:root {
  --black: #000000;
  --white: #ffffff;
  --gray-50: #fafafa;
  --gray-100: #f5f5f5;
  --gray-200: #e5e5e5;
  --gray-300: #d4d4d4;
  --gray-400: #a3a3a3;
  --gray-500: #737373;
  --gray-600: #525252;
  --gray-700: #404040;
  --gray-800: #262626;
  --gray-900: #171717;

  --accent: #2f6fff;

  --surface:       var(--white);   /* page + card surfaces */
  --surface-alt:   var(--gray-50); /* the compute (hero) column */
  --surface-panel: var(--white);   /* inner blocks */
  --ink:        var(--black);      /* primary text */
  --ink-muted:  var(--gray-600);   /* secondary text */
  --ink-faint:  var(--gray-400);   /* eyebrows / units */
  --line:        var(--gray-200);  /* thin 1px rules */
  --line-strong: var(--gray-300);  /* card borders */

  --pipe-bg:      var(--gray-900);
  --pipe-ink:     var(--white);
  --pipe-ink-dim: var(--gray-600);
  --pipe-fill:    var(--white);

  /* ---- radii ---- */
  --radius: 8px;
  --radius-lg: 12px;
  --radius-pill: 999px;

  /* ---- shadows ---- */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px -1px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);

  /* ---- fonts ---- */
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;

  --ease-out:      cubic-bezier(0.16, 1, 0.3, 1);    /* snappy decel - the house curve */
  --ease-out-soft: cubic-bezier(0.22, 1, 0.36, 1);
  --ease-in-out:   cubic-bezier(0.65, 0, 0.35, 1);
  --dur-snap:  140ms;   /* result cards / log line snap-in */
  --dur-fast:  180ms;   /* bar fills, fades, hovers */
  --dur-flow:  300ms;   /* pipeline left→right sweep */
  --dur-count: 260ms;   /* big latency odometer roll (driven in compute.js) */
  --lift: -2px;         /* hover lift distance for interactive cards */

  --col-left:  320px;   /* LEFT model card (doubled on wide screens, see below) */
  --col-right: 360px;   /* RIGHT live compute */
  --mid-max:   640px;   /* MIDDLE canvas cap so the 96×96 field is not upscaled huge */
  --pad-panel: 1.5rem;
}

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

body {
  margin: 0;
  font-family: var(--sans);
  background: var(--surface);
  color: var(--ink);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--ink); text-decoration: underline; text-underline-offset: 2px; }
a:hover { color: var(--ink-muted); }

.fela-demo { display: block; background: var(--surface); color: var(--ink); }

/* ------------------------------------------------------------------ header */
.demo-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  height: 56px;
  padding: 0 1.25rem;
  border-bottom: 1px solid var(--gray-200);
  background: var(--white);
  position: sticky;
  top: 0;
  z-index: 50;
}
.demo-brand {
  display: flex;
  align-items: center;
  gap: 0.55rem;
  text-decoration: none;
  color: var(--black);
  font-weight: 700;
  font-size: 1.0625rem;
  letter-spacing: -0.01em;
}
.demo-brand .mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 26px;
  height: 26px;
  background: var(--black);
  color: var(--white);
  border-radius: 5px;
  font-size: 0.85rem;
  font-weight: 800;
}
.demo-header .crumb {
  font-family: var(--mono);
  font-size: 0.75rem;
  color: var(--gray-500);
  text-transform: lowercase;
}
.demo-header .cap-slot { margin-left: auto; }

.degraded-banner {
  display: none;
  align-items: center;
  gap: 0.6rem;
  padding: 0.55rem 1.25rem;
  background: var(--gray-900);
  color: var(--white);
  font-size: 0.8125rem;
  border-bottom: 1px solid var(--black);
}
.degraded-banner.show { display: flex; }
.degraded-banner .mono { font-family: var(--mono); color: var(--gray-400); }

