/* Scene 4 -- "Local minima & the optimizer zoo"
   Style only. Colors come from the editorial palette in css/style.css plus
   four scene-specific tokens defined below for the per-optimizer hue. No
   transitions on color/opacity/position (headless screenshot compatibility). */

:root,
:root[data-theme="light"] {
  --s4-gd:        #2f6cb1;   /* blue (matches existing --fit) */
  --s4-sgd:       #c08a3e;   /* amber (matches existing --trajectory) */
  --s4-momentum:  #2f8f5a;   /* green */
  --s4-adam:      #7a3aa5;   /* purple */
}
:root[data-theme="dark"] {
  --s4-gd:        #6ea3dc;
  --s4-sgd:       #d6a766;
  --s4-momentum:  #6fc28e;
  --s4-adam:      #b483de;
}

/* ---- Layout ---------------------------------------------------------- */

.s4-wrap {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.s4-hero {
  margin-bottom: 4px;
}

.s4-h1 {
  margin-bottom: 6px;
}

.s4-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  align-items: stretch;
}

@media (max-width: 880px) {
  .s4-grid { grid-template-columns: 1fr; }
}

.s4-pane {
  display: flex;
  flex-direction: column;
  padding: 12px 14px 10px;
}

.s4-svg {
  width: 100%;
  height: auto;
  display: block;
  cursor: default;
}
.s4-svg-curve {
  cursor: crosshair;
}

.s4-pane-bg {
  fill: var(--card-bg);
  stroke: none;
}

.s4-plot-frame {
  fill: none;
  stroke: var(--rule);
  stroke-width: 1;
}

/* ---- Axes / ticks ----------------------------------------------------- */

.s4-axis {
  stroke: var(--axis);
  stroke-width: 1;
  fill: none;
}

.s4-tick {
  stroke: var(--axis);
  stroke-width: 1;
}

.s4-tick-label {
  fill: var(--ink-secondary);
  font-family: "SF Mono", Menlo, monospace;
  font-size: 10px;
  font-variant-numeric: tabular-nums;
}

.s4-axis-label {
  fill: var(--ink-secondary);
  font-family: "Iowan Old Style", Palatino, Georgia, serif;
  font-style: italic;
  font-size: 12px;
}

/* ---- Loss-curve pane -------------------------------------------------- */

.s4-curve {
  fill: none;
  stroke: var(--ink);
  stroke-width: 1.4;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.s4-theta0 {
  stroke: var(--ink-secondary);
  stroke-width: 1;
  stroke-dasharray: 3 3;
  fill: none;
}

.s4-traj {
  fill: none;
  stroke-width: 1.5;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-dasharray: 4 3;
  fill-opacity: 0;
}

.s4-traj-gd       { stroke: var(--s4-gd); }
.s4-traj-sgd      { stroke: var(--s4-sgd); }
.s4-traj-momentum { stroke: var(--s4-momentum); }
.s4-traj-adam     { stroke: var(--s4-adam); }

.s4-marble {
  stroke: var(--card-bg);
  stroke-width: 1.2;
}
.s4-marble.hidden {
  visibility: hidden;
}

.s4-marble-gd       { fill: var(--s4-gd); }
.s4-marble-sgd      { fill: var(--s4-sgd); }
.s4-marble-momentum { fill: var(--s4-momentum); }
.s4-marble-adam     { fill: var(--s4-adam); }

/* ---- Loss-vs-step pane ----------------------------------------------- */

.s4-loss-line {
  fill: none;
  stroke-width: 1.6;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.s4-loss-line-gd       { stroke: var(--s4-gd); }
.s4-loss-line-sgd      { stroke: var(--s4-sgd); }
.s4-loss-line-momentum { stroke: var(--s4-momentum); }
.s4-loss-line-adam     { stroke: var(--s4-adam); }

.s4-loss-note {
  fill: var(--ink-secondary);
  font-family: "Iowan Old Style", Palatino, Georgia, serif;
  font-style: italic;
  font-size: 11px;
}
.s4-loss-note.hidden {
  visibility: hidden;
}

/* ---- Caption / footnote tightening ----------------------------------- */

.s4-caption {
  margin-top: 6px;
  margin-bottom: 0;
}

.s4-controls {
  margin-top: 14px;
  row-gap: 10px;
}

.s4-foot {
  margin-top: 8px;
}

/* ---- Optimizer-enable checkboxes ------------------------------------- */

.s4-opt-checks {
  flex-wrap: wrap;
  gap: 10px;
}

.s4-cbwrap {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  text-transform: none;
  letter-spacing: 0;
  font-size: 12px;
  color: var(--ink);
}

.s4-cblabel {
  font-family: -apple-system, BlinkMacSystemFont, "Inter", "Segoe UI", Helvetica, Arial, sans-serif;
}

/* ---- Color swatches -------------------------------------------------- */

.s4-swatch {
  display: inline-block;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  border: 1px solid var(--rule);
  vertical-align: middle;
}
.s4-swatch-gd       { background: var(--s4-gd); }
.s4-swatch-sgd      { background: var(--s4-sgd); }
.s4-swatch-momentum { background: var(--s4-momentum); }
.s4-swatch-adam     { background: var(--s4-adam); }

/* ---- Effective-lr legend (right side of controls) -------------------- */

.s4-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-left: auto;
  font-family: "SF Mono", Menlo, monospace;
  font-size: 11px;
  font-variant-numeric: tabular-nums;
  color: var(--ink);
  text-transform: none;
  letter-spacing: 0;
}

.s4-legend-row {
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.s4-legend-text {
  color: var(--ink);
}

/* ---- Optimizer-info column (4 cards stacked) ------------------------- */

.s4-info-col {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: 14px;
}

.s4-info-card {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.s4-info-head {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px 0;
  background: var(--card-bg);
  border: 1px solid var(--rule);
  border-bottom: none;
  border-radius: 4px 4px 0 0;
  font-family: "Iowan Old Style", Palatino, Georgia, serif;
  font-size: 13px;
  color: var(--ink-secondary);
}

.s4-info-headlabel {
  font-style: italic;
}

.s4-info-body {
  margin: 0;
  border-radius: 0 0 4px 4px;
}