:root{
  --bg: #060606;
  --panel: #0a0a0a;
  --fg: #f3f3f3;
  --muted: rgba(243,243,243,0.64);
  --muted2: rgba(243,243,243,0.40);
  --line: rgba(243,243,243,0.12);
  --line2: rgba(243,243,243,0.18);

  --accent: #ff3b30;
  --accent2: rgba(255,59,48,0.18);
  --good: rgba(110,231,183,0.90);

  --r: 10px;
  --rBtn: 8px;
  --rCanvas: 12px;

  --s1: 8px;
  --s2: 12px;
  --s3: 16px;
  --s4: 22px;

  /* Fixed bottom bar nominal height (used for reserving scroll space). */
  --barH: 66px;

  --fs-0: clamp(11px, 0.85vw + 7px, 12px);
  --fs-1: clamp(12px, 0.95vw + 7px, 13px);
  --fs-2: clamp(13px, 1.05vw + 7px, 14px);
  --fs-3: clamp(14px, 1.15vw + 7px, 16px);

  --ls-tight: 0.2px;
  --ls-wide: 0.9px;

  /* Reserve content space for the fixed bottom action bar + iOS safe area. */
  --actionPadY: 10px;
  --actionReserve: calc(var(--barH) + var(--actionPadY) + env(safe-area-inset-bottom, 0px));
}

*{ box-sizing:border-box; }
html, body{ height: 100%; }

body{
  margin:0;
  background: var(--bg);
  color: var(--fg);
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Arial;
  font-size: var(--fs-2);
  line-height: 1.45;
}

.hidden{ display:none; }

.mono{
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  letter-spacing: 0.1px;
}

::selection{
  background: rgba(255,59,48,0.35);
  color: var(--fg);
}

/* Top bar */
.appbar{
  position: sticky;
  top: 0;
  z-index: 60;
  display:flex;
  justify-content:space-between;
  align-items:center;
  padding: var(--s3);
  border-bottom: 1px solid var(--line);
  background: rgba(6,6,6,0.86);
  backdrop-filter: blur(10px);
}

.brandMark{
  font-weight: 720;
  letter-spacing: var(--ls-tight);
  font-size: var(--fs-2);
}

.appbarRight{
  display:flex;
  align-items:center;
  gap: var(--s2);
}

.chip{
  font-size: var(--fs-0);
  color: var(--muted);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 6px 10px;
  letter-spacing: 0.3px;
  background: rgba(255,255,255,0.02);
}

/* Layout */
.shell{
  display:grid;
  grid-template-columns: 1fr 360px;
  gap: var(--s3);
  padding: var(--s4);
  padding-bottom: calc(var(--s4) + var(--actionReserve));
  align-items:start;
}

.mainPane{ min-width:0; }

.sidePane{
  display:flex;
  flex-direction:column;
  gap: var(--s2);
  min-width:0;
}

.card{
  background: transparent;
  border: none;
  border-top: 1px solid var(--line);
  border-radius: 0;
  padding: var(--s2) 0 0 0;
}

/* Titles above canvases */
.vizTitleRow{
  display:flex;
  align-items:baseline;
  justify-content:space-between;
  gap: var(--s2);
  margin-bottom: 6px;
}

.vizTitle{
  font-size: var(--fs-0);
  letter-spacing: var(--ls-wide);
  text-transform: uppercase;
  color: var(--muted2);
  margin-bottom: 6px;
}

.legend{
  font-size: var(--fs-0);
  color: var(--muted);
  white-space: normal;
  overflow: visible;
  text-overflow: clip;
  max-width: none;
  line-height: 1.25;
}

/* Left pane internal grid */
.vizGrid{
  display:grid;
  grid-template-columns: 1.15fr 0.85fr;
  grid-template-rows: max-content max-content;
  column-gap: 14px;
  row-gap: 6px;
  align-items:start;
}

.vizPrimary{ grid-column: 1 / 2; grid-row: 1 / 3; }
.vizNN{ grid-column: 2 / 3; grid-row: 1 / 2; }
.vizLoss{ grid-column: 2 / 3; grid-row: 2 / 3; }

/* Canvases */
canvas{
  width:100%;
  height:auto;
  border: 1px solid var(--line);
  border-radius: var(--rCanvas);
  background: #000;
  display:block;
  box-shadow: 0 0 0 1px rgba(255,255,255,0.02) inset;

  /* Allow scroll gestures by default; override per-canvas below. */
  touch-action: auto;
}

/* Draw canvas should not scroll while drawing. */
#plotCanvas{
  touch-action: none;
}

/* NN/Loss canvases should allow vertical page scroll on mobile. */
#nnCanvas,
#lossCanvas{
  touch-action: pan-y;
}

/* Help loss be visible without scroll by capping displayed heights */
.vizPrimary canvas{ max-height: 72vh; }
.vizNN canvas{ max-height: 44vh; }
.vizLoss canvas{ max-height: 26vh; }

