/* 序页 · Self-hosted, dependency-free stylesheet */
:root{--paper:#f6f6f0;--white:#fff;--ink:#173f35;--body:#3d514b;--muted:#6b7770;--line:#dce2d8;--green:#255c45;--pale:#e9eee3;--orange:#bf5a35;--orange-pale:#f8e9db;--serif:Georgia,'Times New Roman',serif;--radius:16px}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:100px}body{margin:0;background:var(--paper);color:var(--body);font-family:Inter,'Segoe UI','PingFang SC','Microsoft YaHei',sans-serif;font-size:15px;line-height:1.8;-webkit-font-smoothing:antialiased}body:has(dialog[open]){overflow:hidden}a{color:inherit;text-decoration:none}button,input,select{font:inherit}button,a,input,select{touch-action:manipulation}button{cursor:pointer}button:disabled{cursor:default}a:focus-visible,button:focus-visible,input:focus-visible,select:focus-visible,summary:focus-visible{outline:3px solid #ce7047;outline-offset:4px}::selection{background:#d9e4c8;color:var(--ink)}svg{display:block}img{max-width:100%}[hidden]{display:none!important}.wrap{max-width:1184px;margin:auto;padding:0 32px}.skip{position:fixed;left:20px;top:-100px;z-index:100;background:var(--ink);color:white;padding:10px 18px}.skip:focus{top:12px}.site-header{height:90px;border-bottom:1px solid 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#e0e5da;border-radius:12px;background:#eef0e6;overflow:hidden;aspect-ratio:1.27}.hero-visual>svg{width:100%;height:100%}.visual-label{position:absolute;bottom:17px;left:22px;right:22px;display:flex;justify-content:space-between;font-size:9px;letter-spacing:1.5px;color:#617264}.section-line{display:flex;align-items:center;justify-content:space-between;gap:20px;margin-bottom:22px}.section-line h2{font-size:22px;font-weight:650;letter-spacing:-.3px;margin:0}.section-line .sub{font-size:10px;letter-spacing:2px;color:var(--muted);margin-left:14px;font-weight:500}.section-line .count{color:var(--muted);font-size:12px}.topics{padding:28px 0 47px;border-top:1px solid var(--line)}.topic-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:17px}.topic-card{background:transparent;border:1px solid var(--line);padding:20px 21px;border-radius:8px;display:grid;grid-template-columns:44px 1fr 20px;gap:14px;align-items:center;transition:background .2s,border-color 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@media(min-width:1500px){.hero{padding-top:72px;padding-bottom:65px}}
@media(max-width:1000px){.wrap{padding:0 25px}.header-row{gap:20px}.nav{gap:20px}.search-trigger .key{display:none}.hero{gap:25px}.hero h1{font-size:43px}.topic-card{padding:17px 14px;gap:10px;grid-template-columns:36px 1fr 16px}.topic-icon{width:36px;height:36px}.reading-layout{grid-template-columns:1.3fr 1fr}.article-layout{grid-template-columns:minmax(0,1fr) 190px;gap:30px}.library-grid{gap:16px}.note-card-body{padding:18px}.note-card h2{font-size:16px}}
@media(max-width:760px){.site-header{height:74px}.header-row{gap:16px;position:relative}.brand-mark{width:33px;height:33px}.brand-name{font-size:22px}.search-trigger{margin-left:auto;border:0;padding:8px;background:transparent}.search-trigger svg{width:20px;height:20px}.search-trigger>span{display:none}.menu-toggle{display:block}.nav{display:none;position:absolute;z-index:30;left:0;right:0;top:73px;padding:14px 25px;background:var(--paper);border-bottom:1px solid var(--line);box-shadow:0 15px 20px #173f350a;gap:22px;margin:0}.nav.is-open{display:flex}.nav a{font-size:13px}.wrap{padding:0 22px}.hero{grid-template-columns:1fr;gap:30px;padding:39px 0}.hero h1{font-size:42px;letter-spacing:-1.2px;line-height:1.35;margin:19px 