/* Fieldwork · demo.css — field-notebook instrument. System fonts only; no external assets. */
:root {
  --paper: #f4f1ea; --paper-2: #ece7dc; --paper-3: #e1dacb; --well: #fbfaf6;
  --ink: #18191b; --ink-2: #47433c; --rule: #c9c0ae; --faint: #ddd5c5;
  --pos: #b8481a; --neg: #1d5ca3; --cue: #82287e; --err: #a8102a; --ok: #0d6f63;
  --focus: #0a52c7; --hl: #f7e1a6;
  --run-a: #18191b; --run-b: #0d6f63; --run-c: #9a5d00;
  --sans: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
  --mono: ui-monospace, 'SF Mono', Menlo, Consolas, 'Liberation Mono', monospace;
  --rail: 240px; --dissect: 520px;
}
*, *::before, *::after { box-sizing: border-box; }
html { color-scheme: light; -webkit-text-size-adjust: 100%; text-size-adjust: 100%; }
body { margin: 0; background: var(--paper); color: var(--ink); font: 15px/1.45 var(--sans); overflow-x: hidden; }
h2 { margin: 0; font-size: 13px; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; }
h3 { margin: 14px 0 6px; font-size: 13px; }
.sub { font-weight: 400; letter-spacing: 0; text-transform: none; color: var(--ink-2); }
code, output, .chip, .readout, .keys, .compile, .tbl { font-family: var(--mono); font-variant-numeric: tabular-nums; }
code { font-size: .92em; background: var(--paper-3); padding: 0 3px; border-radius: 2px; }
.sr-only { position: absolute !important; width: 1px; height: 1px; margin: -1px; padding: 0; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0; }
.skip { position: absolute; left: 8px; top: -64px; z-index: 100; padding: 10px 14px; background: var(--ink); color: var(--paper); }
.skip:focus { top: 8px; }
button, select, input, textarea { font: inherit; color: inherit; }
button, select, .filebtn { min-height: 44px; min-width: 44px; padding: 0 14px; border: 1px solid var(--ink); border-radius: 2px; background: var(--paper); cursor: pointer; }
button, .filebtn { display: inline-flex; align-items: center; justify-content: center; gap: 6px; }
button:hover:not(:disabled), .filebtn:hover { background: var(--paper-3); }
button.primary { background: var(--ink); color: var(--paper); font-weight: 600; padding: 0 22px; }
button.primary:hover:not(:disabled) { background: #34363b; }
button:disabled { opacity: .45; cursor: not-allowed; }
button[aria-pressed=true] { background: var(--ink); color: var(--paper); }
input[type=text], textarea { width: 100%; min-height: 44px; padding: 10px; border: 1px solid var(--rule); border-radius: 2px; background: var(--well); }
textarea { resize: vertical; }
input[type=range] { width: 100%; min-height: 44px; margin: 0; background: transparent; accent-color: var(--ink); cursor: pointer; }
:focus-visible, .filebtn:focus-within { outline: 3px solid var(--focus); outline-offset: 2px; }
details > summary { min-height: 44px; display: flex; align-items: center; cursor: pointer; font-size: 13px; color: var(--ink-2); }
.chip { display: inline-block; margin: 0; padding: 2px 9px; border: 1px solid var(--rule); border-radius: 999px; font-size: 12px; color: var(--ink-2); background: var(--well); }
.noscript { margin: 24px; padding: 16px; border: 2px solid var(--err); }
[data-run=A] { --run: var(--run-a); } [data-run=B] { --run: var(--run-b); } [data-run=C] { --run: var(--run-c); }

