/* Hallmark · route: custom (bespoke) · structure: lesson notebook (margin rule, main column, marginalia) · idea: "a coach marks up your game in pencil and pen"
 * paper: oklch(98.4% 0.008 95) · accent: oklch(54% 0.2 27) red pen + oklch(44% 0.17 264) blue ink · display + body: Vollkorn · hand: Kalam · print: Courier Prime
 * axes: light / roman-serif + handwritten / warm red + cool blue · gates: audited · studied: no
 *
 * AskTheMove site styles. No framework, no build step for CSS. See DESIGN.md.
 * Colour and type come only from the tokens in :root.
 */

@font-face {
  font-family: 'Vollkorn';
  src: url('/assets/fonts/vollkorn-var.woff2') format('woff2');
  font-weight: 400 900;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: 'Kalam';
  src: url('/assets/fonts/kalam-400.woff2') format('woff2');
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: 'Kalam';
  src: url('/assets/fonts/kalam-700.woff2') format('woff2');
  font-weight: 700;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: 'Courier Prime';
  src: url('/assets/fonts/courier-prime-400.woff2') format('woff2');
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}

:root {
  color-scheme: light;

  /* Paper and ruling */
  --paper: oklch(98.4% 0.008 95);
  --paper-2: oklch(96.5% 0.014 88);
  --card: oklch(99.3% 0.004 95);
  --grid: oklch(86% 0.045 235 / 0.4);
  --margin: oklch(70% 0.12 15);
  --margin-soft: oklch(70% 0.12 15 / 0.45);

  /* Printed matter */
  --ink: oklch(23% 0.025 265);
  --ink-2: oklch(40% 0.02 265);
  --rule: oklch(80% 0.012 260);
  --rule-soft: oklch(88% 0.01 260);

  /* The coach's hand */
  --graphite: oklch(46% 0.006 270);
  --graphite-2: oklch(62% 0.006 270);
  --red: oklch(54% 0.2 27);
  --blue: oklch(44% 0.17 264);
  --blue-deep: oklch(36% 0.15 264);
  --highlight: oklch(91% 0.15 102);
  --wood: oklch(84% 0.06 75);

  /* The board: book-diagram hatching on a pale tint */
  --sq-tint: oklch(94% 0.016 245);
  --hatch: oklch(62% 0.03 255);

  --shadow: oklch(23% 0.025 265 / 0.22);
  --focus: oklch(48% 0.2 264);

  --font-book: 'Vollkorn', 'Iowan Old Style', 'Palatino Linotype', Georgia, serif;
  --font-hand: 'Kalam', 'Segoe Print', 'Bradley Hand', 'Comic Sans MS', cursive;
  --font-print: 'Courier Prime', 'Courier New', ui-monospace, monospace;

  --text-hero: clamp(3rem, 1.4rem + 5.4vw, 6rem);
  --text-h2: clamp(2rem, 1.3rem + 2.5vw, 3.4rem);
  --text-h3: 1.375rem;
  --text-body: 1.125rem;
  --text-small: 0.9375rem;
  --text-hand: 1.375rem;

  --s-1: 4px;
  --s-2: 8px;
  --s-3: 12px;
  --s-4: 16px;
  --s-5: 24px;
  --s-6: 32px;
  --s-7: 48px;
  --s-8: 64px;
  --s-9: 96px;
  --s-10: 128px;

  --radius: 4px;
  --ease-out: cubic-bezier(0.23, 1, 0.32, 1);
  --ease-stroke: cubic-bezier(0.65, 0, 0.35, 1);

  /* The notebook grid: where the content starts, and the margin rule just left of it. */
  --content-x: max(128px, calc(50% - 544px));
  --pad-r: 40px;
  --rule-x: calc(var(--content-x) - 40px);
  --measure: 1112px;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--s-5);
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  overflow-x: clip;
}

body {
  position: relative;
  margin: 0;
  overflow-x: clip;
  color: var(--ink);
  font-family: var(--font-book);
  font-size: var(--text-body);
  line-height: 1.6;
  background-color: var(--paper);
  /* Quad ruling, like a maths exercise book. */
  background-image: linear-gradient(var(--grid) 1px, transparent 1px), linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size: 26px 26px;
  background-position: -1px -1px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  font-kerning: normal;
}

/* The red double margin rule, the full height of the page. */
body::before {
  content: '';
  position: absolute;
  top: 0;
  bottom: 0;
  left: var(--rule-x);
  width: 5px;
  border-left: 1.5px solid var(--margin);
  border-right: 1px solid var(--margin-soft);
  pointer-events: none;
  z-index: 0;
}

::selection {
  background: var(--highlight);
  color: var(--ink);
}

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

a {
  color: inherit;
  text-decoration-thickness: 1px;
  text-underline-offset: 0.2em;
}

@media (hover: hover) and (pointer: fine) {
  a:hover {
    text-decoration-color: var(--red);
    text-decoration-thickness: 2px;
  }
}

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

input,
select,
button,
textarea {
  caret-color: var(--blue);
  accent-color: var(--blue);
}

.nowrap {
  white-space: nowrap;
}

.skip {
  position: absolute;
  left: var(--s-4);
  top: -100px;
  z-index: 20;
  padding: var(--s-2) var(--s-4);
  background: var(--ink);
  color: var(--card);
  font-weight: 600;
}

.skip:focus {
  top: var(--s-4);
}

/* ---------- The page grid ---------- */

main,
.masthead,
.colophon {
  position: relative;
  z-index: 1;
}

/* Everything aligns to the margin rule: content starts 40px right of it. */
.rows,
.wrap,
.masthead__inner,
.colophon__inner {
  margin-left: var(--content-x);
  margin-right: var(--pad-r);
  max-width: var(--measure);
}

.rows {
  display: grid;
  grid-template-columns: [main] minmax(0, 46fr) [gap] minmax(var(--s-6), 3.5rem) [side] minmax(15rem, 20fr) [end];
  align-items: start;
}

.rows > * {
  grid-column: main;
  min-width: 0;
}

/* ---------- Type ---------- */

h1,
h2,
h3 {
  font-style: normal;
  text-wrap: balance;
  overflow-wrap: anywhere;
  min-width: 0;
}

.h2 {
  margin: 0;
  font-family: var(--font-book);
  font-size: var(--text-h2);
  font-weight: 750;
  line-height: 1.04;
  letter-spacing: -0.02em;
}

p {
  margin: 0;
}

.prose p + p {
  margin-top: var(--s-4);
}

.prose,
.open__lede,
.lesson__intro,
.how__note,
.status-sec__intro {
  max-width: 62ch;
  text-wrap: pretty;
}

