@font-face {
  font-family: "Source Serif 4";
  src: url("./assets/fonts/source-serif-4-latin-400-normal.woff2") format("woff2");
  font-style: normal;
  font-weight: 400;
  font-display: block;
}

:root {
  color-scheme: light;
  --paper: #fffdf7;
  --paper-warm: #f7f0e2;
  --ground: #f1eadb;
  --ink: #1d1b17;
  --muted: #70685d;
  --line: #27241f;
  --soft-line: #c8bcaa;
  --blue: #285f8f;
  --blue-soft: #dce8ef;
  --red: #a54835;
  --green: #426a4d;
  --shadow: 4px 4px 0 var(--line);
  --serif: "Source Serif 4", Georgia, serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; background: var(--ground); }
body {
  min-width: 320px;
  margin: 0;
  overflow-x: clip;
  color: var(--ink);
  background:
    linear-gradient(rgba(39, 36, 31, .045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(39, 36, 31, .035) 1px, transparent 1px),
    var(--ground);
  background-size: 28px 28px;
}

button, input, textarea { font: inherit; }
button, input, textarea, a { -webkit-tap-highlight-color: transparent; }
button:focus-visible, input:focus-visible, textarea:focus-visible, a:focus-visible, [tabindex]:focus-visible, summary:focus-visible {
  outline: 3px solid var(--blue);
  outline-offset: 3px;
}
button {
  min-height: 44px;
  border: 2px solid var(--line);
  border-radius: 1px;
  padding: .62rem .78rem;
  color: var(--ink);
  background: #fffaf0;
  box-shadow: 2px 2px 0 var(--line);
  cursor: pointer;
  font-family: var(--mono);
  font-size: .74rem;
  font-weight: 800;
  text-transform: lowercase;
}
button:hover:not(:disabled) { transform: translate(-1px, -1px); box-shadow: 3px 3px 0 var(--line); }
button:active:not(:disabled) { transform: translate(1px, 1px); box-shadow: none; }
button:disabled { cursor: not-allowed; opacity: .45; box-shadow: none; }
button.primary { color: #fffdf7; background: var(--blue); }

.shell {
  width: min(1040px, calc(100% - 28px));
  margin: 0 auto;
  padding: 0 0 64px;
}

.intro { display: grid; gap: 5px; min-height: 78px; padding: 0 2px 10px; }
.eyebrow, .act-index {
  margin: 0;
  color: var(--muted);
  font-family: var(--mono);
  font-size: .68rem;
  font-weight: 800;
  letter-spacing: .07em;
  text-transform: uppercase;
}
.intro h1 {
  margin: 0;
  font-size: clamp(1.85rem, 8.8vw, 4.7rem);
  line-height: .9;
  letter-spacing: -.055em;
}
.intro h1 em { color: var(--blue); font-family: var(--serif); font-weight: 400; }
.deck { max-width: 62ch; margin: 4px 0 0; color: var(--muted); font: 400 .9rem/1.4 var(--serif); }

.mental-model {
  display: grid;
  gap: 6px;
  margin: 0 0 6px;
  border: 2px solid var(--line);
  padding: 9px;
  background: var(--paper);
  box-shadow: var(--shadow);
}
.mental-model h2 { margin: 3px 0 0; font-size: 1.2rem; line-height: 1; letter-spacing: -.025em; }
.model-paths { display: grid; gap: 6px; }
.model-paths p {
  display: grid;
  grid-template-columns: 104px minmax(0,1fr);
  gap: 8px;
  margin: 0;
  border-left: 4px solid var(--soft-line);
  padding: 7px 8px;
  background: var(--paper-warm);
  font: 700 .67rem/1.35 var(--mono);
}
.model-paths b { text-transform: uppercase; }
.model-paths span { color: var(--muted); }
.model-paths .model-path-good { border-color: var(--blue); background: var(--blue-soft); }
.model-path-good b, .model-path-good span { color: var(--blue); }
.model-why { display: none; margin: 0; color: var(--muted); font: 400 .8rem/1.42 var(--serif); }
.model-why b { color: var(--ink); font-family: var(--mono); font-size: .7rem; text-transform: uppercase; }

.runtime-status {
  display: flex;
  align-items: center;
  gap: 8px;
  min-height: 24px;
  margin: 0 0 5px;
  border: 0;
  padding: 3px 2px;
  color: var(--muted);
  background: rgba(255,253,247,.7);
  font: 700 .68rem/1 var(--mono);
}
.status-dot { width: 8px; height: 8px; border-radius: 50%; background: #c3913d; }
body[data-fallback-state="none"] .status-dot { background: var(--green); }
body[data-fallback-state="active"] .status-dot { background: var(--red); }

