@font-face {
  font-family: "Noto Sans SC";
  src: url("/assets/fonts/NotoSansSC-Regular.otf") format("opentype");
  font-style: normal;
  font-weight: 100 900;
  font-display: swap;
}

:root {
  color-scheme: light dark;
  --bg: #eef2ec;
  --surface: #f8faf6;
  --surface-strong: #e3e9df;
  --ink: #14221a;
  --muted: #59675e;
  --line: rgba(20, 34, 26, .18);
  --accent: #12643f;
  --accent-strong: #0d4b30;
  --accent-soft: rgba(18, 100, 63, .10);
  --danger: #9a3f34;
  --danger-soft: rgba(154, 63, 52, .09);
  --radius: 12px;
  --max: 1240px;
  font-family: "Noto Sans SC", ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--ink); background: var(--bg); line-height: 1.65; }
body::before { content: ""; position: fixed; inset: 0; z-index: -1; pointer-events: none; opacity: .4; background-image: linear-gradient(rgba(20,34,26,.035) 1px, transparent 1px), linear-gradient(90deg, rgba(20,34,26,.035) 1px, transparent 1px); background-size: 28px 28px; }
a { color: inherit; text-underline-offset: .22em; }
button, input { font: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }

.skip-link { position: fixed; top: 10px; left: 10px; z-index: 20; padding: 9px 13px; background: var(--ink); color: var(--bg); transform: translateY(-160%); }
.skip-link:focus { transform: translateY(0); }
.site-header { width: min(var(--max), calc(100% - 32px)); min-height: 70px; margin: 0 auto; display: flex; align-items: center; justify-content: space-between; gap: 24px; border-bottom: 1px solid var(--line); }
.brand { font-size: 1.05rem; font-weight: 900; letter-spacing: -.03em; text-decoration: none; }
.site-header nav { display: flex; gap: 22px; font-size: .83rem; font-weight: 760; white-space: nowrap; }
.site-header nav a { color: var(--muted); text-decoration: none; }
.site-header nav a:hover, .site-header nav a:focus-visible { color: var(--accent); }
main, footer { width: min(var(--max), calc(100% - 32px)); margin-inline: auto; }

.hero { min-height: min(760px, calc(100dvh - 70px)); display: grid; grid-template-columns: minmax(0, 1.2fr) minmax(340px, .8fr); gap: clamp(48px, 9vw, 128px); align-items: center; padding: 78px 0 70px; }
.kicker { margin: 0 0 16px; color: var(--accent); font-size: .75rem; font-weight: 900; letter-spacing: .14em; text-transform: uppercase; }
h1, h2, h3, p { margin-top: 0; }
h1, h2 { letter-spacing: -.055em; }
h1 { max-width: 760px; margin-bottom: 26px; font-size: clamp(3.4rem, 7vw, 6.8rem); line-height: .98; font-weight: 920; }
h1 mark { color: var(--accent); background: transparent; }
.hero-intro { max-width: 600px; margin-bottom: 0; color: var(--muted); font-size: clamp(1.05rem, 1.7vw, 1.3rem); }
.hero-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 30px; }
.button { min-height: 44px; padding: 10px 17px; display: inline-flex; align-items: center; justify-content: center; border: 1px solid var(--line); border-radius: var(--radius); background: transparent; color: var(--ink); font-weight: 850; text-decoration: none; cursor: pointer; transition: transform .18s ease, color .18s ease, border-color .18s ease, background-color .18s ease; }
.button:hover, .button:focus-visible { border-color: var(--accent); color: var(--accent); }
.button:active { transform: translateY(1px); }
.button.primary { border-color: var(--accent); background: var(--accent); color: #f5fff9; }
.button.primary:hover, .button.primary:focus-visible { border-color: var(--accent-strong); background: var(--accent-strong); color: #f5fff9; }
.answer-board { align-self: end; margin-bottom: 24px; padding: 26px; border: 1px solid var(--line); border-radius: var(--radius); background: color-mix(in srgb, var(--surface) 86%, transparent); box-shadow: 0 22px 70px rgba(27, 53, 38, .09); }
.answer-board > p { margin-bottom: 28px; color: var(--muted); font-size: .78rem; font-weight: 800; }
.board-result { padding: 20px 0; border-top: 1px solid var(--line); }
.board-result span, .board-result small { display: block; color: var(--muted); }
.board-result span { margin-bottom: 8px; font-size: .78rem; font-weight: 850; }
.board-result strong { display: block; font-size: clamp(2rem, 3.8vw, 3.45rem); line-height: 1.08; letter-spacing: -.055em; color: var(--accent); }
.board-result small { margin-top: 6px; font-size: .75rem; }

