform: uppercase;
}
figure { margin: 0; }
figcaption {
  margin-top: 10px; font-size: 0.85rem; line-height: 1.5; color: var(--slate-mute); max-width: 52ch;
}
.hero-fig figcaption { max-width: none; }
.plate { margin-block: 26px 4px; max-width: 640px; }

.sheet {
  border-top: 2px solid var(--ink);
  background-image: linear-gradient(var(--rule), var(--rule));
  background-size: 100% 1px; background-repeat: no-repeat; background-position: 0 4px;
  padding-block: var(--seam);
}
.band { background-color: var(--paper-2); }
.sheet-in { display: grid; grid-template-columns: 6rem minmax(0, 1fr); gap: 0 clamp(18px, 3vw, 44px); }
.sheet-body { min-width: 0; }
.folio {
  font: 400 0.82rem/1 var(--mono); letter-spacing: 0.06em; color: var(--slate-mute);
  padding-top: 0.5em; border-top: 1px solid var(--ink); display: inline-block;
}
.sheet-body h2 {
  font-size: clamp(1.45rem, 2.4vw, 2.05rem); line-height: 1.16; max-width: 28ch; text-wrap: balance;
}
.lead { margin-top: 14px; font-size: 1.08rem; color: var(--slate); max-width: 58ch; }
.sheet-body h3 {
  font: 600 0.72rem/1.3 var(--sans); letter-spacing: 0.13em; text-transform: uppercase;
  color: var(--slate-mute); padding-bottom: 8px; border-bottom: 1px solid var(--rule);
}

.guide { margin-top: 30px; border-top: 1px solid var(--ink); border-bottom: 1px solid var(--ink); }
.guide + .guide { margin-top: -1px; }
.guide summary {
  list-style: none; cursor: pointer; display: flex; justify-content: space-between; align-items: center;
  gap: 16px; padding: 13px 0; font: 600 0.74rem/1 var(--sans); letter-spacing: 0.13em;
  text-transform: uppercase; color: var(--ink);
}
.guide summary::-webkit-details-marker { display: none; }
.guide summary:hover .sum-label { color: var(--gall); }
.sum-label::before { content: "+ "; font-family: var(--mono); color: var(--gall); }
.guide[open] .sum-label::before { content: "\2212\a0"; }
.sum-meta { color: var(--slate-mute); letter-spacing: 0.1em; }
.guide-body { padding-bottom: 26px; max-width: 64ch; }
.guide-body p { margin-top: 14px; }
.guide-body p:first-child { margin-top: 2px; }
.drills { margin-top: 18px; padding-left: 0; list-style: none; counter-reset: drill; }
.drills li {
  counter-increment: drill; border-top: 1px solid var(--rule); padding: 12px 0 12px 2.6rem;
  position: relative;
}
.drills li::before {
  content: counter(drill, decimal-leading-zero); position: absolute; left: 0; top: 14px;
  font: 400 0.78rem/1 var(--mono); color: var(--oxide);
}
.tight { padding-left: 1.1rem; margin-top: 12px; }
.tight li { margin-top: 7px; }

.scroll-hint {
  display: none; margin-top: 22px; font: 600 0.68rem/1.3 var(--sans); letter-spacing: 0.1em;
  text-transform: uppercase; color: var(--slate-mute); text-align: right;
}
.scroll-hint + .scroller { margin-top: 8px; }
.scroller {
  margin-top: 26px; max-width: 100%; overflow-x: auto; overscroll-behavior-x: contain;
  border-top: 1px solid var(--ink);
}
.compare { width: 100%; min-width: 34rem; border-collapse: collapse; font-size: 0.95rem; }
.compare th, .compare td { text-align: left; vertical-align: top; padding: 11px 14px 11px 0; }
.compare thead th {
  font: 600 0.72rem/1.3 var(--sans); letter-spacing: 0.12em; text-transform: uppercase;
  color: var(--gall); border-bottom: 1px solid var(--ink); padding-top: 9px;
}
.compare thead th:first-child { position: sticky; left: 0; background: var(--paper-2); }
.compare tbody th {
  font-weight: 400; color: var(--slate-mute); font-size: 0.86rem; white-space: nowrap;
  position: sticky; left: 0; background: inherit; padding-right: 20px;
}
.compare tbody tr { border-bottom: 1px solid var(--rule); background: var(--paper-2); }
.compare tbody tr:last-child { border-bottom: 1px solid var(--ink); }

