:root {
  --ink: #17282c;
  --ink-soft: #52666a;
  --teal: #123c42;
  --teal-2: #1f6b72;
  --aqua: #dfeeed;
  --aqua-2: #edf5f3;
  --cream: #f7f3eb;
  --paper: #fcfbf7;
  --white: #ffffff;
  --line: #cbd7d4;
  --line-dark: rgba(255, 255, 255, 0.16);
  --gold: #b88735;
  --red: #9b433b;
  --shadow: 0 24px 70px rgba(18, 60, 66, 0.12);
  --radius: 22px;
  --serif: "Noto Serif SC", "Songti SC", SimSun, serif;
  --sans: "Microsoft YaHei", "PingFang SC", "Noto Sans CJK SC", Arial, sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: var(--sans);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
button, input, select { font: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }
a { color: inherit; }
[hidden] { display: none !important; }

.site-header {
  position: relative;
  z-index: 10;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  width: min(1220px, calc(100% - 48px));
  min-height: 78px;
  margin: 0 auto;
  border-bottom: 1px solid rgba(18, 60, 66, 0.12);
}
.brand { display: inline-flex; align-items: center; gap: 12px; width: fit-content; text-decoration: none; }
.brand-mark { display: grid; place-items: center; width: 36px; height: 36px; border-radius: 11px; color: #fff; background: var(--teal); font-family: Georgia, serif; font-size: 19px; font-weight: 700; }
.brand strong, .brand small { display: block; }
.brand strong { font-size: 14px; line-height: 1.25; }
.brand small { color: var(--ink-soft); font-size: 10px; letter-spacing: 0.04em; }
.site-nav { display: flex; gap: 30px; }
.site-nav a { position: relative; color: var(--ink-soft); font-size: 13px; font-weight: 700; text-decoration: none; }
.site-nav a::after { content: ""; position: absolute; right: 0; bottom: -7px; left: 0; height: 2px; background: var(--teal-2); transform: scaleX(0); transition: transform 180ms ease; }
.site-nav a:hover::after, .site-nav a:focus-visible::after { transform: scaleX(1); }
.privacy-pill { justify-self: end; display: inline-flex; align-items: center; gap: 7px; padding: 7px 11px; border: 1px solid var(--line); border-radius: 999px; color: var(--ink-soft); background: rgba(255,255,255,.66); font-size: 11px; font-weight: 700; }
.privacy-pill i { width: 7px; height: 7px; border-radius: 50%; background: #50a47b; box-shadow: 0 0 0 4px rgba(80,164,123,.13); }

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(360px, .65fr);
  gap: 70px;
  align-items: center;
  width: min(1220px, calc(100% - 48px));
  min-height: 610px;
  margin: 0 auto;
  padding: 74px 0 66px;
}
.eyebrow { margin: 0 0 16px; color: var(--teal-2); font-size: 11px; font-weight: 900; letter-spacing: .17em; }
.hero h1 { margin: 0; max-width: 820px; font-family: var(--serif); font-size: clamp(56px, 6.1vw, 92px); font-weight: 700; letter-spacing: -.06em; line-height: .98; }
.hero h1 em { color: var(--teal-2); font-style: normal; }
.hero-lead { max-width: 760px; margin: 28px 0 0; color: var(--ink-soft); font-size: 17px; line-height: 1.9; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 28px; }
.button { display: inline-flex; align-items: center; justify-content: center; min-height: 46px; padding: 0 20px; border: 1px solid transparent; border-radius: 10px; font-weight: 800; font-size: 13px; text-decoration: none; cursor: pointer; transition: transform 160ms ease, box-shadow 160ms ease, background 160ms ease; }
.button:hover:not(:disabled) { transform: translateY(-1px); }
.button:focus-visible { outline: 3px solid rgba(31,107,114,.28); outline-offset: 2px; }
.button:disabled { opacity: .45; cursor: not-allowed; }
.button-primary { color: #fff; background: var(--teal); box-shadow: 0 10px 24px rgba(18,60,66,.18); }
.button-secondary { border-color: var(--teal); color: var(--teal); background: transparent; }
.button-quiet { border-color: var(--line); color: var(--ink-soft); background: #fff; }
.button-accent { color: var(--teal); background: #f0c66d; }
.hero-note { margin: 14px 0 0; color: var(--ink-soft); font-size: 11px; }
.hero-note span { color: #4d9c75; }

