:root {
  --paper: oklch(0.985 0.006 78);
  --surface: oklch(0.968 0.008 76);
  --surface-strong: oklch(0.935 0.011 74);
  --ink: oklch(0.235 0.018 60);
  --muted: oklch(0.51 0.018 65);
  --faint: oklch(0.72 0.014 70);
  --line: oklch(0.875 0.013 72);
  --accent: oklch(0.57 0.135 42);
  --accent-hover: oklch(0.51 0.14 42);
  --accent-soft: oklch(0.93 0.034 48);
  --blue: oklch(0.55 0.12 250);
  --danger: oklch(0.55 0.19 20);
  --danger-soft: oklch(0.94 0.036 18);
  --success: oklch(0.49 0.09 155);
  --focus: oklch(0.68 0.15 70);
  --shadow: 0 18px 54px oklch(0.25 0.02 55 / 0.12);
  --radius-sm: 7px;
  --radius: 12px;
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  color: var(--ink);
  background: var(--paper);
  font-synthesis: none;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }

html, body { margin: 0; min-height: 100%; }

body {
  background:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px),
    var(--paper);
  background-size: 40px 40px;
  background-position: -1px -1px;
  color: var(--ink);
  font-size: 14px;
  line-height: 1.45;
  text-wrap: pretty;
}

h1, h2, h3 { text-wrap: balance; }

button, input, select { font: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }

button:focus-visible, a:focus-visible, input:focus-visible, select:focus-visible, summary:focus-visible {
  outline: 3px solid color-mix(in oklch, var(--focus) 55%, transparent);
  outline-offset: 2px;
}

.topbar {
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 28px;
  background: color-mix(in oklch, var(--paper) 92%, transparent);
  border-bottom: 1px solid var(--line);
  position: relative;
  z-index: 10;
}

.brand {
  color: var(--ink);
  display: inline-flex;
  gap: 10px;
  align-items: center;
  text-decoration: none;
  font-weight: 720;
  letter-spacing: -0.02em;
  font-size: 16px;
}

.brand-mark {
  width: 31px;
  height: 31px;
  display: grid;
  place-items: center;
  color: var(--accent);
}

.brand-mark svg { width: 100%; height: 100%; }

.service-state {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--muted);
  font-size: 12px;
}

.state-dot { width: 7px; height: 7px; border-radius: 50%; background: var(--faint); }
.service-state.ready .state-dot { background: var(--success); }
.service-state.warning .state-dot { background: var(--accent); }

.welcome {
  min-height: calc(100vh - 64px);
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(380px, 0.72fr);
  gap: clamp(56px, 8vw, 128px);
  align-items: center;
  max-width: 1180px;
  margin: 0 auto;
  padding: 72px 42px 100px;
}

.eyebrow, .section-kicker {
  margin: 0 0 9px;
  color: var(--accent);
  text-transform: uppercase;
  font-size: 10px;
  font-weight: 760;
  letter-spacing: 0.16em;
}

.welcome h1 {
  font-size: clamp(42px, 5vw, 66px);
  line-height: 0.99;
  letter-spacing: -0.055em;
  margin: 0;
  max-width: 11ch;
  font-weight: 735;
}

.welcome-summary {
  margin: 28px 0 36px;
  color: var(--muted);
  max-width: 58ch;
  font-size: 16px;
  line-height: 1.62;
}

.capability-list { margin: 0; max-width: 560px; }
.capability-list div { display: grid; grid-template-columns: 88px 1fr; gap: 20px; padding: 12px 0; border-top: 1px solid var(--line); }
.capability-list div:last-child { border-bottom: 1px solid var(--line); }
.capability-list dt { color: var(--muted); font-size: 12px; }
.capability-list dd { margin: 0; font-weight: 610; }

.upload-area {
  min-height: 430px;
  border: 1px dashed color-mix(in oklch, var(--accent) 42%, var(--line));
  background: color-mix(in oklch, var(--paper) 94%, var(--accent-soft));
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: 46px;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: transform 180ms var(--ease), border-color 180ms var(--ease), background 180ms var(--ease);
}

.upload-area.dragging { transform: translateY(-3px); border-color: var(--accent); background: var(--accent-soft); }
.upload-area.busy { pointer-events: none; opacity: 0.72; }
.upload-glyph { width: 64px; height: 64px; color: var(--accent); margin-bottom: 20px; }
.upload-glyph svg { width: 100%; height: 100%; }
.upload-area h2 { margin: 0; font-size: 22px; letter-spacing: -0.025em; }
.upload-area > p { color: var(--muted); max-width: 34ch; margin: 10px 0 24px; }
.upload-area .upload-note { margin: 16px 0 0; font-size: 11px; }

