:root{--bg:#f6f5ef;--ink:#233b32;--muted:#657068;--line:#d9dcd3;--sage:#dfe4d9;--red:#aa503a;--serif:"Songti SC","STSong","Noto Serif CJK SC",serif;font-family:-apple-system,BlinkMacSystemFont,PingFang SC,Microsoft YaHei,sans-serif;color:var(--ink);background:var(--bg);font-synthesis:none}*{box-sizing:border-box}body{margin:0}button,input,textarea{font:inherit}button,a{-webkit-tap-highlight-color:transparent}button{cursor:pointer;color:inherit}button:disabled{cursor:default;opacity:.55}button:focus-visible,a:focus-visible,input:focus-visible,textarea:focus-visible{outline:2px solid var(--red);outline-offset:4px}button{background:none;border:0}a{color:inherit;text-decoration:none}header{height:76px;border-bottom:1px solid var(--line);padding:0 48px;display:flex;align-items:center;justify-content:space-between;gap:26px}.brand{display:flex;align-items:center;gap:16px;white-space:nowrap;font-family:var(--serif)}.brand>span{display:grid;place-items:center;background:var(--ink);color:var(--bg);font-size:34px;width:44px;height:44px;border-radius:3px;line-height:1}.brand strong{font-size:34px;letter-spacing:2px}header nav{display:flex;align-items:stretch;height:100%;gap:46px}header nav button{font-size:19px;border-bottom:4px solid transparent;padding:3px 0 0}header nav button.active{border-color:var(--ink);font-weight:600}.text-button{display:inline-flex;align-items:center;justify-content:center;gap:10px;padding:0;font-size:16px}.text-button:hover{color:var(--red)}.mobile-menu{display:none}.app-layout{display:grid;grid-template-columns:278px minmax(0,1fr) 286px;max-width:1600px;margin:16px auto 0;padding:0 48px;min-height:912px}.sidebar{padding:16px 26px 24px 0;border-right:1px solid var(--line);display:flex;flex-direction:column}.sidebar h2,.method h2{font-size:28px;font-family:var(--serif);margin:0 0 23px;letter-spacing:1px}.search{display:flex;align-items:center;border:1px solid var(--line);gap:12px;height:48px;padding:0 14px;border-radius:3px;color:var(--muted);margin-bottom:20px}.search input{width:100%;min-width:0;border:0;background:none;outline:none;color:var(--ink);font-size:17px}.search button{padding:0;display:flex}.chapter{border-bottom:1px solid var(--line);padding:12px 0}.chapter:last-child{border:0}.chapter-toggle{display:flex;align-items:center;gap:13px;width:100%;text-align:left;padding:0 2px 8px;font-family:var(--serif);font-size:21px}.chapter-toggle strong{font-weight:600;flex:1}.chapter-toggle small{font:15px/1.4 -apple-system,BlinkMacSystemFont,sans-serif;color:var(--muted)}.chapter-entries{padding:0;margin-top:3px}.chapter-entries button{display:flex;align-items:center;justify-content:space-between;width:100%;text-align:left;padding:7px 12px 7px 38px;font:19px/1.35 var(--serif)}.chapter-entries button:hover{background:#e9ebe3}.chapter-entries button.selected{background:var(--sage)}.complete-dot{width:6px;height:6px;border-radius:50%;background:var(--ink)}.progress{margin-top:auto;padding-top:55px}.progress-track{height:10px;border-radius:3px;background:#e5e6df;overflow:hidden}.progress-track span{display:block;height:100%;background:var(--ink);transition:width .3s}.progress p{font-size:14px;color:var(--muted);margin:12px 0 0;display:flex;justify-content:space-between}.progress p span{font-size:12px}main{padding:18px 36px 30px 38px;min-width:0}.lesson-meta{display:flex;justify-content:space-between;align-items:center;font-size:16px;color:var(--muted);min-height:28px;margin-bottom:22px}h1{font:700 72px/1.18 var(--serif);letter-spacing:3px;margin:0 0 8px;color:#173b30}.subtitle{font:24px/1.6 var(--serif);margin:0 0 22px}.tabs{display:flex;gap:56px;border-bottom:1px