@charset "UTF-8";
:root{--bg:#faf9f5;--ink:#172e29;--muted:#52655e;--accent:#176452;--light:#eaf0e8;--border:#d4ded4;--paper:#fffef9;--serif:"Songti SC","Noto Serif CJK SC","PMingLiU",serif;--sans:Inter,-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei",sans-serif}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:32px}body{margin:0;background:var(--bg);color:var(--ink);font:16px/1.8 var(--sans);-webkit-font-smoothing:antialiased}body.theme-comparison{--bg:#f3f5fa;--ink:#17243e;--muted:#4e5e79;--accent:#2449ad;--light:#e7ecfa;--border:#cdd5e7;--paper:#fff}body.theme-cost{--bg:#fbf6f0;--ink:#392c35;--muted:#705b64;--accent:#71455e;--light:#f1e6e9;--border:#dfcdd3;--paper:#fffaf5}a{color:var(--accent);text-underline-offset:4px;overflow-wrap:anywhere}a:hover{text-decoration-thickness:2px}button,input{font:inherit}button,.button{display:inline-flex;justify-content:center;align-items:center;gap:18px;background:var(--accent);border:1px solid var(--accent);color:#fff;border-radius:5px;padding:13px 22px;font-weight:650;text-decoration:none;cursor:pointer;line-height:1.5}button:hover,.button:hover{filter:brightness(.93)}button:focus-visible,a:focus-visible,input:focus-visible,summary:focus-visible,[tabindex]:focus-visible{outline:3px solid #b56914;outline-offset:4px}input{width:100%;min-width:0;border:1px solid var(--border);border-radius:5px;background:var(--paper);color:var(--ink);padding:13px 14px}img{max-width:100%;height:auto;display:block}h1,h2,h3{line-height:1.4;text-wrap:pretty}h1{font-family:var(--serif);font-size:clamp(34px,4.2vw,64px);font-weight:650;letter-spacing:-.02em;margin:16px 0 24px}h2{font-size:28px;font-family:var(--serif);margin:0 0 22px}h3{font-size:21px;margin:12px 0}p{margin:0 0 20px}small{font-size:13px}strong,b{font-weight:650}[hidden]{display:none!important}.shell{max-width:1240px;padding-inline:48px;margin-inline:auto}.narrow{max-width:930px}.section{padding-block:62px}.eyebrow{font-size:12px;font-weight:750;letter-spacing:.13em;color:var(--accent);margin:0 0 18px}.lead{font-size:19px;line-height:1.9;color:var(--muted);max-width:790px}.skip{position:absolute;top:-80px;left:20px;z-index:99;padding:12px;background:var(--ink);color:#fff}.skip:focus{top:12px}.site-header{border-bottom:1px solid var(--border);background:var(--paper)}.header-inner{min-height:94px;display:flex;align-items:center;gap:34px}.brand{display:flex;align-items:center;gap:11px;color:var(--ink);font-weight:750;white-space:nowrap;font-size:21px;text-decoration:none}.brand-mark{display:grid;place-items:center;background:var(--accent);color:#fff;width:38px;height:42px;border-radius:4px;font-family:var(--serif);font-size:25px}.header-inner nav{display:flex;gap:25px;flex:1;justify-content:center}.header-inner nav a{font-size:14px;text-decoration:none;color:var(--ink);white-space:nowrap}.language{font-size:13px;text-decoration:none;border:1px solid var(--border);padding:6px 11px;border-radius:4px;white-space:nowrap}.hero{display:grid;grid-template-columns:1.25fr .8fr;gap:75px;align-items:center;padding-block:82px 72px}.hero h1{max-width:680px}.hero .lead{font-size:18px;max-width:650px}.hero-actions{display:flex;align-items:center;flex-wrap:wrap;gap:24px;margin-top:30px}.text-link{text-decoration:none;font-size:15px}.hero-stats{display:flex;gap:32px;border-top:1px solid var(--border);margin-top:40px;padding-top:24px}.hero-stats span{display:flex;flex-direction:column;gap:3px;font-size:12px;color:var(--muted)}.hero-stats b{font-size:22px;color:var(--ink)}.hero-proof{padding:34px;background:var(--light);border:1px solid var(--border);border-radius:8px;position:relative}.hero-proof:before{content:"";position:absolute;width:60px;height:4px;background:var(--accent);left:34px;top:-2px}.proof-number{font-family:Georgia,serif;font-size:100px;line-height:1.2;display:block;letter-spacing:-.06em;margin:24px 0;color:var(--accent)}.proof-number>span{font-family:var(--sans);font-size:21px;letter-spacing:0;margin-left:14px}.hero-proof h2{font-size:24px}.hero-proof