.chapter-rail {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  min-height: 44px;
  margin: 0 0 12px;
  border: 2px solid var(--line);
  background: var(--paper-warm);
  box-shadow: var(--shadow);
}
.chapter-rail a {
  display: flex;
  min-width: 0;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  gap: 6px;
  color: var(--ink);
  font: 800 .7rem/1 var(--mono);
  text-decoration: none;
  text-transform: uppercase;
}
.chapter-rail a + a { border-left: 2px solid var(--line); }
.chapter-rail a[data-state="active"] { color: #fffdf7; background: var(--blue); }
.chapter-rail a[data-state="active"] b { color: #fffdf7; }
.chapter-rail a[data-state="complete"] { background: linear-gradient(90deg, var(--blue-soft) 0 6px, transparent 6px); }
.chapter-rail b { color: var(--blue); }

.instrument { overflow: clip; }
.instrument-titlebar { position: sticky; top: 48px; z-index: 20; }
.act {
  position: relative;
  min-height: 520px;
  padding: 14px;
  scroll-margin-top: 88px;
  background: var(--paper);
}
.act + .act { border-top: 2px solid var(--line); }
.act::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: radial-gradient(rgba(39,36,31,.11) .55px, transparent .7px);
  background-size: 7px 7px;
  opacity: .22;
}
.act > * { position: relative; }
.act-heading { display: grid; gap: 4px; margin: 0 0 10px; }
.act-heading h2 { max-width: 18ch; margin: 0; font-size: clamp(1.52rem, 7vw, 3.1rem); line-height: .92; letter-spacing: -.035em; }
.act-heading p:last-child { max-width: 68ch; margin: 0; color: var(--muted); font: 400 .82rem/1.36 var(--serif); }
.act-heading p:last-child b { color: var(--ink); font-family: var(--mono); font-size: .72rem; text-transform: uppercase; }
.act-explanation {
  display: grid;
  gap: 5px;
  margin: 0 0 10px;
  border: 1px solid var(--soft-line);
  padding: 7px;
  background: rgba(255,253,247,.76);
}
.act-explanation p {
  display: grid;
  grid-template-columns: 105px minmax(0,1fr);
  gap: 7px;
  margin: 0;
  font: 700 .64rem/1.35 var(--mono);
}
.act-explanation b { color: var(--blue); text-transform: uppercase; }
.act-explanation span { color: var(--muted); font-weight: 600; }

.shoreline-stage {
  position: relative;
  width: 100%;
  height: 260px;
  overflow: hidden;
  border: 2px solid var(--line);
  background:
    linear-gradient(90deg, transparent 0 calc(100% - 44px), rgba(40,95,143,.08) calc(100% - 44px)),
    #fbf6eb;
  touch-action: pan-y;
  cursor: crosshair;
}
.shoreline-stage canvas { display: block; width: 100%; height: 100%; }
.shoreline-edge {
  position: absolute;
  inset: 0 0 0 auto;
  width: 44px;
  border-left: 1px dashed var(--blue);
  pointer-events: none;
  color: var(--blue);
}
.shoreline-edge span {
  position: absolute;
  right: 5px;
  top: 10px;
  writing-mode: vertical-rl;
  font: 800 .58rem/1 var(--mono);
  letter-spacing: .08em;
  text-transform: uppercase;
}
.stage-footer { display: grid; gap: 8px; margin-top: 8px; padding-bottom: max(0px, env(safe-area-inset-bottom)); }
.proof-line {
  min-height: 18px;
  margin: 0;
  color: var(--muted);
  font: 700 .65rem/1.35 var(--mono);
}
.button-row { display: grid; grid-template-columns: auto auto minmax(0, 1fr); gap: 7px; }