.hero-map { padding: 30px 32px 26px; border-radius: 26px; color: #fff; background: linear-gradient(145deg, #0e353a, #123f45 68%, #184b51); box-shadow: var(--shadow); overflow: hidden; }
.hero-map > p { margin: 0 0 8px; color: rgba(255,255,255,.56); font-size: 11px; font-weight: 800; letter-spacing: .12em; text-transform: uppercase; }
.hero-map ol { margin: 0; padding: 0; list-style: none; }
.hero-map li { display: grid; grid-template-columns: 46px 1fr; gap: 8px; align-items: start; padding: 22px 0; border-bottom: 1px solid rgba(255,255,255,.12); }
.hero-map li:last-child { border-bottom: 0; }
.hero-map b { color: #f2c96f; font-size: 12px; }
.hero-map strong, .hero-map small { display: block; }
.hero-map strong { font-family: var(--serif); font-size: 18px; }
.hero-map small { margin-top: 5px; color: rgba(255,255,255,.62); font-size: 12px; line-height: 1.55; }

.task-strip { display: grid; grid-template-columns: repeat(3, 1fr); width: min(1220px, calc(100% - 48px)); margin: 0 auto 72px; border: 1px solid var(--line); background: #fff; }
.task-strip article { position: relative; padding: 20px 24px; border-right: 1px solid var(--line); }
.task-strip article:last-child { border-right: 0; }
.task-strip article.active::before { content: ""; position: absolute; top: -1px; right: -1px; left: -1px; height: 3px; background: var(--teal-2); }
.task-strip span, .task-strip strong, .task-strip p { display: block; }
.task-strip span { color: var(--teal-2); font-size: 10px; font-weight: 900; letter-spacing: .12em; }
.task-strip strong { margin-top: 4px; font-family: var(--serif); font-size: 18px; }
.task-strip p { margin: 3px 0 0; color: var(--ink-soft); font-size: 12px; }

.section { padding: 94px max(24px, calc((100% - 1220px) / 2)); }
.section-light { background: #fff; }
.section-tint { background: var(--aqua-2); }
.section-dark { color: #fff; background: var(--teal); }
.section-heading { display: grid; grid-template-columns: minmax(0, 1.4fr) minmax(300px, .6fr); gap: 60px; align-items: end; margin-bottom: 46px; }
.section-heading h2 { margin: 0; font-family: var(--serif); font-size: clamp(34px, 4vw, 54px); letter-spacing: -.04em; line-height: 1.2; }
.section-heading > p { margin: 0; color: var(--ink-soft); font-size: 15px; line-height: 1.85; }
.section-heading.inverse .eyebrow { color: #e9c46d; }
.section-heading.inverse > p { color: rgba(255,255,255,.7); }

.explain-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; }
.explain-grid article { min-height: 245px; padding: 25px 24px; border: 1px solid var(--line); border-radius: 16px; background: var(--paper); }
.explain-grid span { display: inline-flex; align-items: center; justify-content: center; width: 34px; height: 24px; border-radius: 999px; color: #fff; background: var(--teal); font-size: 10px; font-weight: 900; }
.explain-grid h3 { margin: 22px 0 9px; font-family: var(--serif); font-size: 21px; line-height: 1.35; }
.explain-grid p { margin: 0; color: var(--ink-soft); font-size: 13px; line-height: 1.85; }
.explain-grid b { color: var(--teal); }