/* Question bar: the primary instrument control, full width */
.qbar { display: grid; grid-template-columns: var(--rail) minmax(0, 1fr); gap: 4px 24px; padding: 14px 24px 10px 16px; border-bottom: 2px solid var(--ink); background: var(--paper); }
.qbar > :not(.qbar-top) { grid-column: 2; }
.qbar-top { grid-column: 1; grid-row: 1 / span 4; display: flex; flex-direction: column; gap: 8px; }
#thread-toggle, .sheet-close { display: none; }
.brand { margin: 0; font-size: 13px; color: var(--ink-2); }
.brand b { display: block; font-size: 24px; letter-spacing: -.01em; color: var(--ink); }
.status { margin: 0; font: 12px var(--mono); color: var(--ink-2); }
body[data-run-state=running] .status::before { content: '● '; color: var(--pos); }
body[data-run-state=error] .status { color: var(--err); font-weight: 700; }
.qform { display: grid; grid-template-columns: minmax(0, 1fr) auto auto; gap: 10px; align-items: end; }
.qlabel { grid-column: 1 / -1; font-size: 12px; letter-spacing: .08em; text-transform: uppercase; color: var(--ink-2); }
#question-input { min-height: 56px; padding: 6px 2px; font-size: 22px; border: 0; border-bottom: 2px solid var(--ink); border-radius: 0; background: transparent; }
#question-input[aria-invalid=true] { border-bottom-color: var(--err); }
.compile { min-height: 2.6em; font-size: 13px; }
.compile p { margin: 3px 0; }
.summary b { padding: 0 6px; background: var(--ink); color: var(--paper); font-weight: 600; }
.errors { margin: 2px 0; padding: 0; list-style: none; color: var(--err); }
.errors li::before { content: '✕ '; }
.diff { color: var(--ink); }
.diff mark { padding: 0 3px; background: var(--hl); color: var(--ink); }
.diff .fixed { color: var(--ink-2); }
.echo { color: var(--ink-2); }
.echo .tok-ok { color: var(--neg); text-decoration: underline 2px var(--neg); text-underline-offset: 4px; }
.echo .tok-err { color: var(--err); text-decoration: underline wavy var(--err); text-underline-offset: 4px; }
.echo .tok-note { color: var(--ink-2); }
.grammar { font-size: 12px; color: var(--ink-2); }
.grammar p { margin: 0 0 6px; max-width: 90ch; }
.starters { display: flex; flex-wrap: wrap; gap: 6px; margin: 4px 0 0; padding: 0; list-style: none; }
.starters button, .alts button { border-style: dashed; text-align: left; font-size: 13px; }

/* Shell: thread rail + bench */
.shell { display: grid; grid-template-columns: var(--rail) minmax(0, 1fr); align-items: stretch; }
.thread { display: flex; flex-direction: column; gap: 8px; padding: 16px; border-right: 1px solid var(--rule); background: var(--paper-2); min-width: 0; }
.thread > label { font-size: 12px; letter-spacing: .06em; text-transform: uppercase; color: var(--ink-2); margin-top: 6px; }
.thread-list { display: grid; gap: 6px; margin: 0 0 6px 6px; padding: 0 0 0 16px; list-style: none; border-left: 2px solid var(--ink); font-size: 13px; }
.thread-list li { position: relative; overflow-wrap: anywhere; }
.thread-list li::before { content: ''; position: absolute; left: -23px; top: .45em; width: 10px; height: 10px; border: 2px solid var(--ink); border-radius: 50%; background: var(--paper-2); }
.thread-list li[data-kind=run]::before { border-radius: 0; background: var(--run, var(--ink)); border-color: var(--run, var(--ink)); }
.thread-list li[data-kind=note]::before { left: -21px; top: .7em; width: 8px; height: 2px; border: 0; border-radius: 0; background: var(--ink); }
.thread-list li[data-kind=open] { color: var(--cue); }
.thread-list li[data-kind=open]::before { border-style: dashed; border-color: var(--cue); }
.thread-list button { width: 100%; justify-content: flex-start; padding: 4px 6px; border-color: transparent; background: transparent; text-align: left; font-size: 13px; }
.thread-list [aria-current=true] { border-color: var(--ink); background: var(--paper); }
.thread-list .meta { display: block; font: 11px var(--mono); color: var(--ink-2); }
.reflect { margin: 0; padding: 8px 10px; border-left: 3px solid var(--cue); background: var(--paper); font-size: 13px; }
.io { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 8px; }
.io button, .io .filebtn { font-size: 13px; }
.verify { margin: 0; font: 12px var(--mono); }
.verify[data-result=ok] { color: var(--ok); }
.verify[data-result=fail] { color: var(--err); font-weight: 700; }