.button {
  min-height: 40px;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  padding: 9px 15px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-weight: 680;
  text-decoration: none;
  cursor: pointer;
  transition: background 150ms var(--ease), border-color 150ms var(--ease), color 150ms var(--ease), transform 150ms var(--ease);
}
.button:active { transform: scale(0.96); }
.button.primary { background: var(--accent); color: oklch(0.98 0.008 70); }
.button.primary:hover { background: var(--accent-hover); }
.button.quiet { color: var(--ink); background: var(--paper); border-color: var(--line); }
.button.quiet:hover { border-color: var(--faint); background: var(--surface); }
.button.danger { background: var(--danger-soft); color: var(--danger); border-color: color-mix(in oklch, var(--danger) 18%, var(--line)); }
.button.danger:hover { background: color-mix(in oklch, var(--danger-soft) 80%, var(--danger)); }
.button.full { width: 100%; }
.button.disabled, .button:disabled { opacity: 0.5; cursor: not-allowed; pointer-events: none; }

.workspace { min-height: calc(100vh - 64px); background: var(--surface); }
.steps { height: 52px; background: var(--paper); border-bottom: 1px solid var(--line); display: flex; align-items: center; padding: 0 28px; }
.steps ol { list-style: none; display: flex; gap: 30px; margin: 0; padding: 0; }
.steps li { color: var(--faint); display: flex; align-items: center; gap: 7px; font-size: 12px; font-weight: 650; }
.steps li span { width: 21px; height: 21px; display: grid; place-items: center; border: 1px solid var(--line); border-radius: 50%; font-size: 10px; }
.steps li.active { color: var(--ink); }
.steps li.active span { color: var(--paper); background: var(--accent); border-color: var(--accent); }
.steps li.complete { color: var(--muted); }
.steps li.complete span { color: var(--success); border-color: color-mix(in oklch, var(--success) 40%, var(--line)); }

.workspace-grid { height: calc(100vh - 116px); display: grid; grid-template-columns: minmax(0, 1fr) 360px; }
.drawing-column { display: grid; grid-template-rows: auto minmax(0, 1fr) auto; min-width: 0; }
.drawing-toolbar { min-height: 64px; display: flex; justify-content: space-between; align-items: center; gap: 20px; padding: 12px 20px; border-bottom: 1px solid var(--line); }
.filename { margin: 0 0 3px; font-weight: 680; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; max-width: 55vw; }
.file-meta { margin: 0; color: var(--muted); font-size: 11px; }
.toolbar-actions { display: flex; align-items: center; gap: 14px; }
.zoom-control { display: flex; align-items: center; gap: 9px; color: var(--muted); font-size: 11px; }
.zoom-control input { accent-color: var(--accent); width: 90px; }

.canvas-shell { position: relative; overflow: auto; padding: 24px; background: oklch(0.91 0.009 75); }
.drawing-stage { position: relative; margin: auto; background: var(--paper); box-shadow: 0 5px 22px oklch(0.25 0.02 55 / 0.16); outline: 1px solid rgb(0 0 0 / 0.1); outline-offset: -1px; transform-origin: top left; transition: width 180ms var(--ease); }
.drawing-stage img { width: 100%; height: 100%; object-fit: fill; display: block; user-select: none; -webkit-user-drag: none; }
#drawing-overlay { position: absolute; inset: 0; width: 100%; height: 100%; overflow: visible; cursor: crosshair; }
.segment-line { fill: none; stroke-linecap: round; stroke-linejoin: round; vector-effect: non-scaling-stroke; stroke-width: 2.2; cursor: pointer; transition: stroke-width 120ms var(--ease), opacity 120ms var(--ease); }
.segment-line:hover, .segment-line.selected { stroke-width: 5; opacity: 1; }
.segment-line.unresolved { stroke: var(--danger); stroke-dasharray: 6 3; }
.segment-line.excluded { stroke: var(--muted); stroke-dasharray: 2 4; opacity: 0.62; }
.calibration-marker { fill: var(--paper); stroke: var(--accent); stroke-width: 2.2; vector-effect: non-scaling-stroke; }
.calibration-link { stroke: var(--accent); stroke-width: 1.5; stroke-dasharray: 5 4; vector-effect: non-scaling-stroke; }
.canvas-empty { position: absolute; inset: 0; display: grid; place-content: center; justify-items: center; color: var(--muted); background: oklch(0.91 0.009 75); }
.canvas-empty.error { color: var(--danger); text-align: center; padding: 24px; }
.canvas-empty.error .loader { display: none; }
.canvas-empty .button { margin-top: 8px; }
.loader { width: 30px; height: 30px; border: 2px solid var(--line); border-top-color: var(--accent); border-radius: 50%; animation: spin 0.8s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }
@media (prefers-reduced-motion: reduce) { *, *::before, *::after { scroll-behavior: auto !important; animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; } }