.act-postcard { background: #f8f0e0; }
.postcard-workbench { display: grid; gap: 16px; }
.postcard-visual {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
  border: 2px solid var(--line);
  padding: 10px 0;
  background: rgba(255,253,247,.52);
}
.postcard {
  --card-width: 248px;
  --card-height: 140px;
  position: relative;
  width: min(100%, var(--card-width));
  height: var(--card-height);
  margin: 0 auto;
  border: 2px solid var(--line);
  padding: 18px 16px 22px;
  overflow: hidden;
  background: #fffdf7;
  box-shadow: 5px 5px 0 rgba(39,36,31,.2);
  transition: border-color .2s ease;
}
.postcard[data-format="postal"] { --card-width: 290px; --card-height: 160px; }
.postcard[data-format="broadside"] { --card-width: 340px; --card-height: 190px; }
.postcard[data-fit="no"] { border-color: var(--red); }
.postcard[data-fit="yes"] { border-color: var(--green); }
.postcard-rules { position: absolute; inset: 8px; border: 1px solid rgba(39,36,31,.2); pointer-events: none; }
.carried-contour { position: absolute; z-index: 3; inset: 0 0 0 auto; width: 44px; height: 100%; pointer-events: none; }
.carried-contour path, .record-contour path { fill: none; stroke: var(--blue); stroke-width: 1.5; vector-effect: non-scaling-stroke; stroke-dasharray: 3 2; }
.postcard-lines { position: relative; min-height: 80px; font: 400 17px/22px var(--serif); }
.postcard-lines p { margin: 0; color: var(--muted); }
.postcard-line { min-height: 22px; white-space: nowrap; }
.postcard-fragment { display: inline-block; vertical-align: baseline; }
.postcard-gap { display: inline-block; height: 1px; }
.postcard-chip {
  display: inline-block;
  border: 1px solid var(--blue);
  padding: 0 8px;
  color: var(--blue);
  background: var(--blue-soft);
  font: 400 12px/16px var(--serif);
  vertical-align: 1px;
}
.postcard-mark { position: absolute; right: 12px; bottom: 8px; color: var(--muted); font: 700 .56rem/1 var(--mono); }
.fit-ruler { display: grid; grid-template-columns: 100px minmax(0,1fr); gap: 10px; align-items: end; border-top: 1px solid var(--soft-line); padding-top: 9px; }
.fit-ruler-bars { display: grid; grid-template-columns: 1fr 1fr; gap: 7px; height: 72px; }
.fit-bar-column { position: relative; overflow: hidden; border: 1px solid var(--soft-line); background: repeating-linear-gradient(to top, transparent 0 17px, rgba(39,36,31,.12) 17px 18px), #fffaf0; }
.fit-bar { position: absolute; inset: auto 0 0; min-height: 2px; transition: height .22s ease; }
.fit-bar.available { background: rgba(40,95,143,.48); }
.fit-bar.required { background: var(--red); }
.fit-ruler[data-fit="yes"] .fit-bar.required { background: var(--green); }
.fit-ruler-labels { display: grid; grid-template-columns: 1fr 1fr; gap: 6px; }
.fit-ruler-labels p { display: grid; gap: 2px; margin: 0; }
.fit-ruler-labels span { color: var(--muted); font: 800 .58rem/1.2 var(--mono); text-transform: uppercase; }
.fit-ruler-labels strong { font: 800 1.1rem/1 var(--mono); }
.fit-verdict { margin: 0; border-left: 5px solid var(--soft-line); padding: 9px 10px; background: var(--paper); font: 800 .78rem/1.35 var(--mono); }
.postcard-visual:has(.fit-ruler[data-fit="no"]) .fit-verdict { border-color: var(--red); color: var(--red); }
.postcard-visual:has(.fit-ruler[data-fit="yes"]) .fit-verdict { border-color: var(--green); color: var(--green); }
.postcard-controls { display: grid; gap: 10px; align-content: start; }
.postcard-controls > label, fieldset legend { color: var(--muted); font: 800 .66rem/1 var(--mono); text-transform: uppercase; letter-spacing: .05em; }
textarea, input[type="number"] {
  width: 100%;
  border: 2px solid var(--line);
  border-radius: 1px;
  padding: .72rem;
  color: var(--ink);
  background: #fffdf7;
  font: 400 16px/1.4 var(--serif);
}
textarea { resize: vertical; }
fieldset { min-width: 0; margin: 0; border: 0; padding: 0; }
.format-cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 6px; margin-top: 7px; }
.format-cards label { position: relative; }
.format-cards input { position: absolute; opacity: 0; }
.format-cards label > span { display: grid; min-height: 94px; place-items: end center; gap: 3px; border: 2px solid var(--line); padding: 8px 4px; background: #fffaf0; cursor: pointer; }
.format-cards input:checked + span { color: #fff; background: var(--blue); box-shadow: 3px 3px 0 var(--line); transform: translate(-1px,-1px); }
.format-cards input:focus-visible + span { outline: 3px solid var(--blue); outline-offset: 3px; }
.format-cards b { font: 800 .68rem/1 var(--mono); }
.format-cards small { font: 700 .55rem/1 var(--mono); opacity: .78; }
.format-shape { display: block; border: 2px solid currentColor; background: rgba(255,255,255,.24); }
.format-shape.pocket { width: 36px; height: 22px; }
.format-shape.postal { width: 44px; height: 26px; }
.format-shape.broadside { width: 52px; height: 30px; }
.atomic-toggle { display: grid; grid-template-columns: auto 1fr; gap: 2px 9px; align-items: center; text-align: left; text-transform: none; }
.atomic-toggle span { grid-row: 1 / 3; border: 1px solid var(--blue); padding: 5px 8px; color: var(--blue); background: var(--blue-soft); font-family: var(--serif); font-weight: 400; }
.atomic-toggle b { text-transform: uppercase; }
.atomic-toggle small { color: var(--muted); font-weight: 600; }
.message-editor { border: 2px solid var(--line); background: #fffaf0; }
.message-editor summary { display: flex; min-height: 44px; align-items: center; justify-content: space-between; padding: 0 10px; cursor: pointer; font: 800 .65rem/1 var(--mono); text-transform: uppercase; }
.message-editor summary span { color: var(--muted); font-size: .56rem; }
.message-editor[open] summary { border-bottom: 1px solid var(--soft-line); }
.message-editor textarea { display: block; border: 0; }
.fit-status { margin: 0; }
#postcard-dispatch:disabled { opacity: .48; cursor: not-allowed; box-shadow: none; }

