:root {
  --bg: #f6f4ef;
  --ink: #1c1b19;
  --muted: #6b6560;
  --card: #fffdf8;
  --line: #e4ddd2;
  --accent: #0f5c4c;
  --accent-soft: #e6f2ef;
  --warn: #8a3b12;
  --warn-soft: #fbefe6;
  --mono: "JetBrains Mono", "SF Mono", Consolas, monospace;
  --sans: "PingFang SC", "Microsoft YaHei", -apple-system, sans-serif;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: var(--sans);
  background: var(--bg);
  color: var(--ink);
  line-height: 1.55;
  font-size: 15px;
}
header {
  background: var(--ink);
  color: #f3efe8;
  padding: 28px 24px 22px;
}
header h1 {
  margin: 0 0 6px;
  font-size: 22px;
  font-weight: 600;
}
header p {
  margin: 0;
  color: #b7b0a6;
  font-size: 13px;
  max-width: 820px;
}
main {
  max-width: 1080px;
  margin: 0 auto;
  padding: 24px 16px 64px;
}
.tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 20px;
}
.tab {
  border: 1px solid var(--line);
  background: var(--card);
  color: var(--muted);
  padding: 8px 14px;
  border-radius: 999px;
  cursor: pointer;
  font-size: 13px;
  font-family: var(--sans);
}
.tab.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}
.panel {
  display: none;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 20px;
}
.panel.active { display: block; }
h2 {
  margin: 0 0 4px;
  font-size: 18px;
  font-weight: 600;
}
.sub {
  color: var(--muted);
  font-size: 13px;
  margin: 0 0 14px;
}
.formula {
  background: var(--accent-soft);
  border-left: 3px solid var(--accent);
  padding: 10px 14px;
  border-radius: 0 8px 8px 0;
  font-family: var(--mono);
  font-size: 12.5px;
  margin: 0 0 16px;
  overflow-x: auto;
  white-space: pre-wrap;
}
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 12px;
  margin-bottom: 12px;
}
.grid2 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 12px;
  margin-bottom: 12px;
}
.card {
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 12px;
  background: #faf8f3;
}
.card h3 {
  margin: 0 0 8px;
  font-size: 14px;
}
label {
  display: block;
  font-size: 12px;
  color: var(--muted);
  margin-bottom: 4px;
}
input, select {
  width: 100%;
  padding: 8px 10px;
  border: 1px solid var(--line);
  border-radius: 8px;
  font-size: 14px;
  font-family: var(--mono);
  background: #fff;
  color: var(--ink);
}
input:focus {
  outline: 2px solid var(--accent-soft);
  border-color: var(--accent);
}
.row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: end;
  margin: 10px 0 14px;
}
.check {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
}
.check input { width: auto; }
button.primary {
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 8px;
  padding: 10px 16px;
  font-size: 14px;
  cursor: pointer;
  font-family: var(--sans);
}
button.primary:hover { filter: brightness(1.08); }
button.ghost {
  background: transparent;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 9px 12px;
  font-size: 13px;
  cursor: pointer;
  color: var(--muted);
  font-family: var(--sans);
}
.results {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
  gap: 10px;
  margin: 8px 0 12px;
}
.metric {
  background: #f3f0e9;
  border-radius: 10px;
  padding: 12px;
}
.metric .k {
  font-size: 11px;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
.metric .v {
  font-family: var(--mono);
  font-size: 20px;
  font-weight: 600;
  color: var(--accent);
  margin-top: 2px;
}
.metric .v.warn { color: var(--warn); }
.note {
  background: var(--warn-soft);
  color: var(--warn);
  border-radius: 8px;
  padding: 10px 12px;
  font-size: 13px;
  margin: 10px 0;
}
table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
  margin: 8px 0 12px;
}
th, td {
  border-bottom: 1px solid var(--line);
  padding: 8px 6px;
  text-align: left;
  font-family: var(--mono);
  font-size: 12.5px;
}
th {
  color: var(--muted);
  font-weight: 500;
  font-size: 12px;
}
td input {
  padding: 5px 6px;
  font-size: 12.5px;
}
canvas {
  width: 100%;
  max-width: 640px;
  height: auto;
  display: block;
  margin: 12px 0;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
}
.examples {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 8px 0 14px;
}
.chip {
  border: 1px dashed var(--line);
  background: #fff;
  border-radius: 8px;
  padding: 6px 10px;
  font-size: 12px;
  cursor: pointer;
  color: var(--muted);
  font-family: var(--sans);
}
.chip:hover { border-color: var(--accent); color: var(--accent); }
.copula-btn.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}
.multi-rows { display: flex; flex-direction: column; gap: 8px; }
.multi-row {
  display: grid;
  grid-template-columns: 1.1fr 1fr 1fr 1fr;
  gap: 8px;
  align-items: end;
}
/* 宽表格/相关矩阵可横向滑动 */
#n-corr, #n-corr .corr-table, .corr-table {
  max-width: 100%;
}
#n-corr { overflow-x: auto; -webkit-overflow-scrolling: touch; }
table {
  display: table;
  max-width: 100%;
}
.panel table, #m-compare-table, #s-table, #n-joint, #t-joint, #n-weights, #t-weights, #o-weights {
  overflow-x: auto;
}
.corr-table input {
  width: 72px;
  text-align: center;
}
.src {
  font-size: 12px;
  color: var(--muted);
  margin-top: 10px;
  font-family: var(--mono);
}
footer {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 16px 40px;
  color: var(--muted);
  font-size: 12px;
}
@media (max-width: 720px) {
  body { font-size: 14px; }
  header { padding: 18px 14px 14px; }
  header h1 { font-size: 18px; }
  main { padding: 14px 10px 48px; }
  .panel { padding: 12px; }
  .formula { font-size: 11px; padding: 8px 10px; }
  .tab { padding: 7px 10px; font-size: 12px; }
  .row {
    gap: 8px;
    margin: 8px 0 12px;
  }
  .row > * { flex: 1 1 140px; min-width: 0; }
  .row button.primary,
  .row button.ghost { width: 100%; }
  .grid, .grid2 {
    grid-template-columns: 1fr 1fr;
    gap: 8px;
  }
  .card { padding: 8px; }
  /* 状态/概率/收益 两列铺满，避免 4 列挤爆 */
  .multi-row {
    grid-template-columns: 1fr 1fr;
    gap: 6px;
  }
  .multi-row > div:first-child { grid-column: 1 / -1; }
  .corr-table input { width: 56px; padding: 6px 4px; }
  #n-corr input { width: 52px; }
  .results {
    grid-template-columns: 1fr 1fr;
    gap: 8px;
  }
  .metric .v { font-size: 16px; }
  table { font-size: 11px; }
  th, td { padding: 6px 4px; }
  .note { font-size: 12px; }
  canvas { height: 200px; }
}