/* ── Reset & Base ─────────────────────────────────────────────────────────── */
* { box-sizing: border-box; margin: 0; padding: 0; }

body {
  background: #fff;
  color: #333;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Helvetica, Arial, sans-serif;
  font-size: 15px;
  line-height: 1.6;
  min-height: 100vh;
}

a { color: #2563eb; text-decoration: none; }
a:hover { text-decoration: underline; }

/* ── Page shell ───────────────────────────────────────────────────────────── */
.page-header {
  border-bottom: 1px solid #e5e7eb;
  padding: 1.25rem 2rem;
  background: #fafafa;
}
.page-header h1 {
  font-size: 1.4rem;
  font-weight: 600;
  color: #111;
}
.page-header .subtitle {
  font-size: 0.88rem;
  color: #666;
  margin-top: 0.15rem;
}
.page-header a {
  color: #666;
  font-size: 0.85rem;
}
.page-header a:hover { color: #111; }

.page-body {
  max-width: 960px;
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
}

/* ── Landing page: network cards ──────────────────────────────────────────── */
.network-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
  margin-top: 1.5rem;
}

.network-card {
  display: block;
  background: #fff;
  border: 1px solid #e5e7eb;
  border-radius: 8px;
  padding: 1.25rem 1.5rem;
  transition: border-color 0.15s, box-shadow 0.15s;
  text-decoration: none;
  color: inherit;
}
.network-card:hover {
  border-color: #2563eb;
  box-shadow: 0 2px 8px rgba(37, 99, 235, 0.08);
  text-decoration: none;
}
.network-card h2 {
  font-size: 1.1rem;
  font-weight: 600;
  color: #111;
  margin-bottom: 0.3rem;
}
.network-card .arch {
  font-family: 'SFMono-Regular', Consolas, monospace;
  font-size: 0.82rem;
  color: #666;
  margin-bottom: 0.5rem;
}
.network-card .desc {
  font-size: 0.88rem;
  color: #555;
  margin-bottom: 0.5rem;
}
.network-card .accuracy {
  display: inline-block;
  background: #ecfdf5;
  color: #065f46;
  font-size: 0.82rem;
  font-weight: 600;
  padding: 0.2rem 0.6rem;
  border-radius: 12px;
}
.network-card .techniques {
  font-size: 0.8rem;
  color: #888;
  margin-top: 0.4rem;
}

/* ── Network page layout ──────────────────────────────────────────────────── */
.network-page-body {
  max-width: 1100px;
  margin: 0 auto;
  padding: 1.5rem 1.5rem 4rem;
}

.network-meta {
  margin-bottom: 1.5rem;
}
.network-meta h1 {
  font-size: 1.5rem;
  font-weight: 600;
  color: #111;
}
.network-meta .arch {
  font-family: 'SFMono-Regular', Consolas, monospace;
  font-size: 0.88rem;
  color: #666;
  margin-top: 0.25rem;
}
.network-meta .result-summary {
  font-size: 0.88rem;
  color: #555;
  margin-top: 0.35rem;
}

/* Try-it widget */
.try-it-section {
  background: #f9fafb;
  border: 1px solid #e5e7eb;
  border-radius: 8px;
  padding: 1.25rem 1.5rem;
  margin-bottom: 2rem;
}
.try-it-section h2 {
  font-size: 0.95rem;
  font-weight: 600;
  color: #333;
  margin-bottom: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
.try-it-layout {
  display: flex;
  gap: 1.5rem;
  align-items: flex-start;
}
.try-it-left {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.6rem;
  flex-shrink: 0;
}
.canvas-wrapper {
  border: 2px solid #d1d5db;
  border-radius: 8px;
  overflow: hidden;
  background: #000;
}
#draw-canvas {
  display: block;
  cursor: crosshair;
  touch-action: none;
}
.demo-video {
  display: block;
  width: 320px;
  height: auto;
  max-width: 100%;
  background: #000;
}
.canvas-buttons {
  display: flex;
  gap: 0.5rem;
}
.canvas-hint {
  font-size: 0.78rem;
  color: #999;
}

button {
  padding: 0.45rem 1.1rem;
  border-radius: 6px;
  border: 1px solid #d1d5db;
  background: #fff;
  font-size: 0.88rem;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.12s, border-color 0.12s;
  color: #333;
}
button:hover { background: #f3f4f6; border-color: #bbb; }
button:active { transform: scale(0.98); }

