/* Live neural-net trainer — Karpathy's "the program is grown, not authored."
   A tiny MLP, implemented from scratch, learns a decision boundary from dots
   via gradient descent, live. Vanilla JS, no deps, no build. Dark theme. */

#nn-trainer-demo {
  --kp-accent: #5ac8fa;   /* learned / the win */
  --kp-c0: #ff9f0a;       /* class 0 (orange) */
  --kp-c1: #5ac8fa;       /* class 1 (cyan)  */
  font-family: var(--font-family, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif);
  background: var(--color-bg-elevated, #111111);
  border: 1px solid var(--color-border, rgba(255, 255, 255, 0.1));
  border-radius: 16px;
  padding: clamp(16px, 3vw, 26px);
  margin: 2.5rem 0;
  color: var(--color-text-primary, #ffffff);
}

.kp-title { font-size: 1rem; font-weight: 650; letter-spacing: -0.01em; }
.kp-explain {
  font-size: 0.9rem; line-height: 1.55; margin: 8px 0 18px;
  color: var(--color-text-secondary, rgba(255, 255, 255, 0.7));
}

/* dataset segmented control — calm */
#nn-trainer-demo .kp-modes {
  display: flex; gap: 4px; margin: 0 0 16px; padding: 4px;
  background: var(--color-bg-surface, #1a1a1a);
  border: 1px solid var(--color-border-subtle, rgba(255,255,255,0.07));
  border-radius: 11px; max-width: 360px;
}
#nn-trainer-demo .kp-mode {
  appearance: none; flex: 1 1 0; border: 0; background: transparent !important;
  color: var(--color-text-secondary, rgba(255,255,255,0.62));
  font: inherit; font-size: 0.82rem; font-weight: 550; padding: 8px 10px;
  border-radius: 8px; cursor: pointer; transition: color 0.18s, background 0.18s;
}
#nn-trainer-demo .kp-mode:hover { color: var(--color-text-primary, #fff); }
#nn-trainer-demo .kp-mode.is-on {
  color: #0b0b0b !important; font-weight: 650;
  background: var(--color-accent, #ffffff) !important;
}

/* canvas */
.kp-stage { display: flex; justify-content: center; }
.kp-canvas {
  width: 100%; max-width: 380px; height: auto; aspect-ratio: 1 / 1;
  background: var(--color-bg-surface, #1a1a1a);
  border: 1px solid var(--color-border-subtle, rgba(255,255,255,0.08));
  border-radius: 12px; display: block; image-rendering: auto;
}

/* readout card — shows it learning */
.kp-readout {
  display: flex; align-items: center; flex-wrap: wrap; gap: 8px 22px;
  margin: 16px 0 14px; padding: 13px 18px;
  background: var(--color-bg-surface, #1a1a1a);
  border: 1px solid var(--color-border, rgba(255,255,255,0.12));
  border-radius: 12px; transition: border-color 0.25s;
}
.kp-readout.is-trained { border-color: var(--kp-accent); }
.kp-stat { font-size: 0.84rem; color: var(--color-text-secondary, rgba(255,255,255,0.65)); }
.kp-stat b {
  font-family: var(--font-mono, "SF Mono", Monaco, monospace);
  font-size: 1.25rem; font-weight: 700; color: #fff; margin-right: 4px;
  font-variant-numeric: tabular-nums;
}
.kp-stat--acc b { color: var(--kp-accent); }
.kp-badge {
  margin-left: auto; align-self: center; white-space: nowrap; display: none;
  font-size: 0.8rem; font-weight: 700; padding: 6px 12px; border-radius: 999px;
  background: rgba(90,200,250,0.16); color: var(--kp-accent);
}
.kp-readout.is-trained .kp-badge { display: inline-block; }
@media (max-width: 520px) { .kp-badge { margin-left: 0; } }

/* controls */
.kp-controls { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.kp-btn {
  appearance: none; border: 1px solid var(--color-border, rgba(255,255,255,0.15));
  background: transparent; color: var(--color-text-primary, #fff);
  font: inherit; font-size: 0.92rem; padding: 9px 18px; border-radius: 9px; cursor: pointer;
  transition: border-color 0.18s, background 0.18s, opacity 0.18s;
}
.kp-btn:hover { border-color: rgba(255,255,255,0.35); background: rgba(255,255,255,0.05); }
.kp-btn--primary { background: var(--kp-accent); border-color: var(--kp-accent); color: #0b0b0b; font-weight: 650; }
.kp-btn--primary:hover { background: var(--kp-accent); opacity: 0.9; }

.kp-status {
  margin-top: 14px;
  background: var(--color-bg-surface, #1a1a1a);
  border: 1px solid var(--color-border-subtle, rgba(255,255,255,0.09));
  border-radius: 10px; padding: 12px 16px; font-size: 0.9rem; line-height: 1.55;
  color: var(--color-text-secondary, rgba(255,255,255,0.78)); min-height: 1.4em;
  transition: border-color 0.25s;
}
.kp-status strong { color: #fff; }
.kp-status.is-trained { border-color: var(--kp-accent); }
.kp-noscript { font-size: 0.9rem; color: var(--color-text-secondary, rgba(255,255,255,0.65)); line-height: 1.6; }