.metric-strip { display: grid; grid-template-columns: repeat(4, 1fr); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.metric-strip article { min-height: 162px; padding: 22px; display: flex; flex-direction: column; border-right: 1px solid var(--line); }
.metric-strip article:first-child { padding-left: 0; }
.metric-strip article:last-child { padding-right: 0; border-right: 0; }
.metric-strip span, .metric-strip small { color: var(--muted); }
.metric-strip span { font-size: .75rem; font-weight: 800; }
.metric-strip strong { margin: auto 0 3px; font-size: clamp(2rem, 4vw, 4rem); line-height: 1; letter-spacing: -.06em; color: var(--accent); }
.metric-strip small { font-size: .75rem; }

.section { padding-top: 110px; }
.section-heading { max-width: 800px; margin-bottom: 38px; }
.section-heading h2 { margin-bottom: 14px; font-size: clamp(2.7rem, 5.4vw, 5.2rem); line-height: 1.02; }
.section-heading > p:last-child { max-width: 66ch; margin-bottom: 0; color: var(--muted); font-size: 1rem; }
.verdict-layout { display: grid; grid-template-columns: 1.15fr .85fr; gap: 16px; }
.plan-result { min-height: 460px; padding: clamp(24px, 4vw, 42px); display: flex; flex-direction: column; border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); }
.plan-result header { display: flex; align-items: baseline; justify-content: space-between; gap: 18px; }
.plan-result header span { color: var(--accent); font-size: .75rem; font-weight: 900; letter-spacing: .1em; }
.plan-result h3 { margin: 0; font-size: 1.25rem; }
.primary-number { margin: auto 0 36px; }
.primary-number strong, .primary-number span { display: block; }
.primary-number strong { font-size: clamp(3.3rem, 7vw, 6.8rem); line-height: .95; letter-spacing: -.065em; color: var(--accent); }
.primary-number span { margin-top: 10px; color: var(--muted); }
.plan-result dl { margin: 0 0 24px; display: grid; grid-template-columns: repeat(3, 1fr); border-top: 1px solid var(--line); }
.plan-result dl div { padding: 15px 10px 0 0; }
.plan-result dt { color: var(--muted); font-size: .72rem; }
.plan-result dd { margin: 4px 0 0; font-size: .85rem; font-weight: 850; }
.plan-result > p { margin-bottom: 0; color: var(--muted); font-size: .88rem; }
.plan-b { background: var(--accent-soft); }
.hard-warning { margin-top: 16px; padding: 30px; display: grid; grid-template-columns: .65fr 1.35fr; gap: 46px; align-items: center; border: 1px solid color-mix(in srgb, var(--danger) 55%, var(--line)); border-radius: var(--radius); background: var(--danger-soft); }
.hard-warning strong { font-size: clamp(1.8rem, 3.3vw, 3.2rem); line-height: 1.05; letter-spacing: -.045em; color: var(--danger); }
.hard-warning p { margin: 0; color: var(--muted); }