.legend { min-height: 38px; background: var(--paper); border-top: 1px solid var(--line); display: flex; align-items: center; gap: 22px; padding: 0 20px; color: var(--muted); font-size: 11px; }
.legend span { display: inline-flex; align-items: center; gap: 7px; }
.legend-line { width: 24px; height: 0; border-top: 3px solid var(--blue); }
.legend-line.unresolved { border-color: var(--danger); border-top-style: dashed; }
.legend-line.excluded { border-color: var(--muted); border-top-style: dotted; }

.inspector { min-width: 0; background: var(--paper); border-left: 1px solid var(--line); }
.inspector-scroll { height: 100%; overflow: auto; }
.inspector-section { padding: 24px 24px 26px; border-bottom: 1px solid var(--line); }
.inspector-section h2 { font-size: 18px; letter-spacing: -0.025em; margin: 0; }
.section-help { color: var(--muted); font-size: 12px; margin: 9px 0 20px; line-height: 1.55; }
.field { display: grid; gap: 7px; margin-top: 18px; }
.field > span, fieldset legend { color: var(--muted); font-size: 11px; font-weight: 650; }
.field small { font-weight: 500; color: var(--faint); }
.field input, .field select, select {
  width: 100%; min-height: 40px; border: 1px solid var(--line); border-radius: var(--radius-sm); background: var(--paper); color: var(--ink); padding: 8px 10px;
}
.field input:hover, .field select:hover, select:hover { border-color: var(--faint); }
.field.compact { margin-top: 14px; }
.input-unit { display: grid; grid-template-columns: 1fr auto; align-items: center; border: 1px solid var(--line); border-radius: var(--radius-sm); overflow: hidden; }
.input-unit:focus-within { outline: 3px solid color-mix(in oklch, var(--focus) 55%, transparent); outline-offset: 2px; }
.input-unit input { border: 0; border-radius: 0; outline: 0 !important; }
.input-unit span { padding: 0 11px; color: var(--muted); font-size: 12px; }

.swatch-fieldset { border: 0; padding: 0; margin: 20px 0 0; }
.swatch-fieldset legend { padding: 0; margin-bottom: 9px; }
.swatch-list { display: flex; flex-wrap: wrap; gap: 8px; }
.swatch-option { position: relative; }
.swatch-option input { position: absolute; opacity: 0; pointer-events: none; }
.swatch-option label { min-width: 60px; height: 40px; padding: 0 8px; display: inline-flex; gap: 6px; align-items: center; justify-content: center; border: 1px solid var(--line); border-radius: var(--radius-sm); color: var(--muted); cursor: pointer; font-size: 10px; }
.swatch-option i { width: 12px; height: 12px; border-radius: 50%; border: 1px solid oklch(0.4 0.01 70 / 0.2); }
.swatch-option input:checked + label { border-color: var(--accent); color: var(--ink); background: var(--accent-soft); }
.swatch-option input:focus-visible + label { outline: 3px solid color-mix(in oklch, var(--focus) 55%, transparent); outline-offset: 2px; }

details summary { cursor: pointer; color: var(--muted); min-height: 40px; display: flex; align-items: center; font-size: 12px; font-weight: 650; }
.advanced { margin-top: 16px; }
.layer-list { margin-top: 10px; max-height: 150px; overflow: auto; border: 1px solid var(--line); border-radius: var(--radius-sm); padding: 6px; }
.layer-list label { display: flex; gap: 8px; align-items: center; padding: 6px; font-size: 11px; }
.layer-list input { accent-color: var(--accent); }

