:root {
  --ground: #EEF1F4;
  --surface: #FFFFFF;
  --surface-sunk: #E4E9ED;
  --ink: #131820;
  --ink-soft: #4E5A67;
  --ink-faint: #8794A1;
  --rule: #D2DAE1;
  --rule-firm: #B3BFC9;
  --tungsten: #B0700A;
  --tungsten-wash: #F6E9D2;
  --teal: #0C6E78;
  --teal-wash: #DCEBEC;
  --alarm: #A33224;
  --shadow: 0 1px 2px rgba(19, 24, 32, .06), 0 8px 24px -16px rgba(19, 24, 32, .18);

  --mono: ui-monospace, "SF Mono", SFMono-Regular, "Cascadia Mono", Menlo, Consolas, monospace;
  --serif: ui-serif, Charter, "Iowan Old Style", Georgia, "Times New Roman", serif;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --ground: #0F1318;
    --surface: #171C23;
    --surface-sunk: #10151A;
    --ink: #E6EBF0;
    --ink-soft: #A3AFBB;
    --ink-faint: #6C7885;
    --rule: #2A323B;
    --rule-firm: #3C4650;
    --tungsten: #E5A63D;
    --tungsten-wash: #33260F;
    --teal: #4FB8C0;
    --teal-wash: #102A2C;
    --alarm: #E0705E;
    --shadow: 0 1px 2px rgba(0, 0, 0, .4), 0 8px 24px -16px rgba(0, 0, 0, .7);
  }
}

:root[data-theme="dark"] {
  --ground: #0F1318;
  --surface: #171C23;
  --surface-sunk: #10151A;
  --ink: #E6EBF0;
  --ink-soft: #A3AFBB;
  --ink-faint: #6C7885;
  --rule: #2A323B;
  --rule-firm: #3C4650;
  --tungsten: #E5A63D;
  --tungsten-wash: #33260F;
  --teal: #4FB8C0;
  --teal-wash: #102A2C;
  --alarm: #E0705E;
  --shadow: 0 1px 2px rgba(0, 0, 0, .4), 0 8px 24px -16px rgba(0, 0, 0, .7);
}

/* Chinese edition: a CJK serif for running text, mono still carries every number. */
:root[lang="zh-Hans"] {
  --serif: "Songti SC", "Noto Serif CJK SC", "Source Han Serif SC", "SimSun", ui-serif, Georgia, serif;
}

* { box-sizing: border-box; }

html { color-scheme: light dark; }

body {
  margin: 0;
  background: var(--ground);
  color: var(--ink);
  font-family: var(--serif);
  font-size: 17px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

:root[lang="zh-Hans"] body { line-height: 1.85; }

.page {
  max-width: 60rem;
  margin: 0 auto;
  padding: 3.5rem 1.5rem 6rem;
  display: flex;
  flex-direction: column;
  gap: 3.25rem;
}

/* ---------- language switch ---------- */
.langbar {
  display: flex;
  justify-content: flex-end;
  gap: .4rem;
  font-family: var(--mono);
  font-size: .72rem;
  letter-spacing: .08em;
  text-transform: uppercase;
}
.langbar a {
  color: var(--ink-faint);
  text-decoration: none;
  padding: .25rem .6rem;
  border: 1px solid var(--rule);
  border-radius: 2px;
}
.langbar a:hover { color: var(--ink); border-color: var(--rule-firm); }
.langbar a[aria-current="page"] {
  color: var(--teal);
  border-color: var(--teal);
  font-weight: 700;
}

/* ---------- type ---------- */
.eyebrow {
  font-family: var(--mono);
  font-size: .72rem;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin: 0;
}

h1 {
  font-family: var(--mono);
  font-size: clamp(2rem, 5.5vw, 3rem);
  font-weight: 600;
  letter-spacing: -.02em;
  line-height: 1.05;
  text-wrap: balance;
  margin: .5rem 0 0;
}

h2 {
  font-family: var(--mono);
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: .04em;
  text-transform: uppercase;
  margin: 0;
  padding-bottom: .6rem;
  border-bottom: 1px solid var(--rule-firm);
  color: var(--ink);
}

h3 {
  font-family: var(--mono);
  font-size: .82rem;
  font-weight: 600;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--ink-soft);
  margin: 0;
}

p { margin: 0; max-width: 65ch; }
.lede { font-size: 1.18rem; color: var(--ink-soft); max-width: 58ch; }
strong { font-weight: 600; color: var(--ink); }
.num { font-family: var(--mono); font-variant-numeric: tabular-nums; }

section { display: flex; flex-direction: column; gap: 1.25rem; }

/* ---------- header meta ---------- */
.meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0 2rem;
  font-family: var(--mono);
  font-size: .78rem;
  color: var(--ink-soft);
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
  padding: .75rem 0;
}
.meta span { white-space: nowrap; }
.meta b { color: var(--ink); font-weight: 600; }

/* ---------- option cards ---------- */
.options {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(17rem, 1fr));
  gap: 1.25rem;
}

.card {
  background: var(--surface);
  border: 1px solid var(--rule);
  border-top: 3px solid var(--edge);
  box-shadow: var(--shadow);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: .85rem;
}
.card.a { --edge: var(--tungsten); }
.card.b { --edge: var(--teal); }