.demo-shell {
  display: grid;
  grid-template-columns:
    minmax(0, var(--col-left))
    minmax(0, 1fr)
    minmax(0, var(--col-right));
  gap: 0;
  align-items: stretch;
  min-height: calc(100vh - 56px);
}
.panel {
  min-width: 0;
  padding: var(--pad-panel) var(--pad-panel) 2.5rem;
  border-right: 1px solid var(--line);
}
.panel:last-child { border-right: none; }
.panel-left  { background: var(--surface); }
.panel-mid   { background: var(--surface); }
.panel-right { background: var(--surface-alt); }

@media (min-width: 1640px) {
  :root { --col-left: clamp(360px, calc((100vw - 640px) / 2), 640px); }
  .demo-shell .panel-mid {
    padding-left: var(--pad-panel);
    padding-right: max(var(--pad-panel), calc(var(--col-left) - var(--col-right)));
  }
}
.demo-shell .panel-mid > * { max-width: var(--mid-max); margin-left: auto; margin-right: auto; }
.demo-shell .panel-mid > .seg,
.demo-shell .panel-mid > .seg-tabs { display: flex; width: max-content; }

.panel-eyebrow {
  font-family: var(--mono);
  font-size: 0.6875rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--gray-400);
  margin: 0 0 1rem;
  padding-bottom: 0.6rem;
  border-bottom: 1px solid var(--gray-200);
}

.panel-left {
  display: flex;
  flex-direction: column;
  max-height: calc(100vh - 56px);
  position: sticky;
  top: 56px;                /* stick below the sticky header */
  overflow: hidden;         /* the panel itself never scrolls; its body does */
}
.panel-left .panel-eyebrow { flex: none; }
.fela-card-copy {
  flex: 1 1 auto;
  min-height: 0;
  display: flex;
  flex-direction: column;
}
.model-summary {
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  padding: 1rem 1.1rem;
  margin-bottom: 1.25rem;
  flex: none;               /* fixed header - does not scroll or overlap */
}
.model-summary h1 {
  font-size: 1.25rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  margin: 0 0 0.25rem;
}
.model-summary .family {
  font-family: var(--mono);
  font-size: 0.6875rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--gray-500);
  margin: 0 0 0.75rem;
}
.summary-line {
  display: flex;
  gap: 0.6rem;
  align-items: baseline;
  font-size: 0.8125rem;
  color: var(--gray-700);
  padding: 0.3rem 0;
  border-top: 1px solid var(--gray-100);
}
.summary-line:first-of-type { border-top: none; }
.summary-line .k {
  font-family: var(--mono);
  font-size: 0.625rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--gray-400);
  width: 44px;
  flex: none;
}
.summary-line .v { color: var(--black); font-weight: 600; }

.model-card-body {
  font-size: 0.875rem;
  color: var(--gray-700);
  flex: 1 1 auto;           /* takes remaining panel height */
  min-height: 0;            /* allow the flex child to actually scroll */
  overflow-y: auto;
  padding-right: 0.4rem;
}
.model-card-body h2 { font-size: 1rem; margin: 1.25rem 0 0.5rem; }
.model-card-body h3 { font-size: 0.875rem; margin: 1rem 0 0.4rem; }
.model-card-body p { margin: 0 0 0.75rem; }
.model-card-body code {
  font-family: var(--mono);
  font-size: 0.8125rem;
  background: var(--gray-100);
  padding: 0.05rem 0.3rem;
  border-radius: 3px;
}
.hf-link {
  display: inline-block;
  margin-top: 1rem;
  font-size: 0.8125rem;
  font-weight: 600;
}

.demo-stage {
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg);
  background: var(--white);
  padding: 1.25rem;
  margin-bottom: 1.25rem;
}
.demo-stage canvas,
.demo-stage svg,
.demo-stage img { display: block; width: 100%; border-radius: var(--radius); }