/* Notation: lining figures so d1 and 1600 read clearly. Labels that can
   hold notation are never uppercased: Qxg4 is not QXG4, and f7 is not F7. */
.moves,
.ss,
.printout,
.eval,
.keymove,
.note__label {
  font-variant-numeric: lining-nums tabular-nums;
}

.fig {
  display: inline-block;
  width: 1em;
  height: 1em;
  margin: 0 0.04em 0 0.02em;
  vertical-align: -0.14em;
}

/* The coach's voice. */
.note-hand {
  font-family: var(--font-hand);
  font-size: var(--text-hand);
  line-height: 1.3;
  color: var(--blue);
}

.note-hand--red {
  color: var(--red);
}

/* ---------- Ink: marks drawn by the coach ---------- */

.stroke {
  fill: none;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-dasharray: 1 2;
  stroke-dashoffset: 0;
}

.ink {
  /* Where the baseline sits below the top of the text's box, per typeface,
     so marks land on the letters and not on the line below. */
  --base: 0.95em;
  position: relative;
  z-index: 0;
  white-space: nowrap;
}

.printout .ink {
  --base: 0.78em;
}

.note-hand .ink,
.fig-explain__next .ink {
  --base: 1.06em;
}

.ink__svg {
  position: absolute;
  max-width: none;
  overflow: visible;
  pointer-events: none;
}

.ink--circle .ink__svg {
  top: calc(var(--base) - 1.055em);
  left: -0.26em;
  width: calc(100% + 0.52em);
  height: 1.55em;
}

.ink--circle .stroke {
  stroke: var(--red);
  stroke-width: 3.4;
}

.ink--underline .ink__svg {
  left: -0.06em;
  top: calc(var(--base) - 0.265em);
  width: calc(100% + 0.12em);
  height: 0.5em;
}

.ink--double .ink__svg {
  left: -0.06em;
  top: calc(var(--base) - 0.374em);
  width: calc(100% + 0.12em);
  height: 0.6em;
}

.ink--underline .stroke,
.ink--double .stroke {
  stroke: var(--red);
  stroke-width: 11;
}

.ink--highlight .ink__svg {
  z-index: -1;
  left: -0.14em;
  top: 0.06em;
  width: calc(100% + 0.28em);
  height: 1.08em;
  mix-blend-mode: multiply;
}

.ink--highlight .stroke {
  stroke: var(--highlight);
  stroke-width: 62;
  stroke-linecap: butt;
}

.glyph {
  display: inline-block;
  flex: none;
  font-style: normal;
}

.glyph .ink__svg {
  position: static;
  display: block;
  width: 100%;
  height: 100%;
}

.glyph .stroke {
  stroke: currentColor;
  stroke-width: 7;
}

/* ---------- Buttons and fields ---------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--s-2);
  min-height: 48px;
  padding: 0 var(--s-5);
  border: 1.5px solid var(--blue-deep);
  border-radius: var(--radius);
  font-family: var(--font-book);
  font-size: 1.0625rem;
  font-weight: 700;
  line-height: 1;
  white-space: nowrap;
  text-decoration: none;
  cursor: pointer;
  transition: background-color 160ms var(--ease-out), transform 160ms var(--ease-out);
}

.btn--pen {
  background: var(--blue);
  color: var(--card);
}

@media (hover: hover) and (pointer: fine) {
  .btn--pen:hover {
    background: var(--blue-deep);
    text-decoration: none;
  }
}

.btn:active {
  transform: scale(0.97);
}

.btn:disabled,
.btn[aria-busy='true'] {
  cursor: progress;
  opacity: 0.75;
}

.btn--small {
  min-height: 40px;
  padding: 0 var(--s-4);
  font-size: 0.9375rem;
}

.btn--large {
  min-height: 56px;
  padding: 0 var(--s-6);
  font-size: 1.1875rem;
}

.field label,
.check label {
  font-size: 1rem;
  font-weight: 600;
  color: var(--ink);
}

.field label {
  display: block;
  margin-bottom: var(--s-2);
}

.optional {
  font-weight: 400;
  color: var(--ink-2);
}

.field--rating label {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  column-gap: var(--s-2);
}

.field input,
.field select {
  display: block;
  width: 100%;
  height: 54px;
  padding: 0 var(--s-4);
  border: 1.5px solid var(--ink);
  border-radius: var(--radius);
  background-color: var(--card);
  color: var(--ink);
  font-family: var(--font-book);
  font-size: 1.125rem;
}

.field input::placeholder {
  color: var(--graphite);
  opacity: 1;
}

.field select {
  appearance: none;
  padding-right: 44px;
  background-image: url('/assets/select-arrow.svg');
  background-repeat: no-repeat;
  background-position: right 14px center;
  background-size: 14px 14px;
  cursor: pointer;
}

.field input[aria-invalid='true'] {
  border-color: var(--red);
  box-shadow: 0 0 0 1.5px var(--red);
}

.check {
  display: flex;
  align-items: center;
  gap: var(--s-3);
  min-height: 44px;
}

.check input {
  flex: none;
  width: 22px;
  height: 22px;
  margin: 0;
  cursor: pointer;
}

.check input[aria-invalid='true'] {
  outline: 2px solid var(--red);
  outline-offset: 2px;
}

.check label {
  font-weight: 400;
  cursor: pointer;
}

.hp {
  position: absolute;
  left: -10000px;
  width: 1px;
  height: 1px;
  overflow: hidden;
}

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

.masthead {
  padding-top: var(--s-5);
}

.masthead__inner {
  display: flex;
  align-items: center;
  gap: var(--s-6);
  padding-bottom: var(--s-4);
  border-bottom: 2px solid var(--ink);
  box-shadow: 0 3px 0 -2px var(--ink);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--s-3);
  text-decoration: none;
}

.brand__mark {
  flex: none;
  width: 36px;
  height: 36px;
}

.brand__tile {
  fill: var(--card);
  stroke: var(--ink);
  stroke-width: 3;
}

.brand__q {
  fill: none;
  stroke: var(--blue);
  stroke-width: 6.5;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.brand__dot {
  fill: var(--blue);
}

.brand__loop {
  fill: none;
  stroke: var(--red);
  stroke-width: 3.4;
  stroke-linecap: round;
}

.brand__word {
  font-size: 1.375rem;
  font-weight: 800;
  letter-spacing: -0.01em;
}

/* The masthead is the wordmark and one action, nothing between: the page is a
   single lesson, and the footer carries the section links. */
.masthead__cta {
  margin-left: auto;
}

/* ---------- Opening ---------- */

.open {
  padding-top: var(--s-8);
  padding-bottom: var(--s-9);
  row-gap: var(--s-6);
}

.open__title {
  grid-column: main / end;
  margin: 0;
  font-size: var(--text-hero);
  font-weight: 800;
  line-height: 0.95;
  letter-spacing: -0.03em;
}