.calculator-shell { display: grid; grid-template-columns: .9fr 1.1fr; gap: 16px; }
.calculator-form, .live-results { padding: 28px; border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); }
.input-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 18px 14px; }
.calculator-form label { display: block; min-width: 0; }
.calculator-form label > span { display: block; margin-bottom: 7px; font-size: .78rem; font-weight: 850; }
.calculator-form label > small { display: block; min-height: 2.7em; margin-top: 6px; color: var(--muted); font-size: .69rem; line-height: 1.35; }
.input-unit { position: relative; }
.input-unit input { width: 100%; min-height: 48px; padding: 10px 70px 10px 12px; border: 1px solid var(--line); border-radius: var(--radius); background: var(--bg); color: var(--ink); font-variant-numeric: tabular-nums; }
.input-unit input:focus { outline: 2px solid var(--accent); outline-offset: 2px; border-color: var(--accent); }
.input-unit i { position: absolute; top: 50%; right: 12px; color: var(--muted); font-size: .72rem; font-style: normal; transform: translateY(-50%); pointer-events: none; }
details { margin: 22px 0; padding-top: 18px; border-top: 1px solid var(--line); }
summary { color: var(--accent); font-size: .82rem; font-weight: 850; cursor: pointer; }
.advanced-grid { margin-top: 18px; }
.form-error { margin: 0 0 14px; padding: 12px; border-radius: var(--radius); background: var(--danger-soft); color: var(--danger); font-size: .8rem; font-weight: 800; }
.calculator-form > .button { width: 100%; }
.live-results { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; align-content: start; }
.live-results article { min-height: 192px; padding: 22px; display: flex; flex-direction: column; border: 1px solid var(--line); border-radius: var(--radius); background: var(--bg); }
.live-results .result-main { background: var(--accent); color: #f5fff9; }
.live-results article span { color: var(--muted); font-size: .76rem; font-weight: 800; }
.live-results .result-main span { color: rgba(245,255,249,.92); }
.live-results article strong { margin-top: auto; font-size: clamp(2rem, 3.5vw, 3.6rem); line-height: 1; letter-spacing: -.055em; color: var(--accent); }
.live-results .result-main strong { color: #f5fff9; }
.live-results article p { margin: 9px 0 0; color: var(--muted); font-size: .74rem; }
.live-results .result-main p { color: rgba(245,255,249,.92); }
.result-explain { grid-column: 1 / -1; padding: 16px 18px; border-left: 3px solid var(--accent); background: var(--accent-soft); color: var(--muted); font-size: .84rem; }
.result-explain.danger { border-left-color: var(--danger); background: var(--danger-soft); color: var(--danger); }

.scenario-matrix { border-top: 1px solid var(--ink); }
.scenario-matrix > div { display: grid; grid-template-columns: 1.2fr repeat(3, 1fr) .85fr; gap: 18px; align-items: center; min-height: 86px; padding: 15px 8px; border-bottom: 1px solid var(--line); }
.scenario-matrix .matrix-head { min-height: 50px; color: var(--muted); font-size: .72rem; font-weight: 800; }
.scenario-matrix strong { font-size: 1rem; }
.scenario-matrix span { font-variant-numeric: tabular-nums; }
.scenario-matrix em { width: fit-content; padding: 5px 8px; border: 1px solid var(--line); border-radius: var(--radius); color: var(--muted); font-size: .72rem; font-style: normal; }
.scenario-matrix .base-row { background: var(--accent-soft); }
.scenario-matrix .base-row strong, .scenario-matrix .base-row em { color: var(--accent); }
.footnote { max-width: 900px; margin: 16px 0 0; color: var(--muted); font-size: .78rem; }

