:root {
  color-scheme: light;
  --bg: #faf8f1;
  --surface: #fffefa;
  --text: #24211e;
  --muted: #696258;
  --border: #ded8cb;
  --control: #9e9588;
  --accent: #62518b;
  --soft: #f1edf6;
  --success: #0f766e;
  --warning: #b45309;
  --danger: #b42318;
  --focus: #62518b;
  --radius: 14px;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.6 system-ui, -apple-system, "Segoe UI", "Microsoft YaHei", "PingFang SC", sans-serif;
}
.optimization-studio {
  max-width: 1600px;
  margin: auto;
  padding: 16px 24px 24px;
}
.optimization-studio > header {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  column-gap: 24px;
  margin-bottom: 12px;
}
.eyebrow { display: none; }
h1 {
  margin: 0;
  font: 600 29px/1.3 "Noto Serif CJK SC", "Songti SC", "SimSun", serif;
  letter-spacing: -0.025em;
}
h2 { font-size: 18px; line-height: 1.4; margin: 0 0 12px; }
h3 { font-size: 16px; margin: 0 0 8px; }
p { margin: 6px 0; }
.intro { margin: 0; color: var(--muted); font-size: 15px; }
.panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
}
.function-panel { position: relative; margin-bottom: 16px; padding: 12px 16px; }
.function-row { margin-right: 204px; }
#function-options > summary { position: absolute; top: 39px; right: 16px; width: 188px; border: 1px solid var(--control); border-radius: 8px; padding: 8px 12px; color: var(--muted); background: var(--surface); }
#function-options[open] { margin-top: 16px; border-top: 1px solid var(--border); padding-top: 12px; }
.function-row {
  display: grid;
  grid-template-columns: 186px minmax(0, 1fr) 112px;
  gap: 16px;
  align-items: end;
}
.function-row label, .field label {
  display: block;
  font-weight: 600;
  font-size: 14px;
  margin-bottom: 5px;
}
input, select, button {
  font: inherit;
  max-width: 100%;
  min-width: 0;
  min-height: 44px;
  border: 1px solid var(--control);
  border-radius: 8px;
  background: var(--surface);
  color: var(--text);
}
input:not([type="range"]), select { width: 100%; padding: 8px 10px; }
#expression { font-family: ui-monospace, SFMono-Regular, Consolas, monospace; }
input[type="range"] { width: 100%; min-height: 28px; accent-color: var(--accent); }
input[aria-invalid="true"] { border: 2px solid var(--danger); }
button { padding: 8px 12px; cursor: pointer; font-weight: 600; line-height: 1.45; }
button:hover { background: var(--soft); border-color: var(--accent); }
button:disabled { opacity: .5; cursor: default; }
button.primary { background: var(--accent); color: white; border-color: var(--accent); }
button.primary:hover { background: #514173; }
:focus-visible { outline: 3px solid var(--focus); outline-offset: 3px; }
.hint { font-size: 14px; color: var(--muted); line-height: 1.5; }
.error { color: var(--danger); }
#input-error:empty { display: none; }
details { margin: 8px 0; }
summary {
  cursor: pointer;
  font-size: 14px;
  font-weight: 600;
  min-height: 44px;
  padding: 10px 0;
  line-height: 1.6;
  color: var(--muted);
}
summary:hover { color: var(--accent); }
.function-panel details { margin: 2px 0 0; }
.function-panel details[open] { padding-bottom: 10px; }
.settings-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 16px; margin-top: 12px; }
.lab { display: grid; grid-template-columns: 272px minmax(0, 1fr); gap: 18px; align-items: start; }
.controls { padding: 16px; }
.controls h2 { font-size: 16px; margin: 0; }
.control-heading { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin: -4px 0 8px; }
.math-jump { display: inline-flex; align-items: center; min-height: 44px; padding: 8px 0; color: var(--accent); font-size: 13px; text-decoration-thickness: 1px; text-underline-offset: 4px; white-space: nowrap; }
.actions { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.actions .wide { grid-column: 1/-1; }
