:root {
  --green: #009c5a;
  --green-dark: #006c48;
  --ink: #18221f;
  --muted: #5f6d69;
  --line: #d5e0dc;
  --pale: #edf6f2;
  --paper: #ffffff;
  --warn: #fff7df;
  --warn-line: #e4b33d;
  --navy: #082f59;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: Roboto, "Helvetica Neue", Arial, "Noto Sans SC", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.7;
}
a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; }
.shell { width: min(1160px, calc(100% - 48px)); margin-inline: auto; }

.site-header { border-bottom: 1px solid #e7ecea; background: #fff; }
.nav-row { min-height: 62px; display: flex; align-items: center; justify-content: space-between; gap: 32px; }
.brand img { width: 124px; height: auto; }
.primary-nav { display: flex; align-items: center; justify-content: flex-end; gap: 30px; font-size: 14px; font-weight: 600; color: #202a27; }
.primary-nav a:hover { color: var(--green); }

.breadcrumbs { display: flex; flex-wrap: wrap; gap: 10px; padding-block: 34px 22px; color: #6b7773; font-size: 14px; }
.breadcrumbs a { color: #1676b8; }
.product-intro { display: grid; grid-template-columns: minmax(0, 3fr) minmax(390px, 2fr); gap: 58px; padding-bottom: 58px; margin-bottom: 34px; border-bottom: 1px solid var(--line); }
.eyebrow { margin: 0 0 10px; color: var(--green-dark); font-size: 13px; font-weight: 800; letter-spacing: 0; }
h1 { margin: 0; font-size: 48px; line-height: 1.18; font-weight: 500; letter-spacing: 0; color: #333; }
.lede { max-width: 690px; margin: 26px 0 20px; color: #33433e; font-size: 18px; line-height: 1.72; }
.scope-note { margin: 20px 0; padding: 20px 22px; border-left: 4px solid var(--green); background: #f3f6f5; color: #53625e; }
.scope-note strong { color: #33433e; }
.actions { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 26px; }
.button { min-height: 46px; display: inline-flex; align-items: center; justify-content: center; padding: 10px 20px; border: 1px solid var(--green); border-radius: 0; font-weight: 700; line-height: 1.3; }
.button.primary { color: #fff; background: var(--green); }
.button.secondary { color: #0b6cae; background: #fff; }
.authority-line { margin: 18px 0 0; color: #71807b; font-size: 13px; }
.product-visual { min-width: 0; margin: 0; align-self: stretch; display: flex; flex-direction: column; justify-content: space-between; }
.product-image-wrap { min-height: 440px; display: grid; place-items: start center; margin: 0; background: #fff; overflow: visible; }
.product-image-wrap img { width: min(100%, 430px); height: 430px; object-fit: contain; }
.product-visual figcaption { max-width: 470px; margin: 10px auto 0; color: #63716d; font-size: 12px; line-height: 1.5; text-align: center; }

.key-data { display: grid; grid-template-columns: repeat(4, 1fr); margin-bottom: 58px; border-top: 1px solid #b9cbc5; border-bottom: 1px solid #b9cbc5; }
.key-data div { min-height: 120px; padding: 24px 28px; border-right: 1px solid #cddad6; }
.key-data div:last-child { border-right: 0; }
.key-data strong { display: block; color: #075a43; font-size: 21px; line-height: 1.3; }
.key-data span { display: block; margin-top: 8px; color: #5c6965; }

.engineering-layout { display: grid; grid-template-columns: 220px minmax(0, 880px); gap: 60px; align-items: start; }
.technical-contents { position: sticky; top: 24px; padding-top: 4px; }
.technical-contents > p { margin: 0 0 14px; color: #7c8984; font-size: 12px; font-weight: 800; }
.technical-contents ol { margin: 0; padding: 0; list-style: none; counter-reset: toc; }
.technical-contents li { counter-increment: toc; border-bottom: 1px solid #e2e9e6; }
.technical-contents a { display: block; padding: 9px 4px; color: #4382a9; font-size: 13px; line-height: 1.35; }
.technical-contents a::before { content: counter(toc) ". "; color: #8b9994; }
.technical-contents a:hover { color: var(--green-dark); }
.technical-body > section { scroll-margin-top: 24px; margin-bottom: 58px; }
.technical-body h2 { margin: 0 0 14px; color: #17211e; font-size: 30px; line-height: 1.22; font-weight: 700; letter-spacing: 0; }
.technical-body h2 + p { margin-top: 0; color: #53615d; }

.feature-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 0 34px; margin: 24px 0; }
.feature-grid div { position: relative; padding: 15px 0 15px 20px; border-bottom: 1px solid #e1e8e5; }
.feature-grid div::before { content: ""; position: absolute; left: 0; top: 24px; width: 7px; height: 7px; background: var(--green); }
.feature-grid strong, .feature-grid span { display: block; }
.feature-grid span { margin-top: 3px; color: #5b6964; font-size: 14px; line-height: 1.55; }
.warning { margin: 24px 0 0; padding: 18px 20px; border-left: 4px solid var(--warn-line); background: var(--warn); color: #675b38; font-size: 14px; }
.warning strong { color: #4f4426; }

.code-strip { display: grid; grid-template-columns: repeat(9, 1fr); margin: 24px 0 30px; border: 1px solid var(--line); }
.code-strip span { min-width: 0; padding: 15px 7px; border-right: 1px solid var(--line); text-align: center; }
.code-strip span:last-child { border-right: 0; }
.code-strip b, .code-strip small { display: block; }
.code-strip b { color: var(--green-dark); font-size: 17px; }
.code-strip small { margin-top: 5px; color: #687570; font-size: 11px; line-height: 1.3; }

table { width: 100%; margin: 24px 0; border-collapse: collapse; font-size: 14px; line-height: 1.45; }
th, td { padding: 12px 14px; border: 1px solid #cfddd8; vertical-align: top; text-align: left; }
thead th { color: #174a3b; background: #eaf4f0; font-size: 12px; text-transform: uppercase; }
tbody tr:nth-child(even) { background: #f8faf9; }