.demo {
  margin-top: 28px; display: grid; gap: clamp(22px, 3.5vw, 48px); align-items: start;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
}
.letterset { border: 0; padding: 0; margin: 0 0 12px; }
.letterset legend, .label {
  padding: 0; font: 600 0.7rem/1 var(--sans); letter-spacing: 0.13em; text-transform: uppercase;
  color: var(--slate-mute);
}
.letterset-row { display: flex; gap: 8px; margin-top: 9px; position: relative; }
.letterset-row input { position: absolute; width: 1px; height: 1px; opacity: 0; }
.letterset-row label {
  flex: 1; text-align: center; cursor: pointer; border: 1px solid var(--rule); background: var(--paper);
  font: 400 1.5rem/1 var(--serif); padding: 8px 0 12px; color: var(--slate);
}
.letterset-row label:hover { border-color: var(--ink); color: var(--ink); }
.letterset-row input:checked + label { background: var(--ink); border-color: var(--ink); color: var(--paper); }
.letterset-row input:focus-visible + label { outline: 2px solid var(--gall); outline-offset: 2px; }
#ductus-ink path {
  fill: var(--gall); stroke: var(--gall); stroke-width: 0.8; stroke-linejoin: round;
  transition: fill .32s ease, stroke .32s ease, fill-opacity .32s ease, stroke-opacity .32s ease;
}
#ductus-ink path.ink-done { fill: var(--slate); stroke: var(--slate); fill-opacity: .5; stroke-opacity: .5; }
#ductus-ink path.ink-live { fill-opacity: 1; stroke-opacity: 1; }
#ductus-ink path.ink-ghost { fill-opacity: 0; stroke: var(--rule); stroke-width: 1; }
.ink-num {
  fill: var(--oxide); font: 400 11px/1 var(--mono); text-anchor: middle; transition: opacity .32s ease;
  stroke: var(--paper); stroke-width: 3; paint-order: stroke fill;
}
.ink-num.is-off { opacity: 0; }
.arrow { fill: var(--oxide); transition: transform .32s ease; }
.controls { display: flex; flex-wrap: wrap; gap: 8px; }
.controls button {
  font: 600 0.72rem/1 var(--sans); letter-spacing: 0.1em; text-transform: uppercase; cursor: pointer;
  background: var(--paper); border: 1px solid var(--ink); color: var(--ink); padding: 11px 14px;
}
.controls button:hover:not(:disabled) { background: var(--ink); color: var(--paper); }
.controls button:disabled { opacity: .38; cursor: default; }
.controls button[aria-pressed="true"] { background: var(--gall); border-color: var(--gall); color: var(--paper); }
.slider { margin-top: 22px; padding-top: 16px; border-top: 1px solid var(--rule); }
.slider output { font-family: var(--mono); color: var(--gall); letter-spacing: 0; }
.slider input[type="range"] { width: 100%; margin: 12px 0 0; accent-color: var(--gall); }
.hint { margin-top: 10px; font-size: 0.86rem; line-height: 1.5; color: var(--slate-mute); }
.steps { list-style: none; padding: 0; margin-top: 22px; border-top: 1px solid var(--ink); }
.steps li { border-bottom: 1px solid var(--rule); }
.steps button {
  width: 100%; text-align: left; background: none; border: 0; cursor: pointer; color: var(--slate);
  font: 400 0.95rem/1.4 var(--serif); padding: 10px 2px; display: flex; gap: 12px; align-items: baseline;
}
.steps .num { font: 400 0.75rem/1 var(--mono); color: var(--oxide); }
.steps button:hover { color: var(--ink); }
.steps button[aria-current="step"] { color: var(--gall); }
.steps button[aria-current="step"] .num { color: var(--gall); }
.note {
  margin-top: 16px; font-size: 0.96rem; line-height: 1.55; color: var(--slate); max-width: 46ch;
  border-left: 2px solid var(--oxide); padding-left: 14px; min-height: 6.2em;
}