.bench { display: grid; grid-template-columns: minmax(0, 1fr) var(--dissect); grid-template-areas: 'field dissect' 'ribbon ribbon'; min-width: 0; }
.zone-head { display: flex; flex-wrap: wrap; align-items: center; gap: 8px 10px; margin-bottom: 10px; }
.zone-head .chip { margin-left: auto; }

/* Field */
.field-zone { grid-area: field; min-width: 0; padding: 16px 20px; border-right: 1px solid var(--rule); }
.field-row { display: grid; grid-template-columns: minmax(0, 564px) 64px; gap: 12px; }
.field { position: relative; display: grid; grid-template-columns: minmax(0, 1fr); align-content: start; width: 100%; min-height: 240px; border: 2px solid var(--ink); background-color: var(--well); cursor: crosshair; touch-action: pan-y pinch-zoom; }
.field canvas, .field-overlay { position: absolute; inset: 0; grid-area: 1 / 1 / 2 / 2; display: block; width: 100%; height: 100%; }
.field::after { content: ''; position: absolute; inset: 0; grid-area: 1 / 1 / 2 / 2; pointer-events: none; opacity: 0; background: repeating-linear-gradient(135deg, rgba(24, 25, 27, .24) 0 2px, transparent 2px 10px); transition: opacity .2s; }
.field-zone[data-stale=true] .field::after { opacity: 1; }
.stale-flag { position: absolute; left: 8px; top: 8px; z-index: 2; display: none; margin: 0; padding: 4px 8px; background: var(--ink); color: var(--paper); font: 12px var(--mono); }
.field-zone[data-stale=true] .stale-flag { display: block; }
.field-empty { position: relative; z-index: 1; grid-area: 1 / 1 / 2 / 2; display: none; place-items: center; aspect-ratio: 1; margin: 0; padding: 32px; text-align: center; color: var(--ink-2); }
.field-stage { position: relative; grid-area: 1 / 1 / 2 / 2; min-width: 0; overflow: hidden; background-image: linear-gradient(var(--faint) 1px, transparent 1px), linear-gradient(90deg, var(--faint) 1px, transparent 1px); background-size: 10% 10%; }
.field-caption { margin: 0; padding: 6px 12px; border-top: 1px solid var(--faint); background: var(--paper); color: var(--ink-2); font-size: 12px; line-height: 1.45; overflow-wrap: anywhere; cursor: auto; }
.field-stage + .field-caption { padding-top: 8px; border-top: 2px solid var(--ink); }
.field[data-empty=true] .field-empty { display: grid; }
.field-overlay .contour-plus { fill: none; stroke: var(--ink); stroke-width: 2.5; }
.field-overlay .contour-minus { fill: none; stroke: var(--cue); stroke-width: 2.5; stroke-dasharray: 7 4; }
.field-overlay .axis { stroke: var(--ink-2); stroke-width: 1; stroke-dasharray: 2 3; }
.field-overlay .pt { stroke: var(--well); stroke-width: 1; }
.field-overlay .pt.y1 { fill: var(--pos); }
.field-overlay .pt.y0 { fill: var(--neg); }
.field-overlay .pt.wrong { stroke: var(--err); stroke-width: 2; }
.field-overlay .ring { fill: none; stroke: var(--err); stroke-width: 2.5; }
.field-overlay .sel { fill: none; stroke: var(--focus); stroke-width: 3; }
.field-overlay .specimen { fill: var(--well); stroke: var(--ink); stroke-width: 2.5; cursor: grab; }
.field-overlay text { font: 11px var(--mono); fill: var(--ink); stroke: none; }
.cue-control { display: flex; flex-direction: column; align-items: center; gap: 6px; font-size: 12px; }
.cue-control label, .cue-control output { color: var(--cue); font-weight: 700; }
.cue-control input[type=range] { flex: 1; width: 44px; min-height: 240px; writing-mode: vertical-lr; direction: rtl; accent-color: var(--cue); }
.field-tools { display: flex; flex-wrap: wrap; align-items: flex-end; gap: 10px; margin-top: 12px; }
.seg { display: flex; flex-wrap: wrap; margin: 0; padding: 0; border: 0; }
.seg legend { margin-bottom: 4px; padding: 0; font-size: 12px; color: var(--ink-2); }
.seg label { position: relative; display: inline-flex; align-items: center; min-height: 44px; margin-left: -1px; padding: 0 12px; border: 1px solid var(--ink); background: var(--paper); font-size: 13px; cursor: pointer; }
.seg input { position: absolute; inset: 0; margin: 0; opacity: 0; cursor: pointer; }
.seg label:has(input:checked) { background: var(--ink); color: var(--paper); }
.seg label:has(input:focus-visible) { z-index: 1; outline: 3px solid var(--focus); outline-offset: 2px; }
.readout { margin: 10px 0 0; font-size: 13px; }
.readout b { color: var(--cue); }
.keys { margin: 6px 0 0; font-size: 12px; color: var(--ink-2); }