.impact-chain { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr) 28px) minmax(0, 1fr); align-items: center; margin: 44px 0; padding: 26px; border-radius: 18px; background: var(--teal); }
.impact-chain div { text-align: center; }
.impact-chain small, .impact-chain strong { display: block; }
.impact-chain small { color: #e8c46f; font-size: 10px; font-weight: 900; letter-spacing: .12em; }
.impact-chain strong { margin-top: 5px; color: #fff; font-size: 14px; }
.impact-chain i { color: rgba(255,255,255,.35); font-style: normal; text-align: center; }

.two-results { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.two-results article { padding: 28px 30px; border-radius: 18px; background: var(--aqua-2); }
.two-results article:nth-child(2) { color: #fff; background: var(--teal); }
.two-results article > p:first-child { margin: 0; color: var(--teal-2); font-size: 10px; font-weight: 900; letter-spacing: .13em; }
.two-results article:nth-child(2) > p:first-child { color: #e7c56f; }
.two-results h3 { margin: 8px 0 10px; font-family: var(--serif); font-size: 27px; }
.two-results p { margin: 0 0 10px; color: var(--ink-soft); font-size: 13px; }
.two-results article:nth-child(2) p { color: rgba(255,255,255,.68); }
.two-results strong { font-size: 12px; }

.plain-callout { display: flex; gap: 30px; align-items: center; justify-content: space-between; margin-top: 24px; padding: 25px 28px; border: 1px solid #e0c99e; border-radius: 16px; background: #fff7e8; }
.plain-callout span, .plain-callout strong { display: block; }
.plain-callout span { color: #986e27; font-size: 10px; font-weight: 900; letter-spacing: .12em; }
.plain-callout strong { margin-top: 5px; max-width: 850px; font-size: 14px; }

.builder-shell { border: 1px solid #cadbd8; border-radius: var(--radius); background: #fff; box-shadow: var(--shadow); overflow: hidden; }
.builder-step { padding: 34px 38px 38px; border-bottom: 1px solid var(--line); }
.builder-step:last-child { border-bottom: 0; }
.builder-step > header { display: grid; grid-template-columns: 42px 1fr; gap: 16px; align-items: start; margin-bottom: 26px; }
.builder-step > header > span { display: grid; place-items: center; width: 40px; height: 40px; border-radius: 12px; color: #fff; background: var(--teal); font-size: 11px; font-weight: 900; }
.builder-step h3 { margin: 0; font-family: var(--serif); font-size: 25px; }
.builder-step header p { margin: 3px 0 0; color: var(--ink-soft); font-size: 13px; }

.material-groups { display: grid; gap: 24px; }
.material-group h4 { margin: 0 0 10px; color: var(--teal-2); font-size: 11px; letter-spacing: .12em; }
.material-cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; }
.material-card { position: relative; display: block; min-height: 108px; padding: 17px 42px 16px 17px; border: 1px solid var(--line); border-radius: 13px; background: #fff; cursor: pointer; transition: border-color 160ms ease, background 160ms ease, transform 160ms ease; }
.material-card:hover { transform: translateY(-1px); border-color: var(--teal-2); }
.material-card input { position: absolute; top: 17px; right: 16px; width: 18px; height: 18px; opacity: 0; }
.material-card:focus-within { outline: 3px solid rgba(31,107,114,.18); outline-offset: 2px; }
.material-card::after { content: ""; position: absolute; top: 17px; right: 16px; width: 18px; height: 18px; border: 1.5px solid #96aaa7; border-radius: 6px; background: #fff; }
.material-card:has(input:checked) { border-color: var(--teal-2); background: var(--aqua-2); box-shadow: inset 0 0 0 1px var(--teal-2); }
.material-card:has(input:checked)::after { content: "✓"; display: grid; place-items: center; color: #fff; border-color: var(--teal-2); background: var(--teal-2); font-size: 12px; font-weight: 900; }
.material-card strong, .material-card small, .material-card em { display: block; }
.material-card strong { font-size: 14px; }
.material-card small { margin-top: 4px; color: var(--ink-soft); font-size: 11px; line-height: 1.5; }
.material-card em { margin-top: 8px; color: var(--teal-2); font-size: 10px; font-style: normal; font-weight: 800; }