.payload-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1rem;
}
.chip {
  font-family: var(--mono);
  font-size: 0.75rem;
  padding: 0.4rem 0.75rem;
  border: 1px solid var(--gray-300);
  border-radius: 999px;
  background: var(--white);
  color: var(--gray-700);
  cursor: pointer;
  transition: color var(--dur-fast) var(--ease-out),
              border-color var(--dur-fast) var(--ease-out),
              background var(--dur-fast) var(--ease-out),
              transform var(--dur-fast) var(--ease-out),
              box-shadow var(--dur-fast) var(--ease-out);
}
.chip:hover { border-color: var(--black); color: var(--black); transform: translateY(-1px); box-shadow: var(--shadow-sm); }
.chip:active { transform: translateY(0); }
.chip:focus-visible { outline: 2px solid var(--ink); outline-offset: 2px; }
.chip.active {
  background: var(--black);
  color: var(--white);
  border-color: var(--black);
}

.scrub {
  margin: 1rem 0;
}
.scrub label {
  display: flex;
  justify-content: space-between;
  font-family: var(--mono);
  font-size: 0.75rem;
  color: var(--gray-500);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 0.5rem;
}
.scrub label .val { color: var(--black); font-weight: 700; }
.scrub input[type="range"] {
  width: 100%;
  -webkit-appearance: none;
  appearance: none;
  height: 3px;
  background: var(--gray-300);
  border-radius: 2px;
  outline: none;
}
.scrub input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--black);
  cursor: pointer;
  border: 2px solid var(--white);
  box-shadow: var(--shadow);
}
.scrub input[type="range"]::-moz-range-thumb {
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--black);
  cursor: pointer;
  border: 2px solid var(--white);
}

.demo-controls {
  display: flex;
  gap: 0.6rem;
  flex-wrap: wrap;
  align-items: center;
  margin-top: 0.75rem;
}

.off-script-note {
  display: flex;
  gap: 0.6rem;
  align-items: flex-start;
  margin-top: 1.25rem;
  padding: 0.7rem 0.85rem;
  border: 1px dashed var(--gray-300);
  border-radius: var(--radius);
  font-size: 0.75rem;
  color: var(--gray-600);
  background: var(--gray-50);
}
.off-script-note .badge {
  font-family: var(--mono);
  font-size: 0.625rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  padding: 0.15rem 0.4rem;
  border: 1px solid var(--gray-400);
  border-radius: 4px;
  color: var(--gray-600);
  flex: none;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.5rem 1rem;
  border-radius: 6px;
  font-family: var(--sans);
  font-weight: 600;
  font-size: 0.875rem;
  text-decoration: none;
  cursor: pointer;
  border: 1px solid var(--gray-300);
  background: var(--white);
  color: var(--black);
  transition: background var(--dur-fast) var(--ease-out),
              border-color var(--dur-fast) var(--ease-out),
              color var(--dur-fast) var(--ease-out),
              transform var(--dur-fast) var(--ease-out),
              box-shadow var(--dur-fast) var(--ease-out);
}
.btn:hover { background: var(--gray-50); border-color: var(--gray-400); transform: translateY(-1px); box-shadow: var(--shadow-sm); }
.btn:active { transform: translateY(0); box-shadow: none; }
.btn:focus-visible { outline: 2px solid var(--ink); outline-offset: 2px; }
.btn-primary { background: var(--black); color: var(--white); border-color: var(--black); }
.btn-primary:hover { background: var(--gray-800); }
.btn-sm { padding: 0.35rem 0.7rem; font-size: 0.8125rem; }
.btn:disabled { opacity: 0.45; cursor: not-allowed; transform: none; box-shadow: none; }

.seg {
  display: inline-flex;
  border: 1px solid var(--gray-300);
  border-radius: 6px;
  overflow: hidden;
  background: var(--white);
}
.seg button {
  font-family: var(--mono);
  font-size: 0.75rem;
  letter-spacing: 0.02em;
  padding: 0.35rem 0.7rem;
  border: none;
  border-right: 1px solid var(--gray-300);
  background: var(--white);
  color: var(--gray-500);
  cursor: pointer;
  transition: background var(--dur-fast) var(--ease-out), color var(--dur-fast) var(--ease-out);
}
.seg button:hover { color: var(--black); }
.seg button:focus-visible { outline: 2px solid var(--ink); outline-offset: -2px; }
.seg button:last-child { border-right: none; }
.seg button.active { background: var(--black); color: var(--white); }

