.article-main { width: min(1080px, calc(100% - 40px)); margin: 0 auto; }
.breadcrumb { min-height: 54px; display: flex; flex-wrap: wrap; align-items: center; gap: 8px; padding-top: 12px; color: var(--muted); font: 11px var(--font-mono); }
.breadcrumb a { min-height: 34px; display: inline-flex; align-items: center; }
.breadcrumb a:hover { color: var(--blue-dark); }

.article-hero { padding: 62px 0 56px; border-bottom: 2px solid var(--ink); position: relative; }
.article-hero::after { content: ""; position: absolute; left: 0; right: 0; bottom: -10px; height: 9px; background: repeating-linear-gradient(90deg,var(--ink) 0 1px,transparent 1px 13px); opacity: .32; }
.article-hero h1 { max-width: 920px; margin: 12px 0 23px; font-family: var(--font-display); font-size: clamp(50px,7vw,90px); line-height: .92; letter-spacing: -.055em; }
.article-hero .lead { max-width: 780px; color: var(--muted); font-size: 17px; line-height: 1.85; }
.fact-row { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 26px; }
.fact-row span { min-height: 38px; display: inline-flex; align-items: center; padding: 0 12px; border: 1px solid var(--line-strong); border-radius: 999px; background: var(--white); color: var(--ink-soft); font: 700 11px var(--font-mono); }

.mini-converter { margin: 58px 0 76px; padding: 30px; border: 2px solid var(--ink); border-radius: 20px; background: var(--white); box-shadow: var(--shadow); }
.mini-converter h2 { margin: 0 0 7px; font-family: var(--font-display); font-size: 32px; letter-spacing: -.035em; }
.mini-converter > p { margin: 0 0 23px; color: var(--muted); }
.mini-grid { min-width: 0; display: grid; grid-template-columns: minmax(0,1fr) 48px minmax(0,1fr); gap: 14px; align-items: end; }
.mini-field { min-width: 0; }
.mini-field label { display: block; margin-bottom: 8px; color: var(--muted); font-size: 12px; font-weight: 750; }
.mini-field input, .mini-field output { width: 100%; min-width: 0; min-height: 62px; display: flex; align-items: center; overflow: hidden; padding: 0 14px; border: 1px solid var(--line-strong); border-radius: 11px; background: var(--canvas); color: var(--ink); font-family: var(--font-display); font-size: 28px; font-weight: 850; text-overflow: ellipsis; white-space: nowrap; outline: none; }
.mini-field output { background: var(--ink); color: var(--aqua); }
.mini-field select { width: 100%; min-height: 48px; margin-top: 8px; padding: 0 10px; border: 1px solid var(--line-strong); border-radius: 9px; background: var(--white); color: var(--ink); }
.mini-swap { width: 46px; height: 46px; margin-bottom: 3px; border: 2px solid var(--ink); border-radius: 50%; background: var(--coral); color: var(--ink); box-shadow: 3px 3px 0 var(--ink); font-size: 20px; }

.article-layout { display: grid; grid-template-columns: minmax(0,1fr) 260px; gap: 66px; align-items: start; padding-bottom: 100px; }
.article-content { min-width: 0; }
.article-content section { margin-bottom: 54px; }
.article-content h2 { margin: 0 0 17px; font-family: var(--font-display); font-size: clamp(32px,4vw,48px); line-height: 1.04; letter-spacing: -.045em; }
.article-content h3 { margin: 27px 0 9px; font-family: var(--font-display); font-size: 22px; }
.article-content p, .article-content li { color: #49646a; line-height: 1.9; }
.article-content a { color: var(--blue-dark); text-decoration: underline; text-decoration-thickness: 1px; text-underline-offset: 3px; }
.article-content ul, .article-content ol { padding-left: 22px; }
.formula-box { padding: 21px 22px; border: 2px solid var(--ink); border-left: 9px solid var(--blue); border-radius: 0 12px 12px 0; background: var(--aqua); color: var(--ink); font: 800 14px/1.9 var(--font-mono); overflow-wrap: anywhere; }
.table-wrap { max-width: 100%; overflow-x: auto; border: 2px solid var(--ink); border-radius: 12px; background: var(--white); -webkit-overflow-scrolling: touch; scrollbar-color: var(--blue) var(--canvas-deep); }
.article-table { width: 100%; border-collapse: collapse; min-width: 580px; }
.article-table th, .article-table td { padding: 14px 16px; border-bottom: 1px solid var(--line); text-align: left; }
.article-table th { background: var(--ink); color: var(--white); font: 800 11px var(--font-mono); }
.article-table td { color: #49646a; font-size: 14px; }
.article-table tr:last-child td { border-bottom: 0; }
.article-table tbody tr:nth-child(even) { background: rgba(189,235,240,.25); }
.side-nav { position: sticky; top: 24px; padding: 19px; border: 2px solid var(--ink); border-radius: 13px; background: var(--white); box-shadow: 5px 5px 0 rgba(10,45,53,.16); }
.side-nav b { display: block; margin-bottom: 11px; font-family: var(--font-display); font-size: 18px; }
.side-nav a { min-height: 42px; display: flex; align-items: center; padding: 0 3px; border-bottom: 1px solid var(--line); color: var(--muted); font-size: 13px; }
.side-nav a:last-child { border-bottom: 0; }
.side-nav a:hover { color: var(--blue-dark); }
.notice { padding: 18px 20px; border: 1px solid #e36b4f; border-left: 8px solid var(--coral); border-radius: 0 10px 10px 0; background: #ffe9e2; color: #6f321f; line-height: 1.75; }