.open__title .ink--circle .stroke {
  stroke-width: 2.6;
}

.open__lede {
  font-size: 1.375rem;
  line-height: 1.5;
  max-width: 50ch;
}

.open__side {
  grid-column: side;
  display: grid;
  gap: var(--s-7);
  padding-top: var(--s-2);
}

.note-hand--why {
  display: grid;
  grid-template-columns: 64px minmax(0, 1fr);
  align-items: start;
  gap: var(--s-2);
  margin-top: calc(-1 * var(--s-6));
  transform: rotate(-2deg);
}

.glyph--back {
  width: 64px;
  height: 44px;
  color: var(--blue);
  transform: translateY(-14px);
}

.note-hand--who {
  max-width: 15em;
  transform: rotate(1deg);
}

.note-hand--free {
  position: relative;
  transform: rotate(-1.5deg);
}

.glyph--to-form {
  display: block;
  width: 176px;
  height: 80px;
  margin: var(--s-2) 0 0 calc(-1 * var(--s-8));
  color: var(--blue);
}

/* The sign-up slip */

.slip {
  margin-top: var(--s-6);
  max-width: 40rem;
  outline: none;
}

.slip__title {
  margin-bottom: var(--s-4);
  font-size: 1.25rem;
  font-weight: 700;
}

.slip__row {
  display: flex;
  align-items: flex-end;
  gap: var(--s-3);
}

.field--email {
  flex: 1;
  min-width: 0;
}

.slip__submit {
  min-height: 54px;
}

.slip__more {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  gap: var(--s-4) var(--s-6);
  margin-top: var(--s-4);
}

.field--rating {
  width: min(100%, 19rem);
}

.slip__status {
  min-height: 1.6em;
  margin-top: var(--s-3);
  font-weight: 600;
}

.slip__status.is-error {
  color: var(--red);
}

/* After a plain form post (no JavaScript) the redirect targets one of these. */
.slip__result {
  display: none;
}

html:not(.has-js) .slip__result:target {
  display: block;
}

.slip__fine {
  font-size: var(--text-small);
  color: var(--ink-2);
}

.slip__done {
  display: grid;
  grid-template-columns: 56px minmax(0, 1fr);
  column-gap: var(--s-4);
  align-items: center;
  padding: var(--s-5) 0;
}

.slip__done[hidden] {
  display: none;
}

.slip__done .glyph--tick {
  grid-row: span 2;
  width: 56px;
  height: 50px;
  color: var(--red);
}

.slip__done .glyph--tick .stroke {
  stroke-width: 9;
}

.slip__done-title {
  font-family: var(--font-hand);
  font-size: 2rem;
  font-weight: 700;
  line-height: 1.1;
  color: var(--blue);
  outline: none;
}

.slip__done-body {
  font-size: 1.125rem;
}

/* ---------- The lesson ---------- */

.lesson {
  padding-bottom: var(--s-9);
}

.lesson__head {
  row-gap: var(--s-3);
  margin-bottom: var(--s-6);
}

.lesson__intro {
  font-size: 1.1875rem;
  color: var(--ink-2);
}

.lesson__you {
  grid-column: side;
  grid-row: 1 / span 2;
  align-self: end;
  transform: rotate(-2deg);
}

.note-hand--side {
  font-size: 1.625rem;
}

.lesson__fine {
  margin-left: var(--content-x);
  margin-right: var(--pad-r);
  max-width: 62ch;
  margin-top: var(--s-6);
  font-size: var(--text-small);
  color: var(--ink-2);
}

.demo {
  display: grid;
  grid-template-columns: minmax(150px, 190px) minmax(0, 560px) minmax(15rem, 1fr);
  grid-template-areas:
    'sheet board note'
    'sheet ctrl note';
  column-gap: var(--s-6);
  row-gap: var(--s-5);
  align-items: start;
  margin-left: calc(var(--content-x) - 8px);
  margin-right: var(--pad-r);
  max-width: calc(var(--measure) + 8px);
}

.demo__sheet {
  grid-area: sheet;
}

.demo__board {
  grid-area: board;
  margin: 0;
  min-width: 0;
}

.note {
  grid-area: note;
  min-width: 0;
}

.demo__controls {
  grid-area: ctrl;
  display: flex;
  flex-wrap: wrap;
  gap: var(--s-2);
  padding-left: 1.4rem;
}

/* Score sheet */

.ss {
  width: 100%;
  border-collapse: collapse;
  background: var(--card);
  border: 1.5px solid var(--ink);
  font-family: var(--font-print);
  font-size: 0.875rem;
}

.ss__cap {
  caption-side: top;
  padding-bottom: var(--s-2);
  text-align: left;
  font-family: var(--font-print);
  font-size: 0.8125rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-2);
}

.ss thead th {
  padding: var(--s-1) var(--s-2);
  border-bottom: 1.5px solid var(--ink);
  font-weight: 400;
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  text-align: left;
  color: var(--ink-2);
}

.ss tbody th {
  width: 2.4em;
  padding: 0 var(--s-2) 0 0;
  border-right: 1px solid var(--rule);
  font-weight: 400;
  text-align: right;
  color: var(--graphite);
}

.ss td {
  height: 2.4rem;
  padding: 0 var(--s-2);
  border-bottom: 1px solid var(--rule-soft);
  border-left: 1px solid var(--rule-soft);
  white-space: nowrap;
}

.ss tbody tr:last-child td,
.ss tbody tr:last-child th {
  border-bottom: 0;
}

.ss__mv {
  font-family: var(--font-hand);
  font-size: 1.1875rem;
  line-height: 1;
  color: var(--graphite);
}

.ss__btn {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  min-height: 36px;
  padding: var(--s-1) var(--s-1);
  margin: 0 calc(-1 * var(--s-1));
  border: 0;
  background: none;
  color: var(--ink);
  cursor: pointer;
}

.ss__btn:disabled {
  cursor: default;
  color: var(--ink);
}

@media (hover: hover) and (pointer: fine) {
  .ss__btn:not(:disabled):hover .ss__san {
    text-decoration: underline;
    text-decoration-color: var(--blue);
    text-decoration-thickness: 2px;
    text-underline-offset: 0.18em;
  }
}

.ss__ann {
  margin-left: 2px;
  font-weight: 700;
  color: var(--red);
}

.ss__ring {
  position: absolute;
  max-width: none;
  top: -2px;
  left: -10px;
  width: calc(100% + 20px);
  height: calc(100% + 4px);
  overflow: visible;
  pointer-events: none;
}

.ss__ring .stroke {
  stroke: var(--red);
  stroke-width: 4;
  stroke-dashoffset: 1.01;
  transition: stroke-dashoffset 280ms var(--ease-stroke);
}