.compute {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}
.compute-toprow {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  flex-wrap: wrap;
}
.compute-block {
  border: 1px solid var(--gray-200);
  border-radius: var(--radius);
  background: var(--white);
  padding: 0.9rem 1rem;
  transition: transform var(--dur-fast) var(--ease-out),
              box-shadow var(--dur-fast) var(--ease-out),
              border-color var(--dur-fast) var(--ease-out);
}
.compute-block:hover {
  transform: translateY(var(--lift));
  box-shadow: var(--shadow-md);
  border-color: var(--line-strong);
}

.compute > .compute-block {
  animation: cmp-enter var(--dur-fast) var(--ease-out) both;
}
.compute > .compute-block:nth-child(1) { animation-delay: 0ms; }
.compute > .compute-block:nth-child(2) { animation-delay: 55ms; }
.compute > .compute-block:nth-child(3) { animation-delay: 110ms; }
.compute > .compute-block:nth-child(4) { animation-delay: 165ms; }
.compute-block .cb-title {
  font-family: var(--mono);
  font-size: 0.625rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--gray-400);
  margin: 0 0 0.6rem;
}

.meter {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  line-height: 1.1;
}
.meter-xl { font-size: 2rem; font-weight: 700; letter-spacing: -0.02em; }
.meter-lg { font-size: 1.4rem; font-weight: 700; }
.meter-sm { font-size: 0.8125rem; color: var(--gray-600); }
.meter-plain {
  font-family: var(--sans);
  font-size: 0.75rem;
  color: var(--gray-500);
  margin-top: 0.35rem;
}
.meter .unit { font-size: 0.7em; color: var(--gray-400); font-weight: 500; margin-left: 0.15rem; }

.act-status {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--mono);
  font-size: 0.8125rem;
  color: var(--gray-500);
  margin-bottom: 0.7rem;
}
.act-status .dot {
  width: 8px; height: 8px; flex: none;
  border-radius: 50%;
  border: 1px solid var(--gray-400);
  background: transparent;             /* hollow = idle */
  transition: background var(--dur-fast) var(--ease-out), border-color var(--dur-fast) var(--ease-out);
}
.act-status.busy { color: var(--black); }
.act-status.busy .dot {
  background: var(--accent);
  border-color: var(--accent);
  animation: cmp-pulse 1.4s var(--ease-out) infinite;
}
@keyframes cmp-pulse {
  0%   { box-shadow: 0 0 0 0 color-mix(in srgb, var(--accent) 45%, transparent); }
  70%  { box-shadow: 0 0 0 7px color-mix(in srgb, var(--accent) 0%, transparent); }
  100% { box-shadow: 0 0 0 0 color-mix(in srgb, var(--accent) 0%, transparent); }
}

.solve-log {
  font-family: var(--mono);
  font-size: 0.6875rem;
  line-height: 1.55;
  color: var(--gray-600);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding: 0.5rem 0;
  margin-bottom: 0.7rem;
  min-height: 4.4rem;
}
.solve-log .sl-empty { color: var(--gray-400); font-style: italic; }
.solve-log .sl-line {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  color: var(--gray-500);
}
.solve-log .sl-line.sl-new {
  color: var(--black);
  animation: cmp-slide-down var(--dur-snap) var(--ease-out);
}

.act-totals {
  font-family: var(--sans);
  font-size: 0.75rem;
  color: var(--gray-600);
  line-height: 1.5;
  margin-bottom: 0.55rem;
}
.act-totals .tv {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  color: var(--black);
}

.act-hw {
  font-family: var(--mono);
  font-size: 0.625rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--gray-400);
}

.histo {
  display: flex;
  align-items: flex-end;
  gap: 2px;
  height: 48px;
  margin-top: 0.5rem;
}
.histo .hb {
  flex: 1;
  min-width: 2px;
  background: var(--gray-300);
  border-radius: 1px 1px 0 0;
  transition: height var(--dur-fast) var(--ease-out), background var(--dur-fast) var(--ease-out);
}
.histo .hb.recent { background: var(--gray-800); }