p{font-size:15px;color:var(--muted)}.hero-proof a{font-size:14px;font-weight:700}.section-heading{display:flex;align-items:end;justify-content:space-between;gap:24px;margin-bottom:28px}.section-heading h2{margin-bottom:0}.section-heading .eyebrow{margin-bottom:8px}.section-heading>a{font-size:14px;white-space:nowrap}.cards{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px}.card{display:flex;flex-direction:column;background:var(--paper);border:1px solid var(--border);padding:28px;border-radius:6px;min-width:0}.card-index{font-size:11px;color:var(--muted);letter-spacing:.06em}.card h3{margin:17px 0 14px}.card h3 a{color:var(--ink);text-decoration:none}.card p{font-size:14px;color:var(--muted)}.card .watch{border-top:1px solid var(--border);padding-top:13px}.watch span{display:block;color:var(--ink);font-size:11px;font-weight:750;margin-bottom:4px}.card-link{display:flex;justify-content:space-between;align-items:center;font-size:13px;font-weight:700;text-decoration:none;margin-top:auto;padding-top:16px}.tinted{background:var(--light);border-block:1px solid var(--border)}.sponsor{display:flex;align-items:center;gap:24px;border:1px solid var(--border);border-left:4px solid var(--accent);padding:20px 24px;margin-block:36px;background:var(--paper);font-size:13px}.sponsor .eyebrow{margin:0;white-space:nowrap}.sponsor>div{flex:1}.sponsor strong{font-size:14px;display:block}.sponsor a{font-size:12px}.site-footer{margin-top:60px;border-top:1px solid var(--border);padding-block:48px;background:var(--light)}.footer-brand{font-size:24px;font-weight:700;text-decoration:none;color:var(--ink)}.site-footer p{font-size:13px;color:var(--muted);max-width:790px;margin-top:14px}.site-footer nav{display:flex;gap:14px 25px;flex-wrap:wrap;margin:26px 0}.site-footer nav a{font-size:13px}.site-footer small{color:var(--muted)}.page-heading{padding-block:60px 26px;border-bottom:1px solid var(--border)}.page-heading h1{font-size:46px}.page-heading .lead{font-size:17px}.search-box{max-width:580px;margin-bottom:30px}.search-box label{display:block;font-weight:650;margin-bottom:8px}.search-box p{font-size:13px;color:var(--muted);margin:8px 0}.article-top{padding-block:38px 32px}.breadcrumb{font-size:12px;margin-bottom:32px;color:var(--muted)}.breadcrumb a{text-decoration:none}.article-top h1{font-size:clamp(30px,3.5vw,48px);max-width:980px}.article-top .lead{font-size:18px;max-width:980px}.article-meta{display:flex;flex-direction:column;gap:3px;font-size:12px;color:var(--muted);padding-block:20px;border-block:1px solid var(--border)}.article-layout{display:grid;grid-template-columns:230px minmax(0,1fr);gap:55px;align-items:start;padding-bottom:30px}.toc{position:sticky;top:25px;font-size:13px;padding:23px 0}.toc h2{font-family:var(--sans);font-size:14px}.toc ol{padding-left:20px}.toc li{margin-bottom:13px}.toc a{text-decoration:none;color:var(--muted)}.prose{font-size:17px;line-height:1.95;min-width:0;overflow-wrap:break-word}.prose>section{margin-block:46px}.prose h2{font-size:27px}.prose p{margin-bottom:25px}.prose ul,.prose ol{padding-left:24px}.prose li{margin-bottom:12px}.section-number{font-family:Georgia,serif;font-size:18px;color:var(--accent);display:block;margin-bottom:9px}.citations{display:flex;gap:4px 13px;flex-wrap:wrap;font-size:11px;line-height:1.6;border-top:1px solid var(--border);padding-top:9px;margin-top:12px}.citations a{color:var(--muted);max-width:100%}.facts{background:var(--light);padding:28px;border-radius:6px}.facts h2{font-size:21px}.facts dl{margin:0}.facts dl>div{padding-block:16px;border-top:1px solid var(--border)}.facts dl>div:first-child{border-top:0}.facts dt{font-size:13px;font-weight:750;margin-bottom:5px}.facts dd{margin:0;font-size:15px}.table-scroll{overflow-x:auto;max-width:100%;border:1px solid var(--border);border-radius:5px;margin-block:24px}table{width:100%;border-collapse:collapse;font-size:14px;line-height:1.75}th,td{text-align:left;padding:14px 16px;vertical-align:top;border-bottom:1px solid