/* Calcd — a quiet technical-manual look: warm paper, ink, and the same
   cable blue as the app's title bar. One loud colour (signal orange) is kept
   for the primary action and live status only. */

:root {
  --paper: #f3f1ea;
  --paper-raised: #fbfaf6;
  --ink: #1b1c1f;
  --ink-soft: #4a4b50;
  --rule: #d8d4c8;
  --cable: #203864;
  --cable-soft: #dfe5ef;
  --signal: #e2551f;
  --signal-ink: #ffffff;
  --ok: #2f7a4f;
  --error: #b3261e;
  --bezel: #26272b;
  --bezel-edge: #3a3b41;
  --key: #3d3e45;
  --key-ink: #f1f1ee;

  --font-display: "Iowan Old Style", "Palatino Linotype", Palatino, "Book Antiqua", Georgia, serif;
  --font-body: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-mono: ui-monospace, "Cascadia Mono", "SF Mono", Consolas, monospace;

  --text-hero: clamp(2.4rem, 1.4rem + 4.2vw, 4.6rem);
  --text-h2: clamp(1.6rem, 1.2rem + 1.4vw, 2.3rem);
  --radius: 6px;
  --gutter: clamp(16px, 4vw, 48px);
  --duration: 160ms;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #15161a;
    --paper-raised: #1d1e23;
    --ink: #ecebe6;
    --ink-soft: #a9a8a2;
    --rule: #33343a;
    --cable: #8fa9d6;
    --cable-soft: #222a3a;
    --signal: #ff7a45;
    --signal-ink: #1b1c1f;
    --ok: #6cc391;
    --error: #ff8a80;
    --bezel: #0d0d10;
    --bezel-edge: #2a2b31;
  }
}

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

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

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 1rem/1.6 var(--font-body);
  -webkit-font-smoothing: antialiased;
}

a { color: var(--cable); text-underline-offset: 3px; }
a:hover { color: var(--signal); }

:focus-visible { outline: 3px solid var(--signal); outline-offset: 2px; }

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

.skip-link {
  position: absolute; left: 12px; top: -48px; z-index: 10;
  background: var(--ink); color: var(--paper); padding: 8px 12px; border-radius: var(--radius);
}
.skip-link:focus { top: 12px; }

/* Header */
.site-header {
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
  padding: 18px var(--gutter);
  border-bottom: 1px solid var(--rule);
}
.wordmark {
  font: 600 1.35rem/1 var(--font-mono);
  color: var(--ink); text-decoration: none; letter-spacing: -0.02em;
}
.cursor {
  display: inline-block; width: 0.55em; height: 1em; margin-left: 2px;
  background: var(--signal); vertical-align: -0.12em;
  animation: blink 1.1s steps(1) infinite;
}
@keyframes blink { 50% { opacity: 0; } }
.site-header nav { display: flex; gap: clamp(12px, 3vw, 28px); font-size: 0.95rem; }
.site-header nav a { white-space: nowrap; }
@media (max-width: 640px) {
  .site-header { flex-wrap: wrap; row-gap: 10px; }
  .site-header nav { width: 100%; justify-content: space-between; font-size: 0.88rem; }
}
.site-header nav a { color: var(--ink-soft); text-decoration: none; }
.site-header nav a:hover { color: var(--ink); }

main { padding: 0 var(--gutter); }

/* Intro */
.intro { max-width: 60rem; padding: clamp(40px, 8vw, 96px) 0 clamp(24px, 4vw, 48px); }
.eyebrow {
  margin: 0 0 12px; font: 600 0.8rem/1 var(--font-mono);
  letter-spacing: 0.12em; text-transform: uppercase; color: var(--cable);
}
h1 {
  margin: 0; font: 500 var(--text-hero)/1.02 var(--font-display);
  letter-spacing: -0.025em; text-wrap: balance;
}
.lede { max-width: 38rem; margin: 20px 0 0; font-size: 1.12rem; color: var(--ink-soft); }

/* Maker: editor + device */
.maker {
  display: grid; gap: clamp(24px, 4vw, 56px);
  grid-template-columns: minmax(0, 1fr);
  align-items: start;
  padding-bottom: 24px;
}
@media (min-width: 1040px) {
  .maker { grid-template-columns: minmax(0, 1fr) minmax(420px, 46%); }
  .device { position: sticky; top: 24px; }
}

.editor { display: flex; flex-direction: column; gap: 16px; min-width: 0; }
.field-row { display: grid; gap: 16px; grid-template-columns: minmax(0, 1fr); }
@media (min-width: 560px) { .field-row { grid-template-columns: minmax(0, 1fr) 11rem; } }