.cost-ledger { display: grid; grid-template-columns: 1.45fr 1fr 1fr; border-top: 1px solid var(--ink); border-left: 1px solid var(--line); }
.cost-ledger article { min-height: 210px; padding: 24px; display: flex; flex-direction: column; border-right: 1px solid var(--line); border-bottom: 1px solid var(--line); background: color-mix(in srgb, var(--surface) 76%, transparent); }
.cost-ledger .dominant { grid-row: span 2; min-height: 420px; background: var(--accent); color: #f5fff9; }
.cost-ledger span { color: var(--muted); font-size: .76rem; font-weight: 800; }
.cost-ledger .dominant span { color: rgba(245,255,249,.92); }
.cost-ledger strong { margin: auto 0 10px; font-size: clamp(2rem, 3.7vw, 4.1rem); line-height: 1; letter-spacing: -.06em; color: var(--accent); }
.cost-ledger .dominant strong { color: #f5fff9; }
.cost-ledger p { margin: 0; color: var(--muted); font-size: .76rem; }
.cost-ledger .dominant p { color: rgba(245,255,249,.92); }
.formula-row { margin-top: 16px; display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.formula-row div { padding: 22px; border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); }
.formula-row span { display: block; margin-bottom: 10px; color: var(--accent); font-size: .74rem; font-weight: 900; }
.formula-row code { font-family: ui-monospace, SFMono-Regular, Consolas, monospace; font-size: .82rem; white-space: normal; }

.changsha-layout { display: grid; grid-template-columns: .85fr 1.15fr; gap: 16px; }
.city-facts { display: grid; border-top: 1px solid var(--ink); }
.city-facts article { padding: 24px 0; display: grid; grid-template-columns: 170px 1fr; gap: 24px; align-items: start; border-bottom: 1px solid var(--line); }
.city-facts strong { font-size: 1.75rem; letter-spacing: -.045em; color: var(--accent); }
.city-facts p { margin: 0; color: var(--muted); font-size: .84rem; }
.city-verdict { padding: clamp(26px, 4vw, 44px); border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); }
.city-verdict h3 { font-size: 2rem; }
.city-verdict p { color: var(--muted); }
.city-verdict p:last-child { margin-bottom: 0; }
.city-verdict b { color: var(--ink); }

.decision-list { border-top: 1px solid var(--ink); }
.decision-list > div { display: grid; grid-template-columns: 130px minmax(260px, .8fr) 1.2fr; gap: 34px; padding: 28px 0; border-bottom: 1px solid var(--line); }
.decision-list span { color: var(--accent); font-size: .78rem; font-weight: 900; }
.decision-list strong { font-size: 1.25rem; line-height: 1.25; }
.decision-list p { margin: 0; color: var(--muted); }

.source-list { border-top: 1px solid var(--ink); }
.source-list article { display: grid; grid-template-columns: 42px minmax(0, 1fr) 190px; gap: 22px; padding: 24px 0; border-bottom: 1px solid var(--line); }
.source-list article > b { color: var(--accent); font-size: 1.15rem; }
.source-list h3 { margin-bottom: 7px; font-size: 1rem; }
.source-list p { margin-bottom: 8px; color: var(--muted); font-size: .82rem; }
.source-list a { color: var(--accent); font-size: .78rem; font-weight: 850; }
.source-list time { color: var(--muted); font-size: .74rem; text-align: right; }
.method-note { margin: 110px 0 72px; padding: 30px; border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); }
.method-note h2 { margin-bottom: 12px; font-size: 1.5rem; }
.method-note p { max-width: 1000px; color: var(--muted); font-size: .82rem; }
.method-note p:last-child { margin-bottom: 0; }
footer { min-height: 120px; display: flex; align-items: center; gap: 20px; border-top: 1px solid var(--line); color: var(--muted); font-size: .8rem; }
footer p { margin: 0 auto 0 0; }

