:root{--red:#d3202f;--red-dark:#a8141f;--red-soft:#fdecee;--ink:#1a1a1f;--muted:#5d6068;--line:#ececf0;--bg:#fff;--alt:#faf6f6;--radius:14px;--shadow:0 8px 30px rgba(26,26,31,.07);--font:"Inter",system-ui,-apple-system,"Segoe UI",Roboto,Arial,sans-serif;--serif:"Source Serif 4",Georgia,"Times New Roman",serif}
*{box-sizing:border-box}html{scroll-behavior:smooth}
body{margin:0;font-family:var(--font);color:var(--ink);background:var(--bg);line-height:1.75;font-size:1.0625rem;-webkit-font-smoothing:antialiased}
img{max-width:100%;height:auto;display:block}
a{color:var(--red);text-underline-offset:3px}a:hover{color:var(--red-dark)}
h1,h2,h3,h4{font-family:var(--serif);line-height:1.2;color:var(--ink);letter-spacing:-.01em}
:focus-visible{outline:3px solid var(--red);outline-offset:2px}
.container{width:min(1160px,92%);margin-inline:auto}.narrow{max-width:800px}
.sr{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0)}
.skip{position:absolute;left:-999px}.skip:focus{left:8px;top:8px;background:#fff;padding:8px;z-index:99}
.progress{position:fixed;top:0;left:0;height:3px;width:0;background:var(--red);z-index:100}
.totop{position:fixed;right:18px;bottom:18px;width:44px;height:44px;border-radius:50%;border:0;background:var(--red);color:#fff;font-size:1.3rem;cursor:pointer;box-shadow:var(--shadow);z-index:90}
.totop[hidden]{display:none}

.site-header{background:#fff;border-bottom:1px solid var(--line);border-top:4px solid var(--red)}
.header-inner{display:flex;align-items:center;justify-content:space-between;padding:12px 0;flex-wrap:wrap;gap:8px}
.brand{display:inline-flex;align-items:center;font:700 1.55rem var(--serif);color:var(--ink);text-decoration:none}.brand:hover{color:var(--red)}
.logo{width:38px;height:38px;margin-right:10px;border-radius:9px}
.nav ul{display:flex;gap:4px;list-style:none;margin:0;padding:0;align-items:center}
.nav a{color:var(--ink);text-decoration:none;padding:9px 14px;border-radius:9px;font-weight:600;font-size:.95rem}
.nav a:hover,.nav a.active{background:var(--red-soft);color:var(--red)}
.nav a.nav-cta{background:var(--red);color:#fff;margin-left:8px}.nav a.nav-cta:hover{background:var(--red-dark);color:#fff}
.nav-toggle{display:none;background:#fff;border:1px solid var(--line);color:var(--ink);border-radius:9px;padding:9px 14px;font:600 .95rem var(--font);cursor:pointer}
@media(max-width:820px){.nav-toggle{display:block}.nav{display:none;width:100%}.nav.open{display:block}.nav ul{flex-direction:column;align-items:stretch;padding:8px 0}.nav a.nav-cta{margin:6px 0 0;text-align:center}}

.btn{display:inline-block;background:var(--red);color:#fff;font:700 1rem var(--font);padding:13px 24px;border-radius:10px;text-decoration:none;border:0;cursor:pointer;transition:background .15s,transform .15s}
.btn:hover{background:var(--red-dark);color:#fff;transform:translateY(-1px)}
.btn.ghost{background:#fff;color:var(--red);border:2px solid var(--red)}.btn.ghost:hover{background:var(--red-soft);color:var(--red-dark)}
.cta-row{display:flex;gap:12px;flex-wrap:wrap}
.hero{background:linear-gradient(180deg,#fff 0%,#fff3f4 100%);padding:72px 0 64px;border-bottom:1px solid var(--line)}
.hero.slim{padding:44px 0}
.hero h1{font-size:clamp(2.1rem,5vw,3.4rem);margin:0 0 .4em;max-width:820px}
.hero p{max-width:640px;font-size:1.18rem;color:var(--muted)}
.stats{display:flex;gap:16px;flex-wrap:wrap;margin:36px 0 0}
.stat{display:flex;flex-direction:column;background:#fff;border:1px solid var(--line);border-top:3px solid var(--red);border-radius:12px;padding:16px 22px;min-width:170px;box-shadow:var(--shadow)}
.stat dt{order:2;font-size:.9rem;color:var(--muted)}.stat dd{margin:0;font:700 2.1rem var(--serif);color:var(--red)}
.section{padding:64px 0}.section.alt{background:var(--alt)}
.section-title{margin:0 0 26px;font-size:clamp(1.6rem,3vw,2.1rem)}
.lead{font-size:1.15rem;max-width:720px;color:var(--muted)}.narrow-text{max-width:820px}