[aria-current='step'] > .ss__ring .stroke {
  stroke-dashoffset: 0;
}

.ss__var td {
  height: auto;
  padding: var(--s-2) var(--s-3);
  border-left: 0;
}

.ss__var-line {
  position: relative;
  display: inline-block;
  font-family: var(--font-hand);
  font-size: 1.0625rem;
  color: var(--blue);
}

.ss__var-line .ss__ring .stroke {
  stroke: var(--blue);
  stroke-width: 3;
}

.ss__result {
  margin-top: var(--s-2);
  font-family: var(--font-hand);
  font-size: 1.25rem;
  color: var(--graphite);
}

.ss__result-label {
  font-family: var(--font-print);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink-2);
}

/* The diagram: coordinates outside a crisp, double-ruled board */

.diagram {
  display: grid;
  grid-template-columns: 1.4rem minmax(0, 1fr);
  grid-template-rows: auto 1.6rem;
}

.diagram__ranks {
  display: grid;
  grid-template-rows: repeat(8, minmax(0, 1fr));
  align-items: center;
  font-family: var(--font-hand);
  font-size: 1rem;
  line-height: 1;
  color: var(--graphite);
}

.diagram__files {
  grid-column: 2;
  display: grid;
  grid-template-columns: repeat(8, minmax(0, 1fr));
  align-items: end;
  text-align: center;
  font-family: var(--font-hand);
  font-size: 1rem;
  line-height: 1;
  color: var(--graphite);
}

.diagram--mini {
  grid-template-columns: minmax(0, 1fr);
  grid-template-rows: auto;
}

.board {
  position: relative;
  width: 100%;
  aspect-ratio: 1;
  container-type: inline-size;
  background: var(--card);
  border: 1px solid var(--ink);
  box-shadow: 0 0 0 3px var(--card), 0 0 0 5px var(--ink);
  user-select: none;
  -webkit-user-select: none;
}

.board--mini {
  box-shadow: 0 0 0 2px var(--card), 0 0 0 3.5px var(--ink);
}

/* Dark squares: diagonal hatching, the way chess books print them. */
.board::before {
  content: '';
  position: absolute;
  inset: 0;
  background: repeating-linear-gradient(-45deg, var(--hatch) 0 1px, transparent 1px 4.5px), var(--sq-tint);
  -webkit-mask: repeating-conic-gradient(var(--ink) 0 25%, transparent 0 50%) 0 0 / 25% 25%;
  mask: repeating-conic-gradient(var(--ink) 0 25%, transparent 0 50%) 0 0 / 25% 25%;
}

.board__layer {
  position: absolute;
  inset: 0;
}

.board .pc,
.board .hl,
.board .badge {
  --x: 0;
  --y: 0;
  position: absolute;
  top: 0;
  left: 0;
  width: 12.5%;
  height: 12.5%;
  transform: translate(calc(var(--x) * 100%), calc(var(--y) * 100%));
}

.board [data-x='1'] { --x: 1; }
.board [data-x='2'] { --x: 2; }
.board [data-x='3'] { --x: 3; }
.board [data-x='4'] { --x: 4; }
.board [data-x='5'] { --x: 5; }
.board [data-x='6'] { --x: 6; }
.board [data-x='7'] { --x: 7; }
.board [data-y='1'] { --y: 1; }
.board [data-y='2'] { --y: 2; }
.board [data-y='3'] { --y: 3; }
.board [data-y='4'] { --y: 4; }
.board [data-y='5'] { --y: 5; }
.board [data-y='6'] { --y: 6; }
.board [data-y='7'] { --y: 7; }

.board .pc {
  z-index: 2;
  max-width: none;
  padding: 2%;
  transition: transform 420ms var(--ease-out), opacity 240ms var(--ease-out);
  pointer-events: none;
}

.board .pc.is-moving {
  z-index: 3;
}

.board .pc.is-out,
.board .pc.is-in {
  opacity: 0;
}

/* The last move: a highlighter swipe on both squares. */
.board .hl {
  background: var(--highlight);
  mix-blend-mode: multiply;
  opacity: 0.7;
}

.board__ink {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  overflow: visible;
  pointer-events: none;
  z-index: 4;
}

.board__ink .stroke {
  stroke-width: 0.78;
}

.board--mini .board__ink .stroke {
  stroke-width: 1.05;
}

.board__ink .tone--red .stroke {
  stroke: var(--red);
}

.board__ink .tone--blue .stroke {
  stroke: var(--blue);
}

.board__ink .tone--graphite .stroke {
  stroke: var(--graphite);
  stroke-width: 0.6;
}

.board__ink .mk--cross .stroke {
  stroke-width: 0.62;
}

.board__badges {
  z-index: 5;
  pointer-events: none;
}

.badge {
  display: flex;
  align-items: flex-start;
  justify-content: flex-end;
  padding: 0 1.2% 0 0;
  font-family: var(--font-hand);
  font-weight: 700;
  font-size: 5.6cqi;
  line-height: 0.9;
  color: var(--red);
}

.badge {
  margin: -2.6cqi 0 0 2.4cqi;
}

.badge--mate {
  font-size: 6.4cqi;
}

/* The red-blue pencil that follows a stroke while it is drawn. */
.pencil {
  opacity: 0;
  transition: opacity 180ms var(--ease-out);
}

.board.is-drawing .pencil {
  opacity: 1;
}

.pencil__wood {
  fill: var(--wood);
}

.pencil__lead,
.pencil__barrel {
  fill: var(--red);
}

.pencil.tone--blue .pencil__lead,
.pencil.tone--blue .pencil__barrel {
  fill: var(--blue);
}

.pencil.tone--graphite .pencil__lead,
.pencil.tone--graphite .pencil__barrel {
  fill: var(--graphite);
}

.pencil__shine {
  fill: var(--card);
  opacity: 0.35;
}

/* The coach's note beside the board */

.note__stack {
  display: grid;
}

.note__page {
  grid-area: 1 / 1;
  visibility: hidden;
}

.note__page.is-current {
  visibility: visible;
}

.note__label {
  display: flex;
  flex-wrap: wrap;
  gap: var(--s-1) var(--s-3);
  margin-bottom: var(--s-3);
  font-family: var(--font-print);
  font-size: 0.8125rem;
  letter-spacing: 0.01em;
  color: var(--ink-2);
}

.note__count {
  color: var(--graphite);
}

.note__title {
  margin-bottom: var(--s-3);
  font-family: var(--font-hand);
  font-size: 1.875rem;
  font-weight: 700;
  line-height: 1.12;
  color: var(--blue);
}

.note__body {
  font-family: var(--font-hand);
  font-size: 1.3125rem;
  line-height: 1.38;
  color: var(--blue);
}