solid #b9c1b5;margin-bottom:32px}.tabs button{font-size:20px;padding:8px 4px 11px;border-bottom:3px solid transparent;color:var(--muted);margin-bottom:-1px}.tabs button[aria-selected=true]{border-color:var(--ink);color:var(--ink);font-weight:600}.characters{display:grid;grid-template-columns:1fr 1fr;justify-items:center;gap:24px;padding:0 30px}.characters>div{text-align:center}.character-grid{width:232px;height:232px;border:1px solid #bcc6b8;position:relative;display:grid;place-items:center;background:linear-gradient(45deg,transparent calc(50% - .4px),#cbd0c6 calc(50% - .4px),#cbd0c6 calc(50% + .4px),transparent calc(50% + .4px)),linear-gradient(-45deg,transparent calc(50% - .4px),#cbd0c6 calc(50% - .4px),#cbd0c6 calc(50% + .4px),transparent calc(50% + .4px))}.character-grid:before,.character-grid:after{content:"";position:absolute}.character-grid:before{height:100%;left:50%;border-left:1px dashed #bdc6b7}.character-grid:after{width:100%;top:50%;border-top:1px dashed #bdc6b7}.character-grid span{font:196px/1 var(--serif);position:relative;z-index:1;color:#173b30;padding-bottom:12px}.characters p{font:600 27px/1.35 var(--serif);margin:14px 0 25px}blockquote{margin:4px 0 26px;background:#efede4;border-left:5px solid var(--red);padding:18px 25px;display:flex;gap:20px;align-items:center;justify-content:space-between;font:24px/1.5 var(--serif)}blockquote small{font-size:16px;color:var(--muted);white-space:nowrap}.reading{border-top:1px solid var(--line);padding-top:17px}h2{font:600 30px/1.4 var(--serif);margin:0 0 8px}h3{font:600 24px/1.5 var(--serif);margin:0}.reading>p{font:19px/1.9 var(--serif);margin:0}.reading .source-caption,.source-caption{font:12px/1.7 -apple-system,BlinkMacSystemFont,PingFang SC,sans-serif;color:var(--muted);margin-top:12px}.lesson-actions{display:flex;align-items:center;justify-content:center;gap:28px;margin:24px 0 0}.primary{display:inline-flex;align-items:center;justify-content:center;gap:10px;border:1px solid var(--ink);background:var(--ink);color:var(--bg);min-height:52px;padding:11px 30px;border-radius:2px;font-size:19px;font-weight:500}.primary:hover:not(:disabled){background:#345448}.primary.done{background:var(--sage);color:var(--ink)}.lesson-actions>.primary{min-width:235px}.next{font-size:18px;border-left:1px solid var(--line);padding-left:28px;line-height:2}.method{border-left:1px solid var(--line);padding:16px 0 24px 28px}.method-steps{list-style:none;margin:0;padding:0}.method-steps li{display:flex;gap:16px;min-height:108px;position:relative}.method-steps li:not(:last-child):after{content:"";position:absolute;height:48px;width:1px;background:#bcc6b8;left:23px;top:56px}.step-number{display:grid;place-items:center;flex:none;width:47px;height:47px;border-radius:50%;background:var(--sage);font:23px/1 var(--serif);margin-top:7px}.method-steps h3{font-size:28px;margin:5px 0 0}.method-steps p{font:18px/1.6 var(--serif);margin:0;color:var(--muted)}.thought{background:var(--sage);padding:24px 25px;margin-top:24px}.thought h3{font-size:27px}.thought p{font:20px/1.85 var(--serif);margin:15px 0 22px}.thought .primary{width:100%;padding:10px 12px;font-size:18px}.thought .hint{font-size:17px;border-top:1px solid #bfc8b9;padding-top:12px;margin-bottom:15px}.medical-note{font:14px/1.85 var(--serif);color:var(--muted);margin:44px 2px 0}footer{max-width:1600px;margin:auto;padding:24px 48px;display:flex;align-items:center;justify-content:space-between;gap:20px;color:var(--muted);font-size:12px;border-top:1px solid var(--line)}footer button{font-size:12px!important}.secondary{display:inline-flex;align-items:center;justify-content:center;gap:9px;border:1px