:root {
  --paper: oklch(95.5% 0.015 85);
  --sheet: oklch(99% 0.006 85);
  --ink: oklch(19% 0.01 60);
  --ink-soft: oklch(45% 0.015 60);
  --rule: oklch(82% 0.02 80);
  --accent: oklch(62% 0.21 35);
  --accent-ink: oklch(98% 0.01 85);
  --focus: oklch(55% 0.2 260);

  --font-ui: 'Bricolage Grotesque', system-ui, sans-serif;
  --font-num: 'JetBrains Mono', ui-monospace, monospace;
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 400 1rem/1.5 var(--font-ui);
  background-image: radial-gradient(oklch(80% 0.02 80 / 0.5) 1px, transparent 1px);
  background-size: 18px 18px;
}

.masthead {
  display: flex;
  gap: 1.25rem;
  align-items: center;
  padding: clamp(1.25rem, 4vw, 3rem) 16px 1rem;
  max-width: 1180px;
  margin: 0 auto;
}
.masthead h1 {
  margin: 0;
  font-size: clamp(2rem, 1rem + 5vw, 4.25rem);
  font-weight: 800;
  line-height: 0.95;
  letter-spacing: -0.03em;
}
.masthead .brand { margin: 0 0 0.5rem; font: 600 0.8rem var(--font-num); letter-spacing: 0.22em; text-transform: uppercase; color: var(--accent); }
.masthead p { margin: 0.5rem 0 0; max-width: 46ch; color: var(--ink-soft); }
.reg { width: clamp(40px, 8vw, 72px); flex: none; fill: none; stroke: var(--accent); stroke-width: 1.5; }

.layout {
  display: grid;
  gap: 1.5rem;
  max-width: 920px;
  margin: 0 auto;
  padding: 0.5rem 16px 4rem;
}
[hidden] { display: none !important; }

.tabs { display: flex; border-bottom: 1.5px solid var(--ink); }
.tab {
  padding: 0.7rem 1.25rem; border: 1.5px solid transparent; border-bottom: 0; margin-bottom: -1.5px;
  background: transparent; color: var(--ink-soft); font: 600 0.95rem var(--font-ui); cursor: pointer;
  transition: color 150ms, background 150ms;
}
.tab:hover { color: var(--ink); background: oklch(94% 0.03 80); }
.tab[aria-selected=true] { color: var(--ink); background: var(--sheet); border-color: var(--ink); }
.stage { display: grid; gap: 1.5rem; min-width: 0; }

.panel {
  background: var(--sheet);
  border: 1.5px solid var(--ink);
  padding: 1.25rem;
  box-shadow: 6px 6px 0 var(--ink);
}
.panel h2 {
  display: flex; align-items: baseline; gap: 0.6rem;
  margin: 0 0 1rem; font-size: 1.15rem; font-weight: 600;
}
.panel h2:not(:first-child) { margin-top: 1.75rem; }
.step { font: 600 0.75rem var(--font-num); color: var(--accent); }

.fields { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 0.9rem 0.75rem; }
label { display: grid; gap: 0.25rem; font-size: 0.8125rem; font-weight: 600; }
.unit { font: 400 0.7rem var(--font-num); color: var(--ink-soft); }
input[type=number], select {
  width: 100%; padding: 0.55rem 0.6rem;
  font: 600 1rem var(--font-num); color: var(--ink);
  background: var(--paper); border: 1.5px solid var(--rule); border-radius: 0;
  transition: border-color 150ms;
}
select { font-family: var(--font-ui); }
input:hover, select:hover { border-color: var(--ink); }
:focus-visible { outline: 2px solid var(--focus); outline-offset: 2px; }
.check { grid-column: 1 / -1; display: flex; align-items: center; gap: 0.5rem; font-weight: 400; font-size: 0.9rem; }
.check input { width: 1.1rem; height: 1.1rem; accent-color: var(--accent); }
.custom[hidden] { display: none; }

.readout { margin: 0.9rem 0 0; font: 400 0.75rem/1.5 var(--font-num); color: var(--ink-soft); }
.readout b { color: var(--ink); }