/* NN */
.nnWrap{ position:relative; }

.hoverCard{
  position:absolute;
  left: 12px;
  top: 12px;
  width: max-content;
  max-width: min(380px, 80%);
  border-radius: var(--r);
  border: 1px solid var(--line2);
  background: rgba(0,0,0,0.90);
  padding: 10px 12px;
  font-size: var(--fs-1);
  color: var(--fg);
  pointer-events:none;
  white-space: pre;
}

/* Slider sections under NN */
.nnSliders{
  margin-top: 8px;
  padding-top: 8px;
  border-top: 1px solid var(--line);
}

/* Forms */
label{
  color: var(--muted);
  font-size: var(--fs-1);
  letter-spacing: 0.15px;
}

.form{ display:grid; gap: var(--s2); }

.field{
  display:flex;
  justify-content:space-between;
  align-items:center;
  gap: var(--s2);
  flex-wrap: wrap;
}

/* Inputs: minimal dark */
select, input[type="number"]{
  width: 160px;
  padding: 9px 10px;
  border-radius: var(--r);
  border: 1px solid var(--line);
  background: rgba(255,255,255,0.03);
  color: var(--fg);
  font-size: var(--fs-1);
}

select option{
  background: #0b0b0b;
  color: var(--fg);
}

select:focus-visible,
input[type="number"]:focus-visible,
input[type="range"]:focus-visible{
  outline: 2px solid rgba(255,59,48,0.55);
  outline-offset: 2px;
}

/* Ranges */
.rangeField{ align-items:center; }

.rangeVal{
  margin-left: auto;
  color: var(--muted);
  font-size: var(--fs-0);
  letter-spacing: 0.15px;
}

input[type="range"]{
  width: 100%;
  accent-color: var(--fg);
  height: 18px;
}

/* Layer editor */
.layersBox{
  display:flex;
  flex-direction:column;
  gap: var(--s2);
  margin-top: var(--s2);
  min-width: 0;
}

.layerRow{
  display: grid;
  grid-template-columns: 92px 1fr;
  grid-template-rows: auto auto;
  gap: 8px 10px;
  align-items: center;

  padding: 10px 0 0 0;
  border-top: 1px solid rgba(243,243,243,0.08);
  background: transparent;
}

.layerRow input[type="number"]{ width: 100%; }
.layerRow select{ width: 100%; }

.layerRow label:nth-of-type(1){ grid-column: 1; grid-row: 1; }
.layerRow .unitsInp{ grid-column: 2; grid-row: 1; }
.layerRow label:nth-of-type(2){ grid-column: 1; grid-row: 2; }
.layerRow .actSel{ grid-column: 2; grid-row: 2; }

/* Stats */
.statGrid{
  display:grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--s2);
  padding-top: 8px;
}

.statKey{
  font-size: var(--fs-0);
  color: var(--muted2);
  text-transform: uppercase;
  letter-spacing: var(--ls-wide);
}

.statVal{
  margin-top: 4px;
  font-size: var(--fs-2);
  font-weight: 720;
  color: var(--fg);
}

.debugLine{
  margin-top: var(--s2);
  font-size: var(--fs-1);
  color: var(--muted);
}

/* Fixed bottom controls */
.actionCard{
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 80;

  background: rgba(6,6,6,0.86);
  backdrop-filter: blur(10px);
  border-top: 1px solid var(--line);

  /* Include iOS safe area inset so controls are not obscured. */
  padding: var(--actionPadY) var(--s4) calc(var(--actionPadY) + env(safe-area-inset-bottom, 0px));
}

.actionGrid{
  display:grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--s2);
  max-width: 1100px;
  margin: 0 auto;
}

/* Buttons */
.btn{
  width:100%;
  padding: 12px 12px;
  border-radius: var(--rBtn);
  border: 1px solid rgba(243,243,243,0.20);
  background: rgba(255,255,255,0.02);
  color: var(--fg);
  cursor: pointer;

  font-size: var(--fs-1);
  font-weight: 700;
  letter-spacing: 0.25px;
  transition: border-color 140ms ease, background 140ms ease, transform 80ms ease;
}

.btn:hover{
  border-color: rgba(255,59,48,0.55);
  background: rgba(255,59,48,0.06);
}

.btn:active{ transform: translateY(1px); }

.btn:disabled{
  opacity: .45;
  cursor: not-allowed;
}

.btn:focus-visible{
  outline: 2px solid rgba(255,59,48,0.70);
  outline-offset: 3px;
}

/* Responsive */
@media (max-width: 1100px){
  .shell{
    grid-template-columns: 1fr;
    padding: var(--s3);
    padding-bottom: calc(var(--s3) + var(--actionReserve));
  }

  .vizGrid{
    grid-template-columns: 1fr;
    grid-template-rows: max-content max-content max-content;
    row-gap: var(--s2);
  }

  .vizPrimary{ grid-column: 1; grid-row: 1; }
  .vizNN{ grid-column: 1; grid-row: 2; }
  .vizLoss{ grid-column: 1; grid-row: 3; }

  .vizPrimary canvas{ max-height: 56vh; }
  .vizNN canvas{ max-height: 38vh; }
  .vizLoss canvas{ max-height: 24vh; }

  .actionGrid{ grid-template-columns: 1fr 1fr; }

  select, input[type="number"]{ width: 100%; }
}