.site-header .header-inner{min-height:76px}
.brand-copy strong{font-size:1.02rem;letter-spacing:-.02em}
.brand-copy small{font-size:.74rem}
.main-nav{display:flex;align-items:center;gap:.2rem;margin-left:auto}
.main-nav>a,.nav-group>button{border:0;background:transparent;color:var(--ink);text-decoration:none;min-height:42px;padding:.55rem .68rem;border-radius:9px;font-weight:700;font-size:.88rem}
.main-nav>a:hover,.main-nav>a:focus-visible,.nav-group>button:hover,.nav-group>button:focus-visible{background:var(--surface-2);color:var(--green)}
.nav-group{position:relative}
.nav-group>button::after{content:"⌄";font-size:.78rem;margin-left:.35rem;color:var(--muted)}
.nav-menu{position:absolute;left:0;top:calc(100% + .35rem);width:270px;padding:.55rem;background:var(--surface);border:1px solid var(--line);border-radius:14px;box-shadow:var(--shadow);display:none;z-index:80}
.nav-group:hover .nav-menu,.nav-group:focus-within .nav-menu,.nav-group.is-open .nav-menu{display:grid}
.nav-menu a{padding:.58rem .65rem;color:var(--ink);text-decoration:none;border-radius:9px;font-size:.86rem;font-weight:650}
.nav-menu a:hover,.nav-menu a:focus-visible{background:var(--green-soft);color:var(--green)}
.mobile-menu{display:none}
.header-search-wrap{position:relative;min-width:215px}
.header-search{width:100%;min-height:40px;border:1px solid var(--line);border-radius:999px;padding:.55rem 2.3rem .55rem .85rem;background:var(--surface);color:var(--ink)}
.header-search:focus{outline:none;border-color:var(--green);box-shadow:0 0 0 3px color-mix(in srgb,var(--green) 15%,transparent)}
.search-results{position:absolute;right:0;top:calc(100% + .45rem);width:min(390px,88vw);max-height:420px;overflow:auto;background:var(--surface);border:1px solid var(--line);border-radius:14px;box-shadow:var(--shadow);padding:.45rem;display:none;z-index:90}
.search-results.is-open{display:grid}
.search-results a{display:grid;gap:.15rem;padding:.68rem .72rem;border-radius:10px;text-decoration:none;color:var(--ink)}
.search-results a:hover,.search-results a:focus-visible{background:var(--green-soft)}
.search-results strong{font-size:.9rem}.search-results small{color:var(--muted);line-height:1.35}
.page-hero{padding:clamp(2.2rem,5vw,4.7rem) 0 1.8rem;border-bottom:1px solid var(--line)}
.breadcrumbs{display:flex;flex-wrap:wrap;gap:.35rem;align-items:center;color:var(--muted);font-size:.8rem;margin-bottom:1rem}
.breadcrumbs a{color:var(--green);text-decoration:none}
.page-hero-grid{display:grid;grid-template-columns:minmax(0,1.55fr) minmax(270px,.55fr);gap:clamp(1.5rem,4vw,4rem);align-items:end}
.page-hero h1{font-size:clamp(2.35rem,6vw,4.9rem);line-height:1;letter-spacing:-.052em;margin:0;max-width:15ch}
.page-hero .lead{font-size:clamp(1.02rem,1.7vw,1.18rem);color:var(--muted);max-width:72ch;margin:1rem 0 0}
.hero-meta{display:grid;grid-template-columns:1fr 1fr;gap:.7rem;background:var(--surface);border:1px solid var(--line);border-radius:18px;padding:1rem;box-shadow:var(--shadow-sm)}
.hero-meta div{padding:.5rem}.hero-meta span{display:block;font-size:.7rem;text-transform:uppercase;letter-spacing:.08em;color:var(--muted);font-weight:800}.hero-meta strong{display:block;margin-top:.18rem;font-size:.95rem}
.content-shell{display:grid;grid-template-columns:minmax(0,1fr) 270px;gap:2rem;padding:clamp(2rem,5vw,4rem) 0}
.article-content{min-width:0}
.article-section{background:var(--surface);border:1px solid var(--line);border-radius:18px;padding:clamp(1rem,2.5vw,1.5rem);box-shadow:var(--shadow-sm);margin-bottom:1rem}
.article-section h2{margin:0 0 .75rem;font-size:clamp(1.45rem,2.5vw,2rem);letter-spacing:-.035em;line-height:1.15}
.article-section h3{margin:1.15rem 0 .45rem;font-size:1.05rem}
.article-section p{margin:.65rem 0;color:color-mix(in srgb,var(--ink) 90%,var(--muted))}
.article-section ul,.article-section ol{padding-left:1.2rem}.article-section li+li{margin-top:.38rem}