.card-tag {
  font-family: var(--mono);
  font-size: .7rem;
  letter-spacing: .13em;
  text-transform: uppercase;
  color: var(--edge);
  font-weight: 700;
}
.card-name {
  font-family: var(--mono);
  font-size: 1.35rem;
  font-weight: 600;
  letter-spacing: -.01em;
  line-height: 1.2;
  margin: 0;
}
.price {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: 2.5rem;
  font-weight: 600;
  letter-spacing: -.03em;
  line-height: 1;
  color: var(--edge);
}
.price small {
  display: block;
  font-size: .74rem;
  font-weight: 400;
  letter-spacing: .06em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin-top: .4rem;
}
.card p { font-size: .95rem; color: var(--ink-soft); max-width: none; }
.card dl {
  margin: 0;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: .3rem 1rem;
  font-family: var(--mono);
  font-size: .8rem;
  font-variant-numeric: tabular-nums;
  border-top: 1px solid var(--rule);
  padding-top: .85rem;
}
.card dt { color: var(--ink-faint); }
.card dd { margin: 0; text-align: right; color: var(--ink); }

.pill {
  align-self: flex-start;
  font-family: var(--mono);
  font-size: .68rem;
  letter-spacing: .1em;
  text-transform: uppercase;
  padding: .22rem .55rem;
  border-radius: 2px;
  background: var(--teal-wash);
  color: var(--teal);
  font-weight: 700;
}

/* ---------- 24h capacity strip ---------- */
.strip-block {
  background: var(--surface);
  border: 1px solid var(--rule);
  box-shadow: var(--shadow);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  overflow-x: auto;
}
.strip-row { display: flex; flex-direction: column; gap: .5rem; min-width: 30rem; }
.strip-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 1rem;
  font-family: var(--mono);
  font-size: .78rem;
  color: var(--ink-soft);
}
.strip-head b {
  color: var(--ink);
  font-weight: 600;
  letter-spacing: .06em;
  text-transform: uppercase;
  font-size: .72rem;
}
.strip {
  display: grid;
  grid-template-columns: repeat(24, 1fr);
  gap: 2px;
  height: 76px;
  align-items: end;
  background: var(--surface-sunk);
  padding: 3px;
}
.strip i { display: block; width: 100%; }
.strip.a i { background: var(--tungsten); }
.strip.b i { background: var(--teal); }
.strip i.low { opacity: .32; }
.axis {
  display: grid;
  grid-template-columns: repeat(24, 1fr);
  gap: 2px;
  padding: 0 3px;
  font-family: var(--mono);
  font-size: .58rem;
  color: var(--ink-faint);
  font-variant-numeric: tabular-nums;
}
.axis span { text-align: center; }

/* ---------- tables ---------- */
.scroll {
  overflow-x: auto;
  border: 1px solid var(--rule);
  background: var(--surface);
  box-shadow: var(--shadow);
}
table {
  border-collapse: collapse;
  width: 100%;
  font-family: var(--mono);
  font-size: .84rem;
  font-variant-numeric: tabular-nums;
}
th, td {
  text-align: left;
  padding: .6rem .9rem;
  border-bottom: 1px solid var(--rule);
  white-space: nowrap;
}
thead th {
  font-size: .68rem;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--ink-faint);
  font-weight: 600;
  background: var(--surface-sunk);
  border-bottom: 1px solid var(--rule-firm);
}
td.n, th.n { text-align: right; }
tbody tr:last-child td { border-bottom: 0; }
tr.total td {
  font-weight: 700;
  background: var(--surface-sunk);
  border-top: 1px solid var(--rule-firm);
}
.swatch-a { color: var(--tungsten); font-weight: 700; }
.swatch-b { color: var(--teal); font-weight: 700; }
.warn { color: var(--alarm); font-weight: 600; }

/* ---------- sensitivity bars ---------- */
.bars { display: flex; flex-direction: column; gap: .45rem; }
.bar-row {
  display: grid;
  grid-template-columns: 6rem 1fr 5rem;
  align-items: center;
  gap: .75rem;
  font-family: var(--mono);
  font-size: .8rem;
  font-variant-numeric: tabular-nums;
}
.bar-row .label { color: var(--ink-soft); text-align: right; }
.track { background: var(--surface-sunk); height: 20px; }
.fill { display: block; height: 100%; background: var(--teal); opacity: .85; }
.bar-row.peak .fill { background: var(--tungsten); }
.bar-row.pick .label, .bar-row.pick .val { color: var(--teal); font-weight: 700; }
.bar-row .val { text-align: right; }

/* ---------- notes ---------- */
.notes { display: flex; flex-direction: column; gap: 1rem; }
.note {
  border-left: 2px solid var(--rule-firm);
  padding-left: 1rem;
  display: flex;
  flex-direction: column;
  gap: .3rem;
}
.note.risk { border-left-color: var(--alarm); }
.note h3 { color: var(--ink); }
.note p { font-size: .95rem; color: var(--ink-soft); }

code {
  font-family: var(--mono);
  font-size: .86em;
  background: var(--surface-sunk);
  padding: .1em .35em;
  border-radius: 2px;
  color: var(--ink);
}

pre {
  font-family: var(--mono);
  font-size: .8rem;
  line-height: 1.55;
  background: var(--surface);
  border: 1px solid var(--rule);
  box-shadow: var(--shadow);
  padding: 1.1rem 1.25rem;
  margin: 0;
  overflow-x: auto;
}

.verdict {
  background: var(--teal-wash);
  border: 1px solid var(--teal);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: .75rem;
}
.verdict h2 { border-bottom-color: var(--teal); color: var(--teal); }
.verdict p { color: var(--ink); }

footer {
  border-top: 1px solid var(--rule);
  padding-top: 1.25rem;
  font-family: var(--mono);
  font-size: .74rem;
  line-height: 1.7;
  color: var(--ink-faint);
  display: flex;
  flex-direction: column;
  gap: .5rem;
}
footer b { color: var(--ink-soft); font-weight: 600; }

:focus-visible { outline: 2px solid var(--teal); outline-offset: 2px; }