.custom-material { display: flex; gap: 12px; align-items: flex-start; margin-top: 20px; padding: 17px 18px; border: 1px dashed #a9bbb8; border-radius: 13px; background: #fafcfb; cursor: pointer; }
.custom-material input { margin-top: 5px; accent-color: var(--teal-2); }
.custom-material strong, .custom-material small { display: block; }
.custom-material strong { font-size: 13px; }
.custom-material small { margin-top: 2px; color: var(--ink-soft); font-size: 11px; }
.custom-name-field { max-width: 520px; margin-top: 12px; }

.selected-materials { display: grid; gap: 10px; }
.selected-row { display: grid; grid-template-columns: minmax(180px, .8fr) minmax(260px, 1.2fr) auto; gap: 16px; align-items: center; padding: 16px 18px; border: 1px solid var(--line); border-radius: 13px; background: #fafcfb; }
.selected-row strong, .selected-row small { display: block; }
.selected-row strong { font-size: 13px; }
.selected-row small { margin-top: 3px; color: var(--ink-soft); font-size: 10px; }
.selected-row select { width: 100%; }
.selected-row b { color: var(--teal-2); font-size: 11px; font-weight: 800; text-align: right; }
.empty-state { margin: 0; padding: 20px; border: 1px dashed var(--line); border-radius: 12px; color: var(--ink-soft); text-align: center; font-size: 12px; }

.choice-grid { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 14px; margin-top: 20px; }
.field { display: grid; align-content: start; gap: 7px; margin: 0; padding: 16px; border: 1px solid var(--line); border-radius: 12px; background: #fff; }
.field > span, .field legend { color: var(--ink); font-size: 12px; font-weight: 800; }
.field small { color: var(--ink-soft); font-size: 10px; line-height: 1.45; }
.field label { display: flex; gap: 8px; align-items: flex-start; color: var(--ink-soft); font-size: 11px; }
.field input[type="radio"], .field input[type="checkbox"] { margin-top: 4px; accent-color: var(--teal-2); }
fieldset.field { min-width: 0; }
input[type="text"], input[type="number"], select { min-width: 0; height: 43px; padding: 0 11px; border: 1px solid #aebfbc; border-radius: 8px; color: var(--ink); background: #fff; outline: none; }
input:focus, select:focus { border-color: var(--teal-2); box-shadow: 0 0 0 3px rgba(31,107,114,.12); }

.builder-output { background: #fbfcfa; }
.formula-status { padding: 13px 15px; border-radius: 10px; color: var(--ink-soft); background: #edf2f1; font-size: 12px; }
.formula-status.ready { color: #fff; background: var(--teal); }
.formula-preview { display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(300px, .85fr); gap: 20px; margin-top: 18px; }
.formula-panel, .checklist-panel { padding: 22px; border: 1px solid var(--line); border-radius: 14px; background: #fff; }
.formula-panel h4, .checklist-panel h4 { margin: 0 0 12px; font-family: var(--serif); font-size: 20px; }
.formula-list { display: grid; gap: 9px; margin: 0; padding: 0; list-style: none; counter-reset: formula; }
.formula-list li { position: relative; padding: 12px 13px 12px 42px; border-radius: 9px; background: var(--aqua-2); font-size: 12px; line-height: 1.65; }
.formula-list li::before { counter-increment: formula; content: counter(formula); position: absolute; top: 12px; left: 13px; display: grid; place-items: center; width: 20px; height: 20px; border-radius: 50%; color: #fff; background: var(--teal-2); font-size: 9px; font-weight: 900; }
.formula-list b { color: var(--teal); }
.formula-list strong, .formula-list b, .formula-list small { display: block; }
.formula-list strong { margin-bottom: 4px; color: var(--teal-2); font-size: 10px; }
.formula-list b { font-size: 12px; line-height: 1.65; }
.formula-list small { margin-top: 4px; color: var(--ink-soft); font-size: 9px; line-height: 1.55; }
.checklist-block + .checklist-block { margin-top: 17px; padding-top: 17px; border-top: 1px solid var(--line); }
.checklist-block strong { color: var(--teal); font-size: 12px; }
.checklist-block ol { margin: 8px 0 0; padding-left: 19px; color: var(--ink-soft); font-size: 11px; }
.checklist-block li { margin: 5px 0; }
.warning-list { margin-top: 12px; padding: 12px 14px; border: 1px solid #ecd4aa; border-radius: 9px; color: #805c1f; background: #fff8e9; font-size: 11px; }
.warning-list p { margin: 3px 0; }
.builder-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 20px; }
.action-note { margin: 10px 0 0; color: var(--ink-soft); font-size: 10px; }