.btn-primary {
  background: #2563eb;
  color: #fff;
  border-color: #2563eb;
}
.btn-primary:hover { background: #1d4ed8; border-color: #1d4ed8; }
.btn-primary:disabled { opacity: 0.4; cursor: not-allowed; }

.try-it-right {
  flex: 1;
  min-width: 0;
  overflow: hidden;
}
.try-it-right > .notes-body { min-width: 0; max-width: 100%; }
.prediction-display {
  text-align: center;
  padding: 0.5rem 0;
}
.prediction-label { color: #999; font-size: 0.88rem; }
.prediction-number {
  font-size: 3.5rem;
  font-weight: 700;
  color: #111;
  line-height: 1.1;
}
.prediction-conf {
  font-size: 0.82rem;
  color: #666;
  margin-top: 0.2rem;
}

#bar-chart {
  display: flex;
  flex-direction: column;
  gap: 3px;
  margin-top: 0.5rem;
}
.bar-row {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.8rem;
}
.bar-digit {
  width: 14px;
  text-align: right;
  color: #888;
  font-family: monospace;
  flex-shrink: 0;
}
.bar-track {
  flex: 1;
  background: #e5e7eb;
  border-radius: 3px;
  height: 14px;
  overflow: hidden;
}
.bar-fill {
  height: 100%;
  border-radius: 3px;
  background: #93c5fd;
  transition: width 0.3s ease;
}
.bar-fill.top { background: #2563eb; }
.bar-pct {
  width: 40px;
  text-align: right;
  color: #888;
  font-family: monospace;
  flex-shrink: 0;
}

/* ── Notebook container ───────────────────────────────────────────────────── */
.nb-container {
  background: #fff;
  border: 1px solid #e5e7eb;
  border-radius: 8px;
  overflow: hidden;
}

.nb-top-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: #f9fafb;
  border-bottom: 1px solid #e5e7eb;
  padding: 0.5rem 1rem;
  gap: 0.75rem;
}
.nb-title {
  font-size: 0.95rem;
  font-weight: 600;
  color: #333;
}
.nb-top-bar-right {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.nb-kernel-indicator {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.8rem;
  color: #666;
}
.nb-kernel-dot {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: #d1d5db;
  border: 1px solid #aaa;
  transition: background 0.3s;
}
.nb-kernel-dot.idle   { background: #34d399; border-color: #059669; }
.nb-kernel-dot.busy   { background: #fbbf24; border-color: #d97706; }
.nb-kernel-dot.error  { background: #f87171; border-color: #dc2626; }

.nb-toolbar-btn {
  background: #fff;
  color: #555;
  border: 1px solid #d1d5db;
  border-radius: 4px;
  padding: 0.25rem 0.65rem;
  font-size: 0.78rem;
  font-weight: 600;
  cursor: pointer;
}
.nb-toolbar-btn:hover { background: #f3f4f6; color: #333; }

/* ── Notebook cells ───────────────────────────────────────────────────────── */
#notebook-render {
  padding: 0.4rem 0;
}

/* Markdown cell */
.nb-md-cell {
  padding: 0.6rem 1rem 0.6rem 4.5rem;
  border-left: 3px solid transparent;
  line-height: 1.7;
  color: #333;
  font-size: 0.92rem;
}
.nb-md-cell:hover { border-left-color: #e5e7eb; }
.nb-md-cell h1 {
  font-size: 1.6rem;
  color: #111;
  margin: 0.5rem 0 0.4rem;
  border-bottom: 1px solid #e5e7eb;
  padding-bottom: 0.3rem;
}
.nb-md-cell h2 {
  font-size: 1.3rem;
  color: #111;
  margin: 1rem 0 0.4rem;
  border-bottom: 1px solid #e5e7eb;
  padding-bottom: 0.2rem;
}
.nb-md-cell h3 { font-size: 1.1rem; color: #111; margin: 0.8rem 0 0.3rem; }
.nb-md-cell p  { margin-bottom: 0.6rem; }
.nb-md-cell ul, .nb-md-cell ol { padding-left: 1.5rem; margin-bottom: 0.6rem; }
.nb-md-cell li { margin-bottom: 0.2rem; }
.nb-md-cell code {
  background: #f3f4f6;
  padding: 0.1em 0.35em;
  border-radius: 3px;
  font-family: 'SFMono-Regular', Consolas, monospace;
  font-size: 0.88em;
  color: #c7254e;
}
.nb-md-cell pre {
  background: #f3f4f6;
  padding: 0.8rem;
  border-radius: 4px;
  overflow-x: auto;
  margin-bottom: 0.6rem;
}
.nb-md-cell pre code { background: none; color: #333; }
.nb-md-cell table { border-collapse: collapse; margin: 0.5rem 0; font-size: 0.88rem; }
.nb-md-cell th, .nb-md-cell td { border: 1px solid #e5e7eb; padding: 0.35rem 0.7rem; }
.nb-md-cell th { background: #f9fafb; font-weight: 600; }
.nb-md-cell strong { font-weight: 700; }
.nb-md-cell em { font-style: italic; }

