*{box-sizing:border-box;margin:0;padding:0}
:root{
  --ink:#1a1a1a;--ink2:#444;--ink3:#777;--ink4:#aaa;
  --bg:#faf9f7;--bg2:#f3f1ee;
  --border:#ddd;--border2:#e8e6e2;
  --accent:#1a4a7a;--accent2:#e8f0f8;
  --serif:'Georgia','Noto Serif SC',serif;
  --sans:-apple-system,'Helvetica Neue','PingFang SC','Microsoft YaHei',sans-serif;
  --gold:#8b6914;
}
body{font-family:var(--sans);background:var(--bg);color:var(--ink);line-height:1.6;font-size:15px}
nav{background:#fff;border-bottom:1px solid var(--border2);position:sticky;top:0;z-index:100}
.nav-inner{max-width:1100px;margin:0 auto;padding:0 2rem;display:flex;align-items:center;justify-content:space-between;height:60px}
.nav-logo{text-decoration:none}
.nav-logo-en{font-family:var(--serif);font-size:16px;color:var(--accent);font-weight:400;letter-spacing:.04em;line-height:1.2}
.nav-logo-zh{font-size:11px;color:var(--ink3);letter-spacing:.06em;margin-top:2px}
.nav-links{display:flex;gap:2rem;align-items:center}
.nav-links a{font-size:13px;color:var(--ink2);text-decoration:none;letter-spacing:.02em}
.nav-links a:hover{color:var(--accent)}
.nav-lang{font-size:12px;padding:3px 10px;border:1px solid var(--border);border-radius:3px;color:var(--ink3);cursor:pointer;background:transparent;font-family:var(--sans)}
.nav-lang:hover{border-color:var(--accent);color:var(--accent)}
.hero{background:#fff;border-bottom:1px solid var(--border2);padding:5rem 2rem 4rem}
.hero-inner{max-width:840px;margin:0 auto;text-align:center}
.hero-en-main{font-family:var(--serif);font-size:clamp(26px,3.5vw,40px);color:var(--ink);font-weight:400;line-height:1.3;letter-spacing:.03em;margin-bottom:.5rem}
.hero-zh-sub{font-size:15px;color:var(--ink3);letter-spacing:.08em;margin-bottom:.5rem}
.hero-tagline{font-size:12px;color:var(--ink4);letter-spacing:.03em;margin-bottom:2.5rem;line-height:1.7}
.hero-divider{width:48px;height:1px;background:var(--gold);margin:0 auto 2.5rem}
.hero-slogan{font-family:var(--serif);font-size:clamp(15px,2vw,18px);color:var(--ink2);line-height:2;margin-bottom:0}
.hero-slogan em{color:var(--accent);font-style:normal;font-weight:500}
.intro-banner{background:var(--accent2);border-top:1px solid #c8d8eb;border-bottom:1px solid #c8d8eb;padding:1.25rem 2rem}
.intro-banner-inner{max-width:1100px;margin:0 auto;display:flex;align-items:center;justify-content:space-between;gap:1.5rem;flex-wrap:wrap}
.intro-banner-left{display:flex;align-items:center;gap:.875rem}
.intro-pin{font-size:10px;font-weight:600;letter-spacing:.08em;color:var(--accent);background:#fff;border:1px solid #c8d8eb;padding:2px 8px;border-radius:2px;white-space:nowrap}
.intro-text{font-family:var(--serif);font-size:14px;color:var(--accent);font-weight:400}
.intro-desc{font-size:12px;color:var(--ink3)}
.intro-btn{font-size:13px;padding:6px 20px;border:1px solid var(--accent);border-radius:3px;color:var(--accent);background:#fff;cursor:pointer;white-space:nowrap;text-decoration:none;font-family:var(--sans)}
.intro-btn:hover{background:var(--accent);color:#fff}
.section-diagrams{padding:4rem 2rem;background:var(--bg)}
.section-inner{max-width:1100px;margin:0 auto}
.section-label{font-size:11px;letter-spacing:.12em;color:var(--ink3);text-align:center;margin-bottom:.5rem;text-transform:uppercase}
.section-title{font-family:var(--serif);font-size:20px;color:var(--ink);text-align:center;margin-bottom:.5rem;font-weight:400}