0}.hero p{font-size:14px;max-width:480px}.hero-visual{aspect-ratio:1.6;max-height:290px}.hero-note{margin-top:23px}.topics{padding-top:24px;padding-bottom:35px}.section-line{margin-bottom:18px}.section-line h2{font-size:20px}.section-line .sub{font-size:8px;letter-spacing:1px;margin-left:9px}.topic-grid{grid-template-columns:1fr;gap:10px}.topic-card{grid-template-columns:42px 1fr 18px;padding:15px 18px}.topic-icon{width:42px;height:42px}.topic-card p{font-size:12px}.reading-layout{grid-template-columns:1fr;gap:21px}.feature-visual{height:170px}.feature-body{padding:22px}.feature-body h3{font-size:21px}.article-row{padding:20px 0}.article-row:first-child{padding-top:12px}.article-row h3{font-size:16px}.article-row p{font-size:12px}.tool-strip{padding:23px;flex-wrap:wrap;gap:16px;margin-bottom:39px}.tool-strip .strip-icon{display:none}.tool-strip .btn{margin:0}.reading-section{padding-bottom:32px}.library-intro{padding-top:29px}.page-title{font-size:33px}.library-controls{flex-direction:column;align-items:stretch;gap:21px}.filter-btn{padding:7px 13px}.inline-search{width:100%}.library-grid{grid-template-columns:1fr 1fr;gap:14px}.note-cover{height:120px}.note-card-body{padding:16px}.note-card h2{font-size:16px}.article-header{padding:28px 0}.article-header h1{font-size:30px;line-height:1.5}.article-header .lede{font-size:14px}.article-layout{display:flex;flex-direction:column;padding-top:23px;gap:24px}.article-sidebar{position:static;order:-1;width:100%}.toc{padding-left:16px}.toc ol{display:flex;gap:6px 20px;flex-wrap:wrap}.toc li{margin:0;font-size:11px}.sidebar-tip{display:none}.article-body{width:100%;font-size:14px}.article-body h2{font-size:22px}.table-scroll{max-width:100%}table{font-size:12px}th,td{padding:12px}.about-layout{grid-template-columns:1fr;gap:10px}.about-note{margin:0}.tool-grid{grid-template-columns:1fr;gap:18px}.calculator{padding:23px}.download-panel{flex-direction:column;align-items:start}.download-panel .btn{margin-left:0}.footer-row{align-items:start;flex-direction:column;gap:18px}.footer-links{gap:22px}.article-end{flex-wrap:wrap}.search-dialog{max-height:85vh}.dialog-top{padding:18px 16px;gap:10px}.dialog-top input{font-size:15px}.related-grid{grid-template-columns:1fr}.not-found{margin-top:50px}.error-code{font-size:100px}}
@media(max-width:440px){.hero h1{font-size:37px}.hero-visual{aspect-ratio:1.35}.hero-actions{gap:15px}.hero-actions .btn{padding:10px 16px}.hero-note{gap:12px;font-size:10px}.hero-note span+span:before{margin-right:12px}.library-grid{grid-template-columns:1fr}.note-cover{height:150px}.note-card h2{font-size:19px}.note-card p{font-size:13px}.section-line .sub{display:none}.filter-group{gap:6px}.filter-btn{padding:7px 10px;font-size:11px}.calc-fields{gap:12px}.calc-result output{font-size:27px}.nav{gap:20px}.brand-name small{font-size:7px}.hero-actions .plain-link{font-size:12px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*:before,*:after{transition:none!important;animation:none!important}}
@media print{body{background:#fff;color:#222}.site-header,.site-footer,.article-sidebar,.article-end,.related,.search-dialog,.skip{display:none}.wrap{max-width:none;padding:0}.article-layout{display:block;border:0}.article-header{max-width:none}.article-header h1{font-size:26px}.article-body{font-size:11pt}.article-body h2{font-size:17pt;break-after:avoid}table,pre{break-inside:avoid}a{color:inherit}.article-body a[href^=https]:after{content:' (' attr(href) ')';font-size:9pt}.article-body section{margin-bottom:22px}}