.calculator-panel { border: 1px solid var(--line-dark); border-radius: 18px; overflow: hidden; background: rgba(255,255,255,.06); }
.calculator-panel > summary { display: flex; align-items: center; justify-content: space-between; min-height: 112px; padding: 22px 28px; cursor: pointer; list-style: none; }
.calculator-panel > summary::-webkit-details-marker { display: none; }
.calculator-panel summary span > * { display: block; }
.calculator-panel summary b { color: #e8c66f; font-size: 10px; letter-spacing: .13em; }
.calculator-panel summary strong { margin-top: 4px; font-family: var(--serif); font-size: 25px; }
.calculator-panel summary small { margin-top: 3px; color: rgba(255,255,255,.62); font-size: 12px; }
.calculator-panel summary i { font-size: 30px; font-style: normal; transition: transform 160ms ease; }
.calculator-panel[open] summary i { transform: none; }
.calculator-body { padding: 30px; border-top: 1px solid var(--line-dark); color: var(--ink); background: #f8fbfa; }
.calculator-note { margin-bottom: 18px; padding: 12px 14px; border-radius: 9px; color: var(--ink-soft); background: #e7efed; font-size: 11px; }
.calculator-note.ready { color: #fff; background: var(--teal-2); }
.calculator-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px; }
.unit-input { display: grid; grid-template-columns: minmax(0, 1fr) auto; align-items: center; gap: 8px; }
.unit-input b { color: var(--ink-soft); font-size: 9px; white-space: nowrap; }
.calculation-components { margin-top: 20px; }
.calculation-components h3 { margin: 0; font-family: var(--serif); font-size: 20px; }
.calculation-components > p { margin: 3px 0 12px; color: var(--ink-soft); font-size: 10px; }
.calculation-component-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; }
.component-input { padding: 15px; border: 1px solid var(--line); border-radius: 11px; background: #fff; }
.component-input strong, .component-input small { display: block; }
.component-input strong { font-size: 12px; }
.component-input small { min-height: 32px; margin: 3px 0 8px; color: var(--ink-soft); font-size: 9px; }
.calc-options { display: grid; gap: 8px; margin: 17px 0; }
.calc-options label { display: flex; gap: 9px; align-items: flex-start; color: var(--ink-soft); font-size: 11px; }
.calc-options input { margin-top: 4px; accent-color: var(--teal-2); }
.calc-errors:not(:empty) { margin: 12px 0; padding: 12px 15px; border: 1px solid #e5b9b4; border-radius: 9px; color: #8b3932; background: #fff0ee; font-size: 11px; }
.calculation-result { margin-top: 26px; padding-top: 26px; border-top: 1px solid var(--line); }
.result-status { display: flex; align-items: center; justify-content: space-between; margin-bottom: 14px; }
.result-status h3 { margin: 0; font-family: var(--serif); font-size: 24px; }
.status-badge { padding: 6px 10px; border-radius: 999px; color: #fff; background: var(--teal-2); font-size: 10px; font-weight: 800; }
.status-badge.review { background: #9a5a45; }
.metric-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 9px; }
.metric-card { padding: 17px; border: 1px solid var(--line); border-radius: 11px; background: #fff; }
.metric-card span, .metric-card strong, .metric-card small { display: block; }
.metric-card span { color: var(--ink-soft); font-size: 9px; }
.metric-card strong { margin-top: 5px; color: var(--teal); font-family: Georgia, serif; font-size: 26px; line-height: 1; }
.metric-card small { margin-top: 5px; color: var(--ink-soft); font-size: 9px; }
.result-messages { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin-top: 12px; }
.result-message { padding: 13px 15px; border-radius: 10px; font-size: 10px; }
.result-message.block { color: #873b35; background: #ffefed; }
.result-message.warn { color: #7f5b1f; background: #fff7e8; }
.result-message strong { display: block; margin-bottom: 4px; }
.result-message ul { margin: 0; padding-left: 17px; }
.result-trace { margin-top: 14px; padding: 17px 20px; border: 1px solid var(--line); border-radius: 11px; background: #fff; }
.result-trace h4 { margin: 0 0 8px; font-size: 12px; }
.result-trace ol { margin: 0; padding-left: 20px; color: var(--ink-soft); font-size: 10px; }

