@import url('https://fonts.googleapis.com/css2?family=Noto+Serif+SC:wght@400;500;600;700&display=swap');
:root{--paper:#f7f8f6;--white:#fff;--ink:#182c2b;--muted:#63716e;--green:#24594f;--mint:#e8f1ed;--line:#dde4df;--orange:#ad541e;--serif:'Noto Serif SC','Songti SC',SimSun,serif;--sans:Inter,'Segoe UI','Microsoft YaHei',sans-serif}*{box-sizing:border-box}body{margin:0;background:var(--paper);font-family:var(--sans);color:var(--ink);font-size:16px;line-height:1.75}button,input,select,textarea{font:inherit}button,a,input,select,textarea{-webkit-tap-highlight-color:transparent}button,a{touch-action:manipulation}button{cursor:pointer}a{color:var(--green);text-underline-offset:4px}button{color:inherit}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible{outline:3px solid #c8742b;outline-offset:4px}button:disabled{opacity:.48;cursor:not-allowed}h1,h2,h3,p{margin:0}h1,h2,h3{line-height:1.4}h1{font-family:var(--serif);font-weight:500;font-size:clamp(30px,3vw,43px)}h2{font-size:24px;font-weight:600}h3{font-size:18px;font-weight:600}.muted{color:var(--muted)}.small{font-size:14px}.serif{font-family:var(--serif)}.skip{position:fixed;left:15px;top:-100px;z-index:100;background:white;padding:12px}.skip:focus{top:12px}.sidebar{width:232px;position:fixed;inset:0 auto 0 0;background:#f0f3ef;border-right:1px solid var(--line);padding:32px 22px;display:flex;flex-direction:column;z-index:20}.brand{display:flex;align-items:center;gap:12px;text-decoration:none;margin-bottom:45px}.brand-mark{background:var(--green);color:white;width:40px;height:44px;border-radius:8px;display:grid;place-items:center;font-size:29px;line-height:1}.brand strong{font-family:var(--serif);font-size:25px;font-weight:600}.brand small{display:block;color:var(--muted);font-size:12px;letter-spacing:1.7px;line-height:1.2}.nav{display:grid;gap:7px}.nav a{display:flex;gap:12px;align-items:center;text-decoration:none;color:var(--muted);padding:11px 14px;border-radius:7px;font-size:15px}.nav a.active{background:var(--green);color:white}.nav svg{width:19px;height:19px;flex-shrink:0}.nav-label{font-size:12px;letter-spacing:1.7px;color:#75817c;margin:28px 14px 10px}.sidebar-bottom{margin-top:auto;padding-top:35px;font-size:13px;color:var(--muted)}.sidebar-bottom p{margin-top:8px}.workspace{margin-left:232px}.topbar{height:78px;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;padding:0 45px;gap:16px;background:rgba(255,255,255,.6)}.breadcrumb{font-size:14px;color:var(--muted)}.lang{display:flex;border:1px solid var(--line);border-radius:6px;padding:3px;background:white}.lang button{border:0;background:none;border-radius:4px;padding:4px 11px;font-size:13px}.lang button.active{background:var(--green);color:white}.main{max-width:1390px;margin:auto;padding:35px 45px 70px;min-height:80vh}.eyebrow{font-size:12px;color:var(--green);letter-spacing:2px;font-weight:600;text-transform:uppercase;margin-bottom:12px}.page-head{display:flex;justify-content:space-between;gap:20px;align-items:flex-end;margin-bottom:28px}.page-head p{margin-top:10px;color:var(--muted)}.btn{display:inline-flex;align-items:center;justify-content:center;gap:9px;padding:10px 20px;border:1px solid var(--green);background:var(--green);color:white;text-decoration:none;border-radius:6px;font-size:15px;min-height:44px}.btn.secondary{background:white;color:var(--green);border-color:var(--line)}.btn.ghost{background:transparent;color:var(--green);border-color:transparent}.btn.small{font-size:14px;padding:6px 13px}.hero-study{display:grid;grid-template-columns:1.22fr 1fr;background:white;border:1px solid var(--line);border-radius:12px;overflow:hidden;margin-bottom:30px}.hero-copy{padding:32px 35px;display:flex;flex-direction:column;align-items:flex-start;justify-content:center}.hero-copy h2{font-family:var(--serif);font-size:32px;font-weight:500;margin:12px 0}.hero-copy p{color:var(--muted);max-width:470px;margin-bottom:24px}.pill{display:inline-flex;align-items:center;gap:7px;background:var(--mint);color:var(--green);border-radius:5px;padding:3px 