.note__evidence {
  display: grid;
  grid-template-columns: 22px minmax(0, 1fr);
  gap: var(--s-2);
  align-items: start;
  margin-top: var(--s-5);
  padding-top: var(--s-3);
  border-top: 1px dashed var(--graphite-2);
  font-family: var(--font-print);
  font-size: 0.875rem;
  line-height: 1.45;
  color: var(--graphite);
}

.note__tick {
  width: 22px;
  height: 20px;
  margin-top: 1px;
  overflow: visible;
}

.note__tick .stroke {
  stroke: var(--red);
  stroke-width: 10;
}

.note.is-branch .note__title,
.note.is-branch .note__body {
  color: var(--blue);
}

/* Walkthrough controls */

.ctl {
  display: inline-flex;
  align-items: center;
  gap: var(--s-2);
  min-height: 44px;
  padding: 0 var(--s-4);
  border: 1.5px solid var(--ink);
  border-radius: var(--radius);
  background: var(--card);
  color: var(--ink);
  font-family: var(--font-book);
  font-size: 1rem;
  font-weight: 650;
  white-space: nowrap;
  cursor: pointer;
  transition: background-color 160ms var(--ease-out), transform 160ms var(--ease-out);
}

.ctl:active:not(:disabled) {
  transform: scale(0.97);
}

.ctl:disabled {
  cursor: default;
  opacity: 0.45;
}

.ctl__icon {
  flex: none;
}

.ctl--branch {
  margin-left: auto;
  border-color: var(--blue);
  color: var(--blue);
}

.ctl--branch.is-active {
  background: var(--blue);
  color: var(--card);
}

@media (hover: hover) and (pointer: fine) {
  .ctl:not(:disabled):hover {
    background: var(--paper-2);
  }

  .ctl--branch.is-active:not(:disabled):hover {
    background: var(--blue-deep);
  }
}

/* ---------- What a review leaves out ---------- */

.review {
  padding-top: var(--s-8);
  padding-bottom: var(--s-9);
  row-gap: var(--s-7);
}

.review__title {
  grid-column: main / end;
  max-width: 20ch;
}

.review__main {
  font-size: 1.1875rem;
}

.review__side {
  grid-column: side;
  grid-row: 2 / span 2;
  display: grid;
  gap: var(--s-4);
  padding-top: var(--s-2);
}

/* Engine printouts */

.printout {
  position: relative;
  padding: var(--s-5) var(--s-5) var(--s-4);
  background: var(--paper-2);
  color: var(--ink);
  font-family: var(--font-print);
  font-size: 0.9375rem;
  line-height: 1.45;
  box-shadow: 0 1px 1px var(--shadow), 0 12px 22px -14px var(--shadow);
  transform: rotate(-0.7deg);
}

/* A perforated top edge, torn off a roll. */
.printout::before {
  content: '';
  position: absolute;
  left: 0;
  right: 0;
  top: -4px;
  height: 8px;
  background: radial-gradient(circle at 4px 4px, var(--paper) 2.2px, transparent 2.6px) 0 0 / 10px 8px repeat-x;
}

.printout__head {
  margin-bottom: var(--s-3);
  padding-bottom: var(--s-2);
  border-bottom: 1px dashed var(--graphite-2);
  font-size: 0.8125rem;
  letter-spacing: 0.01em;
  color: var(--ink-2);
}

.printout__head .fig,
.printout__mv .fig {
  vertical-align: -0.16em;
}

.printout__line {
  display: flex;
  flex-wrap: wrap;
  gap: var(--s-1) var(--s-5);
  align-items: baseline;
}

.printout__line + .printout__line {
  margin-top: var(--s-1);
}

.printout__line--dim {
  color: var(--graphite);
}

.printout__mv {
  font-size: 1.0625rem;
}

.printout .ink--circle .stroke {
  stroke-width: 7;
}

.printout__flag {
  margin-left: 1px;
  color: var(--red);
  font-weight: 700;
}

.review__but {
  display: grid;
  grid-template-columns: 52px minmax(0, 1fr);
  gap: var(--s-2);
  align-items: start;
  font-size: 1.5rem;
  transform: rotate(-1.5deg);
}

.glyph--up {
  width: 52px;
  height: 40px;
  color: var(--red);
  transform: translate(8px, -6px) scaleX(-1) rotate(180deg) scaleY(-1);
}

.review__questions {
  grid-column: main;
}

.review__lead {
  margin-bottom: var(--s-5);
  font-weight: 650;
  font-size: 1.1875rem;
}

.questions {
  display: grid;
  gap: var(--s-6);
  margin: 0;
  padding: 0;
  list-style: none;
}

.question__q {
  margin: 0 0 var(--s-1);
  font-family: var(--font-hand);
  font-size: clamp(1.625rem, 1.3rem + 1vw, 2.125rem);
  font-weight: 700;
  line-height: 1.15;
  color: var(--blue);
}

.question p {
  max-width: 52ch;
  color: var(--ink-2);
}

/* ---------- How it works ---------- */

.how {
  padding-top: var(--s-8);
  padding-bottom: var(--s-7);
  border-top: 2px solid var(--ink);
  box-shadow: inset 0 3px 0 -2px var(--ink);
}

.how__head {
  row-gap: var(--s-4);
  padding-top: var(--s-6);
  margin-bottom: var(--s-6);
}

.how__title {
  grid-column: main / end;
  max-width: 22ch;
}

.how__note {
  color: var(--ink-2);
}

.steps {
  margin: 0 var(--pad-r) 0 var(--content-x);
  padding: 0;
  max-width: var(--measure);
  list-style: none;
}

.step {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr);
  gap: var(--s-7);
  padding: var(--s-7) 0;
  border-top: 1px solid var(--rule);
}

.step__text p + p {
  margin-top: var(--s-4);
}

.step__title {
  display: flex;
  align-items: baseline;
  gap: var(--s-3);
  margin: 0 0 var(--s-3);
  font-size: 1.75rem;
  font-weight: 750;
  line-height: 1.1;
}

/* Step numbers hang in the notebook margin, written in red. */
.step__n {
  position: absolute;
  left: -92px;
  top: calc(var(--s-7) - 2px);
  width: 40px;
  text-align: center;
  font-family: var(--font-hand);
  font-size: 2.125rem;
  font-weight: 700;
  line-height: 1;
  color: var(--red);
}

.status {
  display: inline-flex;
  align-items: center;
  gap: var(--s-2);
  font-family: var(--font-hand);
  font-size: 1.3125rem;
  font-weight: 700;
  line-height: 1;
}

.status .glyph {
  width: 30px;
  height: 27px;
}

.status--live {
  color: var(--red);
}

.status--dev {
  color: var(--graphite);
}

.status--dev .glyph {
  width: 30px;
  height: 26px;
}

.step__fig {
  margin: 0;
  min-width: 0;
}

.step__fig figcaption {
  margin-top: var(--s-4);
  padding-top: var(--s-2);
  border-top: 1px solid var(--rule);
  font-size: var(--text-small);
  color: var(--ink-2);
  max-width: 56ch;
}

