body.light-mode{--background-color:#f6f8fc;--second-background-color:#fff;--third-background-color:#edf3fa;--arc-accent:#147da6;--arc-line:#dbe4ef;--arc-muted:#57687e}body.dark-mode{--background-color:#0c1421;--second-background-color:#111e30;--third-background-color:#17283d;--arc-accent:#63d6ec;--arc-line:#293b53;--arc-muted:#adbed2;--first-text-color:#e7eff8;--second-text-color:#bdcce0;--default-text-color:#dce5f1;--border-color:#293b53}body{font-family:Geist,'PingFang SC',sans-serif}.main-content{width:100%;min-width:0}.arc-eyebrow,.eyebrow{font:12px/1.6 GeistMono,monospace;letter-spacing:.1em;color:var(--arc-accent);margin-bottom:20px}.arc-hero{display:grid;grid-template-columns:1.3fr 1fr;gap:24px;align-items:center;padding:70px 0}.arc-hero h1{font-size:clamp(32px,4vw,52px);line-height:1.4;font-weight:650;margin:18px 0 24px;letter-spacing:-.04em}.arc-hero h1 span,.serif-accent{color:var(--arc-accent)}.arc-lead{line-height:1.9;color:var(--arc-muted)}.arc-actions{display:flex;align-items:center;gap:28px;margin-top:30px}.arc-button{display:inline-block;padding:13px 24px;border-radius:10px;background:var(--arc-accent);color:var(--background-color)!important;font-weight:600}.arc-section{padding:36px 0 64px;border-top:1px solid var(--arc-line)}.arc-section h2,.arc-callout h2{font-size:26px;font-weight:600;margin-bottom:28px}.arc-paths{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}.arc-card{display:flex;flex-direction:column;padding:24px 20px;background:var(--second-background-color);border:1px solid var(--arc-line);border-radius:16px;transition:transform .2s,border-color .2s}.arc-card:hover{transform:translateY(-4px);border-color:var(--arc-accent)}.arc-card h3{font-size:19px;margin:20px 0 12px}.arc-card p{font-size:14px;color:var(--arc-muted);line-height:1.85;flex:1;margin-bottom:24px}.arc-card>span:last-child{font-size:13px;color:var(--arc-accent)}.arc-card .arc-eyebrow{font-size:10px}.arc-callout{border:1px solid var(--arc-line);background:var(--second-background-color);border-radius:18px;padding:32px;display:flex;align-items:center;justify-content:space-between;gap:24px;margin-bottom:50px}.arc-callout p{color:var(--arc-muted)}.wrap{width:100%;max-width:1120px;margin:auto}.page-heading{padding:48px 0 32px}.page-heading h1{font-size:32px;font-weight:650;margin-bottom:22px}.page-heading>p,.article-description{color:var(--arc-muted);line-height:1.9}.search-label{display:block;margin-top:28px;font-size:13px;margin-bottom:8px}.search-box{display:flex;align-items:center;gap:12px;padding:14px 18px;border:1px solid var(--arc-line);background:var(--second-background-color);border-radius:12px}.search-box input{background:transparent;border:0;outline:none;color:inherit;min-width:0;flex:1;font:inherit}.search-box:focus-within{outline:2px solid var(--arc-accent)}#search-count{font-size:12px;color:var(--arc-muted);white-space:nowrap}.learning-layout{display:grid;grid-template-columns:205px minmax(0,1fr);gap:32px;padding-bottom:48px}.learning-nav,.article-toc{align-self:start;position:sticky;top:100px}.learning-nav a{display:block;font-size:14px;padding:12px 0;border-bottom:1px solid var(--arc-line)}.learning-nav a span{margin-right:12px;color:var(--arc-accent)}.download-link{font-size:12px!important}.lesson-group{scroll-margin-top:100px;margin-bottom:30px}.group-heading{display:flex;gap:18px;margin-bottom:18px}.group-heading>span{font:24px GeistMono,monospace;color:var(--arc-accent)}.group-heading h2{font-size:23px;margin-bottom:10px;font-weight:600}.group-heading p,.lesson-row p{color:var(--arc-muted);font-size:14px;line-height:1.8}.lesson-list{border:1px solid var(--arc-line);border-radius:14px;overflow:hidden;background:var(--second-background-color)}.lesson-row{padding:20px 22px;display:flex;gap:12px;justify-content:space-between;align-items:center;border-bottom:1px solid var(--arc-line)}.lesson-row:last-child{border-bottom:0}.lesson-row:hover{background:var(--third-background-color)}.lesson-row