solid #abb8a7;min-height:49px;padding:11px 24px;font-size:17px}.secondary:hover{background:var(--sage)}.quiz{padding:6px 0 30px}.muted{color:var(--muted);font-size:16px;line-height:1.7}.quiz h3{margin:30px 0 20px}.options{display:flex;flex-direction:column;gap:12px;margin-bottom:27px}.option{display:flex;align-items:center;gap:17px;text-align:left;border:1px solid var(--line);padding:18px;font-size:18px;background:#f9f8f3}.option>span{font-family:var(--serif);border-right:1px solid var(--line);padding-right:17px}.option.chosen{border-color:var(--ink);background:var(--sage)}.option.correct{border-color:#5a7a54;opacity:1}.option>svg{margin-left:auto}.feedback{background:var(--sage);border-left:3px solid var(--ink);padding:22px;font-size:18px}.feedback.retry{border-color:var(--red)}.feedback p{font:18px/1.9 var(--serif)}.note-editor{padding-top:10px}.note-editor label{display:block;font-size:16px;margin:28px 0 12px}.note-editor textarea{width:100%;min-height:245px;resize:vertical;border:1px solid #cbd1c4;background:#faf9f4;padding:20px;font:18px/1.9 var(--serif);color:var(--ink);border-radius:2px}.review-filters{display:flex;gap:10px;flex-wrap:wrap;border-bottom:1px solid var(--line);padding:10px 0 22px}.review-filters button{font-size:16px;padding:8px 13px}.review-filters button.active{background:var(--sage);color:var(--ink)}.flashcard{display:block;width:100%;text-align:center;border-bottom:1px solid var(--line);padding:25px 0}.flashcard h2{font-size:30px;margin:0 0 22px}.flashcard .characters p{font-size:21px;font-weight:400}.flash-answer{font:23px/1.7 var(--serif)}.flip-label{display:inline-flex;align-items:center;gap:8px;color:var(--muted);font-size:14px}.review-actions{display:flex;justify-content:center;gap:18px;margin:25px 0}.review-bottom{display:flex;align-items:center;justify-content:space-between;margin:25px 0 30px;gap:10px;font-size:14px;color:var(--muted)}.empty{border-top:1px solid var(--line);padding:25px 0;line-height:1.8}.section-title{margin:34px 0 12px}.section-title small{font-size:16px;color:var(--muted);margin-left:8px}.note-row{padding:22px 0;border-top:1px solid var(--line)}.note-row>button{width:100%;justify-content:space-between}.note-row p{font:18px/1.9 var(--serif);white-space:pre-wrap;margin:12px 0 0}.favorite-list{display:flex;flex-wrap:wrap;gap:10px}.save-error{margin:0;padding:14px 48px;color:var(--red);font-size:14px}@media(min-width:1550px){.app-layout{grid-template-columns:278px minmax(0,1fr) 286px}}@media(max-width:1300px){header{padding:0 30px}header nav{gap:30px}.app-layout{padding:0 30px;grid-template-columns:230px minmax(0,1fr) 240px}main{padding-left:28px;padding-right:28px}.sidebar{padding-right:20px}.method{padding-left:23px}.brand strong{font-size:28px}.character-grid{width:190px;height:190px}.character-grid span{font-size:165px}.characters{padding:0;gap:18px}.characters p{font-size:23px}.thought{padding:20px}.tabs{gap:33px}h1{font-size:64px}.subtitle{font-size:21px}blockquote{font-size:22px;padding:17px 20px}.lesson-actions{gap:18px}.lesson-actions>.primary{min-width:190px}.next{padding-left:18px}}@media(max-width:1080px){.app-layout{grid-template-columns:220px minmax(0,1fr);min-height:850px}.method{display:none}.tabs{gap:36px}.character-grid{width:210px;height:210px}.character-grid span{font-size:180px}header nav{gap:24px}.brand strong{font-size:27px}.brand{gap:10px}.brand>span{width:38px;height:38px;font-size:30px}header nav button{font-size:17px}}@media(max-width:760px){header{height:118px;padding:14px 20px 0;display:grid;grid-template-columns:1fr auto;gap:8px}.brand