10px;font-size:12px}.hero-art{background:#eaf0eb;min-height:330px;display:flex;align-items:center;justify-content:center;position:relative;gap:34px;padding:36px}.hero-art:before{content:'';position:absolute;width:265px;height:265px;border:1px solid #cdd9cf;border-radius:50%;pointer-events:none}.hero-art .hex{width:135px;z-index:1}.hex{display:flex;flex-direction:column-reverse;gap:10px;width:104px}.yao{height:12px;display:flex;gap:13px;width:100%;background:none;border:0;padding:0;min-height:12px}.yao span{height:100%;background:var(--green);flex:1;transition:background .2s,transform .2s}.yao:hover span{background:#9d601e}.yao[aria-pressed=true] span{background:#ad541e}.hex-caption{font-size:13px;color:var(--muted);z-index:1;writing-mode:vertical-rl;letter-spacing:3px}.section-title{display:flex;justify-content:space-between;align-items:center;margin:25px 0 17px;gap:12px}.section-title h2{font-size:20px}.grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:17px}.card{background:white;border:1px solid var(--line);border-radius:9px;padding:24px}.course-card{display:flex;flex-direction:column;text-decoration:none;color:var(--ink);transition:transform .2s,border-color .2s}.course-card:hover{border-color:var(--green);transform:translateY(-3px)}.course-card .num{color:var(--orange);font-family:Georgia,serif;font-size:30px;margin-bottom:12px}.course-card p{color:var(--muted);font-size:14px;margin:12px 0 18px}.course-card footer{font-size:13px;color:var(--green);margin-top:auto;display:flex;justify-content:space-between}.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:1px;border:1px solid var(--line);border-radius:9px;overflow:hidden;background:var(--line);margin:24px 0}.stat{background:white;padding:18px 22px}.stat strong{display:block;font:30px Georgia,serif}.stat span{font-size:13px;color:var(--muted)}.notice{border-left:3px solid #b68a4e;background:#f6f1e8;color:#6b542e;padding:15px 20px;font-size:14px;margin:18px 0}.notice.info{border-color:var(--green);background:var(--mint);color:var(--green)}.duo-en{display:block;color:var(--muted);font-size:.9em;font-weight:400;margin-top:5px;letter-spacing:0}.filters{display:flex;flex-wrap:wrap;gap:8px;margin:20px 0}.chip{padding:7px 14px;border:1px solid var(--line);background:white;border-radius:30px;font-size:14px}.chip.active{background:var(--green);border-color:var(--green);color:white}.search{width:100%;padding:12px 16px;border:1px solid var(--line);border-radius:7px;background:white;color:var(--ink);margin:5px 0 12px}.lesson-layout{display:grid;grid-template-columns:minmax(0,1fr) 265px;gap:25px}.lesson-body{min-width:0}.lesson-aside{align-self:start;position:sticky;top:20px}.stepnav{display:flex;gap:5px;border-bottom:1px solid var(--line);margin-bottom:23px;overflow-x:auto}.stepnav button{white-space:nowrap;padding:11px 14px;border:0;background:none;color:var(--muted);border-bottom:2px solid transparent;font-size:14px}.stepnav button.active{border-color:var(--green);color:var(--green);font-weight:600}.prose p{margin:16px 0}.prose h3{margin:25px 0 12px}.prose li{margin:10px 0}.prose{line-height:1.95}.lesson-title{margin:12px 0}.flow{display:grid;gap:12px;counter-reset:flow}.flow-item{display:grid;grid-template-columns:35px 1fr;gap:14px;padding:17px;border:1px solid var(--line);border-radius:7px;background:white}.flow-item:before{counter-increment:flow;content:counter(flow);border-radius:50%;width:30px;height:30px;background:var(--mint);color:var(--green);text-align:center;font-size:14px}.flow-item h3{font-size:16px}.flow-item p{margin-top:5px;font-size:15px;color:var(--muted)}.actions{display:flex;gap:10px;flex-wrap:wrap;margin-top:24px;align-items:center}.option{display:flex;gap:12px;align-items:flex-start;padding:14px 17px;border:1px solid var(--line);background:white;border-radius:7px;margin:9px 0;cursor:pointer}.option:has(input:checked){border-color:var(--green);background:var(--mint)}.option input{margin-top:7px;accent-color:var(--green)}.feedback{border:1px solid var(--line);border-radius:7px;padding:17px;margin:16px 0;background:var(--mint)}.feedback.wrong{background:#fbefe7;border-color:#e5bc9f}.progress-track{height:5px;background:#e1e8e2;border-radius:5px;overflow:hidden;margin:15px 