.act-dispatch { min-height: 670px; }
.dispatch-stats { display: grid; grid-template-columns: repeat(3, 1fr); margin-bottom: 9px; border: 2px solid var(--line); background: var(--paper); }
.dispatch-stats p { display: grid; gap: 3px; min-width: 0; margin: 0; padding: 10px; }
.dispatch-stats p + p { border-left: 1px solid var(--soft-line); }
.dispatch-stats strong { overflow: hidden; font: 800 clamp(1.05rem, 5vw, 1.65rem)/1 var(--mono); text-overflow: ellipsis; white-space: nowrap; }
.dispatch-stats span { color: var(--muted); font: 800 .56rem/1.25 var(--mono); text-transform: uppercase; }
.dispatch-controls { display: grid; gap: 8px; margin-bottom: 9px; border: 1px solid var(--soft-line); padding: 9px; background: rgba(255,253,247,.7); }
.dispatch-map { display: grid; grid-template-columns: 38px minmax(0,1fr) 38px; align-items: center; gap: 6px; }
.map-label { color: var(--muted); font: 800 .58rem/1 var(--mono); }
.map-label.end { text-align: right; }
.map-track { position: relative; height: 42px; overflow: hidden; border: 2px solid var(--line); background: repeating-linear-gradient(90deg, transparent 0 calc(10% - 1px), rgba(39,36,31,.18) calc(10% - 1px) 10%), var(--paper-warm); }
.dispatch-viewport-marker { position: absolute; z-index: 2; top: 5px; bottom: 5px; left: 0; min-width: 12px; border: 2px solid var(--blue); background: rgba(40,95,143,.28); transition: left .24s ease, width .24s ease; }
.dispatch-target-marker { position: absolute; top: 0; bottom: 0; left: 0; width: 3px; background: var(--red); transition: left .24s ease; }
.dispatch-map-legend { display: flex; flex-wrap: wrap; gap: 6px 14px; }
.dispatch-map-legend span { display: inline-flex; align-items: center; gap: 6px; color: var(--muted); font: 800 .56rem/1.2 var(--mono); text-transform: uppercase; }
.dispatch-map-legend i { display: block; width: 16px; height: 9px; }
.dispatch-map-legend .viewport-key { border: 1px solid var(--blue); background: rgba(40,95,143,.28); }
.dispatch-map-legend .target-key { width: 3px; background: var(--red); }
.dispatch-position { margin: 0; color: var(--muted); font: 700 .64rem/1.35 var(--mono); }
.dispatch-presets { display: grid; grid-template-columns: repeat(4, 1fr); gap: 6px; }
.dispatch-presets button { min-width: 0; padding-inline: 4px; }
.jump-form { display: grid; grid-template-columns: minmax(0,1fr) auto; align-items: end; gap: 7px; margin: 0; }
.jump-form label { grid-column: 1 / -1; color: var(--muted); font: 800 .6rem/1 var(--mono); text-transform: uppercase; }
.jump-form input { min-height: 44px; padding: .55rem; font-family: var(--mono); }
.ledger {
  position: relative;
  height: 320px;
  overflow: auto;
  overscroll-behavior: auto;
  border: 2px solid var(--line);
  background:
    linear-gradient(90deg, transparent 46px, rgba(165,72,53,.24) 46px 47px, transparent 47px),
    repeating-linear-gradient(#fffdf7 0 31px, rgba(39,36,31,.08) 31px 32px);
}
.ledger-spacer { width: 1px; opacity: 0; }
.ledger-window { position: absolute; inset: 0 0 auto; }
.ledger-placeholder {
  width: min(420px, calc(100% - 32px));
  margin: 32px auto;
  border: 1px dashed var(--blue);
  padding: 14px;
  color: var(--muted);
  background: rgba(220,232,239,.55);
  font: 700 .7rem/1.45 var(--mono);
}
.dispatch-row {
  position: absolute;
  left: 0;
  width: 100%;
  display: grid;
  grid-template-columns: 42px minmax(0, 1fr) 46px;
  gap: 8px;
  border-bottom: 1px solid rgba(39,36,31,.2);
  padding: 8px 8px 8px 4px;
  background: rgba(255,253,247,.92);
  font: 400 14px/19px var(--serif);
}
.dispatch-row:focus { z-index: 2; outline: 3px solid var(--blue); outline-offset: -3px; }
.dispatch-row.is-highlighted { border: 2px solid var(--blue); background: #eaf1f5; box-shadow: inset 5px 0 0 var(--blue); }
.dispatch-row .record-index, .dispatch-row .record-stamp { color: var(--muted); font: 700 .64rem/1.3 var(--mono); }
.dispatch-row .record-body { min-width: 0; }
.dispatch-row .record-stamp { text-align: right; }
.record-contour { position: absolute; z-index: 2; top: 3px; right: 2px; width: 18px; height: calc(100% - 6px); pointer-events: none; }
.act-dispatch.is-sending .ledger { animation: ledgerLeap .55s cubic-bezier(.2,.8,.2,1); }