strong{font-size:26px}.brand>span{width:34px;height:34px;font-size:27px}.brand{gap:11px}header nav{grid-column:1/-1;grid-row:2;height:45px;gap:30px}header nav button{font-size:16px}.mobile-menu{display:flex;grid-column:2;grid-row:1;padding:4px}.app-layout{display:block;margin:0;padding:0;min-height:calc(100vh - 118px)}main{padding:25px 22px 35px}.sidebar{display:none}.sidebar.mobile-open{display:flex;position:fixed;inset:118px 0 0;background:var(--bg);overflow:auto;z-index:10;padding:24px;border:0}.sidebar .progress{margin-top:30px;padding-top:10px}.lesson-meta{font-size:13px;margin-bottom:18px}.lesson-meta button{font-size:13px;gap:7px}.lesson-meta svg{width:17px}.lesson-meta>span{max-width:65%}h1{font-size:51px;letter-spacing:2px}.subtitle{font-size:18px;margin-bottom:22px}.tabs{justify-content:space-between;gap:10px;margin-bottom:27px}.tabs button{font-size:16px;padding:8px 0 10px}.characters{gap:15px}.character-grid{width:135px;height:135px}.character-grid span{font-size:116px;padding-bottom:6px}.characters p{font-size:19px;margin:13px 0 24px}blockquote{display:block;font-size:20px;padding:14px 18px;margin-bottom:24px}blockquote small{display:block;font-size:12px;text-align:right;margin-top:8px}h2{font-size:26px}.reading>p{font-size:17px;line-height:1.95}.reading .source-caption{font-size:11px;line-height:1.8}.lesson-actions{flex-direction:column;gap:15px;margin-top:25px}.lesson-actions>.primary{width:100%}.next{border:0;padding:0;font-size:16px}.primary{font-size:17px;min-height:48px}footer{padding:20px 22px;align-items:flex-start;flex-direction:column;gap:13px;font-size:11px}.quiz h3{font-size:21px}.option{font-size:16px;padding:15px}.quiz .muted{font-size:14px}.feedback{font-size:17px;padding:18px}.feedback p{font-size:16px}.note-editor textarea{font-size:17px;min-height:225px;padding:16px}.review-filters{gap:4px;padding:4px 0 15px}.review-filters button{font-size:14px;padding:8px 10px}.flashcard{padding-top:23px}.flashcard .characters p{font-size:16px}.flash-answer{font-size:19px}.review-actions>*{padding:10px 21px}.review-bottom{font-size:12px}.review-bottom button{font-size:13px;gap:6px}}@media(prefers-reduced-motion:reduce){*{transition:none!important;scroll-behavior:auto!important}}.compact-medical{display:none}@media(max-width:1080px){footer{flex-wrap:wrap}.compact-medical{display:block;flex-basis:100%;margin:0;font-size:12px;line-height:1.8}}header nav{gap:30px}header nav button{white-space:nowrap}.tabs{gap:0;justify-content:space-between}.tabs button{font-size:18px}.deeper-link{margin-top:22px;font-size:18px}.depth-intro{padding-top:3px}.depth-intro .muted{margin:10px 0 22px}.argument-steps{display:flex;border-bottom:1px solid var(--line);gap:20px}.argument-steps button{flex:1;text-align:left;padding:14px 0;font-size:17px;border-bottom:2px solid transparent}.argument-steps button[aria-pressed=true]{border-color:var(--ink)}.argument-steps span{font:19px var(--serif);color:var(--muted);margin-right:10px}.argument-content{padding:27px 0 30px;min-height:200px;border-bottom:1px solid var(--line)}.argument-content>p{font:24px/1.9 var(--serif);margin:12px 0 23px}.example-section{padding:24px 0;border-bottom:1px solid var(--line)}.example-section h3{margin-bottom:12px}.example-section>p,.reflection-section>p,.reading-boundary>p{font:18px/1.9 var(--serif)}.reflection-section{padding:25px 0 0}.reflection-section textarea{width:100%;min-height:155px;resize:vertical;padding:17px;background:#faf9f4;border:1px solid var(--line);font:18px/1.9 var(--serif);color:var(--ink)}.reflection-section .source-caption{font:12px/1.8 sans-serif}.reading-boundary{padding:18px 0;border-bottom:1px