0}.progress-track span{height:100%;display:block;background:var(--green)}.sidebar-list{display:grid;gap:9px;padding:0;list-style:none;font-size:14px}.sidebar-list a{display:block;text-decoration:none}.source-item{padding:20px 0;border-bottom:1px solid var(--line)}.source-item time{font-variant-numeric:tabular-nums;font-size:13px;color:var(--orange)}.source-item p{margin-top:7px;overflow-wrap:anywhere}.empty{padding:45px 20px;text-align:center;color:var(--muted)}.hex-grid{display:grid;grid-template-columns:repeat(8,1fr);gap:10px}.hex-card{border:1px solid var(--line);background:white;border-radius:8px;padding:15px 9px;display:flex;align-items:center;flex-direction:column;gap:10px;text-align:center}.hex-card .hex{width:48px;gap:4px}.hex-card .yao{height:5px;min-height:5px;gap:5px}.hex-card strong{font-size:15px}.hex-card small{font-size:12px;color:var(--muted)}.lab{display:grid;grid-template-columns:1fr 1fr;gap:25px}.lab-display{min-height:350px;background:var(--mint);border-radius:10px;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:24px}.lab-display .hex{width:180px;gap:17px}.lab-display .yao{height:17px}.field{display:block;margin:17px 0}.field span{display:block;font-size:14px;margin-bottom:7px}.field select,.field textarea,.field input{width:100%;border:1px solid var(--line);background:white;color:var(--ink);padding:10px 12px;border-radius:6px}.field textarea{min-height:100px;resize:vertical}.table-wrap{overflow:auto}table{border-collapse:collapse;width:100%;font-size:14px}th,td{text-align:left;padding:13px;border-bottom:1px solid var(--line);vertical-align:top}th{color:var(--muted);font-weight:500}.rubric{display:grid;gap:10px;margin:20px 0}.rubric label{display:flex;gap:12px;align-items:flex-start;font-size:15px}.rubric input{margin-top:6px;accent-color:var(--green)}.toast{position:fixed;right:24px;bottom:24px;background:var(--green);color:white;padding:12px 20px;border-radius:8px;box-shadow:0 4px 20px #0002;z-index:80}.mobile-brand{display:none}.meter{display:flex;justify-content:space-between;font-size:14px;margin:15px 0 4px}.source-links{display:flex;flex-wrap:wrap;gap:8px;margin:15px 0}.source-links a{font-size:13px;padding:3px 9px;background:var(--mint);border-radius:4px;text-decoration:none}.circle-progress{display:grid;place-items:center;width:110px;height:110px;border-radius:50%;margin:15px auto;background:conic-gradient(var(--green) var(--pct),var(--mint) 0)}.circle-progress div{width:90px;height:90px;border-radius:50%;background:white;display:grid;place-items:center;font-size:24px}.inline-link{font-size:14px;text-decoration:none}.banner-row{display:flex;align-items:center;justify-content:space-between;gap:20px}.disclosure{border:1px solid var(--line);border-radius:8px;padding:15px 18px;background:white;margin:10px 0}.disclosure summary{cursor:pointer;font-weight:500}.disclosure p{margin:10px 0}.compass{display:grid;grid-template-columns:repeat(3,1fr);gap:8px;max-width:430px;margin:20px auto}.compass button,.compass .center{padding:20px 8px;border:1px solid var(--line);border-radius:5px;background:white;text-align:center}.compass button.active{background:var(--green);color:white}.compass .center{background:var(--mint);display:grid;place-items:center}.lesson-body .card+.card{margin-top:18px}.qcount{font-size:14px;color:var(--muted);margin-bottom:15px}.question{margin:14px 0;font-size:19px}.footnote{margin-top:35px;font-size:12px;color:var(--muted);border-top:1px solid var(--line);padding-top:17px}.split{display:grid;grid-template-columns:1fr 1fr;gap:18px}.read-status{font-size:13px;color:var(--green)}.results-list{display:grid;gap:12px}.result-row{display:flex;align-items:center;gap:15px;padding:18px;background:white;border:1px solid var(--line);border-radius:7px}.result-row>div{flex:1}.result-row small{display:block;color:var(--muted)}.score{font:32px Georgia,serif;color:var(--green)}.tag-warn{background:#f4eadb;color:#815f2c}.visually-hidden{position:absolute;clip:rect(0,0,0,0);width:1px;height:1px;overflow:hidden}.readmore{margin-top:10px}body:has(.duo-en) .nav a{line-height:1.35}body:has(.duo-en) .nav .duo-en{font-size:11px}mark{background:#efe2b6;color:inherit}#live{position:fixed;bottom:0}.subtitle{max-width:760px}.module-head{margin:34px 0 16px}.flex-between{display:flex;justify-content:space-between;gap:15px;align-items:center}