/* Dissection */
.dissect-zone { grid-area: dissect; min-width: 0; padding: 16px 20px; background: var(--paper); }
.specimen { display: grid; grid-template-columns: minmax(0, 1fr); grid-template-areas: 'glyph' 'cap' 'values'; gap: 8px; align-items: start; }
.glyph { grid-area: glyph; display: block; width: 100%; height: auto; border: 1px solid var(--rule); background: var(--well); }
.cap { grid-area: cap; margin: 0; font-size: 12px; line-height: 1.5; color: var(--ink-2); }
.values { grid-area: values; display: grid; grid-template-columns: auto minmax(0, 1fr); gap: 2px 10px; margin: 0; font: 13px var(--mono); }
.values > dl { grid-column: 1 / -1; display: grid; grid-template-columns: max-content minmax(0, 1fr); gap: 2px 10px; margin: 0; min-width: 0; }
.values > .note { grid-column: 1 / -1; margin: 4px 0; font: 12px/1.5 var(--sans); }
.values dt { color: var(--ink-2); }
.values dd { margin: 0; overflow-wrap: anywhere; }
.values .flip { color: var(--cue); font-weight: 700; }
.spec-controls { display: grid; grid-template-columns: 34px minmax(0, 1fr) 64px; gap: 0 8px; align-items: center; margin: 12px 0; padding: 6px 12px 10px; border: 1px solid var(--rule); }
.spec-controls legend { padding: 0 4px; font-size: 12px; color: var(--ink-2); }
.spec-controls label { font: 700 14px var(--mono); }
.spec-controls label[for=spec-cue], #spec-cue-out { color: var(--cue); }
#spec-cue { accent-color: var(--cue); }
#spec-support { grid-column: 1 / -1; }
.spec-actions { grid-column: 1 / -1; display: flex; flex-wrap: wrap; gap: 8px; margin-top: 6px; }
.tabs { display: flex; margin-top: 4px; border-bottom: 2px solid var(--ink); }
.tabs [role=tab] { margin-bottom: -2px; border: 0; border-bottom: 4px solid transparent; border-radius: 0; background: transparent; font-weight: 600; }
.tabs [role=tab][aria-selected=true] { border-bottom-color: var(--cue); }
[role=tabpanel] { padding-top: 10px; }
.net { display: block; width: 100%; height: auto; }
.waterfall { display: block; width: 100%; height: auto; margin-top: 6px; }
.net text, .waterfall text { font: 11px var(--mono); fill: var(--ink); }
.net .edge { fill: none; stroke-linecap: round; opacity: .85; }
.net .edge.pos, .waterfall .bar.pos { stroke: #2f6db5; fill: #2f6db5; }
.net .edge.neg, .waterfall .bar.neg { stroke: #c7642c; fill: #c7642c; }
.net .edge { fill: none; }
.net .node { fill: none; stroke: var(--ink); stroke-width: 1.5; }
.waterfall .bar.total { fill: var(--ink); }
.waterfall .zero { stroke: var(--ink); stroke-width: 1; }
.term { cursor: pointer; outline: none; }
.term:focus-visible > *, .term[aria-pressed=true] > * { stroke: var(--focus); stroke-width: 3; }
.sens { display: grid; gap: 4px; margin-top: 8px; font: 12px var(--mono); }
button.sens-row { display: grid; grid-template-columns: 28px minmax(0, 1fr) minmax(0, 1fr); align-items: center; gap: 8px; width: 100%; padding: 6px; border-color: transparent; background: transparent; font: inherit; text-align: left; }
.sens-measure { display: grid; gap: 3px; min-width: 0; }
.sens-measure .val { font-size: 11px; overflow-wrap: anywhere; }
.sens-measure .sens-track { display: block; width: 100%; }
button.sens-row[aria-pressed=true] { border-color: var(--focus); background: var(--well); color: var(--ink); }
.sens-track { position: relative; height: 12px; background: var(--faint); }
.sens-bar { position: absolute; top: 0; bottom: 0; }
.sens-bar.pos { background: var(--pos); }
.sens-bar.neg { background: var(--neg); }
.math { font: 14px/1.7 var(--mono); }
.math .eq { margin: 0 0 10px; padding: 8px 10px; overflow-x: auto; border-left: 3px solid var(--ink); background: var(--well); }
.math .val { padding: 0 3px; background: var(--hl); }
.math .note { font: 13px/1.5 var(--sans); color: var(--ink-2); }
.code { max-height: 380px; margin: 0; padding: 10px 0; overflow: auto; border-radius: 2px; background: #1d1e21; color: #ecebe6; font: 12.5px/1.6 var(--mono); }
.code .line { display: block; padding: 0 12px; white-space: pre; }
.code .ln { display: inline-block; width: 4ch; margin-right: 1.5ch; color: #a19e96; text-align: right; user-select: none; }
.code .hl { background: #4a3a10; box-shadow: inset 3px 0 #f2c14e; }
.code .src { display: block; padding: 0 12px 8px; color: #c9c5bb; font: 12px var(--sans); white-space: normal; }