.section-sub{font-size:13px;color:var(--ink3);text-align:center;margin-bottom:2.5rem}
.diagrams-grid{display:grid;grid-template-columns:1fr 1fr;gap:1.5rem}
.diagram-card{background:#fff;border:1px solid var(--border2);border-radius:4px;overflow:hidden}
.diagram-fig{padding:1.25rem;background:#fff}
.diagram-fig svg{width:100%;height:auto;display:block}
.diagram-cap{padding:.875rem 1.25rem;border-top:1px solid var(--border2);background:var(--bg2)}
.diagram-cap-title{font-size:12px;font-weight:500;color:var(--ink);margin-bottom:3px}
.diagram-cap-desc{font-size:11px;color:var(--ink3);line-height:1.65}
.section-about{padding:4rem 2rem;background:#fff;border-top:1px solid var(--border2);border-bottom:1px solid var(--border2)}
.about-inner{max-width:720px;margin:0 auto}
.about-label{font-size:11px;letter-spacing:.12em;color:var(--ink3);margin-bottom:1.5rem;text-transform:uppercase}
.about-body{font-family:var(--serif);font-size:16px;line-height:2.1;color:var(--ink2);margin-bottom:2rem}
.about-body strong{color:var(--ink);font-weight:500}
.about-en{font-size:13px;line-height:1.9;color:var(--ink3);font-style:italic;border-left:2px solid var(--border);padding-left:1.25rem}
.section-articles{padding:4rem 2rem;background:var(--bg)}
.col-header{display:flex;align-items:baseline;gap:.75rem;margin-bottom:1.5rem;padding-bottom:.875rem;border-bottom:1px solid var(--border2)}
.col-title{font-family:var(--serif);font-size:18px;color:var(--ink);font-weight:400}
.col-en{font-size:11px;color:var(--ink3);letter-spacing:.08em}
.col-more{font-size:12px;color:var(--accent);margin-left:auto;text-decoration:none}
.articles-grid{display:grid;grid-template-columns:1fr 1fr;gap:2rem}
.col-articles{display:flex;flex-direction:column;gap:1px;background:var(--border2);border:1px solid var(--border2);border-radius:4px;overflow:hidden}
.article-card{background:#fff;padding:1.25rem 1.5rem;cursor:pointer;transition:background .15s}
.article-card:hover{background:var(--accent2)}
.article-card-top{display:flex;align-items:center;gap:.625rem;margin-bottom:.5rem}
.ac-tag{font-size:10px;padding:1px 6px;border-radius:2px;letter-spacing:.04em;font-weight:500}
.tag-theory{background:#f0ede8;color:#5a4a2a}
.tag-applied{background:#e8f0f8;color:#1a4a7a}
.tag-pinned{background:#faf3e0;color:var(--gold);border:1px solid #e8d89a}
.article-card h3{font-family:var(--serif);font-size:14px;color:var(--ink);font-weight:400;line-height:1.5;margin-bottom:.375rem}
.article-card p{font-size:12px;color:var(--ink3);line-height:1.6}
.article-card-meta{display:flex;gap:.75rem;margin-top:.625rem;font-size:11px;color:var(--ink4)}
footer{background:#1a1a1a;padding:2.5rem 2rem}
.footer-inner{max-width:1100px;margin:0 auto;display:flex;justify-content:space-between;align-items:center;gap:2rem;flex-wrap:wrap}
.footer-left{font-family:var(--serif);font-size:13px;color:#aaa}
.footer-left strong{color:#ddd;display:block;margin-bottom:.25rem}
.footer-right{font-size:12px;color:#666;line-height:1.9;text-align:right}
.footer-right a{color:#666;text-decoration:none}
.footer-right a:hover{color:#aaa}
@media(max-width:768px){
  .diagrams-grid,.articles-grid{grid-template-columns:1fr}
  .nav-links{gap:1rem}
}


.progress{position:fixed;top:0;left:0;height:3px;background:var(--accent);z-index:200;width:0}
.article-layout{max-width:1100px;margin:0 auto;padding:3rem 2rem;display:grid;grid-template-columns:minmax(0,680px) 220px;gap:3rem;align-items:start}