.notecols {
  margin-top: 28px; display: grid; gap: clamp(22px, 3vw, 44px);
  grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
}
.notecols p { margin-top: 12px; font-size: 0.95rem; line-height: 1.6; color: var(--slate); }
.notecols ul { font-size: 0.95rem; color: var(--slate); }

.foot { background: var(--ink); color: var(--paper); border-top: 2px solid var(--ink); }
.foot-in {
  padding-block: 32px 36px; display: grid; gap: 10px 32px; align-items: baseline;
  grid-template-columns: auto minmax(0, 1fr) auto;
}
.foot-mark { font: 400 1.1rem/1.2 var(--serif); letter-spacing: 0.02em; }
.foot-note { font-size: 0.7rem; letter-spacing: 0.12em; text-transform: uppercase; opacity: .72; }
.foot-links { display: flex; flex-wrap: wrap; gap: 4px 20px; }
.foot-links a {
  color: var(--paper); font: 600 0.7rem/1 var(--sans); letter-spacing: 0.1em; text-transform: uppercase;
  text-decoration: none; border-bottom: 1px solid rgba(248, 250, 251, .45); padding-bottom: 3px;
}
.foot-links a:hover { color: var(--paper); border-bottom-color: var(--paper); }
.foot :focus-visible { outline-color: var(--paper); }

@media (max-width: 980px) {
  .hero { grid-template-columns: minmax(0, 1fr); align-items: start; }
  .hero-fig { max-width: 560px; }
  .notecols { grid-template-columns: minmax(0, 1fr); }
  .demo { grid-template-columns: minmax(0, 1fr); }
  .demo-plate { max-width: 520px; }
}

@media (max-width: 760px) {
  .masthead-in { grid-template-columns: minmax(0, 1fr) auto; row-gap: 2px; }
  .masthead-note { grid-row: 2; grid-column: 1; text-align: left; }
  .navtoggle { display: block; grid-row: 1 / 3; grid-column: 2; align-self: center; }
  .nav { display: none; }
  .masthead.is-open .nav { display: block; }
  .nav ul { flex-direction: column; gap: 0; }
  .nav li + li { border-top: 1px solid var(--rule); }
  .nav a { padding: 11px 0; width: 100%; }
  .sheet-in { grid-template-columns: minmax(0, 1fr); }
  .folio { margin-bottom: 16px; }
  .foot-in { grid-template-columns: minmax(0, 1fr); }
}

@media (max-width: 590px) {
  .scroll-hint { display: block; }
}

@media (max-width: 520px) {
  body { font-size: 16.5px; }
  h1 { max-width: 22ch; }
  .sheet-body h2 { max-width: 24ch; }
  .keylines { flex-direction: column; }
  .keylines li { display: flex; align-items: baseline; gap: 12px; padding: 10px 0; }
  .keylines li + li { border-left: 0; border-top: 1px solid var(--rule); padding-left: 0; }
  .fig { min-width: 3.2rem; }
  .cap { margin-top: 0; }
  .controls button { flex: 1 1 auto; }
  .note { min-height: 0; }
  .compare { min-width: 30rem; font-size: 0.9rem; }
  .compare th, .compare td { padding: 10px 12px 10px 0; }
  .compare tbody th { padding-right: 14px; }
  .foot-links { gap: 8px 14px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: 0.001ms !important; animation-duration: 0.001ms !important; }
}