/* Palette: every colour sampled from a Wikimedia Commons photo of a 1980 maths
   worksheet run off a spirit duplicator ("Aufgabenbeispiele Klasse 5 November
   1980", KurtSchwitters, CC BY 4.0): ditto violet for the copied hand, the
   pupil's blue fountain-pen ink for yours, the teacher's red ticks. */
:root {
  --bg: #e5e4e3;
  --surface: #fefdfd;
  --rule: #c2c8db;
  --ditto: #8c7692;
  --haze: #d3c0d1;
  --pupil: #41466a;
  --tick: #ac505e;
  --text: #303154;
  --muted: #595c81;
  --line: rgba(48, 49, 84, 0.12);
  --serif: "Newsreader", Georgia, serif;
  --sans: "Figtree", system-ui, sans-serif;
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.55 var(--sans);
}

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

button, input { font: inherit; color: inherit; }

.masthead {
  max-width: 980px;
  margin: 0 auto;
  padding: 44px 24px 22px;
}

.masthead h1 {
  margin: 0;
  font: 500 clamp(2.3rem, 5vw, 3.2rem)/1.05 var(--serif);
  letter-spacing: -0.01em;
}

.masthead p {
  margin: 10px 0 0;
  max-width: 40em;
  color: var(--muted);
  font-size: 1.08rem;
}

.desk {
  max-width: 980px;
  margin: 0 auto;
  padding: 0 24px;
  display: grid;
  gap: 16px;
}

.step, .sheet-step {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 18px 20px 20px;
}

.step-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 6px 18px;
  margin-bottom: 12px;
}

.step-head h2 {
  margin: 0;
  font: 600 0.78rem/1.2 var(--sans);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
}

.num {
  display: inline-grid;
  place-items: center;
  width: 1.55em; height: 1.55em;
  margin-right: 6px;
  border-radius: 50%;
  border: 1px solid var(--rule);
  color: var(--text);
  letter-spacing: 0;
}

.prompt { margin: 0; color: var(--muted); }

.prompt q {
  quotes: "“" "”";
  color: var(--text);
  font: italic 500 1.12rem var(--serif);
}

.pad-wrap, .sheet-wrap { position: relative; }

.pad, .sheet {
  display: block;
  width: 100%;
  border-radius: 6px;
  background: var(--surface);
  box-shadow: inset 0 0 0 1px var(--line);
}

.pad {
  height: 168px;
  cursor: crosshair;
  touch-action: none;
}

.pad:focus-visible, button:focus-visible, input:focus-visible {
  outline: 2px solid var(--pupil);
  outline-offset: 2px;
}

.pad-empty {
  position: absolute;
  left: 18px; top: 14px;
  margin: 0;
  color: var(--muted);
  font-size: 0.86rem;
  pointer-events: none;
}

.pad-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 16px;
  margin-top: 10px;
}

.pad-actions { display: flex; gap: 6px; }

.pad-status {
  margin: 0;
  color: var(--muted);
  font-size: 0.9rem;
}

button.quiet {
  border: 1px solid var(--rule);
  background: transparent;
  border-radius: 999px;
  padding: 5px 14px;
  font-size: 0.88rem;
  cursor: pointer;
}

button.quiet:hover { background: rgba(194, 200, 219, 0.28); }
button:disabled { opacity: 0.45; cursor: default; }

.borrow {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 14px;
  margin-top: 16px;
  padding-top: 14px;
  border-top: 1px dashed var(--rule);
  color: var(--muted);
  font-size: 0.9rem;
}

.hands { display: flex; flex-wrap: wrap; gap: 8px; }

.hand {
  padding: 0;
  border: 1px solid var(--rule);
  border-radius: 6px;
  background: var(--surface);
  cursor: pointer;
  line-height: 0;
}

.hand canvas { width: 132px; height: 34px; }
.hand[aria-pressed="true"] { border-color: var(--pupil); box-shadow: 0 0 0 1px var(--pupil); }

.compose {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 14px;
}

.compose input[type="text"] {
  flex: 1 1 320px;
  min-width: 0;
  padding: 10px 14px;
  border: 1px solid var(--rule);
  border-radius: 8px;
  background: var(--surface);
  font-size: 1.05rem;
}

.action {
  border: 0;
  border-radius: 8px;
  padding: 10px 20px;
  background: var(--tick);
  color: #fff;
  font-weight: 600;
  cursor: pointer;
}

.action:hover { background: #983f4d; }

.dial {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--muted);
  font-size: 0.9rem;
}

.dial input { width: 130px; accent-color: var(--tick); }

.text-note {
  margin: 8px 0 0;
  min-height: 1.3em;
  color: var(--muted);
  font-size: 0.86rem;
}

.sheet-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 6px; }

.toggle {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-right: 8px;
  color: var(--muted);
  font-size: 0.88rem;
  cursor: pointer;
}

.toggle input { accent-color: var(--tick); }

.sheet { min-height: 220px; }

.sheet-status {
  position: absolute;
  right: 14px; bottom: 10px;
  margin: 0;
  color: var(--muted);
  font-size: 0.84rem;
  pointer-events: none;
}

.sheet-foot {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  margin-top: 12px;
}

.strip {
  flex: 1;
  display: flex;
  align-items: baseline;
  gap: 14px;
  min-width: 0;
  overflow: hidden;
}

.loupe {
  flex: none;
  margin: 0;
  text-align: center;
}

.loupe canvas {
  display: block;
  width: 150px; height: 150px;
  border-radius: 50%;
  box-shadow: inset 0 0 0 1px var(--line), 0 0 0 1px var(--line);
}

.loupe figcaption {
  margin-top: 4px;
  color: var(--muted);
  font-size: 0.78rem;
  font-variant-numeric: tabular-nums;
}

.loupe[hidden] { display: none; }

.strip-label {
  flex: none;
  font: 600 0.72rem var(--sans);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
}

.strip-text {
  font: 500 1rem/1.6 ui-monospace, "SF Mono", Menlo, monospace;
  white-space: pre-wrap;
  word-break: break-word;
  color: var(--rule);
}

.strip-text .done { color: var(--text); }

.strip-text .now {
  color: var(--text);
  background: var(--haze);
  border-radius: 3px;
  box-shadow: 0 0 0 2px var(--haze);
}

.essay {
  max-width: 680px;
  margin: 0 auto;
  padding: 48px 24px 72px;
}

.essay h2 { font: 500 2rem/1.2 var(--serif); margin: 0 0 12px; }
.essay h3 { font: 500 1.3rem/1.3 var(--serif); margin: 30px 0 6px; }
.essay p { margin: 0 0 14px; }
.essay a { color: var(--pupil); }

.essay table { width: 100%; border-collapse: collapse; margin: 6px 0 18px; font-size: 0.94rem; }
.essay caption { text-align: left; color: var(--muted); font-size: 0.86rem; padding-bottom: 6px; }
.essay th, .essay td { padding: 6px 8px; border-bottom: 1px solid var(--line); text-align: left; }
.essay .num-col { text-align: right; font-variant-numeric: tabular-nums; }

@media (max-width: 640px) {
  .masthead { padding: 28px 16px 16px; }
  .desk { padding: 0 16px; }
  .step, .sheet-step { padding: 14px 14px 16px; }
  .pad { height: 140px; }
  .hand canvas { width: 104px; height: 28px; }
  .dial input { width: 110px; }
  .loupe canvas { width: 110px; height: 110px; }
  .essay { padding: 36px 16px 56px; }
}