.article{background:#fff;border:1px solid var(--border2);padding:2.5rem;border-radius:4px}
.article-header{border-bottom:1px solid var(--border2);padding-bottom:1.5rem;margin-bottom:2rem}
.article-series{font-size:12px;color:var(--gold);letter-spacing:.08em;margin-bottom:.75rem}
.article h1{font-family:var(--serif);font-size:30px;line-height:1.35;font-weight:400;color:var(--ink);margin-bottom:1rem}
.article-meta{display:flex;flex-wrap:wrap;gap:.5rem 1rem;font-size:12px;color:var(--ink3);background:var(--bg2);padding:.875rem 1rem;border-left:3px solid var(--accent);margin-bottom:1.5rem}
.abstract-en{background:var(--accent2);border:1px solid #c8d8eb;padding:1rem;margin-top:1rem;border-radius:4px}
.abstract-en summary{cursor:pointer;color:var(--accent);font-weight:600}
.abstract-text{font-family:var(--serif);font-size:13px;line-height:1.8;color:var(--ink2);margin-top:.75rem}
.article-body{font-family:var(--serif);font-size:17px;line-height:2;color:var(--ink2)}
.article-body h2{font-size:23px;line-height:1.45;color:var(--ink);font-weight:500;margin:2.4rem 0 1rem;padding-top:.5rem;border-top:1px solid var(--border2)}
.article-body h3{font-size:19px;line-height:1.5;color:var(--ink);font-weight:500;margin:1.8rem 0 .75rem}
.article-body p{margin:0 0 1rem}
.article-body blockquote{border-left:3px solid var(--gold);padding:.75rem 1rem;background:var(--bg2);margin:1.25rem 0;color:var(--ink2)}
.article-body ul{margin:0 0 1rem 1.4rem}
.table-wrap{overflow-x:auto;margin:1.25rem 0}
.article-body table{width:100%;border-collapse:collapse;font-family:var(--sans);font-size:14px;line-height:1.55;background:#fff}
.article-body th,.article-body td{border:1px solid var(--border2);padding:.65rem .75rem;text-align:left;vertical-align:top}
.article-body th{background:var(--bg2);color:var(--ink);font-weight:600}
.article-body tr:nth-child(even) td{background:#fbfaf7}
.lead{color:var(--accent)}
.fn-ref{font-size:.8em;color:var(--accent);text-decoration:none;vertical-align:super}
.footnotes{font-size:14px;line-height:1.7;border-top:1px solid var(--border2);margin-top:2rem;padding-top:1rem}
.discuss{margin-top:2.5rem;padding:1.25rem;background:var(--bg2);border:1px solid var(--border2)}
.discuss h2{font-size:18px;margin-bottom:.5rem}
.toc{position:sticky;top:84px;background:#fff;border:1px solid var(--border2);padding:1rem;border-radius:4px}
.toc-title{font-size:12px;color:var(--ink3);letter-spacing:.08em;margin-bottom:.75rem}
.toc a{display:block;font-size:12px;line-height:1.5;color:var(--ink3);text-decoration:none;padding:.28rem 0;border-left:2px solid transparent;padding-left:.5rem}
.toc a.active,.toc a:hover{color:var(--accent);border-left-color:var(--accent)}
.simple-page{max-width:820px;margin:0 auto;padding:4rem 2rem}
.simple-page h1{font-family:var(--serif);font-weight:400;font-size:30px;margin-bottom:1rem}
.simple-list{background:#fff;border:1px solid var(--border2);border-radius:4px;margin-top:2rem}
.simple-list a{display:block;padding:1rem 1.25rem;border-bottom:1px solid var(--border2);text-decoration:none;color:var(--ink)}
.simple-list a:last-child{border-bottom:0}
.simple-list span{display:block;color:var(--ink3);font-size:12px;margin-top:.2rem}
@media(max-width:860px){.article-layout{display:block;padding:1.5rem}.article{padding:1.5rem}.toc{display:none}.article h1{font-size:24px}}