.journal { margin-top: 18px; overflow: hidden; }
.journal summary { cursor: pointer; padding: 14px; background: var(--paper-warm); font: 800 .75rem/1 var(--mono); }
.journal-body { display: grid; gap: 20px; padding: 18px; }
.journal h2, .journal h3 { margin: 0 0 7px; }
.journal p, .journal li { color: var(--muted); font: 400 .92rem/1.55 var(--serif); }
.journal ul { padding-left: 1.1rem; }
.journal a { color: var(--blue); }

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

@keyframes ledgerLeap {
  0% { filter: blur(0); transform: translateY(0); }
  45% { filter: blur(2px); transform: translateY(-12px); }
  100% { filter: blur(0); transform: translateY(0); }
}

@media (min-width: 760px) {
  .shell { padding-top: 8px; }
  .intro { min-height: 150px; align-content: end; padding: 18px 4px; }
  .deck { font-size: 1.05rem; }
  .mental-model { grid-template-columns: 210px minmax(0,1fr); align-items: start; padding: 15px; }
  .model-why { display: block; grid-column: 1 / -1; }
  .chapter-rail { width: 520px; }
  .act { padding: 28px; }
  .act-heading { margin-bottom: 12px; }
  .act-explanation { grid-template-columns: repeat(3, 1fr); margin-bottom: 18px; padding: 9px; }
  .act-explanation p { grid-template-columns: 1fr; gap: 3px; padding: 0 8px; }
  .act-explanation p + p { border-left: 1px solid var(--soft-line); }
  .shoreline-stage { width: min(100%, 820px); height: 310px; }
  .postcard-workbench { grid-template-columns: minmax(500px, 1.2fr) minmax(300px, .8fr); align-items: start; }
  .postcard-visual { grid-template-columns: minmax(340px, 1fr) 110px; align-items: end; padding: 14px; }
  .postcard { grid-column: 1; grid-row: 1; transform: rotate(-.35deg); }
  .fit-ruler { grid-column: 2; grid-row: 1; grid-template-columns: 1fr; border-top: 0; border-left: 1px solid var(--soft-line); padding: 0 0 0 12px; }
  .fit-ruler-bars { height: 150px; }
  .fit-ruler-labels { grid-template-columns: 1fr; }
  .fit-verdict { grid-column: 1 / -1; }
  .dispatch-controls { grid-template-columns: minmax(0, 1fr) minmax(360px, 1fr); align-items: end; }
  .dispatch-map, .dispatch-map-legend, .dispatch-position { grid-column: 1 / -1; }
  .dispatch-presets { grid-column: 1; }
  .jump-form { grid-column: 2; }
  .journal-body { grid-template-columns: 1fr 1fr; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition-duration: 0s !important; }
}

@media (forced-colors: active) {
  .status-dot { border: 1px solid currentColor; }
  .postcard, .ledger, .shoreline-stage { forced-color-adjust: auto; }
}