.engineering-figure { margin: 22px 0; border: 1px solid var(--line); background: #fff; }
.engineering-figure img { width: 100%; max-height: 470px; object-fit: contain; }
.engineering-figure figcaption { padding: 10px 14px; border-top: 1px solid var(--line); color: #687570; font-size: 12px; line-height: 1.45; }
.engineering-figure.wide img { max-height: 420px; }
.figure-pair { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; align-items: stretch; }
.figure-pair .engineering-figure { display: grid; grid-template-rows: 1fr auto; }
.formula-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; margin: 22px 0; }
.formula-grid.three { grid-template-columns: repeat(3, 1fr); }
.formula-grid div { padding: 18px; border-top: 3px solid var(--green); background: #f3f7f5; }
.formula-grid span, .formula-grid strong { display: block; }
.formula-grid span { color: #65736e; font-size: 12px; text-transform: uppercase; }
.formula-grid strong { margin-top: 9px; font-size: 16px; line-height: 1.45; }

.application-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 14px; margin: 26px 0; }
.application-item { min-width: 0; padding: 18px 13px; border: 1px solid #d5e0dc; text-align: center; background: #fff; }
.application-item img { width: 82px; height: 82px; margin: 0 auto 12px; object-fit: contain; }
.application-item strong, .application-item span { display: block; }
.application-item strong { color: #0c4f86; font-size: 14px; line-height: 1.35; }
.application-item span { margin-top: 7px; color: #687570; font-size: 12px; line-height: 1.45; }

details { border-bottom: 1px solid #dce5e2; }
summary { position: relative; padding: 17px 34px 17px 0; font-weight: 700; cursor: pointer; list-style: none; }
summary::-webkit-details-marker { display: none; }
summary::after { content: "+"; position: absolute; right: 5px; top: 14px; color: var(--green); font-size: 21px; }
details[open] summary::after { content: "−"; }
details p { margin: 0; padding: 0 34px 18px 0; color: #596762; }
.source-panel { margin-top: 28px; padding: 22px; border: 1px solid var(--line); background: #f3f7f5; }
.source-panel > strong { font-size: 18px; }
.source-panel p { color: #5e6b67; }
.compact-actions { margin-top: 16px; }

.site-footer { margin-top: 72px; color: #d6dedb; background: #202a2f; }
.footer-grid { display: grid; grid-template-columns: 1.5fr 1fr 1fr 1.1fr; gap: 48px; padding-block: 48px 38px; }
.footer-grid > div { display: flex; flex-direction: column; gap: 8px; font-size: 13px; }
.footer-grid strong { color: #fff; margin-bottom: 7px; }
.footer-grid a:hover { color: #5bd39a; }
.footer-brand img { width: 150px; filter: brightness(1.2); }
.footer-brand p { max-width: 300px; margin: 8px 0 0; color: #aebbb6; }
.copyright { padding-block: 16px; border-top: 1px solid #3a454a; color: #97a39f; font-size: 12px; }

@media (max-width: 1040px) {
  .primary-nav { gap: 16px; font-size: 12px; }
  .product-intro { grid-template-columns: minmax(0, 1fr) 350px; gap: 42px; }
  h1 { font-size: 40px; }
  .engineering-layout { grid-template-columns: 180px minmax(0, 1fr); gap: 36px; }
  .application-grid { grid-template-columns: repeat(3, 1fr); }
}

@media (max-width: 800px) {
  .shell { width: min(100% - 32px, 680px); }
  .nav-row { min-height: 58px; }
  .brand img { width: 112px; }
  .primary-nav { display: none; }
  .breadcrumbs { padding-block: 24px 16px; }
  .product-intro { grid-template-columns: 1fr; gap: 32px; padding-bottom: 40px; }
  h1 { font-size: 34px; }
  .lede { font-size: 16px; }
  .product-visual { width: min(100%, 420px); }
  .key-data { grid-template-columns: repeat(2, 1fr); }
  .key-data div:nth-child(2) { border-right: 0; }
  .key-data div:nth-child(-n+2) { border-bottom: 1px solid #cddad6; }
  .engineering-layout { display: block; }
  .technical-contents { position: static; margin-bottom: 38px; padding: 18px; background: #f5f8f7; }
  .technical-contents ol { columns: 2; column-gap: 24px; }
  .technical-contents li { break-inside: avoid; }
  .figure-pair, .formula-grid.three { grid-template-columns: 1fr; }
  .application-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 520px) {
  .shell { width: calc(100% - 24px); }
  h1 { font-size: 30px; }
  h2 { font-size: 25px; }
  .actions { display: grid; }
  .button { width: 100%; }
  .product-image-wrap { min-height: 340px; }
  .product-image-wrap img { width: 330px; height: 330px; }
  .key-data { grid-template-columns: 1fr; }
  .key-data div { border-right: 0; border-bottom: 1px solid #cddad6; }
  .key-data div:last-child { border-bottom: 0; }
  .technical-contents ol { columns: 1; }
  .feature-grid, .figure-pair, .formula-grid, .application-grid { grid-template-columns: 1fr; }
  .code-strip { grid-template-columns: repeat(3, 1fr); }
  .code-strip span { border-bottom: 1px solid var(--line); }
  .code-strip span:nth-child(3n) { border-right: 0; }
  table { display: block; overflow-x: auto; white-space: nowrap; }
  .footer-grid { grid-template-columns: 1fr; }
}