/* Figure 1: evidence */

.fig-evidence {
  display: grid;
  grid-template-columns: minmax(0, 200px) minmax(0, 1fr);
  gap: var(--s-5);
  align-items: start;
}

.fig-evidence figcaption {
  grid-column: 1 / -1;
}

.fig-evidence__board {
  padding: 4px;
}

.facts {
  display: grid;
  gap: var(--s-3);
  margin: 0;
}

.fact {
  display: grid;
  grid-template-columns: 6.5em minmax(0, 1fr);
  gap: var(--s-2);
}

.fact dt {
  font-size: 0.75rem;
  letter-spacing: 0.01em;
  color: var(--ink-2);
  padding-top: 0.2em;
}

.fact dd {
  margin: 0;
}

.fact dd strong {
  display: block;
  font-weight: 400;
}

.fact dd > span {
  display: block;
  font-size: 0.8125rem;
  color: var(--graphite);
}

.printout--facts {
  transform: rotate(0.5deg);
}

/* Figure 2: the explanation, in the coach's hand */

.fig-explain {
  padding: var(--s-5) var(--s-5) var(--s-4);
  background: var(--card);
  border: 1px solid var(--rule);
  box-shadow: 0 12px 22px -16px var(--shadow);
  /* Lined paper: this page is ruled, not squared. */
  background-image: linear-gradient(transparent calc(2.1rem - 1px), var(--grid) calc(2.1rem - 1px), var(--grid) 2.1rem, transparent 2.1rem);
  background-size: 100% 2.1rem;
  background-position: 0 1.2rem;
}

.fig-explain__tag {
  margin-bottom: var(--s-3);
  font-family: var(--font-print);
  font-size: 0.8125rem;
  letter-spacing: 0.01em;
  color: var(--ink-2);
}

.fig-explain__hand {
  font-family: var(--font-hand);
  font-size: 1.25rem;
  line-height: 2.1rem;
  color: var(--blue);
}

.fig-explain__hand p + p {
  margin-top: 0;
}

.fig-explain__title {
  font-weight: 700;
  font-size: 1.5rem;
}

.fig-explain__next {
  margin-top: var(--s-2);
}

.fig-explain__next .ink--underline {
  font-weight: 700;
  color: var(--red);
  margin-right: var(--s-1);
}

.fig-explain__next .ink--underline .stroke {
  stroke-width: 22;
}

.fig-explain__src {
  margin-top: var(--s-3);
  font-family: var(--font-print);
  font-size: 0.8125rem;
  color: var(--graphite);
}

.fig-explain figcaption {
  border-top-color: var(--rule-soft);
}

/* Figure 3: branch */

.tree {
  display: grid;
  gap: var(--s-2);
  margin-bottom: var(--s-4);
}

.tree__row {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: var(--s-1) var(--s-3);
}

.tree__row--branch {
  position: relative;
  padding-left: var(--s-6);
  color: var(--blue);
}

.glyph--fork {
  position: absolute;
  left: 4px;
  top: -14px;
  width: 26px;
  height: 34px;
  color: var(--blue);
}

.tree__tag {
  min-width: 5.5em;
  font-family: var(--font-print);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink-2);
}

.moves {
  font-size: 1.0625rem;
}

.mv {
  white-space: nowrap;
}

.mv__n {
  margin-right: 0.12em;
  color: var(--graphite);
}

.mv--key {
  font-weight: 700;
}

.fig-branch__body {
  display: grid;
  grid-template-columns: minmax(0, 180px) minmax(0, 1fr);
  gap: var(--s-5);
  align-items: start;
}

.fig-branch__board {
  padding: 4px;
}

.eval {
  font-size: 1.125rem;
}

.eval__num {
  font-family: var(--font-print);
  font-size: 1.5rem;
  letter-spacing: -0.1em;
}

.eval__src {
  margin-bottom: var(--s-4);
  font-family: var(--font-print);
  font-size: 0.8125rem;
  color: var(--graphite);
}

.pin {
  max-width: 18em;
  padding: var(--s-3) var(--s-4) var(--s-4);
  background: var(--highlight);
  font-family: var(--font-hand);
  font-size: 1.1875rem;
  line-height: 1.3;
  color: var(--ink);
  box-shadow: 0 10px 18px -12px var(--shadow);
  transform: rotate(1.2deg);
}

.pin__head {
  display: block;
  margin-bottom: var(--s-1);
  font-family: var(--font-print);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

/* Figure 4: return */

.fig-return__label {
  margin-bottom: var(--s-2);
  font-family: var(--font-print);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink-2);
}

.game {
  line-height: 1.9;
  max-width: 34em;
}

.keymove {
  margin-top: var(--s-4);
  padding: var(--s-3) 0;
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
}

.keymove__head {
  font-family: var(--font-print);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink-2);
}

.keymove__move {
  font-size: 1.125rem;
}

.keymove__meta {
  font-size: var(--text-small);
  color: var(--graphite);
}

.fig-return__back {
  display: flex;
  align-items: center;
  gap: var(--s-2);
  margin-top: var(--s-4);
  font-family: var(--font-hand);
  font-size: 1.3125rem;
  color: var(--blue);
}

.glyph--return {
  width: 46px;
  height: 32px;
}

/* ---------- Who it's for ---------- */

.who {
  padding-top: var(--s-8);
  padding-bottom: var(--s-8);
  row-gap: var(--s-6);
}

.who__title {
  grid-column: main / end;
  max-width: 22ch;
}

.who__yes {
  grid-column: main;
}

.who__no {
  grid-column: side;
}

.who__head {
  margin: 0 0 var(--s-4);
  font-size: var(--text-h3);
  font-weight: 700;
}

.marked {
  display: grid;
  gap: var(--s-4);
  margin: 0;
  padding: 0;
  list-style: none;
}

.marked li {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: var(--s-3);
  align-items: start;
  max-width: 48ch;
}

.marked .glyph {
  width: 32px;
  height: 28px;
  color: var(--red);
}

.marked--no .glyph {
  width: 24px;
  height: 24px;
  margin: 2px 0 0 4px;
  color: var(--graphite);
}

.marked--no li {
  color: var(--ink-2);
}

/* ---------- Status: a checklist the coach ticks off ---------- */

.status-sec {
  padding-top: var(--s-8);
  padding-bottom: var(--s-9);
  row-gap: var(--s-6);
}

.status-sec__head {
  display: grid;
  gap: var(--s-4);
}

.status-sec__head .h2 {
  max-width: 18ch;
}

.status-sec__intro {
  color: var(--ink-2);
}

.checklist {
  grid-column: main / end;
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 2px solid var(--ink);
}