h3{font-size:18px;margin-bottom:6px;font-weight:550}.lesson-arrow{color:var(--arc-accent)}[hidden]{display:none!important}.article-top{display:flex;justify-content:space-between;padding:30px 0;font-size:12px;color:var(--arc-muted)}.article-layout{display:grid;grid-template-columns:minmax(0,1fr) 200px;gap:36px}.lesson-article{min-width:0}.lesson-article>header{padding:24px 0;border-bottom:1px solid var(--arc-line);margin-bottom:36px}.lesson-article>header h1{font-size:32px;font-weight:650;line-height:1.45;margin-bottom:16px}.article-meta,.article-bottom{display:flex;justify-content:space-between;gap:16px;font-size:12px;margin-top:24px;color:var(--arc-muted)}.article-bottom{padding:30px 0;border-top:1px solid var(--arc-line);margin-bottom:40px}.article-toc{max-height:calc(100vh - 140px);overflow:auto;font-size:12px;line-height:1.8;border-left:1px solid var(--arc-line);padding-left:18px}.article-toc ol{list-style:none;padding-left:12px}.article-toc>ol{padding-left:0}.article-toc a{display:block;padding:4px 0;color:var(--arc-muted)}.prose{overflow-wrap:anywhere}.prose h1,.prose h2,.prose h3{scroll-margin-top:100px}.prose pre{position:relative;overflow:auto;background:var(--third-background-color);border:1px solid var(--arc-line);border-radius:10px;padding:40px 18px 18px}.prose pre code{font-family:GeistMono,monospace;line-height:1.75;font-size:13px}.arc-copy{position:absolute;top:8px;right:10px;font-size:11px;padding:4px 10px;border:1px solid var(--arc-line);border-radius:5px;background:var(--second-background-color);color:var(--arc-muted);cursor:pointer}.prose table{display:block;max-width:100%;overflow:auto}.katex-display{overflow:auto;max-width:100%}.page-template-container{margin-top:32px}a:focus-visible,button:focus-visible{outline:2px solid var(--arc-accent);outline-offset:4px}@media(max-width:900px){.arc-paths{grid-template-columns:repeat(2,1fr)}.article-layout{grid-template-columns:minmax(0,1fr)}.article-toc{display:none}.arc-hero{padding:48px 0}.learning-layout{grid-template-columns:170px minmax(0,1fr);gap:20px}}@media(max-width:600px){.arc-hero{grid-template-columns:1fr;padding-top:30px}.arc-hero h1{font-size:34px}.arc-paths{grid-template-columns:1fr}.arc-callout{display:block;padding:24px}.arc-callout .arc-button{margin-top:20px}.learning-layout{grid-template-columns:1fr}.learning-nav{position:static;display:flex;flex-wrap:wrap;gap:8px}.learning-nav .eyebrow,.learning-nav .download-link{display:none}.learning-nav a{font-size:12px;border:1px solid var(--arc-line);padding:8px;border-radius:8px}.page-heading h1{font-size:26px}.page-heading h1 .serif-accent{display:block;font-size:18px;margin-top:8px}.search-box{gap:6px;padding:12px}.search-box input{font-size:12px}.article-top>span{display:none}.lesson-article>header h1{font-size:27px}.article-meta{flex-wrap:wrap}}@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}
.right-side-tools-container{z-index:100!important;position:fixed!important}
.arc-mode-toggle{position:fixed;right:20px;bottom:24px;z-index:1000;width:44px;height:44px;border-radius:50%;background:var(--second-background-color);border:1px solid var(--arc-line);color:var(--arc-accent);font-size:26px;cursor:pointer;box-shadow:0 4px 20px #0002}.right-side-tools-container{display:none!important}

.arc-hero-brand{display:grid;place-items:center;min-width:0}.arc-hero-brand img{display:block;width:100%;max-width:440px;height:auto;border-radius:28px}@media(max-width:600px){.arc-hero-brand img{max-width:260px;margin:12px auto 20px}}

.arc-language-toggle{position:fixed;right:20px;bottom:78px;z-index:1000;width:44px;height:44px;border-radius:50%;background:var(--second-background-color);border:1px solid var(--arc-line);color:var(--arc-accent);font-size:14px;cursor:pointer}.arc-language-note{color:var(--arc-muted);font-size:13px;margin-top:16px}
/* Reading and display controls */
