:root {
  --cl-red: #b64335;
  --cl-green: #39734d;
  --cl-gold: #9b6a12;
  --cl-blue: var(--accent, #315f9d);
  --cl-tool-bg: var(--block-bg, #f4f1e9);
  --cl-focus: #1769aa;
}

@supports (color: color-mix(in srgb, white, black)) {
  :root {
    --cl-tool-bg: color-mix(in srgb, var(--block-bg, #f4f1e9) 76%, var(--bg, #fff));
  }
}

html[data-theme="dark"] {
  --cl-red: #f08c7d;
  --cl-green: #72bd8b;
  --cl-gold: #e2b458;
  --cl-focus: #83c8ff;
}

.cl-reading-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin: 16px 0 30px;
  padding: 10px 12px 10px 16px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--cl-tool-bg);
}

.cl-mode-copy { display: grid; gap: 1px; min-width: 0; }
.cl-mode-copy strong { color: var(--fg); font-size: 14px; }
.cl-mode-copy span { color: var(--fg-soft); font-size: 12.5px; line-height: 1.5; }

.cl-segmented {
  display: inline-grid;
  grid-template-columns: repeat(2, minmax(64px, 1fr));
  flex: 0 0 auto;
  padding: 3px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg);
}

.cl-segmented button {
  min-height: 44px;
  padding: 7px 12px;
  border: 0;
  border-radius: 5px;
  background: transparent;
  color: var(--fg-soft);
  font: inherit;
  font-size: 13.5px;
  cursor: pointer;
}

.cl-segmented button[aria-pressed="true"] {
  background: var(--accent);
  color: var(--bg);
  font-weight: 700;
}

html[data-reading-mode="reference"] .learning-layer { display: none; }

.learning-layer {
  margin: 38px 0;
  padding: 4px 0 30px;
  border-top: 2px solid var(--accent);
  border-bottom: 1px solid var(--border);
  min-width: 0;
  max-width: 100%;
  overflow-x: clip;
}

article:has(> .learning-layer) {
  overflow-x: clip;
}

html:has(.learning-layer) {
  overflow-x: clip;
}

.learning-layer > h2:first-child { margin-top: 1.3em; }

.learning-layer div.arithmatex,
article > div.arithmatex {
  display: block;
  max-width: 100%;
  overflow-x: auto;
  overflow-y: hidden;
  -webkit-overflow-scrolling: touch;
}

.learning-layer div.arithmatex .katex-display,
article > div.arithmatex .katex-display {
  overflow-x: auto;
  overflow-y: hidden;
  text-align: left;
}

.learning-layer table {
  max-width: 100%;
}

.learning-layer .katex-mathml {
  left: 0;
}

.learning-layer pre {
  max-width: 100%;
  overflow-x: auto;
}

.learning-layer .cl-prompt,
.cl-transfer {
  padding: 14px 16px;
  border-left: 4px solid var(--cl-gold);
  background: var(--block-bg);
}

.learning-lab {
  margin: 22px 0;
  padding: 18px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--cl-tool-bg);
  color: var(--fg);
  overflow: hidden;
}

html.cl-js:not(.cl-fallback-ready) .learning-lab:not([data-cl-mounted="true"]):not([data-cl-error="true"]) {
  position: relative;
  min-height: 120px;
}

html.cl-js:not(.cl-fallback-ready) .learning-lab:not([data-cl-mounted="true"]):not([data-cl-error="true"]) > * {
  visibility: hidden;
}

html.cl-js:not(.cl-fallback-ready) .learning-lab:not([data-cl-mounted="true"]):not([data-cl-error="true"])::before {
  position: absolute;
  inset: 18px;
  display: grid;
  place-items: center;
  content: "正在装载互动实验...";
  color: var(--fg-soft);
  font-size: 13px;
}

.learning-lab[data-learning-lab="feynman"],
.learning-lab[data-learning-lab="qec"],
.learning-lab[data-learning-lab="backprop"],
.learning-lab[data-learning-lab="transformer"],
.learning-lab[data-learning-lab="wasserstein-geodesic"],
.learning-lab[data-learning-lab="data-provenance"] {
  padding: 0;
  border: 0;
  background: transparent;
}

.learning-lab[data-cl-error="true"] { border-left: 4px solid var(--cl-red); }
.learning-lab h3, .learning-lab h4 { margin-top: 0; }
.learning-lab p { margin: .65em 0; }
.learning-lab svg { display: block; width: 100%; height: auto; color: var(--fg); }
.learning-lab svg text:not([fill]) { fill: currentColor; font-family: inherit; letter-spacing: 0; }

.cl-grid {
  display: grid;
  grid-template-columns: minmax(190px, .75fr) minmax(0, 1.25fr);
  gap: 18px;
  align-items: start;
}

.cl-controls { display: grid; gap: 14px; }
.cl-control { display: grid; gap: 6px; }
.cl-control > span, .cl-label { color: var(--fg-soft); font-size: 13px; font-weight: 650; }
.cl-control output { color: var(--accent); font-variant-numeric: tabular-nums; }