solid var(--line)}.related{padding:22px 0}.related>div{display:flex;flex-wrap:wrap;gap:10px;margin-top:13px}.related .secondary{min-height:42px;font-size:16px;padding:8px 17px}.depth-lesson>.primary{margin-top:5px}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}.exercise-pages{display:flex;border-bottom:1px solid var(--line);margin:22px 0;gap:20px}.exercise-pages button{font-size:16px;padding:10px 4px;border-bottom:2px solid transparent}.exercise-pages button[aria-selected=true]{border-color:var(--ink)}.pair-rows{margin:25px 0;display:flex;flex-direction:column;gap:15px}.pair-rows label{display:flex;align-items:center;gap:22px;padding:15px 0;border-bottom:1px solid var(--line)}.pair-rows strong{font:40px var(--serif)}.pair-rows select{flex:1;min-width:0;padding:13px 10px;font-size:17px;border:1px solid var(--line);background:#faf9f4;color:var(--ink)}.answer-label{display:block;margin:22px 0 10px;font-size:16px}.recall-input{display:block;width:100%;max-width:350px;padding:18px;margin-bottom:24px;border:1px solid var(--line);background:#faf9f4;font-size:21px;color:var(--ink)}.feedback .text-button{margin-right:24px}.feedback .feedback-detail{font-size:15px;color:var(--muted)}.feedback ul{font-size:16px;line-height:1.9;padding-left:22px}.map-routes{display:grid;grid-template-columns:1fr 1fr;gap:0 25px;border-top:1px solid var(--line);margin:25px 0}.map-routes button{text-align:left;border-bottom:1px solid var(--line);padding:16px 10px;display:flex;justify-content:space-between;align-items:center;gap:8px;font-size:17px}.map-routes button[aria-pressed=true]{background:var(--sage)}.map-routes small{font-size:13px;color:var(--muted);white-space:nowrap}.route-intro p{font:19px/1.9 var(--serif);margin:9px 0 22px}.route-flow{padding:0;margin:0 0 27px;list-style:none}.route-flow li{display:flex;gap:20px;align-items:center}.route-index{font:19px var(--serif);color:var(--muted);width:25px}.route-flow button{display:flex;align-items:center;justify-content:space-between;padding:19px 0;gap:20px;flex:1;border-bottom:1px solid var(--line);text-align:left}.route-flow strong{font:26px var(--serif)}.route-flow button>span{display:flex;align-items:center;gap:7px;font-size:14px;color:var(--muted)}.route-flow button:hover strong{color:var(--red)}.review-notice{font-size:16px;line-height:1.7;color:var(--ink);background:var(--sage);padding:14px;margin:20px 0 0}.schedule-note{border-top:1px solid var(--line);padding-top:20px;margin-top:30px;max-width:600px}@media(max-width:1080px){header nav{gap:18px}header nav button{font-size:16px}.brand strong{font-size:25px}.tabs button{font-size:16px}.argument-steps{gap:10px}.argument-steps button{font-size:15px}.argument-steps span{margin-right:5px}}@media(max-width:760px){header nav{gap:0;justify-content:space-between;width:100%}header nav button{font-size:14px}.tabs button{font-size:14px}.argument-steps{gap:8px}.argument-steps button{font-size:14px}.argument-steps span{display:block;margin-bottom:7px}.argument-content>p{font-size:22px}.argument-content{min-height:185px}.reflection-section textarea{font-size:17px}.example-section>p,.reflection-section>p,.reading-boundary>p{font-size:17px}.exercise-pages{justify-content:space-between;gap:5px}.exercise-pages button{font-size:14px}.pair-rows select{font-size:15px}.map-routes{gap:0 10px}.map-routes button{font-size:15px;padding:13px 8px}.map-routes small{font-size:11px}.route-flow strong{font-size:24px}.route-flow li{gap:12px}.route-flow button>span{font-size:12px}.review-actions{flex-wrap:wrap}.review-actions>*{font-size:15px}.review-filters{gap:4px}.schedule-note{font-size:12px}}