@media(min-width:1500px){.main{padding:45px 65px}.topbar{padding:0 65px}.hero-art{min-height:350px}}@media(max-width:1150px){.sidebar{width:195px;padding:28px 14px}.workspace{margin-left:195px}.main{padding:28px}.topbar{padding:0 28px}.lesson-layout{grid-template-columns:1fr}.lesson-aside{position:static}.hex-grid{grid-template-columns:repeat(6,1fr)}.hero-copy{padding:28px}.hero-art{gap:15px}.hero-art:before{width:210px;height:210px}}@media(max-width:800px){.sidebar{position:static;width:100%;padding:12px 18px;display:block;border-right:0;border-bottom:1px solid var(--line)}.brand{margin:0 0 12px}.brand strong{font-size:22px}.brand-mark{height:35px;width:35px}.brand small{display:inline;margin-left:10px}.nav{display:flex;overflow-x:auto;gap:5px}.nav a{white-space:nowrap;padding:9px 12px}.nav a svg{display:none}.nav-label,.sidebar-bottom{display:none}.workspace{margin:0}.topbar{height:auto;min-height:60px;padding:10px 20px}.main{padding:24px 20px 45px}.hero-study{grid-template-columns:1fr 1fr}.hero-copy{padding:25px}.hero-copy h2{font-size:25px}.hero-art{min-height:250px}.hero-art:before{width:160px;height:160px}.hero-art .hex{width:95px}.hex-caption{display:none}.grid{grid-template-columns:repeat(2,minmax(0,1fr))}.stats{grid-template-columns:repeat(2,1fr)}.hex-grid{grid-template-columns:repeat(4,1fr)}.page-head{align-items:flex-start}.lab{grid-template-columns:1fr}.split{grid-template-columns:1fr}.breadcrumb{font-size:12px}.lang button{padding:4px 8px}.hero-copy .btn{padding:8px 12px}.banner-row{align-items:flex-start}.page-head h1{font-size:30px}}@media(max-width:480px){.hero-study{grid-template-columns:1fr}.hero-art{min-height:180px;padding:25px}.hero-art .hex{width:90px;gap:7px}.hero-art .yao{height:8px;min-height:8px}.hero-art:before{width:145px;height:145px}.hero-copy p{margin-bottom:16px}.grid{grid-template-columns:1fr}.card{padding:20px}.page-head{display:block}.page-head>.btn{margin-top:15px}.hex-grid{grid-template-columns:repeat(3,1fr)}.topbar{flex-wrap:wrap}.brand small{font-size:10px}.nav a{font-size:14px}.banner-row{flex-direction:column}.section-title{align-items:flex-start}.hero-copy h2{font-size:27px}.main{padding:22px 16px}.stat{padding:15px}.lab-display{min-height:290px}}@media(prefers-reduced-motion:reduce){*,*:before,*:after{transition:none!important;animation:none!important;scroll-behavior:auto!important}}@media print{.sidebar,.topbar,.stepnav,.actions{display:none}.workspace{margin:0}.main{padding:0}.card{break-inside:avoid}}

/* Classical text reference */
.classic-section{margin-top:18px;scroll-margin-top:24px}.classic-original{font-family:"Noto Serif SC",Georgia,serif;font-size:1.25rem;line-height:2;margin-top:16px;overflow-wrap:anywhere}.classic-excerpt{font-size:1rem;line-height:1.9;margin-top:12px}.classic-selected{border:2px solid var(--accent,#1b4742)}.classic-filters{display:grid;grid-template-columns:1fr 1fr;gap:20px}.classic-line-nav{display:flex;flex-wrap:wrap;gap:10px;margin:22px 0}.classic-overview{display:flex;align-items:center;gap:40px;margin:20px 0 26px}.classic-overview>.hex,.classic-overview>div:first-child{width:130px;flex-shrink:0}.classic-overview p{margin-bottom:16px}.disclosure section{margin-top:25px;scroll-margin-top:24px}.hex-card{text-decoration:none;color:inherit}.classic-section h3 a{text-decoration:none;color:inherit}@media(max-width:600px){.classic-filters{grid-template-columns:1fr;gap:0}.classic-overview{gap:22px}.classic-original{font-size:1.125rem}}
.site-attribution{max-width:1100px;margin:0 auto;padding:22px 28px 30px;color:#59635f;font-size:.88rem;line-height:1.7;border-top:1px solid #d9dfd9;background:#fbfaf6}.site-attribution strong{color:#1b4742}.site-attribution a{color:#1b665d}@media(max-width:600px){.site-attribution{padding:18px;font-size:.8rem}}