/* Code cell */
.nb-code-cell {
  border-left: 3px solid transparent;
  margin: 0.2rem 0;
}
.nb-code-cell:hover { border-left-color: #e5e7eb; }
.nb-code-cell.selected { border-left-color: #2563eb; }
.nb-code-cell.running  { border-left-color: #f59e0b; }

.nb-input-area {
  display: flex;
  align-items: flex-start;
  padding: 0.25rem 0.5rem 0.25rem 0;
}

.nb-in-prompt {
  width: 4.5rem;
  flex-shrink: 0;
  text-align: right;
  padding: 0.4rem 0.5rem 0 0;
  font-size: 0.78rem;
  font-family: monospace;
  color: #2563eb;
  user-select: none;
}

.nb-editor {
  flex: 1;
  font-family: 'SFMono-Regular', Consolas, 'Courier New', monospace;
  font-size: 0.85rem;
  line-height: 1.5;
  color: #333;
  background: #f8f9fa;
  border: 1px solid #e5e7eb;
  border-radius: 3px;
  padding: 0.5rem 0.6rem;
  resize: none;
  overflow: hidden;
  min-height: 2.4rem;
  outline: none;
  transition: border-color 0.15s, background 0.15s;
}
.nb-editor:focus {
  border-color: #2563eb;
  background: #fff;
  box-shadow: 0 0 0 2px rgba(37, 99, 235, 0.1);
}

.nb-run-btn {
  flex-shrink: 0;
  background: none;
  border: none;
  color: #bbb;
  font-size: 0.95rem;
  padding: 0.4rem 0.4rem;
  cursor: pointer;
  margin-left: 0.2rem;
  border-radius: 4px;
  line-height: 1;
}
.nb-run-btn:hover { color: #2563eb; background: #f3f4f6; }

/* Output area */
.nb-output-area {
  display: flex;
  align-items: flex-start;
  padding: 0 0.5rem 0 0;
  min-height: 0;
}
.nb-out-prompt {
  width: 4.5rem;
  flex-shrink: 0;
  text-align: right;
  padding: 0.4rem 0.5rem 0 0;
  font-size: 0.78rem;
  font-family: monospace;
  color: #dc2626;
  user-select: none;
}
.nb-output-content {
  flex: 1;
  padding: 0.15rem 0 0.35rem;
}

.nb-stdout {
  font-family: monospace;
  font-size: 0.82rem;
  line-height: 1.5;
  color: #333;
  white-space: pre-wrap;
  word-break: break-word;
  margin: 0;
  background: none;
  border: none;
  padding: 0.15rem 0;
}

.nb-error-text {
  font-family: monospace;
  font-size: 0.82rem;
  line-height: 1.5;
  color: #dc2626;
  white-space: pre-wrap;
  word-break: break-word;
  margin: 0;
  padding: 0.35rem 0.6rem;
  background: #fef2f2;
  border-left: 3px solid #f87171;
  border-radius: 0 3px 3px 0;
}

.nb-running-text {
  font-size: 0.8rem;
  color: #999;
  font-style: italic;
  padding: 0.25rem 0;
}