@media (prefers-color-scheme: dark) {
  :root { --bg: #101713; --surface: #17221b; --surface-strong: #223128; --ink: #e9f1eb; --muted: #a2afa6; --line: rgba(233,241,235,.16); --accent: #61c492; --accent-strong: #45aa77; --accent-soft: rgba(97,196,146,.10); --danger: #e18273; --danger-soft: rgba(225,130,115,.09); }
  body::before { opacity: .22; }
  .answer-board { box-shadow: 0 22px 70px rgba(0,0,0,.26); }
  .button.primary, .live-results .result-main, .cost-ledger .dominant { color: #0e2318; }
  .button.primary:hover, .button.primary:focus-visible { color: #0e2318; }
  .live-results .result-main span, .live-results .result-main p, .cost-ledger .dominant span, .cost-ledger .dominant p { color: rgba(14,35,24,.72); }
  .live-results .result-main strong, .cost-ledger .dominant strong { color: #0e2318; }
}

@media (max-width: 980px) {
  .hero { min-height: auto; grid-template-columns: 1fr; gap: 42px; padding-top: 72px; }
  .answer-board { align-self: auto; margin: 0; }
  .metric-strip { grid-template-columns: 1fr 1fr; }
  .metric-strip article:nth-child(2) { border-right: 0; }
  .metric-strip article:nth-child(-n+2) { border-bottom: 1px solid var(--line); }
  .metric-strip article:first-child, .metric-strip article:last-child { padding: 22px; }
  .verdict-layout, .calculator-shell, .changsha-layout { grid-template-columns: 1fr; }
  .plan-result { min-height: 400px; }
  .hard-warning { grid-template-columns: 1fr; gap: 18px; }
  .cost-ledger { grid-template-columns: 1fr 1fr; }
  .cost-ledger .dominant { grid-row: auto; grid-column: 1 / -1; min-height: 270px; }
  .decision-list > div { grid-template-columns: 110px 1fr; }
  .decision-list p { grid-column: 2; }
}

@media (max-width: 660px) {
  .site-header { min-height: 62px; }
  .site-header nav { gap: 13px; font-size: .72rem; }
  .site-header nav a:nth-child(2), .site-header nav a:nth-child(3) { display: none; }
  .hero { padding: 56px 0 50px; }
  h1 { font-size: clamp(3rem, 15vw, 4.2rem); }
  .metric-strip { grid-template-columns: 1fr; }
  .metric-strip article, .metric-strip article:first-child, .metric-strip article:last-child { min-height: 126px; padding: 18px 0; border-right: 0; border-bottom: 1px solid var(--line); }
  .section { padding-top: 82px; }
  .section-heading h2 { font-size: clamp(2.6rem, 12vw, 3.8rem); }
  .plan-result { min-height: 440px; padding: 22px; }
  .plan-result header { display: block; }
  .plan-result header span { display: block; margin-bottom: 7px; }
  .plan-result dl { grid-template-columns: 1fr; }
  .plan-result dl div { display: flex; justify-content: space-between; gap: 20px; }
  .hard-warning, .calculator-form, .live-results, .city-verdict, .method-note { padding: 22px; }
  .input-grid, .live-results, .cost-ledger, .formula-row { grid-template-columns: 1fr; }
  .calculator-form label > small { min-height: auto; }
  .result-explain { grid-column: 1; }
  .scenario-matrix { overflow-x: auto; }
  .scenario-matrix > div { min-width: 680px; }
  .cost-ledger .dominant { grid-column: 1; }
  .city-facts article { grid-template-columns: 1fr; gap: 7px; }
  .decision-list > div { grid-template-columns: 1fr; gap: 9px; }
  .decision-list p { grid-column: 1; }
  .source-list article { grid-template-columns: 34px minmax(0, 1fr); }
  .source-list time { grid-column: 2; text-align: left; }
  footer { flex-wrap: wrap; align-items: flex-start; padding: 28px 0; }
  footer p { width: 100%; margin: 0; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .button { transition: none; }
}

@media print {
  :root { color-scheme: light; --bg: white; --surface: white; --ink: black; --muted: #444; --line: #aaa; --accent: #165c40; }
  body::before, .site-header, .hero-actions, .calculator-form, footer { display: none; }
  main { width: 100%; }
  .hero { min-height: auto; padding: 30px 0; }
  .section { padding-top: 46px; }
}