.grid{display:grid;gap:24px;grid-template-columns:repeat(auto-fill,minmax(270px,1fr));margin-bottom:24px}
.grid.three{grid-template-columns:repeat(auto-fit,minmax(260px,1fr))}
.card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;transition:box-shadow .2s,transform .2s}
.card:hover{box-shadow:var(--shadow);transform:translateY(-3px)}
.card img{aspect-ratio:1200/630;object-fit:cover;width:100%;background:var(--red-soft)}
.card-body{padding:20px}.card h3{margin:.25em 0 .45em;font-size:1.18rem}.card h3 a{color:var(--ink);text-decoration:none}.card h3 a:hover{color:var(--red)}
.card p{margin:0;color:var(--muted);font-size:.95rem}
.tag{display:inline-block;font-size:.8rem;font-weight:700;color:var(--red);background:var(--red-soft);padding:3px 10px;border-radius:99px}

.layout{display:grid;grid-template-columns:minmax(0,1fr) 330px;gap:44px;align-items:start;padding:40px 0}
@media(max-width:920px){.layout{grid-template-columns:1fr}}
.widget{background:#fff;border:1px solid var(--line);border-top:3px solid var(--red);border-radius:var(--radius);padding:22px;margin-bottom:24px}
.widget h4{margin:0 0 12px;font-size:1.1rem}.widget ul{margin:0;padding-left:18px}.widget li{margin-bottom:9px;font-size:.96rem}
.crumbs{font-size:.9rem;color:var(--muted);padding-top:22px}.crumbs a{text-decoration:none}
.article-head h1{font-size:clamp(1.9rem,4vw,2.7rem);margin:.35em 0}.meta{color:var(--muted);font-size:.92rem;margin:0}
.share{display:flex;gap:8px;align-items:center;flex-wrap:wrap;margin-top:14px;font-size:.9rem}.share span{font-weight:600;color:var(--muted)}
.share a,.share button{border:1px solid var(--line);background:#fff;color:var(--ink);padding:6px 12px;border-radius:99px;text-decoration:none;font:500 .88rem var(--font);cursor:pointer}
.share a:hover,.share button:hover{border-color:var(--red);color:var(--red)}
.featured{border-radius:var(--radius);margin:22px 0;width:100%;aspect-ratio:1200/630;object-fit:cover}
.prose{padding-bottom:20px}.prose h2{margin-top:1.9em;font-size:1.7rem;padding-top:.2em}.prose h3{margin-top:1.4em;font-size:1.25rem}
.prose li{margin-bottom:.45em}.prose li::marker{color:var(--red)}.narrow .prose{padding-top:32px}
.table-wrap{overflow-x:auto;margin:1.3em 0;border:1px solid var(--line);border-radius:12px}
table{border-collapse:collapse;width:100%;min-width:380px;background:#fff;font-size:.97rem}
th,td{border-bottom:1px solid var(--line);padding:11px 14px;text-align:left}th{background:var(--red);color:#fff;font-weight:600}tr:last-child td{border-bottom:0}tr:nth-child(even) td{background:#fcf8f8}
.toc{background:var(--red-soft);border-left:4px solid var(--red);border-radius:12px;padding:16px 20px;margin:22px 0}
.toc summary{font-weight:700;cursor:pointer}.toc ol{margin:10px 0 0;padding-left:20px}.toc a{color:var(--ink)}.toc a:hover{color:var(--red)}
.author{background:var(--alt);border:1px solid var(--line);border-radius:12px;padding:18px 20px;margin-top:32px}
.related{padding-bottom:24px}

label{display:block;font-weight:600;margin:14px 0 6px}
input,select,textarea{width:100%;padding:12px 14px;border:1px solid #d6d6dc;border-radius:10px;font:inherit;background:#fff}
input:focus,select:focus,textarea:focus{outline:2px solid var(--red);border-color:var(--red)}
.tools{display:grid;gap:24px;grid-template-columns:1fr}@media(max-width:820px){.tools{grid-template-columns:1fr}}
.tool{background:#fff;border:1px solid var(--line);border-top:3px solid var(--red);border-radius:var(--radius);padding:26px;box-shadow:var(--shadow)}.tool.wide{margin-top:24px}.tool h3{margin-top:0}
.rows{display:grid;grid-template-columns:1fr 1fr;gap:0 16px}.rows label{font-weight:500;font-size:.9rem;margin:10px 0 4px}
.out{display:grid;grid-template-columns:1fr auto;gap:8px 16px;margin:20px 0}.out dt{color:var(--muted)}.out dd{margin:0;font-weight:700;font-size:1.15rem;text-align:right;color:var(--red)}
.note{color:var(--muted);font-size:.9rem}
.bar{display:grid;grid-template-columns:56px 1fr 60px;align-items:center;gap:10px;margin:6px 0;font-size:.9rem}
.bar i{display:block;height:14px;background:var(--red);border-radius:4px;min-width:2px}.bar b{text-align:right}

.newsletter{background:var(--red)}
.nl-box{display:grid;grid-template-columns:1.2fr 1fr;gap:32px;align-items:center;color:#fff}
@media(max-width:820px){.nl-box{grid-template-columns:1fr}}
.nl-box h2{color:#fff;margin:0 0 .3em;font-size:clamp(1.6rem,3vw,2.1rem)}.nl-box p{margin:0;color:#ffe3e5}
.nl-form{display:grid;gap:10px}.nl-form .btn{background:#1a1a1f}.nl-form .btn:hover{background:#000}
.nl-form .note,.nl-form .note a{color:#ffe3e5}