var(--border);overflow-wrap:anywhere;min-width:120px}thead th{background:var(--light);font-weight:700}tbody tr:last-child>*{border-bottom:0}caption{text-align:left;padding:14px 16px;font-weight:650;background:var(--paper)}.faq{padding:19px 0;border-top:1px solid var(--border)}summary{cursor:pointer;font-weight:650;font-size:16px}details p{margin-top:16px}details[open] summary{margin-bottom:17px}.method-note{background:var(--light);border-left:3px solid var(--accent);padding:24px;margin-block:28px}.method-note h2{font-size:20px}.method-note p{font-size:14px;margin-bottom:10px}.source-list{font-size:13px;line-height:1.8}.source-list li{margin-bottom:17px}.source-list small{display:block;color:var(--muted);font-size:11px}.official-link{margin-block:36px}.official-link p{font-size:12px;color:var(--muted);margin-top:12px}.study{margin:0 0 45px;background:var(--paper);border:1px solid var(--border);padding:28px;border-radius:7px}.study h3{font-family:Georgia,var(--serif);font-size:25px;margin:0 0 22px}.study img{border:1px solid var(--border);border-radius:6px;width:100%}.study figcaption{font-size:13px;line-height:1.85;margin-top:20px;color:var(--muted)}.study figcaption p{margin-bottom:14px}.study details{margin-block:20px}.study summary{font-size:13px}.study .download{font-size:13px}.calculator{background:var(--paper);border:1px solid var(--border);padding:28px;border-radius:7px;margin-bottom:25px}.field-grid{display:grid;grid-template-columns:1fr 1fr;gap:20px}.field-grid label{font-size:14px;font-weight:650}.field-grid input{margin-top:8px}.calculator button{margin-top:24px}.calculator output{display:block;border-top:1px solid var(--border);padding-top:20px;margin-top:24px;font-size:26px;font-weight:700}.process{background:var(--paper);border:1px solid var(--border);padding:30px;margin:0}.process ol{padding:0;display:grid;grid-template-columns:repeat(5,1fr);gap:18px;list-style:none;margin:30px 0}.process li{border-top:2px solid var(--accent);padding-top:16px}.process li>span{font-family:Georgia,serif;font-size:28px;color:var(--accent);display:block}.process strong{font-size:14px;display:block;margin:10px 0}.process p,.process figcaption{font-size:13px;color:var(--muted)}.gateway{max-width:850px;margin:10vh auto;padding:44px}.gateway>div{display:flex;gap:20px;flex-wrap:wrap;margin-block:34px}.gateway>p:last-child{font-size:14px;color:var(--muted)}.secondary{background:transparent;color:var(--accent)}
.theme-comparison h1,.theme-comparison h2,.theme-comparison h3{font-family:var(--sans)}.theme-comparison .hero{grid-template-columns:1fr 1fr;gap:50px}.theme-comparison .hero-proof{background:var(--ink);color:#fff;border-radius:0}.theme-comparison .hero-proof .eyebrow{color:#bbcfff}.compare-proof>div{display:flex;align-items:center;gap:20px;border-top:1px solid #556580;padding:16px 0}.compare-proof>div>span{color:#bbcfff;font-size:13px}.compare-proof>div p{color:#fff;flex:1;margin:0;font-size:17px}.theme-comparison .directory .cards{grid-template-columns:1fr}.theme-comparison .directory .card{display:grid;grid-template-columns:32px 1fr 1.3fr 1.1fr 90px;align-items:center;gap:24px;padding:23px 26px;border-radius:0}.theme-comparison .directory .card-index{font-size:0}.theme-comparison .directory .card-index:first-letter{font-size:14px}.theme-comparison .directory .card h3{margin:0;font-size:20px}.theme-comparison .directory .card p{margin:0}.theme-comparison .directory .card .watch{border-top:0;border-left:1px solid var(--border);padding:0 0 0 20px}.theme-comparison .directory .card-link{padding:0;margin:0}.theme-cost .hero{grid-template-columns:1.15fr .85fr;gap:60px}.theme-cost .hero-proof{border-radius:22px 4px 22px 4px;background:#f1e6e9}.theme-cost .hero-stats{border-top:0}.theme-cost .card{border-top:4px solid #ac7044}.theme-cost .directory .cards{grid-template-columns:1fr 1fr}.theme-cost .section-heading h2{font-family:var(--serif)}
@media(min-width:1400px){.hero{padding-block:100px 85px}.hero h1{font-size:66px}}