/* Ribbon */
.ribbon-zone { grid-area: ribbon; min-width: 0; padding: 14px 20px 28px; border-top: 2px solid var(--ink); }
.transport { display: flex; flex-wrap: wrap; align-items: center; gap: 6px; }
.transport button { font-family: var(--mono); }
.transport input[type=range] { flex: 1 1 220px; width: auto; }
.ribbon { display: block; width: 100%; height: 190px; min-height: 180px; margin-top: 8px; touch-action: pan-y; }

/* Wide bench: field + ribbon size the workspace rows; dissection is a bounded scroll panel, never a row stretcher */
@media (min-width: 1001px) {
  .dissect-zone { contain: size; max-height: 100vh; overflow-y: auto; }
}
.ribbon .axis { stroke: var(--ink); stroke-width: 1; }
.ribbon .grid { stroke: var(--faint); stroke-width: 1; }
.ribbon text { font: 11px var(--mono); fill: var(--ink-2); }
.ribbon .line { fill: none; stroke: var(--run, var(--ink)); stroke-width: 2; }
.ribbon .line.rev { stroke-dasharray: 7 4; }
.ribbon .line.band { stroke-width: 2.5; stroke-dasharray: 1 5; stroke-linecap: round; }
.ribbon .muted { opacity: .35; }
.ribbon .cursor { stroke: var(--focus); stroke-width: 2; }
.ribbon .end { fill: var(--run, var(--ink)); }
.legend { margin: 4px 0; font-size: 12px; color: var(--ink-2); }
.run-list { display: flex; flex-wrap: wrap; gap: 6px; margin: 6px 0 4px; }
.run-list button { border-left: 6px solid var(--run, var(--ink)); font: 12px var(--mono); }
.run-list button[aria-checked=true] { background: var(--ink); color: var(--paper); }
.alts ul { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 8px; margin: 0; padding: 0; list-style: none; }
.alts button { flex-direction: column; align-items: flex-start; width: 100%; min-height: 60px; padding: 8px 12px; }
.alt-diff { font: 12px var(--mono); color: var(--ink-2); }