.field { display: flex; flex-direction: column; gap: 6px; }
.label {
  font: 600 0.78rem/1 var(--font-mono); letter-spacing: 0.08em; text-transform: uppercase;
  color: var(--ink-soft);
}
.hint { font-size: 0.8rem; color: var(--ink-soft); }

input[type="text"], textarea {
  width: 100%; padding: 12px 14px;
  background: var(--paper-raised); color: var(--ink);
  border: 1px solid var(--rule); border-radius: var(--radius);
  font: 1rem/1.5 var(--font-body);
  transition: border-color var(--duration), box-shadow var(--duration);
}
#note-name { font-family: var(--font-mono); text-transform: uppercase; }
textarea { font: 0.95rem/1.55 var(--font-mono); resize: vertical; min-height: 18rem; }
input[type="text"]:hover, textarea:hover { border-color: var(--ink-soft); }
input[type="text"]:focus, textarea:focus {
  outline: none; border-color: var(--cable);
  box-shadow: 0 0 0 3px var(--cable-soft);
}
input[aria-invalid="true"] { border-color: var(--error); }

.meta { margin: -4px 0 0; min-height: 1.6em; font: 0.85rem/1.6 var(--font-mono); color: var(--ink-soft); }
.meta .warn { color: var(--error); }

/* Buttons */
.actions, .app-actions { display: flex; flex-wrap: wrap; gap: 10px; }
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  min-height: 44px; padding: 0 18px;
  border: 1px solid var(--ink); border-radius: var(--radius);
  background: transparent; color: var(--ink);
  font: 600 0.95rem/1 var(--font-body); text-decoration: none; cursor: pointer;
  transition: transform var(--duration), background var(--duration), color var(--duration);
}
.btn:hover { background: var(--ink); color: var(--paper); }
.btn:active { transform: translateY(1px); }
.btn:disabled { opacity: 0.45; cursor: not-allowed; transform: none; }
.btn:disabled:hover { background: transparent; color: var(--ink); }
.btn-primary { background: var(--signal); border-color: var(--signal); color: var(--signal-ink); }
.btn-primary:hover { background: var(--ink); border-color: var(--ink); color: var(--paper); }
.btn-primary:disabled:hover { background: var(--signal); color: var(--signal-ink); }
.btn-ghost { border-style: dashed; }
.file-btn { position: relative; }
.file-btn input { position: absolute; inset: 0; opacity: 0; cursor: pointer; }
.file-btn:focus-within { outline: 3px solid var(--signal); outline-offset: 2px; }

/* Device */
.device { margin: 0; justify-self: center; width: min(100%, 680px); }
.bezel {
  padding: 20px 20px 16px;
  background: var(--bezel);
  border: 1px solid var(--bezel-edge);
  border-radius: 22px 22px 28px 28px;
  box-shadow: 0 1px 0 rgba(255, 255, 255, 0.06) inset, 0 24px 48px -24px rgba(0, 0, 0, 0.5);
}
.lcd {
  display: block; width: 100%; height: auto; aspect-ratio: 4 / 3;
  image-rendering: pixelated; image-rendering: crisp-edges;
  border-radius: 4px;
  box-shadow: 0 0 0 4px #111215;
  cursor: ns-resize;
}
.lcd:focus-visible { outline-offset: 6px; }
.keys { display: grid; grid-template-columns: repeat(6, 1fr); gap: 8px; margin-top: 16px; }
.key {
  min-height: 40px; border: 0; border-radius: 8px;
  background: var(--key); color: var(--key-ink);
  font: 600 0.8rem/1 var(--font-mono); cursor: pointer;
  box-shadow: 0 2px 0 #18191c;
  transition: transform 80ms, box-shadow 80ms, background var(--duration);
}
.key:hover { background: #4b4c55; }
.key:active { transform: translateY(2px); box-shadow: 0 0 0 #18191c; }
.device figcaption { margin-top: 10px; text-align: center; font-size: 0.85rem; color: var(--ink-soft); }

/* Status: pinned to the bottom so it's visible from any section */
.status {
  position: fixed; left: 50%; bottom: 16px; z-index: 20;
  width: min(calc(100% - 32px), 44rem); transform: translateX(-50%);
  margin: 0; padding: 12px 16px;
  background: var(--ink); color: var(--paper);
  border-left: 4px solid var(--cable-soft); border-radius: var(--radius);
  box-shadow: 0 12px 32px -12px rgba(0, 0, 0, 0.45);
  font: 0.9rem/1.5 var(--font-mono);
  animation: rise var(--duration) ease-out;
}
@keyframes rise { from { opacity: 0; transform: translate(-50%, 8px); } }
.status[data-kind="busy"] { border-left-color: var(--signal); }
.status[data-kind="busy"]::before { content: "\25CF  "; color: var(--signal); animation: blink 0.9s steps(1) infinite; }
.status[data-kind="ok"] { border-left-color: var(--ok); }
.status[data-kind="error"] { border-left-color: var(--error); }
.support-note {
  max-width: 60rem; margin: 0; padding: 10px 14px; border-left: 3px solid var(--signal);
  background: var(--paper-raised); font-size: 0.92rem;
}

