:root{--ink:#15241f;--muted:#64736d;--paper:#f5f3ec;--card:#fffef9;--line:#d9ddd4;--green:#0d6b50;--mint:#cde9dd;--amber:#d98e26;--blue:#3678a8;--serif:"Noto Serif SC", "Songti SC", Georgia, serif;--sans:Inter, "PingFang SC", "Microsoft YaHei", sans-serif}@media (width<=380px){.site-header .nav{gap:10px}.site-header .brand{font-size:18px}.site-header .nav a{white-space:nowrap}}*{box-sizing:border-box}html{scroll-behavior:smooth}body{background:var(--paper);color:var(--ink);font:16px/1.7 var(--sans);margin:0}a{color:inherit;text-decoration:none}main{min-height:70vh}.shell{width:min(1120px,100% - 40px);margin:auto}.site-header{z-index:20;backdrop-filter:blur(12px);border-bottom:1px solid var(--line);background:#f5f3ece6;position:sticky;top:0}.nav{align-items:center;gap:28px;height:68px;display:flex}.brand{font-family:var(--serif);margin-right:auto;font-size:22px;font-weight:800}.brand i{color:var(--green);font-style:normal}.nav a:not(.brand){color:var(--muted);font-size:16px;font-weight:700}.nav a:hover,.nav a[aria-current=page]{color:var(--green)}.hero{grid-template-columns:1.35fr .65fr;align-items:end;gap:64px;padding:88px 0 62px;display:grid}.eyebrow{color:var(--green);letter-spacing:.14em;text-transform:uppercase;font-size:13px;font-weight:800}.hero h1,.concept-title{font:800 clamp(42px, 7vw, 76px)/1.06 var(--serif);letter-spacing:-.04em;margin:16px 0 24px}.lead{color:#3d4d47;max-width:680px;font-size:20px}.hero-note{border-left:3px solid var(--amber);color:var(--muted);padding:12px 0 12px 22px}.section{padding:64px 0}.section-head{justify-content:space-between;align-items:end;margin-bottom:28px;display:flex}.section h2{font:700 32px/1.2 var(--serif);margin:0}.section-head p{color:var(--muted);margin:0}.grid{grid-template-columns:repeat(2,1fr);gap:18px;display:grid}.concept-card{background:var(--card);border:1px solid var(--line);border-radius:18px;padding:28px;transition:all .2s}.concept-card:hover{border-color:#9fc2b4;transform:translateY(-3px);box-shadow:0 14px 30px #174a3820}.concept-card .number{font:800 42px/1 var(--serif);color:var(--green)}.concept-card h3{font:700 24px var(--serif);margin:18px 0 8px}.concept-card p{color:var(--muted);margin:0}.tags{flex-wrap:wrap;gap:8px;margin-top:20px;display:flex}.tag{border:1px solid var(--line);background:#faf9f3;border-radius:20px;padding:4px 9px;font-size:12px}.path{grid-template-columns:repeat(4,1fr);gap:2px;display:grid}.path-step{background:#e6ece7;border-radius:2px;padding:22px}.path-step b{color:var(--green);margin-bottom:8px;display:block}.page-head{border-bottom:1px solid var(--line);padding:68px 0 36px}.breadcrumbs{color:var(--muted);font-size:13px}.concept-title{margin-bottom:12px;font-size:clamp(48px,8vw,84px)}.meta{color:var(--muted);flex-wrap:wrap;gap:18px;font-size:13px;display:flex}.concept-layout{grid-template-columns:minmax(0,1fr) 240px;gap:64px;padding:48px 0 80px;display:grid}.prose{font-size:17px}.prose h2{font:700 29px var(--serif);margin:54px 0 14px}.prose h3{margin-top:32px;font-size:19px}.prose blockquote{border-left:4px solid var(--green);background:#e8f1ec;border-radius:0 12px 12px 0;margin:28px 0;padding:18px 22px}.prose table{border-collapse:collapse;width:100%;margin:24px 0}.prose th,.prose td{border-bottom:1px solid var(--line);text-align:left;padding:12px}.prose th{color:var(--muted);font-size:13px}.prose li{margin:8px 0}.side-nav{height:max-content;color:var(--muted);font-size:13px;position:sticky;top:94px}.side-nav b{color:var(--ink);margin-bottom:10px;display:block}.side-nav a{padding:6px 0;display:block}.viz-card{background:var(--card);border:1px solid var(--line);border-radius:16px;margin:30px 0;padding:18px}.viz-head{justify-content:space-between;align-items:center;margin-bottom:10px;display:flex}.viz-head h3{font:700 19px var(--serif);margin:0}.chart{height:390px}.site-footer{border-top:1px solid var(--line);color:var(--muted);padding:30px 0;font-size:13px}.footer-copy{margin:0}.site-footer a{color:var(--green)}.site-footer a:hover,.site-footer a:focus-visible{color:var(--ink);text-underline-offset:3px;text-decoration:underline}.visitor-stats{flex-wrap:wrap;gap:12px;margin-bottom:8px;font-size:12px;display:flex}.visitor-stats strong{color:var(--ink);font-weight:600}@media (width<=760px){.hero,.concept-layout{grid-template-columns:1fr}.hero{gap:20px;padding-top:55px}.grid,.path{grid-template-columns:1fr}.side-nav{display:none}.nav{gap:14px}.nav a:not(.brand){font-size:12px}.chart{height:320px}.section{padding:44px 0}}.related-block{border-top:1px solid var(--line);margin-top:52px;padding-top:32px}.related-block h2{margin:8px 0 18px}.related-links{grid-template-columns:repeat(2,1fr);gap:10px;display:grid}.related-links a{border:1px solid var(--line);background:var(--card);border-radius:12px;grid-template-columns:1fr auto;gap:2px 12px;padding:16px;display:grid}.related-links span{font-weight:800}.related-links small{color:var(--muted);grid-column:1;line-height:1.4}.related-links b{color:var(--green);grid-area:1/2/3;align-self:center}@media (width<=600px){.related-links{grid-template-columns:1fr}}