@media(max-width:1000px){.shell{padding-inline:30px}.header-inner{gap:20px;flex-wrap:wrap;padding-block:18px}.header-inner nav{order:3;flex-basis:100%;justify-content:flex-start;gap:30px}.language{margin-left:auto}.hero,.theme-comparison .hero,.theme-cost .hero{gap:30px;grid-template-columns:1.2fr .8fr}.hero-proof{padding:25px}.proof-number{font-size:76px}.hero-stats{gap:20px}.cards{grid-template-columns:repeat(2,minmax(0,1fr))}.article-layout{grid-template-columns:190px minmax(0,1fr);gap:30px}.theme-comparison .directory .card{grid-template-columns:1fr 1.5fr 1.5fr}.theme-comparison .directory .card-index{display:none}.theme-comparison .directory .card-link{grid-column:1/-1;justify-content:flex-start;gap:20px}.process ol{grid-template-columns:repeat(3,1fr)}}
@media(max-width:700px){.shell{padding-inline:22px}.header-inner{gap:16px;min-height:85px}.brand{font-size:18px}.brand-mark{width:30px;height:34px;font-size:22px}.language{font-size:12px;padding:5px 9px}.header-inner nav{gap:0;justify-content:space-between}.header-inner nav a{font-size:12px;padding:4px 0}.hero,.theme-comparison .hero,.theme-cost .hero{display:block;padding-block:42px}.hero h1{font-size:42px;margin-top:12px}.hero .lead{font-size:16px}.hero-actions{gap:18px;margin-top:24px}.hero-actions .button{font-size:14px;padding:12px 16px}.text-link{font-size:13px}.hero-stats{gap:24px;margin-top:28px;margin-bottom:30px;padding-top:19px}.hero-stats b{font-size:20px}.hero-stats span{font-size:10px}.hero-proof{padding:26px}.proof-number{font-size:80px;margin:12px 0}.hero-proof h2{font-size:23px}.hero-proof p{font-size:14px}.section{padding-block:38px}.section-heading{align-items:start;flex-direction:column;gap:12px}.section-heading h2{font-size:25px}.section-heading>a{font-size:12px}.cards,.theme-cost .directory .cards{grid-template-columns:1fr;gap:16px}.card{padding:24px}.card h3{font-size:22px}.card p{font-size:15px}.sponsor{display:block;padding:17px 20px}.sponsor .eyebrow{margin-bottom:8px}.sponsor>div{margin-bottom:8px}.site-footer{margin-top:32px;padding-block:35px}.site-footer nav{gap:13px 22px}.page-heading{padding-block:38px 18px}.page-heading h1{font-size:35px}.page-heading .lead{font-size:16px}.article-top{padding-top:25px}.article-top h1{font-size:31px;line-height:1.5}.article-top .lead{font-size:16px}.article-meta{font-size:11px;gap:9px}.breadcrumb{margin-bottom:24px}.article-layout{display:block}.toc{position:static;padding:18px;background:var(--light);border:1px solid var(--border);margin-bottom:30px}.toc h2{margin-bottom:12px}.toc ol{margin:0;padding-left:18px;columns:1}.toc li{margin-bottom:8px;font-size:12px}.prose{font-size:16px;line-height:1.95}.prose h2{font-size:24px}.prose>section{margin-block:35px}.facts{padding:20px}.facts dd{font-size:14px}.citations{font-size:10px}.source-list{font-size:12px}.study{padding:18px}.study h3{font-size:23px}.study figcaption{font-size:12px}.study img{min-height:0}.study .table-scroll{margin-inline:0}.method-note{padding:18px}.calculator{padding:20px}.field-grid{grid-template-columns:1fr;gap:17px}.calculator output{font-size:23px}.process{padding:22px}.process ol{grid-template-columns:1fr;gap:8px}.process li{display:grid;grid-template-columns:30px 1fr;gap:8px}.process li>span{grid-row:1/3;font-size:23px}.process li strong{margin:0}.process li p{grid-column:2;margin:0 0 12px}.theme-comparison .directory .card{display:flex;gap:12px;align-items:stretch}.theme-comparison .directory .card .watch{border-left:0;border-top:1px solid var(--border);padding:12px 0 0}.theme-comparison .directory .card-link{padding-top:8px}.gateway{margin:5vh auto;padding:26px}.gateway h1{font-size:38px}.gateway .lead{font-size:17px}.gateway>div{gap:14px}.gateway .button{font-size:15px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}
.theme-comparison .directory .card-index{display:none}
@media(min-width:1001px){.theme-comparison .directory .card{grid-template-columns:1fr 1.3fr 1.1fr 90px}}

.inline-citation{white-space:nowrap;font-size:.85em;text-decoration:underline;text-underline-offset:.15em}