.checklist__item {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr) minmax(8rem, 12rem);
  gap: var(--s-4);
  align-items: center;
  padding: var(--s-4) 0;
  border-bottom: 1px solid var(--rule);
}

.checklist__item .glyph {
  width: 36px;
  height: 32px;
}

.checklist__text {
  font-size: 1.25rem;
  line-height: 1.35;
}

.checklist__state {
  font-family: var(--font-hand);
  font-size: 1.3125rem;
  font-weight: 700;
  line-height: 1.1;
  text-align: right;
}

.is-live .glyph,
.is-live .checklist__state {
  color: var(--red);
}

.is-dev .glyph,
.is-dev .checklist__state {
  color: var(--graphite);
}

.is-dev .checklist__text {
  color: var(--ink-2);
}

.is-next .glyph,
.is-next .checklist__state {
  color: var(--blue);
}

/* ---------- FAQ ---------- */

.faq {
  padding-top: var(--s-8);
  padding-bottom: var(--s-8);
  row-gap: var(--s-5);
}

.faq__head {
  grid-column: main / end;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--s-3) var(--s-6);
}

.faq__contact {
  transform: rotate(-1deg);
}

.faq__list {
  grid-column: main / end;
  border-top: 2px solid var(--ink);
}

.faq details {
  border-bottom: 1px solid var(--rule);
}

.faq summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--s-4);
  min-height: 60px;
  padding: var(--s-3) 0;
  font-size: 1.25rem;
  font-weight: 650;
  line-height: 1.3;
  cursor: pointer;
  list-style: none;
}

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

@media (hover: hover) and (pointer: fine) {
  .faq summary:hover span {
    text-decoration: underline;
    text-decoration-color: var(--red);
    text-decoration-thickness: 2px;
    text-underline-offset: 0.2em;
  }
}

.glyph--plus {
  width: 22px;
  height: 22px;
  color: var(--red);
  transition: transform 200ms var(--ease-out);
}

details[open] .glyph--plus {
  transform: rotate(45deg);
}

.faq details p {
  max-width: 64ch;
  padding-bottom: var(--s-5);
  color: var(--ink-2);
}

/* ---------- Homework ---------- */

.homework {
  padding-top: var(--s-9);
  padding-bottom: var(--s-10);
  row-gap: var(--s-5);
}

.homework__title {
  grid-column: main / end;
  max-width: 18ch;
  margin: 0;
  font-size: clamp(2.4rem, 1.4rem + 3.6vw, 4.75rem);
  font-weight: 800;
  line-height: 1.02;
  letter-spacing: -0.025em;
}

.homework__label {
  display: inline-block;
  margin-right: 0.15em;
  font-family: var(--font-hand);
  font-size: 0.66em;
  font-weight: 700;
  letter-spacing: 0;
  color: var(--red);
  transform: rotate(-4deg) translateY(-0.06em);
}

.homework__title .ink--double .stroke {
  stroke-width: 7;
}

.homework__body {
  max-width: 44ch;
  font-size: 1.25rem;
}

.homework__act {
  margin-top: var(--s-2);
}

/* ---------- Colophon ---------- */

.colophon {
  padding-bottom: var(--s-7);
}

.colophon__inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: var(--s-5) var(--s-7);
  padding-top: var(--s-6);
  border-top: 2px solid var(--ink);
  box-shadow: inset 0 3px 0 -2px var(--ink);
  font-size: var(--text-small);
}

.colophon__brand p {
  margin-top: var(--s-2);
  color: var(--ink-2);
  max-width: 36ch;
}

.colophon__links {
  display: flex;
  flex-wrap: wrap;
  align-content: flex-start;
  gap: var(--s-2) var(--s-5);
}

.colophon__links a {
  display: inline-block;
  padding: var(--s-1) 0;
  font-weight: 600;
  white-space: nowrap;
}

.colophon__credits,
.colophon__base {
  grid-column: 1 / -1;
  max-width: 80ch;
  color: var(--ink-2);
}

.colophon__base {
  font-family: var(--font-print);
  font-size: 0.8125rem;
}

/* ---------- Privacy, terms and 404 ---------- */

.doc {
  padding-top: var(--s-8);
  padding-bottom: var(--s-9);
}

.doc__template {
  max-width: 62ch;
  margin-bottom: var(--s-6);
  padding: var(--s-4) var(--s-5);
  background: var(--paper-2);
  font-family: var(--font-print);
  font-size: 0.9375rem;
  box-shadow: 0 1px 1px var(--shadow), 0 10px 18px -14px var(--shadow);
}

.doc__kind {
  margin-bottom: var(--s-2);
  font-family: var(--font-hand);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--red);
  transform: rotate(-2deg);
  transform-origin: left center;
}

.doc h1 {
  margin: 0;
  font-size: var(--text-h2);
  font-weight: 800;
  line-height: 1.04;
  letter-spacing: -0.02em;
}

.doc__meta {
  margin-top: var(--s-3);
  font-family: var(--font-print);
  font-size: 0.875rem;
  color: var(--graphite);
}

.doc__body {
  margin-top: var(--s-6);
}

.doc__body h2 {
  margin: var(--s-7) 0 var(--s-3);
  font-size: 1.5rem;
  font-weight: 750;
  line-height: 1.2;
}

.doc__body ul {
  padding-left: 1.2em;
}

.doc__body li + li {
  margin-top: var(--s-2);
}

.lost {
  padding-top: var(--s-9);
  padding-bottom: var(--s-10);
}

.lost__glyph {
  margin: 0 0 var(--s-4);
  font-family: var(--font-hand);
  font-size: clamp(4rem, 2rem + 8vw, 8rem);
  font-weight: 700;
  line-height: 1;
  color: var(--red);
}

.lost h1 {
  margin: 0 0 var(--s-4);
  font-size: var(--text-h2);
  font-weight: 800;
  line-height: 1.04;
  letter-spacing: -0.02em;
  max-width: 18ch;
}

.lost__body {
  max-width: 48ch;
  margin-bottom: var(--s-6);
}

.lost__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--s-3);
}

.btn--plain {
  background: var(--card);
  color: var(--ink);
  border-color: var(--ink);
}

@media (hover: hover) and (pointer: fine) {
  .btn--plain:hover {
    background: var(--paper-2);
  }
}

/* ---------- Drawing states (app.js) ----------
 * Every mark is in the HTML. With scripting on and motion allowed, marks start
 * hidden so the coach can draw them; app.js takes over by adding .ink-ready.
 * If the script never runs, the marks appear after 2.5s anyway.
 */