.status { color: var(--accent); font-size: 14px; margin: 10px 0 16px; line-height: 1.5; overflow-wrap: anywhere; }
.controls .field { margin: 14px 0; }
.controls > .field > .hint { font-size: 13px; margin-top: 2px; }
.controls .algorithm-copy {
  margin: 0 0 4px;
  padding: 0;
  font-size: 14px;
  line-height: 1.6;
  color: var(--muted);
}
.algorithm-copy p { margin: 0; }
.algorithm-help { margin: 0; }
.algorithm-help summary { color: var(--accent); }
.algorithm-help p { margin: 8px 0; }
.controls > details:not(.algorithm-help) { border-top: 1px solid var(--border); margin: 4px 0; }
.controls > .actions:last-of-type { margin-top: 16px; }
.reset-help .control-note { font-size: 13px; color: var(--muted); line-height: 1.55; }
.presets { display: grid; gap: 8px; }
.presets button { text-align: left; font-size: 14px; }
.pairs { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.results { min-width: 0; padding: 14px 16px 16px; }
.metrics {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
  padding: 0 0 12px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 14px;
}
.metrics > div + div { border-left: 1px solid var(--border); padding-left: 16px; }
.metrics small { display: block; font-size: 13px; color: var(--muted); }
.metrics strong { display: block; font-size: 24px; font-weight: 600; font-variant-numeric: tabular-nums; line-height: 1.4; overflow-wrap: anywhere; }
.coordinated-views {
  display: grid;
  grid-template-columns: minmax(0, .94fr) minmax(0, 1.25fr);
  gap: 24px;
  align-items: start;
}
.chart { min-width: 0; }
.chart-head { display: flex; justify-content: space-between; align-items: center; gap: 8px; min-height: 32px; margin-bottom: 4px; }
.chart-head h2 { font-size: 16px; font-weight: 600; margin: 0; }
.chart-head label { font-size: 13px; color: var(--muted); }
.chart-head input { max-width: 78px; vertical-align: middle; }
.chart canvas { display: block; width: 100%; background: var(--surface); touch-action: none; }
.main-contour canvas { height: 366px; }
.chart-instruction { font-size: 13px; color: var(--muted); margin: 2px 0 0; }
.side-evidence { display: grid; gap: 10px; }
.surface-chart canvas { height: 216px; }
.convergence-chart canvas { height: 132px; }
.field-switch { display: inline-flex; align-items: center; min-height: 32px; gap: 6px; cursor: pointer; white-space: nowrap; }
.field-switch input { width: 17px; min-height: 17px; accent-color: var(--accent); }
.legend { display: flex; align-items: center; gap: 6px 16px; flex-wrap: wrap; font-size: 13px; color: var(--muted); margin: 12px 0; }
.line-key { display: inline-block; width: 20px; height: 3px; background: var(--warning); vertical-align: middle; }
.line-key.reference { background: repeating-linear-gradient(90deg, #2457c5 0 5px, transparent 5px 8px); }
.line-key.best { background: var(--success); }
.line-key.gradient { background: #2457c5; }
.scale { display: inline-block; width: 64px; height: 10px; vertical-align: middle; border: 1px solid var(--control); background: linear-gradient(90deg, #f5f4ef, #44689a); }
.comparison-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 12px 0;
  margin: 4px 0 10px;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}
#comparison-summary { display: grid; gap: 4px; min-width: 0; font-size: 13px; line-height: 1.5; }
#comparison-summary strong { font-size: 14px; font-weight: 600; }
.comparison-actions { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 8px; flex-shrink: 0; }
.comparison-actions button { font-size: 13px; min-height: 44px; padding: 6px 10px; }
#batch { background: var(--soft); color: var(--accent); border-color: #aba0bd; }
.comparison-evidence { color: var(--accent); font-weight: 600; }