.tbl-wrap { max-height: 320px; overflow: auto; }
.tbl { width: 100%; border-collapse: collapse; font-size: 12px; }
.tbl caption { padding: 4px 0; text-align: left; color: var(--ink-2); }
.tbl th, .tbl td { padding: 4px 8px; border-bottom: 1px solid var(--faint); text-align: right; white-space: nowrap; }
.tbl th { position: sticky; top: 0; background: var(--paper-2); }
.tbl th:first-child, .tbl td:first-child { text-align: left; }

@media (max-width: 1180px) and (min-width: 761px) { :root { --rail: 200px; --dissect: 400px; } }
@media (max-width: 1000px) and (min-width: 761px) {
  .bench { grid-template-columns: minmax(0, 1fr); grid-template-areas: 'field' 'ribbon' 'dissect'; }
  .field-zone { border-right: 0; }
  .dissect-zone { border-top: 1px solid var(--rule); }
}

/* Phone: field first, sticky compact question bar, thread and dissection as sheets */
@media (max-width: 760px) {
  .qbar { position: sticky; top: 0; z-index: 20; grid-template-columns: minmax(0, 1fr); gap: 4px; padding: 6px 12px 8px; }
  .qbar > :not(.qbar-top), .qbar > .qbar-top { grid-column: 1; grid-row: auto; }
  .qbar-top { flex-direction: row; align-items: center; gap: 10px; }
  #thread-toggle { display: inline-flex; }
  .brand b { display: inline; font-size: 18px; }
  .brand span { display: none; }
  .status { margin-left: auto; text-align: right; }
  .qform { grid-template-columns: minmax(0, 1fr) auto; gap: 8px; }
  .qlabel { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); }
  #question-input { grid-column: 1; grid-row: 1; min-height: 48px; font-size: 17px; }
  #run-btn { grid-column: 2; grid-row: 1; }
  #preset-select { grid-column: 1 / -1; grid-row: 2; }
  .compile { max-height: 32vh; overflow-y: auto; font-size: 12px; }
  .qbar:not(:focus-within) .compile { max-height: 3.1em; overflow: hidden; }
  .qbar:not(:focus-within) #preset-select, .qbar:not(:focus-within) .grammar, .qbar:not(:focus-within) .starters { display: none; }
  .starters { flex-wrap: nowrap; overflow-x: auto; padding-bottom: 4px; }
  .starters li { flex: 0 0 auto; }
  .starters button { white-space: nowrap; }
  .shell { grid-template-columns: minmax(0, 1fr); }
  .thread { position: fixed; top: 0; bottom: 0; left: 0; z-index: 40; width: min(88vw, 320px); overflow-y: auto; border-right: 2px solid var(--ink); transform: translateX(-105%); visibility: hidden; transition: transform .2s ease, visibility 0s linear .2s; }
  .thread[data-open=true] { transform: none; visibility: visible; transition: transform .2s ease; }
  .sheet-close { display: inline-flex; margin-left: auto; }
  .bench { grid-template-columns: minmax(0, 1fr); grid-template-areas: 'field' 'ribbon'; }
  .field-zone { padding: 10px 12px; border-right: 0; }
  .field-zone .sub { display: none; }
  .field-row { grid-template-columns: minmax(0, 1fr); gap: 6px; }
  .cue-control { flex-direction: row; }
  .cue-control input[type=range] { flex: 1; width: auto; height: 44px; min-height: 44px; writing-mode: horizontal-tb; direction: ltr; }
  .keys { display: none; }
  .ribbon-zone { padding: 10px 12px 40px; }
  .ribbon { height: 180px; }
  .transport button { padding: 0 10px; }
  .alts ul { grid-template-columns: minmax(0, 1fr); }
  .dissect-zone { position: fixed; left: 0; right: 0; bottom: 0; z-index: 30; max-height: 82vh; overflow-y: auto; padding: 10px 12px 16px; border-top: 3px solid var(--ink); transform: translateY(105%); visibility: hidden; transition: transform .22s ease, visibility 0s linear .22s; }
  .dissect-zone[data-open=true] { transform: none; visibility: visible; transition: transform .22s ease; }
  .net { height: auto; }
  .waterfall { height: auto; }
}

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