.site-footer{background:var(--alt);border-top:4px solid var(--red);margin-top:48px;color:var(--muted)}
.footer-grid{display:grid;gap:40px;grid-template-columns:1.3fr 1.2fr 1fr;padding:52px 0 36px}
@media(max-width:860px){.footer-grid{grid-template-columns:1fr 1fr}}@media(max-width:560px){.footer-grid{grid-template-columns:1fr}}
.site-footer h4{margin:0 0 14px;font-size:1.1rem;color:var(--ink)}
.site-footer ul{list-style:none;margin:0;padding:0}.site-footer li{margin-bottom:10px;font-size:.96rem}
.site-footer a{color:var(--ink);text-decoration:none}.site-footer a:hover{color:var(--red)}
.fw p{font-size:.96rem;margin:.9em 0 0}.mail{color:var(--red)!important;font-weight:600}
.footer-credit{background:#fff;border-top:1px solid var(--line);padding:18px 0;font-size:.86rem}
.credit-row{display:flex;gap:8px 28px;flex-wrap:wrap;justify-content:space-between}.credit-row p{margin:0}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}.card,.btn{transition:none}}

.router{display:grid;gap:16px;grid-template-columns:repeat(auto-fit,minmax(min(100%,240px),1fr))}
.route{display:block;background:#fff;border:1px solid var(--line);border-left:4px solid var(--red);border-radius:12px;padding:18px 20px;text-decoration:none;color:var(--ink);transition:box-shadow .2s,transform .2s}
.route strong{display:block;font-family:var(--serif);font-size:1.12rem;margin-bottom:4px}.route span{color:var(--muted);font-size:.94rem}
.route:hover{box-shadow:var(--shadow);transform:translateY(-2px);color:var(--ink)}
.igs{display:grid;gap:28px;grid-template-columns:repeat(auto-fit,minmax(min(100%,420px),1fr));margin-top:8px}
.ig{margin:0;background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:14px 14px 10px}
.ig svg{width:100%;height:auto;display:block}.ig figcaption{font-size:.88rem;color:var(--muted);margin-top:8px;text-align:center}
.igs p{margin:12px 2px 0;font-size:.98rem}
.formulas{display:grid;gap:16px;grid-template-columns:repeat(auto-fit,minmax(min(100%,230px),1fr))}
.fcard{background:#fff;border:1px solid var(--line);border-top:3px solid var(--red);border-radius:12px;padding:18px}
.fcard h3{margin:.1em 0 .3em;font-size:1.1rem}.fcard p{margin:.4em 0 0;font-size:.94rem;color:var(--muted)}
.fcard code{display:block;background:var(--red-soft);color:var(--red-dark);padding:10px 12px;border-radius:8px;font:600 .9rem/1.45 ui-monospace,Menlo,Consolas,monospace;overflow-wrap:anywhere}
.gloss{display:grid;gap:12px 32px;grid-template-columns:repeat(auto-fit,minmax(min(100%,280px),1fr));margin:0}
.gloss div{border-bottom:1px solid var(--line);padding-bottom:10px}.gloss dt{font-weight:700;color:var(--red)}.gloss dd{margin:2px 0 0;color:var(--muted);font-size:.97rem}
.faq h3{font-size:1.15rem;margin:1.4em 0 .3em}
html,body{overflow-x:hidden}
@media(max-width:600px){
 body{font-size:1rem}.hero{padding:44px 0 40px}.section{padding:44px 0}.layout{padding:24px 0;gap:28px}
 .stat{flex:1 1 calc(50% - 16px);min-width:0;padding:14px}.stat dd{font-size:1.7rem}
 .rows{grid-template-columns:1fr}.cta-row .btn{flex:1 1 100%;text-align:center}.nl-form .btn{width:100%}
 .credit-row{flex-direction:column}.prose h2{font-size:1.45rem}.tool{padding:20px}.brand{font-size:1.35rem}
 .share a,.share button{padding:8px 13px}.bar{grid-template-columns:48px 1fr 54px}
}

.readable{max-width:780px}
.readable.page{padding-top:36px;padding-bottom:40px}
.gloss{display:grid;gap:16px;grid-template-columns:repeat(auto-fill,minmax(min(100%,290px),1fr));margin:0}
.gloss div{background:#fff;border:1px solid var(--line);border-left:3px solid var(--red);border-radius:12px;padding:16px 18px;height:100%}
.gloss h3{font:700 1.02rem/1.3 var(--font);color:var(--red);margin:0}.gloss p{margin:5px 0 0;color:var(--muted);font-size:.96rem;line-height:1.55}

.author{display:flex;gap:16px;align-items:center}
.author img{width:84px;height:84px;border-radius:50%;object-fit:cover;flex:none;border:2px solid var(--line);background:#fff}
.author p{margin:6px 0 0}
@media (max-width:520px){.author{flex-direction:column;align-items:flex-start}}