.drop {
  position: relative; display: grid; gap: 0.2rem; justify-items: center; text-align: center;
  padding: 1.5rem 1rem; border: 2px dashed var(--ink); cursor: pointer;
  transition: background 200ms var(--ease), transform 200ms var(--ease);
}
.drop input { position: absolute; inset: 0; opacity: 0; cursor: pointer; }
.drop strong { font-size: 1.25rem; }
.drop span { font-size: 0.85rem; color: var(--ink-soft); }
.drop:hover, .drop.over { background: oklch(94% 0.05 60); transform: translateY(-2px); }
.drop:focus-within { outline: 2px solid var(--focus); outline-offset: 3px; }

.tray { list-style: none; margin: 1rem 0 0; padding: 0; display: grid; gap: 0.75rem; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); }
.card { min-width: 0; border: 1.5px solid var(--rule); padding: 0.6rem; display: grid; gap: 0.5rem; background: var(--paper); animation: rise 300ms var(--ease) both; }
.card > * { min-width: 0; }
.card canvas { width: 100%; max-width: 100%; height: auto; display: block; touch-action: none; cursor: grab; background: #fff; border: 1px solid var(--rule); }
.card canvas:active { cursor: grabbing; }
.card input[type=range] { width: 100%; accent-color: var(--accent); }
.card .row { flex-wrap: wrap; display: flex; align-items: center; justify-content: space-between; gap: 0.4rem; }
.remove { border: 0; background: none; color: var(--ink-soft); font: 0.75rem var(--font-ui); text-decoration: underline; cursor: pointer; padding: 0.4rem; }
.remove:hover { color: var(--accent); }
.actions { display: flex; align-items: center; gap: 0.2rem; }
.dup { border: 1.5px solid var(--ink); background: transparent; color: var(--ink); font: 600 0.75rem var(--font-ui); padding: 0.35rem 0.5rem; cursor: pointer; transition: background 150ms, color 150ms; }
.dup:hover { background: var(--ink); color: var(--paper); }
@keyframes rise { from { opacity: 0; transform: translateY(8px); } }

.summary { display: flex; flex-wrap: wrap; gap: 0.75rem 1.5rem; align-items: center; justify-content: space-between; margin-bottom: 1rem; }
.summary p { margin: 0; font: 400 0.85rem var(--font-num); }
.go {
  padding: 0.85rem 1.5rem; border: 1.5px solid var(--ink); background: var(--accent); color: var(--accent-ink);
  font: 800 1rem var(--font-ui); letter-spacing: 0.01em; cursor: pointer; box-shadow: 4px 4px 0 var(--ink);
  transition: transform 150ms var(--ease), box-shadow 150ms var(--ease);
}
.go:hover:not(:disabled) { transform: translate(-2px, -2px); box-shadow: 6px 6px 0 var(--ink); }
.go:active:not(:disabled) { transform: translate(3px, 3px); box-shadow: 1px 1px 0 var(--ink); }
.go:disabled { background: var(--rule); color: var(--ink-soft); box-shadow: none; cursor: not-allowed; }

.pages { display: flex; flex-wrap: wrap; gap: 1.25rem; }
.pages canvas { max-width: 100%; height: auto; background: #fff; border: 1px solid var(--ink); box-shadow: 4px 4px 0 oklch(19% 0.01 60 / 0.25); }
.pages figure { margin: 0; display: grid; gap: 0.4rem; }
.pages figcaption { font: 400 0.7rem var(--font-num); color: var(--ink-soft); }

.tips { margin-top: 1.25rem; font-size: 0.9rem; }
.tips summary { cursor: pointer; font-weight: 600; }
.tips ol { margin: 0.6rem 0 0; padding-left: 1.2rem; color: var(--ink-soft); }
.tips li + li { margin-top: 0.25rem; }

.warn { color: var(--accent); }

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

.howto ol { margin: 0 0 1.25rem; padding-left: 1.3rem; display: grid; gap: 0.3rem; }
.howto li::marker { font: 600 0.85rem var(--font-num); color: var(--accent); }
.paper-row { max-width: 560px; }