.port-list {
  border-top: 1px solid var(--line);
  padding-top: 0.5rem;
  margin-bottom: 0.55rem;
}
.port-list .port-empty {
  font-family: var(--sans);
  font-size: 0.75rem;
  color: var(--gray-400);
  font-style: italic;
}
.port-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.6rem;
  padding: 0.28rem 0;
  border-top: 1px solid var(--gray-100);
}
.port-row:first-child { border-top: none; }
.port-row .pl {
  font-family: var(--mono);
  font-size: 0.6875rem;
  color: var(--gray-600);
  white-space: nowrap;   /* device label stays on one line, fully legible */
  flex: none;
}
.port-row .pv {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--black);
  text-align: right;
  min-width: 0;          /* the estimate+verdict wraps here (not the label) */
}
.port-row .pv .pn {
  font-weight: 400;
  font-size: 0.625rem;
  color: var(--gray-500);
}
.port-foot {
  font-family: var(--sans);
  font-size: 0.625rem;
  line-height: 1.45;
  color: var(--gray-400);
  border-top: 1px solid var(--line);
  padding-top: 0.5rem;
}

.impact-list {
  border-top: 1px solid var(--line);
  padding-top: 0.5rem;
  margin-bottom: 0.55rem;
}
.impact-row {
  display: flex;
  align-items: baseline;
  gap: 0.7rem;
  padding: 0.4rem 0;
  border-top: 1px solid var(--gray-100);
}
.impact-row:first-child { border-top: none; }
.impact-row .ir-label {
  font-family: var(--mono);
  font-size: 0.625rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--gray-400);
  white-space: nowrap;
  flex: none;
  width: 3.6rem;
}
.impact-row .ir-body { flex: 1; min-width: 0; }
.impact-row .ir-main {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--black);
  line-height: 1.35;
}
.impact-row .ir-sub {
  font-family: var(--sans);
  font-size: 0.6875rem;
  color: var(--gray-500);
  line-height: 1.4;
  margin-top: 0.12rem;
}
.impact-caveat {
  font-family: var(--sans);
  font-size: 0.6875rem;
  line-height: 1.45;
  color: var(--gray-600);
  border-left: 2px solid var(--accent);
  padding: 0.1rem 0 0.1rem 0.55rem;
  margin: 0 0 0.55rem;
}
.impact-note {
  font-family: var(--sans);
  font-size: 0.625rem;
  line-height: 1.45;
  color: var(--gray-400);
  margin: 0 0 0.5rem;
}
.impact-method {
  font-family: var(--sans);
  font-size: 0.625rem;
  color: var(--gray-400);
}
.impact-method > summary {
  font-family: var(--mono);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--gray-500);
  cursor: pointer;
  list-style: none;
  user-select: none;
}
.impact-method > summary::-webkit-details-marker { display: none; }
.impact-method > summary::before { content: '+ '; color: var(--gray-400); }
.impact-method[open] > summary::before { content: '- '; }
.impact-method .im-body {
  line-height: 1.5;
  color: var(--gray-400);
  padding-top: 0.4rem;
}

/* Pretty pipeline canvas */
.pipe-wrap {
  position: relative;
  background: var(--pipe-bg);
  border-radius: var(--radius);
  overflow: hidden;
}
.pipe-wrap canvas { display: block; width: 100%; }
.pipe-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 0.9rem;
  margin-top: 0.55rem;
  font-family: var(--mono);
  font-size: 0.625rem;
  color: var(--gray-500);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

@keyframes cmp-enter      { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: translateY(0); } }
@keyframes cmp-snap-in    { from { opacity: 0; transform: translateY(6px);  } to { opacity: 1; transform: translateY(0); } }
@keyframes cmp-slide-down { from { opacity: 0; transform: translateY(-8px); } to { opacity: 1; transform: translateY(0); } }
@keyframes cmp-flow-sweep {
  0%   { transform: translateX(-55%); opacity: 0; }
  18%  { opacity: 1; }
  82%  { opacity: 1; }
  100% { transform: translateX(155%); opacity: 0; }
}