.calibration-instructions { margin: 14px 0; padding-left: 18px; color: var(--muted); font-size: 12px; }
.calibration-instructions li { margin: 6px 0; }
.calibration-points { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.calibration-points span { border: 1px solid var(--line); background: var(--surface); border-radius: var(--radius-sm); padding: 8px; font-size: 10px; color: var(--muted); }
.success-note { display: flex; gap: 9px; color: var(--success); background: color-mix(in oklch, var(--success) 9%, var(--paper)); padding: 11px; border: 1px solid color-mix(in oklch, var(--success) 22%, var(--line)); border-radius: var(--radius-sm); font-size: 12px; }
.declared-note { color: color-mix(in oklch, var(--accent) 82%, var(--ink)); background: var(--accent-soft); padding: 11px; border: 1px solid color-mix(in oklch, var(--accent) 18%, var(--line)); border-radius: var(--radius-sm); font-size: 12px; }
.declared-unit-control { min-height: 40px; display: flex; align-items: center; gap: 9px; color: var(--muted); font-size: 11px; cursor: pointer; }
.declared-unit-control input { accent-color: var(--accent); }
.button-hint { margin: 9px 0 0; color: var(--muted); font-size: 10px; text-align: center; }

.section-heading-row, .segment-heading { display: flex; align-items: flex-start; justify-content: space-between; gap: 12px; }
.review-count, .status-pill { display: inline-flex; align-items: center; min-height: 23px; border-radius: 999px; padding: 3px 8px; font-size: 10px; font-weight: 740; background: var(--danger-soft); color: var(--danger); }
.status-pill.assigned { background: color-mix(in oklch, var(--success) 10%, var(--paper)); color: var(--success); }
.status-pill.excluded { background: var(--surface-strong); color: var(--muted); }
.totals-table { margin-top: 16px; }
.total-row { display: grid; grid-template-columns: 1fr auto; align-items: baseline; gap: 16px; padding: 11px 0; border-top: 1px solid var(--line); }
.total-row:last-child { border-bottom: 1px solid var(--line); }
.total-diameter { font-weight: 710; }
.total-value { font-variant-numeric: tabular-nums; }
.total-value strong { font-size: 17px; }
.total-value small { color: var(--muted); margin-left: 4px; }
.empty-total { color: var(--muted); padding: 16px 0; font-size: 12px; }
.warnings { margin-top: 14px; display: grid; gap: 7px; }
.warning-item { padding: 9px 10px; background: var(--accent-soft); color: color-mix(in oklch, var(--accent) 82%, var(--ink)); border: 1px solid color-mix(in oklch, var(--accent) 18%, var(--line)); border-radius: var(--radius-sm); font-size: 11px; }

.segment-facts { margin: 17px 0 0; }
.segment-facts div { display: grid; grid-template-columns: 1fr 1.25fr; gap: 12px; padding: 9px 0; border-top: 1px solid var(--line); }
.segment-facts dt { color: var(--muted); font-size: 11px; }
.segment-facts dd { margin: 0; text-align: right; font-size: 11px; font-variant-numeric: tabular-nums; overflow-wrap: anywhere; }
.exclude-control { margin-top: 17px; padding-top: 15px; border-top: 1px solid var(--line); }
.exclude-control .button { margin-top: 10px; }
.export-panel { background: color-mix(in oklch, var(--accent-soft) 45%, var(--paper)); }

.toast { position: fixed; left: 50%; bottom: 24px; transform: translateX(-50%); max-width: min(540px, calc(100vw - 32px)); background: var(--ink); color: var(--paper); border-radius: var(--radius-sm); box-shadow: var(--shadow); padding: 11px 15px; z-index: 100; font-size: 12px; }

@media (max-width: 900px) {
  .welcome { grid-template-columns: 1fr; max-width: 680px; gap: 50px; padding-top: 56px; }
  .workspace-grid { grid-template-columns: 1fr; height: auto; }
  .drawing-column { min-height: 65vh; }
  .inspector { border-left: 0; border-top: 1px solid var(--line); }
  .workspace { min-height: 100vh; }
}

@media (max-width: 560px) {
  .topbar { padding: 0 16px; }
  .service-state > span:last-child {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
  }
  .welcome { padding: 42px 20px 70px; }
  .welcome h1 { font-size: 42px; }
  .upload-area { min-height: 350px; padding: 30px 22px; }
  .steps { overflow-x: auto; padding: 0 16px; }
  .steps ol { gap: 18px; min-width: max-content; }
  .drawing-toolbar { align-items: flex-start; }
  .zoom-control { display: none; }
  .canvas-shell { padding: 12px; }
}