.evidence-section { background: var(--cream); }
.evidence-summary { display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px; }
.evidence-card { padding: 18px; border: 1px solid #ddd5c8; border-radius: 12px; background: rgba(255,255,255,.7); }
.evidence-card b, .evidence-card span, .evidence-card small { display: block; }
.evidence-card b { color: var(--teal-2); font-size: 10px; }
.evidence-card span { margin-top: 5px; font-size: 12px; font-weight: 700; }
.evidence-card small { margin-top: 7px; color: var(--ink-soft); font-size: 9px; }
.boundary-details { margin-top: 20px; border-top: 1px solid #d8d0c3; }
.boundary-details summary { padding: 18px 0; color: var(--teal); font-size: 12px; font-weight: 800; cursor: pointer; }
.boundary-details > div { max-width: 940px; padding-bottom: 10px; color: var(--ink-soft); font-size: 12px; }
#evidence-links { display: grid; gap: 7px; margin-top: 14px; }
#evidence-links a { color: var(--teal-2); font-size: 11px; }

.site-footer { display: flex; align-items: center; justify-content: space-between; gap: 30px; padding: 34px max(24px, calc((100% - 1220px) / 2)); border-top: 1px solid var(--line); background: var(--paper); }
.site-footer strong, .site-footer span { display: block; }
.site-footer strong { font-size: 13px; }
.site-footer span { color: var(--ink-soft); font-size: 10px; }
.site-footer p { display: flex; gap: 18px; margin: 0; color: var(--ink-soft); font-size: 10px; }
.toast { position: fixed; right: 24px; bottom: 24px; z-index: 100; max-width: 360px; padding: 12px 16px; border-radius: 10px; color: #fff; background: var(--teal); box-shadow: var(--shadow); font-size: 12px; opacity: 0; transform: translateY(8px); pointer-events: none; transition: opacity 160ms ease, transform 160ms ease; }
.toast.show { opacity: 1; transform: translateY(0); }