.motion-snap-in    { animation: cmp-snap-in var(--dur-fast) var(--ease-out); }
.motion-slide-down { animation: cmp-slide-down var(--dur-snap) var(--ease-out); }
.motion-enter      { animation: cmp-enter var(--dur-fast) var(--ease-out) both; }
.u-bar-fill { transition: width var(--dur-fast) var(--ease-out), height var(--dur-fast) var(--ease-out); }
.u-hover-lift { transition: transform var(--dur-fast) var(--ease-out), box-shadow var(--dur-fast) var(--ease-out); }
.u-hover-lift:hover { transform: translateY(var(--lift)); box-shadow: var(--shadow-md); }

.pipe-wrap, .motion-flow { position: relative; }
.pipe-wrap::after, .motion-flow::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: 2;
  opacity: 0;
  transform: translateX(-55%);
  background: linear-gradient(100deg,
    transparent 34%,
    rgba(255, 255, 255, 0.16) 50%,
    transparent 66%);
}
.pipe-wrap.cmp-flow::after, .motion-flow.cmp-flow::after {
  animation: cmp-flow-sweep var(--dur-flow) var(--ease-out);
}

.cmp-snap-in { animation: cmp-snap-in var(--dur-fast) var(--ease-out); }

.fela-loading {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
  width: 100%;
  color: var(--gray-400);
}
.fela-loading .fela-loading-label {
  font-family: var(--mono);
  font-size: 0.6875rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--gray-400);
}

.fela-spinner {
  display: block;
  width: 26px;
  height: 26px;
  margin: 0 auto;
  border-radius: 50%;
  border: 2px solid var(--gray-200);
  border-top-color: var(--accent);
  animation: fela-spin 0.8s linear infinite;
}
.fela-spinner-sm { width: 18px; height: 18px; border-width: 2px; }
.fela-spinner-lg { width: 34px; height: 34px; border-width: 3px; }
@keyframes fela-spin { to { transform: rotate(360deg); } }

.fela-fade-in { animation: fela-fade-in var(--dur-flow) var(--ease-out) both; }
@keyframes fela-fade-in { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: translateY(0); } }

.fela-fade-in-stagger { animation: fela-fade-in var(--dur-flow) var(--ease-out) both; animation-delay: var(--fela-stagger, 0ms); }

.hidden { display: none !important; }

@media (max-width: 1000px) {
  .demo-shell { grid-template-columns: 1fr; }
  .panel { border-right: none; border-bottom: 1px solid var(--line); }
  .panel-left {
    position: static;
    max-height: none;
    overflow: visible;
    display: block;
  }
  .model-card-body { overflow-y: visible; min-height: 0; }
  .btn { min-height: 44px; }
}
@media (max-width: 520px) {
  .demo-header .crumb { display: none; }
  .ls-grid { grid-template-columns: 1fr; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
  .compute > .compute-block,
  .motion-snap-in, .cmp-snap-in, .motion-slide-down, .motion-enter,
  .solve-log .sl-line.sl-new { animation: none !important; }
  .act-status.busy .dot { animation: none !important; }        /* LED holds solid, no pulse */
  .pipe-wrap::after, .motion-flow::after { display: none !important; }
  .btn:hover, .chip:hover, .compute-block:hover, .u-hover-lift:hover { transform: none !important; }

  .fela-spinner {
    animation: fela-pulse 1.6s var(--ease-out) infinite !important;
    border-color: var(--gray-300);
    border-top-color: var(--gray-300);
    background: var(--gray-300);
  }
  @keyframes fela-pulse { 0%,100% { opacity: 0.35; } 50% { opacity: 0.8; } }
  .fela-fade-in, .fela-fade-in-stagger { animation: none !important; }
}

.is-embedded .demo-shell { min-height: 0; }
.is-embedded .panel-left,
.is-embedded .panel-right {
  position: static;
  max-height: none;
  overflow: visible;
  top: auto;
}
.is-embedded .fela-card-copy,
.is-embedded .panel-right .panel-body,
.is-embedded .panel-mid .panel-body {
  max-height: none;
  overflow: visible;
}
.is-embedded .model-card-body {
  flex: 0 0 auto;
  max-height: none;
  overflow: visible;
}
.is-embedded .demo-header { position: static; }