.learning-lab button,
.learning-lab select,
.learning-lab input[type="number"] {
  min-height: 44px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--bg);
  color: var(--fg);
  font: inherit;
  letter-spacing: 0;
}

.learning-lab button { padding: 8px 13px; cursor: pointer; }
.learning-lab button:hover { border-color: var(--accent); }
.learning-lab button[aria-pressed="true"],
.learning-lab button.cl-primary { background: var(--accent); border-color: var(--accent); color: var(--bg); }
.learning-lab button:disabled { cursor: not-allowed; opacity: .55; }
.learning-lab select, .learning-lab input[type="number"] { width: 100%; padding: 7px 10px; }
.learning-lab input[type="range"] { width: 100%; min-height: 44px; accent-color: var(--accent); }

.learning-lab button:focus-visible,
.learning-lab select:focus-visible,
.learning-lab input:focus-visible,
.cl-segmented button:focus-visible {
  outline: 3px solid var(--cl-focus);
  outline: 3px solid color-mix(in srgb, var(--cl-focus) 55%, transparent);
  outline-offset: 2px;
}

.cl-button-row { display: flex; flex-wrap: wrap; gap: 8px; }
.cl-button-row > * { flex: 1 1 auto; }
.cl-stage { min-width: 0; }
.cl-stage-frame { padding: 10px; border: 1px solid var(--border); border-radius: 6px; background: var(--bg); }
.cl-stage-title { display: flex; justify-content: space-between; gap: 12px; margin-bottom: 8px; font-size: 13px; color: var(--fg-soft); }

.cl-metrics {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 8px;
  margin-top: 12px;
}

.cl-metric { min-width: 0; padding: 10px; border-top: 2px solid var(--border); background: var(--bg); }
.cl-metric span { display: block; color: var(--fg-soft); font-size: 11.5px; line-height: 1.4; }
.cl-metric strong { display: block; margin-top: 3px; color: var(--fg); font-size: 16px; font-variant-numeric: tabular-nums; overflow-wrap: anywhere; }

.cl-checklist { display: grid; gap: 7px; margin: 12px 0 0; padding: 0; list-style: none; }
.cl-checklist li { display: grid; grid-template-columns: 24px 1fr; gap: 7px; align-items: start; }
.cl-checklist .cl-pass { color: var(--cl-green); font-weight: 800; }
.cl-checklist .cl-fail { color: var(--cl-red); font-weight: 800; }

.cl-matrix { width: 100%; border-collapse: separate; border-spacing: 4px; table-layout: fixed; margin: 0; display: table; }
.cl-matrix th, .cl-matrix td { border: 0; padding: 7px 4px; text-align: center; font-variant-numeric: tabular-nums; }
.cl-matrix th { background: transparent; color: var(--fg-soft); font-size: 12px; }
.cl-matrix td {
  border: 1px solid var(--border);
  border: 1px solid color-mix(in srgb, var(--border) 75%, transparent);
  border-radius: 4px;
}

.cl-stepper { display: grid; gap: 12px; }
.cl-step-list { display: grid; grid-template-columns: repeat(auto-fit, minmax(90px, 1fr)); gap: 6px; }
.cl-step-list button { min-width: 0; font-size: 12.5px; padding: 7px; }
.cl-step-list button[aria-current="step"] { border-color: var(--accent); box-shadow: inset 0 -3px 0 var(--accent); font-weight: 700; }
.cl-formula { overflow-x: auto; padding: 10px 12px; border-left: 3px solid var(--accent); background: var(--bg); font-family: "SF Mono", Menlo, Consolas, monospace; font-size: 13px; line-height: 1.65; }
.cl-note { color: var(--fg-soft); font-size: 13px; line-height: 1.65; }
.cl-good { color: var(--cl-green); }
.cl-warn { color: var(--cl-red); }

.cl-sr-only {
  position: absolute !important;
  width: 1px !important;
  height: 1px !important;
  padding: 0 !important;
  margin: -1px !important;
  overflow: hidden !important;
  clip: rect(0, 0, 0, 0) !important;
  white-space: nowrap !important;
  border: 0 !important;
}

@media (max-width: 700px) {
  .cl-reading-toolbar { align-items: stretch; flex-direction: column; }
  .cl-segmented { width: 100%; }
  .cl-segmented button { min-height: 44px; }
  .learning-layer { margin: 30px 0; }
  .learning-lab { margin-left: -8px; margin-right: -8px; padding: 14px; }
  .cl-grid { grid-template-columns: minmax(0, 1fr); }
  .cl-stage-frame { padding: 7px; }
  .cl-matrix { font-size: 12px; border-spacing: 2px; }
  .cl-matrix th, .cl-matrix td { padding: 6px 2px; }
}

@media (prefers-reduced-motion: reduce) {
  .learning-lab *, .cl-reading-toolbar * {
    scroll-behavior: auto !important;
    transition: none !important;
    animation: none !important;
  }
}