.formula-grid{display:grid;grid-template-columns:1fr 1fr;gap:1rem}.formula-card,.example-card,.facts-card{border:1px solid var(--line);border-radius:14px;padding:1rem;background:var(--surface-2)}
.example-card{background:var(--orange-soft);border-color:color-mix(in srgb,var(--orange) 24%,var(--line))}.example-card h3{color:var(--orange);margin-top:0}
.facts-list{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:.6rem;list-style:none;padding:0!important}.facts-list li{border:1px solid var(--line);border-radius:12px;padding:.75rem;background:var(--surface-2)}.facts-list strong{display:block;color:var(--green);font-size:.78rem;text-transform:uppercase;letter-spacing:.05em;margin-bottom:.16rem}
.content-table{overflow:auto;border:1px solid var(--line);border-radius:14px}.content-table table{min-width:690px}.content-table th{position:static}
.faq-list{display:grid;gap:.65rem}.faq-item{border:1px solid var(--line);border-radius:14px;background:var(--surface-2);overflow:hidden}.faq-item summary{cursor:pointer;font-weight:800;padding:.9rem 1rem}.faq-item p{padding:0 1rem 1rem;margin:0}
.card-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(210px,1fr));gap:.75rem}.topic-card{display:block;border:1px solid var(--line);border-radius:14px;padding:1rem;background:var(--surface);text-decoration:none;color:var(--ink);box-shadow:var(--shadow-sm)}.topic-card:hover,.topic-card:focus-visible{border-color:color-mix(in srgb,var(--green) 45%,var(--line));transform:translateY(-1px)}.topic-card strong{display:block;color:var(--green);margin-bottom:.25rem}.topic-card span{font-size:.86rem;color:var(--muted)}
.article-aside{position:sticky;top:94px;align-self:start;display:grid;gap:.8rem}.aside-card{background:var(--surface);border:1px solid var(--line);border-radius:16px;padding:1rem;box-shadow:var(--shadow-sm)}.aside-card h2{font-size:1rem;margin:0 0 .65rem}.aside-card a{display:block;color:var(--ink);text-decoration:none;padding:.42rem 0;border-bottom:1px solid var(--line);font-size:.86rem}.aside-card a:last-child{border-bottom:0}.aside-card a:hover{color:var(--green)}
.reference-list{word-break:break-word}.reference-list a{color:var(--green)}
.converter-focus{padding:clamp(1rem,3vw,2rem) 0 3rem}.converter-focus .utility-card{max-width:800px;margin-inline:auto}.converter-note{color:var(--muted);font-size:.86rem}
.search-page-results{display:grid;gap:.75rem}.search-page-results .topic-card{padding:1.1rem}
.footer-inner{align-items:start}.footer-links{display:grid;grid-template-columns:repeat(2,minmax(130px,1fr));gap:.4rem 1rem}.footer-links a{color:#d7e6db;text-decoration:none;font-size:.86rem}.footer-links a:hover{text-decoration:underline}
.legal-note{font-size:.82rem;color:var(--muted)}
@media(max-width:1100px){.main-nav{display:none}.mobile-menu{display:inline-grid;place-items:center}.header-search-wrap{min-width:190px}.content-shell{grid-template-columns:1fr}.article-aside{position:static;grid-template-columns:repeat(2,minmax(0,1fr))}}
@media(max-width:760px){.header-search-wrap{display:none}.page-hero-grid,.formula-grid{grid-template-columns:1fr}.hero-meta{max-width:560px}.facts-list{grid-template-columns:1fr}.article-aside{grid-template-columns:1fr}.mobile-nav-panel{display:none;position:fixed;inset:64px 0 auto 0;background:var(--surface);border-bottom:1px solid var(--line);padding:1rem;box-shadow:var(--shadow);z-index:75}.mobile-nav-panel.is-open{display:grid}.mobile-nav-panel a{padding:.7rem .3rem;text-decoration:none;color:var(--ink);border-bottom:1px solid var(--line);font-weight:700}.mobile-nav-panel .mobile-search{display:block;margin-top:.7rem;width:100%;min-height:44px;border:1px solid var(--line);border-radius:11px;padding:.7rem;background:var(--surface);color:var(--ink)}}
@media(min-width:761px){.mobile-nav-panel{display:none!important}}
@media print{.main-nav,.header-search-wrap,.mobile-menu,.article-aside,.breadcrumbs{display:none!important}.content-shell{display:block}.article-section{box-shadow:none;break-inside:avoid}}