.surface-note { font-size: 13px; color: var(--muted); line-height: 1.55; margin: 6px 0; overflow-wrap: anywhere; }
.result-note { margin-top: 8px; font-size: 14px; color: var(--text); line-height: 1.6; }
.failure-note { margin: 0 0 12px; padding: 10px 12px; border-left: 3px solid var(--accent); background: var(--soft); font-size: 14px; overflow-wrap: anywhere; }
.failure-note.error { border-color: var(--danger); background: #fff1e8; }
.failure-note[hidden] { display: none; }
.calculation-panel { margin: 16px 0 12px; padding: 6px 16px; }
.calculation-panel > summary { font-size: 16px; color: var(--text); }
.process { border-top: 1px solid var(--border); padding-top: 12px; }
.math-toolbar { display: flex; align-items: center; justify-content: space-between; gap: 16px; flex-direction: row-reverse; margin-bottom: 12px; }
.math-toolbar button { font-size: 14px; min-height: 44px; }
.phase-tabs { display: flex; gap: 6px; flex-wrap: wrap; }
.phase-tabs span { padding: 6px 10px; border-bottom: 2px solid transparent; font-size: 15px; color: var(--muted); }
.phase-tabs .active { color: var(--accent); border-bottom-color: var(--accent); font-weight: 600; }
.process-text { font-size: 14px; min-height: 22px; margin: 8px 0 16px; }
.math-rows { display: grid; gap: 16px; }
.math-row { display: grid; grid-template-columns: 28px repeat(4, minmax(0, 1fr)); align-items: stretch; gap: 24px; }
.coordinate { font-weight: 600; align-self: center; color: var(--accent); font-size: 22px; }
.math-node { position: relative; border: 1px solid var(--border); border-radius: 10px; background: #fbf9f4; padding: 12px 14px; min-width: 0; }
.math-node + .math-node:before { content: "→"; position: absolute; left: -22px; top: 40%; font-size: 20px; color: var(--accent); }
.math-node small { display: block; font-size: 13px; color: var(--muted); margin-bottom: 6px; }
.math-node .equation { font-size: 14px; overflow-wrap: anywhere; line-height: 1.7; }
.math-node strong { font-size: 21px; font-weight: 600; font-variant-numeric: tabular-nums; display: block; color: var(--accent); line-height: 1.45; margin-top: 8px; overflow-wrap: anywhere; }
.math-node.hidden-phase { background: #f7f4ed; border-style: dashed; }
.math-node.commit { background: #f0f6f3; border-color: #b6cbc1; }
.math-node.commit strong { color: var(--success); }
.compare-flow { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 24px; }
.probability { margin-top: 16px; padding: 16px; background: #f4f1e9; border-radius: 10px; }
.probability-labels { display: flex; justify-content: space-between; gap: 12px; font-size: 13px; }
.prob-track { position: relative; height: 28px; margin: 24px 2px 8px; border: 1px solid var(--control); background: var(--surface); }
.prob-accepted { height: 100%; background: #d3e6e2; border-right: 2px solid var(--success); }
.prob-u { position: absolute; top: -10px; height: 46px; border-left: 3px solid var(--warning); }
.prob-u:before { content: "u"; position: absolute; top: -16px; left: -5px; font-size: 13px; color: var(--warning); font-weight: 600; }
.prob-p { position: absolute; bottom: -24px; color: var(--success); font-size: 13px; transform: translateX(-50%); }
.prob-rule { font-size: 14px; margin: 28px 0 0; }
.decision { margin: 16px 0 8px; border-left: 3px solid var(--accent); padding-left: 12px; font-size: 14px; }
.formula-guide { margin: 16px 0 8px; padding-top: 12px; border-top: 1px solid var(--border); }
.formula-guide #algorithm-formula { display: block; overflow-x: auto; padding: 6px 0; font-size: 17px; }
.formula-guide p { margin: 8px 0; }
.empty-process { padding: 10px 0; font-size: 14px; color: var(--muted); }
.ledger-section { padding: 4px 16px; }
.ledger-section details { margin: 0; }
.readings { overflow: auto; }
table { border-collapse: collapse; width: 100%; font-size: 14px; }