.print-formula-pack { display: none; }

@media (max-width: 980px) {
  .site-header { grid-template-columns: 1fr auto; }
  .site-nav { display: none; }
  .hero { grid-template-columns: 1fr; gap: 36px; }
  .hero-map { max-width: 680px; }
  .section-heading { grid-template-columns: 1fr; gap: 18px; }
  .explain-grid { grid-template-columns: repeat(2, 1fr); }
  .impact-chain { grid-template-columns: 1fr; gap: 8px; }
  .impact-chain i { transform: rotate(90deg); }
  .material-cards { grid-template-columns: repeat(2, 1fr); }
  .choice-grid { grid-template-columns: 1fr 1fr; }
  .formula-preview { grid-template-columns: 1fr; }
  .calculator-grid { grid-template-columns: repeat(2, 1fr); }
  .calculation-component-grid { grid-template-columns: repeat(2, 1fr); }
  .evidence-summary { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 640px) {
  .site-header { width: calc(100% - 30px); min-height: 68px; }
  .privacy-pill { padding: 6px 8px; font-size: 9px; }
  .brand small { display: none; }
  .hero { width: calc(100% - 30px); min-height: auto; padding: 48px 0; }
  .hero h1 { font-size: 49px; }
  .hero-lead { font-size: 14px; }
  .hero-actions { display: grid; }
  .hero-map { padding: 23px; }
  .task-strip { grid-template-columns: 1fr; width: calc(100% - 30px); margin-bottom: 46px; }
  .task-strip article { border-right: 0; border-bottom: 1px solid var(--line); }
  .task-strip article:last-child { border-bottom: 0; }
  .section { padding: 66px 15px; }
  .section-heading { margin-bottom: 30px; }
  .section-heading h2 { font-size: 35px; }
  .section-heading > p { font-size: 13px; }
  .explain-grid, .two-results, .material-cards, .choice-grid, .calculator-grid, .calculation-component-grid, .metric-grid, .result-messages, .evidence-summary { grid-template-columns: 1fr; }
  .explain-grid article { min-height: auto; }
  .plain-callout { align-items: stretch; flex-direction: column; }
  .builder-step { padding: 26px 18px 30px; }
  .builder-step > header { grid-template-columns: 36px 1fr; }
  .builder-step > header > span { width: 34px; height: 34px; }
  .builder-step h3 { font-size: 21px; }
  .selected-row { grid-template-columns: 1fr; gap: 9px; }
  .selected-row b { text-align: left; }
  .builder-actions { display: grid; }
  .calculator-panel > summary { padding: 19px; }
  .calculator-body { padding: 20px 14px; }
  .site-footer { align-items: flex-start; flex-direction: column; }
  .site-footer p { flex-direction: column; gap: 4px; }
  .toast { right: 15px; bottom: 15px; left: 15px; max-width: none; }
}

@media print {
  @page { size: A4; margin: 18mm 17mm 18mm; }
  body.printing-formula-pack > :not(#print-formula-pack) { display: none !important; }
  body.printing-formula-pack #print-formula-pack { display: block !important; color: #111; background: #fff; font-family: "等线", "Microsoft YaHei", sans-serif; font-size: 10pt; line-height: 1.55; }
  .print-formula-pack h1 { margin: 0 0 5mm; color: #123c42; font-size: 21pt; line-height: 1.25; }
  .print-formula-pack h2 { margin: 7mm 0 3mm; padding-bottom: 2mm; border-bottom: .5pt solid #7e9693; color: #123c42; font-size: 14pt; }
  .print-formula-pack p { margin: 0 0 2.5mm; }
  .print-formula-pack ol, .print-formula-pack ul { margin: 2mm 0 3mm; padding-left: 6mm; }
  .print-formula-pack li { margin: 1.5mm 0; }
  .print-formula-pack table { width: 100%; border-collapse: collapse; page-break-inside: auto; }
  .print-formula-pack th, .print-formula-pack td { padding: 2.2mm; border: .5pt solid #aebdbb; text-align: left; vertical-align: top; }
  .print-formula-pack th { background: #eaf2f1; }
  .print-formula-pack .print-meta { color: #607176; font-size: 8.5pt; }
  .print-formula-pack .print-note { padding: 3mm; border: .5pt solid #d1b97f; background: #fff8e8; }
  .print-formula-pack .page-break { break-before: page; }
}