.main-content-header{position:relative}.arc-tools{display:flex;gap:8px;justify-content:flex-end;max-width:1120px;margin:8px auto 0;padding:0 16px}.arc-tools .arc-language-toggle,.arc-tools .arc-mode-toggle{position:static;width:44px;height:40px;border-radius:9px;box-shadow:none;font-size:15px;z-index:auto}.arc-tools .arc-mode-toggle{font-size:24px}.arc-hero{padding:38px 0 46px;grid-template-columns:1.5fr 1fr}.arc-hero-brand img{max-width:290px;border-radius:20px}.mobile-toc{display:none}.prose figure.highlight{position:relative;padding-top:36px;background:var(--third-background-color);border:1px solid var(--arc-line);border-radius:10px;overflow:auto}.prose figure.highlight pre{border:0;padding:16px;margin:0}.prose figure.highlight table{margin:0;width:100%}.prose figure.highlight td{border:0;padding:0}.prose figure.highlight .code{width:100%}.hljs-keyword,.hljs-selector-tag{color:#9750b5}.hljs-string,.hljs-attr{color:#19704b}.hljs-number,.hljs-literal{color:#ae4d21}.hljs-comment{color:#637488}.hljs-title,.hljs-built_in{color:#126caa}body.dark-mode .hljs-keyword{color:#d6a6ff}body.dark-mode .hljs-string,body.dark-mode .hljs-attr{color:#a1dfad}body.dark-mode .hljs-number,body.dark-mode .hljs-literal{color:#f5bd90}body.dark-mode .hljs-title,body.dark-mode .hljs-built_in{color:#8bcdf8}body.dark-mode .hljs-comment{color:#a2b0c3}.image-zoom{display:block;border:0;background:transparent;padding:0;width:100%;cursor:zoom-in;color:inherit}.image-zoom img{max-width:100%;height:auto}.arc-image-dialog{max-width:96vw;max-height:94dvh;padding:45px 12px 12px;border:1px solid var(--arc-line);border-radius:12px;background:var(--second-background-color);color:var(--default-text-color);overflow:auto}.arc-image-dialog::backdrop{background:#000b}.arc-image-dialog img{display:block;max-width:none;width:auto;height:auto}.arc-image-dialog>button{position:sticky;top:0;left:0;width:44px;height:40px;font-size:28px;background:var(--second-background-color);color:inherit;border:1px solid var(--arc-line);border-radius:8px}.arc-copy{min-height:32px;min-width:44px}.prose[lang=zh-CN]{line-height:1.9}@media(max-width:900px){.mobile-toc{display:block;border:1px solid var(--arc-line);border-radius:10px;padding:14px;margin-bottom:24px}.mobile-toc summary{cursor:pointer;font-weight:600}.mobile-toc nav{max-height:55vh;overflow:auto;padding-top:12px;font-size:14px}.mobile-toc ol{padding-left:20px}.mobile-toc a{display:block;padding:7px 0}.article-bottom{flex-wrap:wrap}}@media(max-width:600px){.arc-hero{grid-template-columns:1fr;padding-top:20px}.arc-hero-brand img{max-width:180px;margin:0 auto 12px}.arc-tools{margin-top:6px}.arc-hero h1{font-size:32px}.arc-image-dialog img{min-width:850px;max-width:1470px}}
/* Translation wrappers inherit the visual treatment of their semantic parent. */
[data-i18n-en]{font:inherit;color:inherit}.arc-hero h1{color:var(--first-text-color)}.arc-hero h1 [data-i18n-en]{color:inherit}.arc-button,.arc-button [data-i18n-en]{color:var(--background-color)!important}.arc-card p [data-i18n-en],.arc-card .arc-eyebrow [data-i18n-en]{color:inherit}.arc-card>span:last-child [data-i18n-en]{color:var(--arc-accent)}.navbar-content>.right{display:flex;align-items:center;gap:12px}.arc-tools{display:flex;align-items:center;gap:6px;margin:0;padding:0;order:2}.arc-tools .arc-language-toggle,.arc-tools .arc-mode-toggle{height:40px;width:40px;flex-shrink:0}.navbar-container{background:var(--background-color)!important}@media(max-width:600px){.navbar-container{padding-left:16px!important;padding-right:16px!important}.navbar-content>.right{gap:8px}.arc-tools{order:0}.navbar-content>.left{min-width:0;overflow:hidden}.logo-title{white-space:nowrap;overflow:hidden;text-overflow:ellipsis;max-width:150px}.logo-title [data-i18n-en]{font-size:15px}.navbar-content>.right{flex-shrink:0}.logo-image{flex-shrink:0;margin-right:8px!important}}@media(max-width:360px){.logo-title{max-width:105px}}
.image-zoom::after{content:attr(aria-label) ' ↗';display:block;font-size:12px;color:var(--arc-accent);text-align:right;margin:6px 0 20px}

@media(min-width:1000px){.arc-paths{grid-template-columns:repeat(auto-fit,minmax(200px,1fr))}}