.nb-plot-img {
  max-width: 100%;
  display: block;
  margin: 0.3rem 0;
}

/* Cell dividers */
.nb-code-cell + .nb-code-cell,
.nb-md-cell + .nb-code-cell,
.nb-code-cell + .nb-md-cell {
  border-top: 1px solid #f3f4f6;
}

/* ── Notes section ────────────────────────────────────────────────────────── */
.notes-section {
  margin-bottom: 2rem;
}
.notes-section h2 {
  font-size: 0.95rem;
  font-weight: 600;
  color: #333;
  margin-bottom: 0.5rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
.notes-body {
  font-size: 0.9rem;
  line-height: 1.7;
  color: #444;
}
.notes-body h1 { font-size: 1.15rem; color: #111; margin-bottom: 0.5rem; }
.notes-body h2 { font-size: 1rem; color: #111; margin: 1rem 0 0.4rem; }
.notes-body h3 { font-size: 0.92rem; color: #333; margin: 0.8rem 0 0.3rem; }
.notes-body p { margin-bottom: 0.6rem; }
.notes-body ul, .notes-body ol { padding-left: 1.4rem; margin-bottom: 0.6rem; }
.notes-body li { margin-bottom: 0.2rem; }
.notes-body code {
  background: #f3f4f6;
  padding: 0.1em 0.35em;
  border-radius: 3px;
  font-size: 0.85em;
  color: #c7254e;
}
.notes-body pre {
  background: #f3f4f6;
  padding: 0.6rem 0.8rem;
  border-radius: 4px;
  overflow-x: auto;
  margin: 0.4rem 0 0.6rem;
  max-width: 100%;
}
.notes-body pre code {
  background: none;
  padding: 0;
  color: #333;
  font-family: 'SFMono-Regular', Consolas, monospace;
  font-size: 0.82rem;
  white-space: pre;
}
.notes-body em { font-style: italic; color: #555; }

/* ── Tic Tac Toe board (sits inside .try-it-left where the MNIST canvas
 *    would go; uses the same card/border language as .canvas-wrapper) ─── */
.ttt-wrapper {
  border: 1px solid #e5e7eb;
  border-radius: 10px;
  overflow: hidden;
  background: #e5e7eb;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04);
  display: inline-block;
  line-height: 0;
}
.ttt-board {
  display: grid;
  grid-template-columns: repeat(3, 88px);
  grid-template-rows:    repeat(3, 88px);
  gap: 1px;
}
.ttt-cell {
  background: #fff;
  border: none;
  border-radius: 0;
  padding: 0;
  font-size: 2.6rem;
  font-weight: 500;
  font-family: 'SFMono-Regular', Consolas, monospace;
  color: #111;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.12s;
}
.ttt-cell:hover:not(:disabled) { background: #f9fafb; }
.ttt-cell:disabled { cursor: default; }
.ttt-cell.x,
.ttt-cell.o { color: #111; }
.ttt-cell.winning { background: #f0fdf4; }

.ttt-status {
  text-align: center;
  font-size: 0.95rem;
  font-weight: 500;
  color: #444;
  min-height: 1.4rem;
  padding: 0.25rem 0;
}
.ttt-status.win  { color: #065f46; font-weight: 600; }
.ttt-status.loss { color: #991b1b; font-weight: 600; }
.ttt-status.draw { color: #666;    font-weight: 600; }

.ttt-agent-picker {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 0.75rem;
  flex-wrap: wrap;
}
.ttt-agent-btn {
  padding: 0.35rem 0.75rem;
  font-size: 0.85rem;
}
.ttt-agent-btn.active {
  background: #2563eb;
  color: #fff;
  border-color: #2563eb;
}
.ttt-agent-btn.active:hover {
  background: #1d4ed8;
  border-color: #1d4ed8;
}

/* ── Responsive ───────────────────────────────────────────────────────────── */
@media (max-width: 640px) {
  .page-body, .network-page-body { padding: 1rem; }
  .try-it-layout { flex-direction: column; align-items: center; }
  .try-it-right { width: 100%; }
  .nb-in-prompt, .nb-out-prompt { width: 3rem; font-size: 0.7rem; }
  .nb-md-cell { padding-left: 3rem; }
  .ttt-board {
    grid-template-columns: repeat(3, 72px);
    grid-template-rows:    repeat(3, 72px);
  }
}