@media (scripting: enabled) and (prefers-reduced-motion: no-preference) {
  html:not(.ink-ready) [data-draw] .stroke,
  html:not(.ink-ready) .demo .board__ink .stroke {
    stroke-dashoffset: 1.01;
    animation: ink-safety 0s linear 2.5s forwards;
  }

  html:not(.ink-ready) [data-ink-group] [data-write],
  html:not(.ink-ready) .demo [data-write] {
    visibility: hidden;
    animation: write-safety 0s linear 2.5s forwards;
  }

  html:not(.ink-ready) .demo .hl {
    clip-path: inset(0 100% 0 0);
    animation: swipe-safety 0s linear 2.5s forwards;
  }
}

@keyframes swipe-safety {
  to {
    clip-path: inset(0 0 0 0);
  }
}

@keyframes ink-safety {
  to {
    stroke-dashoffset: 0;
  }
}

@keyframes write-safety {
  to {
    visibility: visible;
  }
}

.is-pending .stroke {
  stroke-dashoffset: 1.01;
}

.is-pending[data-write],
.is-pending [data-write] {
  visibility: hidden;
}

.demo.is-pending .hl {
  clip-path: inset(0 100% 0 0);
}

.w {
  display: inline-block;
}

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

  .board .pc,
  .ss__ring .stroke,
  .glyph--plus,
  .btn,
  .ctl,
  .pencil {
    transition: none;
  }

  .pencil {
    display: none;
  }
}

@media print {
  [data-draw] .stroke,
  .board__ink .stroke {
    stroke-dashoffset: 0 !important;
  }

  [data-write] {
    visibility: visible !important;
  }

  .masthead__cta,
  .demo__controls {
    display: none;
  }
}

/* ---------- Responsive ---------- */

@media (max-width: 1240px) {
  .demo {
    grid-template-columns: minmax(0, 1fr) minmax(16rem, 0.62fr);
    grid-template-areas:
      'board note'
      'ctrl note'
      'sheet note';
    max-width: 920px;
  }

  .demo__sheet {
    max-width: 26rem;
  }

  .step__n {
    left: -84px;
  }
}

@media (max-width: 1079px) {
  :root {
    --content-x: 76px;
    --pad-r: 32px;
    --rule-x: 44px;
  }

  .rows {
    grid-template-columns: minmax(0, 1fr);
  }

  .rows > *,
  .open__title,
  .open__side,
  .lesson__you,
  .review__title,
  .review__side,
  .review__questions,
  .how__title,
  .who__title,
  .who__yes,
  .who__no,
  .checklist,
  .faq__head,
  .faq__list,
  .homework__title {
    grid-column: 1;
    grid-row: auto;
  }

  .open__side {
    grid-template-columns: repeat(auto-fit, minmax(14rem, 1fr));
    gap: var(--s-5) var(--s-6);
    margin-top: var(--s-2);
    padding-left: var(--s-4);
  }

  .note-hand--why {
    margin-top: 0;
  }

  .glyph--to-form {
    display: none;
  }

  .lesson__you {
    align-self: start;
    justify-self: start;
  }

  .review__side {
    max-width: 30rem;
  }

  .step {
    grid-template-columns: minmax(0, 1fr);
    gap: var(--s-5);
  }

  .step__n {
    left: -60px;
    width: 32px;
  }

  .who__no {
    margin-top: var(--s-3);
  }
}

@media (max-width: 860px) {
  /* Board and note stay side by side, so the pencil and the writing are seen together. */
  .demo {
    grid-template-columns: minmax(0, 1fr) minmax(12.5rem, 0.66fr);
    grid-template-areas:
      'board note'
      'ctrl ctrl'
      'sheet sheet';
    column-gap: var(--s-5);
  }

  .note__title {
    font-size: 1.5rem;
  }

  .note__body {
    font-size: 1.125rem;
  }

}

@media (max-width: 699px) {
  :root {
    --content-x: 30px;
    --pad-r: 16px;
    --rule-x: 12px;
    --text-hand: 1.25rem;
  }

  body {
    font-size: 1.0625rem;
    background-size: 22px 22px;
  }

  .masthead {
    padding-top: var(--s-4);
  }

  .masthead__inner {
    gap: var(--s-3);
    padding-bottom: var(--s-3);
  }

  .brand__word {
    font-size: 1.1875rem;
  }

  .brand__mark {
    width: 30px;
    height: 30px;
  }

  .open {
    padding-top: var(--s-6);
    padding-bottom: var(--s-8);
    row-gap: var(--s-5);
  }

  .open__lede {
    font-size: 1.1875rem;
  }

  .open__side {
    padding-left: 0;
  }

  .slip {
    margin-top: var(--s-5);
  }

  .slip__row {
    flex-direction: column;
    align-items: stretch;
  }

  .slip__submit {
    width: 100%;
  }

  .demo {
    grid-template-columns: minmax(0, 1fr);
    grid-template-areas:
      'board'
      'note'
      'ctrl'
      'sheet';
    max-width: 640px;
    margin-left: calc(var(--content-x) - 4px);
  }

  .demo__controls {
    padding-left: 0;
  }

  .fact {
    grid-template-columns: minmax(0, 1fr);
    gap: 0;
  }

  .diagram:not(.diagram--mini) {
    grid-template-columns: 1.1rem minmax(0, 1fr);
  }

  .diagram__ranks,
  .diagram__files {
    font-size: 0.875rem;
  }

  .note__title {
    font-size: 1.625rem;
  }

  .note__body {
    font-size: 1.1875rem;
  }

  .demo__controls .ctl {
    flex: 1 1 auto;
    justify-content: center;
    padding: 0 var(--s-3);
  }

  .ctl--branch {
    flex-basis: 100%;
    margin-left: 0;
  }

  .ss td {
    height: 2.75rem;
  }

  .review,
  .who,
  .status-sec,
  .homework {
    padding-top: var(--s-8);
  }

  .review__but {
    font-size: 1.3125rem;
  }

  .step__n {
    position: static;
    width: auto;
    font-size: 1.75rem;
  }

  .fig-evidence,
  .fig-branch__body {
    grid-template-columns: minmax(0, 1fr);
  }

  .fig-evidence__board,
  .fig-branch__board {
    width: 100%;
    max-width: 240px;
  }

  .fig-explain {
    padding: var(--s-4);
  }

  .checklist__item {
    grid-template-columns: 36px minmax(0, 1fr);
    row-gap: var(--s-1);
  }

  .checklist__state {
    grid-column: 2;
    text-align: left;
  }

  .checklist__text {
    font-size: 1.125rem;
  }

  .faq summary {
    font-size: 1.125rem;
  }

  .colophon__inner {
    grid-template-columns: minmax(0, 1fr);
  }
}

@media (pointer: coarse) {
  .ss__btn {
    min-height: 44px;
  }
}