th, td { border-bottom: 1px solid var(--border); padding: 8px 10px; text-align: left; white-space: nowrap; font-variant-numeric: tabular-nums; }
.learning { margin-top: 14px; display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.learning-note { padding: 4px 16px; }
.learning-note > details { margin: 0; }
.learning-note p { font-size: 15px; }
.learning-note > details > summary { color: var(--text); }
.reference-stop { overflow-wrap: anywhere; }
footer { font-size: 13px; color: var(--muted); padding: 16px 0; }
noscript { display: block; background: #fff3e3; padding: 20px; border: 1px solid var(--warning); }
@media (min-width: 1600px) {
  .optimization-studio { padding-top: 22px; }
  .function-panel { margin-bottom: 20px; }
  .lab { grid-template-columns: 288px minmax(0, 1fr); gap: 24px; }
  .coordinated-views { grid-template-columns: minmax(0, 1fr) minmax(0, 1.15fr); gap: 28px; }
  .main-contour canvas { height: 470px; }
  .surface-chart canvas { height: 280px; }
  .convergence-chart canvas { height: 172px; }
  .metrics strong { font-size: 28px; }
  .math-node .equation { font-size: 15px; }
}
@media (max-width: 1120px) {
  .optimization-studio { padding: 16px; }
  .lab { grid-template-columns: 250px minmax(0, 1fr); gap: 16px; }
  .coordinated-views { grid-template-columns: minmax(0, 1fr); gap: 16px; }
  .main-contour canvas { height: 440px; }
  .side-evidence { grid-template-columns: 1fr 1fr; gap: 16px; }
  .surface-chart canvas, .convergence-chart canvas { height: 190px; }
  .comparison-bar { flex-direction: column; align-items: stretch; gap: 12px; }
  .comparison-actions { grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .metrics { gap: 12px; }
  .metrics > div + div { padding-left: 12px; }
  .metrics strong { font-size: 21px; }
  .math-row { grid-template-columns: 24px repeat(2, minmax(0, 1fr)); gap: 12px; }
  .math-node:nth-child(4) { grid-column: 2; }
  .math-node + .math-node:before { display: none; }
  .math-toolbar { align-items: flex-start; flex-direction: column-reverse; }
  .settings-grid { grid-template-columns: 1fr 1fr; }
  .compare-flow { grid-template-columns: 1fr; gap: 12px; }
}
@media (max-width: 760px) {
  .optimization-studio { padding: 12px; }
  .optimization-studio > header { gap: 8px; margin-bottom: 16px; }
  h1 { font-size: 26px; }
  .function-row { grid-template-columns: 1fr; gap: 12px; margin-right: 0; }
  #function-options > summary { position: static; width: auto; border: 0; padding: 10px 0; background: none; }
  #function-options[open] { margin-top: 4px; }
  .function-row button { width: 100%; }
  .lab { grid-template-columns: 1fr; }
  .controls { padding: 16px; }
  .controls .field { margin: 16px 0; }
  .metrics { grid-template-columns: 1fr 1fr; gap: 12px 16px; }
  .metrics > div:nth-child(3) { border-left: 0; padding-left: 0; }
  .metrics strong { font-size: 23px; }
  .coordinated-views { gap: 20px; }
  .side-evidence { grid-template-columns: 1fr; }
  .main-contour canvas { height: 338px; }
  .surface-chart canvas { height: 235px; }
  .convergence-chart canvas { height: 185px; }
  .chart-head h2 { font-size: 16px; }
  .comparison-actions { grid-template-columns: 1fr 1fr; }
  .chart-instruction { font-size: 13px; }
  .calculation-panel { padding: 6px 12px; }
  .math-row { gap: 8px; grid-template-columns: 20px repeat(2, minmax(0, 1fr)); }
  .math-node { padding: 10px; }
  .math-node .equation { font-size: 13px; }
  .math-node strong { font-size: 18px; }
  .phase-tabs span { font-size: 13px; padding: 6px; }
  .legend { gap: 8px 12px; }
  .formula-guide #algorithm-formula { font-size: 15px; }
  .learning { grid-template-columns: 1fr; }
}
@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; scroll-behavior: auto; }
}