.guide-cards { display: grid; grid-template-columns: repeat(2,1fr); gap: 13px; }
.guide-card { min-width: 0; padding: 21px; border: 2px solid var(--ink); border-radius: 13px; background: var(--white); }
.guide-card:nth-child(2n) { background: rgba(189,235,240,.42); }
.guide-card span { font-size: 28px; }
.guide-card h3 { margin: 16px 0 7px; }
.guide-card p { margin: 0; }
.contact-card { margin: 29px 0; padding: 24px; border: 2px solid var(--ink); border-radius: 13px; background: var(--white); }
.contact-card a { color: var(--blue-dark); font-weight: 800; }
.contact-form { display: grid; gap: 17px; margin-top: 27px; }
.contact-form label { display: grid; gap: 8px; color: var(--muted); font-size: 13px; font-weight: 750; }
.contact-form input, .contact-form textarea, .contact-form select { width: 100%; min-height: 48px; padding: 12px 13px; border: 1px solid var(--line-strong); border-radius: 9px; background: var(--white); color: var(--ink); outline: none; }
.contact-form input:focus, .contact-form textarea:focus, .contact-form select:focus { border-color: var(--blue); box-shadow: 0 0 0 3px rgba(47,99,255,.14); }
.contact-form textarea { min-height: 150px; resize: vertical; }
.primary-button { width: fit-content; min-height: 48px; display: inline-flex; align-items: center; justify-content: center; padding: 0 20px; border: 2px solid var(--ink); border-radius: 999px; background: var(--blue); color: var(--white) !important; box-shadow: 3px 3px 0 var(--ink); font-weight: 800; text-decoration: none !important; }
.primary-button:hover { background: var(--blue-dark); }
.page-footer { min-height: 150px; }
.page-footer .footer-center { display: block; }

@media (max-width: 900px) {
  .article-layout { grid-template-columns: 1fr; gap: 18px; }
  .side-nav { position: static; order: -1; display: flex; align-items: center; gap: 7px; overflow-x: auto; padding: 12px; scrollbar-width: none; box-shadow: none; }
  .side-nav::-webkit-scrollbar { display: none; }
  .side-nav b { flex: 0 0 auto; margin: 0 5px 0 0; }
  .side-nav a { flex: 0 0 auto; min-height: 40px; padding: 0 11px; border: 1px solid var(--line); border-radius: 999px; background: var(--canvas); white-space: nowrap; }
  .mini-grid { grid-template-columns: 1fr; }
  .mini-swap { justify-self: center; transform: rotate(90deg); margin: 0; }
}

@media (max-width: 620px) {
  .article-main { width: min(100% - 24px,1080px); }
  .breadcrumb { min-height: 48px; padding-top: 8px; }
  .article-hero { padding: 46px 0 45px; }
  .article-hero h1 { font-size: clamp(46px,14vw,64px); overflow-wrap: anywhere; }
  .article-hero .lead { font-size: 15px; line-height: 1.8; }
  .fact-row { flex-wrap: nowrap; width: 100%; max-width: 100%; overflow-x: auto; padding: 0 0 5px; scrollbar-width: none; }
  .fact-row::-webkit-scrollbar { display: none; }
  .fact-row span { flex: 0 0 auto; }
  .mini-converter { margin: 48px 0 64px; padding: 21px 14px; border-radius: 16px; box-shadow: 5px 6px 0 var(--ink); }
  .mini-converter h2 { font-size: 29px; }
  .mini-converter > p { font-size: 14px; line-height: 1.65; }
  .mini-field input, .mini-field output { min-height: 58px; font-size: 25px; }
  .mini-field select { min-height: 50px; }
  .article-layout { padding-bottom: 76px; }
  .article-content section { margin-bottom: 46px; }
  .article-content h2 { font-size: clamp(31px,10vw,42px); }
  .article-content p, .article-content li { font-size: 15px; line-height: 1.85; }
  .formula-box { padding: 18px 14px; border-left-width: 7px; font-size: 12px; }
  .table-wrap { margin-right: 0; border-radius: 10px; }
  .article-table { min-width: 560px; }
  .article-table th, .article-table td { padding: 13px 14px; }
  .side-nav { margin: 0 -12px; border-left: 0; border-right: 0; border-radius: 0; }
  .guide-cards { grid-template-columns: 1fr; }
  .guide-card { padding: 18px; }
  .contact-form { gap: 15px; }
  .primary-button { width: 100%; }
  .page-footer { display: grid; grid-template-columns: 1fr; gap: 16px; text-align: center; }
  .page-footer > .brand, .page-footer > span { justify-self: center; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition: none !important; animation: none !important; }
}