/* Move to a new calculator */
.move { max-width: 64rem; padding: clamp(48px, 8vw, 96px) 0 0; }
.move h2 { margin: 0 0 12px; font: 500 var(--text-h2)/1.1 var(--font-display); letter-spacing: -0.015em; }
.move-intro, .move-note { max-width: 42rem; color: var(--ink-soft); }
.move-grid {
  display: grid; gap: 0; margin: 28px 0 20px;
  grid-template-columns: minmax(0, 1fr);
  border: 1px solid var(--rule); border-radius: var(--radius); overflow: hidden;
}
@media (min-width: 760px) { .move-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
.move-card { padding: 24px; background: var(--paper-raised); display: flex; flex-direction: column; gap: 12px; align-items: flex-start; }
.move-card + .move-card { border-top: 1px solid var(--rule); }
@media (min-width: 760px) { .move-card + .move-card { border-top: 0; border-left: 1px solid var(--rule); } }
.move-card h3 { margin: 0; font: 600 1.15rem/1.3 var(--font-body); }
.move-card p { margin: 0; }
.step-tag { font: 600 0.75rem/1 var(--font-mono); letter-spacing: 0.1em; text-transform: uppercase; color: var(--cable); }
.parts { margin: 0; padding: 0; border: 0; display: flex; flex-direction: column; gap: 8px; }
.parts legend { margin-bottom: 6px; padding: 0; font: 600 0.78rem/1 var(--font-mono); letter-spacing: 0.08em; text-transform: uppercase; color: var(--ink-soft); }
.parts label { display: flex; gap: 10px; align-items: baseline; cursor: pointer; }
.parts input { accent-color: var(--signal); width: 1.05rem; height: 1.05rem; flex: none; transform: translateY(2px); }
.backup-ready { font: 0.88rem/1.5 var(--font-mono); color: var(--ink-soft); }
.backup-ready[data-ready="true"] { color: var(--ok); }

/* App band: full-bleed, cable blue */
.band {
  margin: clamp(48px, 8vw, 96px) calc(-1 * var(--gutter)) 0;
  padding: clamp(40px, 7vw, 80px) var(--gutter);
  background: var(--cable); color: #f4f5f8;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .band { background: #1a2338; }
}
.band-inner { max-width: 60rem; }
.band h2, .setup h2 { margin: 0 0 12px; font: 500 var(--text-h2)/1.1 var(--font-display); letter-spacing: -0.015em; }
.band p { max-width: 40rem; margin: 0 0 24px; color: #d6dbe6; }
.band .btn { border-color: #f4f5f8; color: #f4f5f8; }
.band .btn:hover { background: #f4f5f8; color: var(--cable); }
.band .btn-primary { background: var(--signal); border-color: var(--signal); color: #fff; }
.band .btn-primary:hover { background: #f4f5f8; border-color: #f4f5f8; color: #203864; }

.controls {
  display: grid; gap: 1px; margin: 36px 0 0;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  background: rgba(255, 255, 255, 0.18); border: 1px solid rgba(255, 255, 255, 0.18);
}
@media (min-width: 720px) { .controls { grid-template-columns: repeat(3, minmax(0, 1fr)); } }
.controls div { padding: 14px 16px; background: var(--cable); }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .controls div { background: #1a2338; }
}
.controls dt { font: 600 0.85rem/1.2 var(--font-mono); color: #fff; }
.controls dd { margin: 4px 0 0; font-size: 0.9rem; color: #c9d0de; }

/* Setup */
.setup { max-width: 60rem; padding: clamp(48px, 8vw, 96px) 0; }
.setup > p { max-width: 40rem; color: var(--ink-soft); }
.steps { list-style: none; counter-reset: step; margin: 32px 0 0; padding: 0; }
.steps li {
  counter-increment: step; position: relative;
  padding: 0 0 28px 64px; border-left: 1px solid var(--rule); margin-left: 18px;
}
.steps li:last-child { border-left-color: transparent; }
.steps li::before {
  content: counter(step);
  position: absolute; left: -19px; top: -4px;
  width: 38px; height: 38px; display: grid; place-items: center;
  background: var(--paper); border: 1px solid var(--ink); border-radius: 50%;
  font: 600 0.95rem/1 var(--font-mono);
}
.steps h3 { margin: 0 0 6px; font: 600 1.1rem/1.3 var(--font-body); }
.steps p { margin: 0 0 10px; color: var(--ink-soft); }
kbd {
  display: inline-block; padding: 1px 7px; border: 1px solid var(--rule); border-bottom-width: 2px;
  border-radius: 4px; background: var(--paper-raised); font: 0.82rem/1.5 var(--font-mono); color: var(--ink);
}
table { border-collapse: collapse; margin: 8px 0 12px; font-size: 0.92rem; width: 100%; max-width: 32rem; }
th, td { text-align: left; padding: 8px 12px 8px 0; border-bottom: 1px solid var(--rule); }
th { font: 600 0.75rem/1 var(--font-mono); letter-spacing: 0.08em; text-transform: uppercase; color: var(--ink-soft); }

/* Footer */
.site-footer {
  padding: 28px var(--gutter) 40px; border-top: 1px solid var(--rule);
  font-size: 0.85rem; color: var(--ink-soft);
}
.site-footer p { max-width: 60rem; margin: 0 0 8px; }
.site-footer .credit {
  margin-top: 20px; font: 0.72rem/1 var(--font-mono);
  letter-spacing: 0.08em; text-transform: uppercase; opacity: 0.75;
}