:root{--paper:#fbfaf6;--white:#fff;--wine:#8e1835;--wine-dark:#71132a;--ink:#25332f;--muted:#6b7871;--rose:#f1e3e3;--rose-light:#faf1f1;--gold:#b8873b;--line:#dfe2db;--green:#3b6956;--green-light:#eaf1e9;--heading:"Trebuchet MS","Segoe UI",sans-serif;--body:"Segoe UI",Arial,sans-serif;--utility:Consolas,"Courier New",monospace}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:24px}body{margin:0;background:var(--paper);color:var(--ink);font-family:var(--body);font-size:16px;line-height:1.6;-webkit-font-smoothing:antialiased}button,input{font:inherit}button,a,input{-webkit-tap-highlight-color:transparent}button{cursor:pointer}a{color:inherit;text-underline-offset:4px}button:focus-visible,a:focus-visible,input:focus-visible,summary:focus-visible{outline:3px solid var(--gold);outline-offset:4px}button:disabled{cursor:default}img{display:block;max-width:100%}svg{display:block;width:20px;height:20px;fill:none;stroke:currentColor;stroke-width:1.7;stroke-linecap:round;stroke-linejoin:round}.hidden{display:none!important}.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}.skip-link{position:fixed;left:18px;top:-100px;padding:10px 18px;background:var(--wine);color:white;z-index:20}.skip-link:focus{top:12px}
.site-header,main,.site-footer{max-width:1280px;margin:auto;padding-left:48px;padding-right:48px}.site-header{height:108px;display:flex;align-items:center;justify-content:space-between;gap:24px;border-bottom:1px solid var(--line)}.brand{display:flex;align-items:center;gap:13px;text-decoration:none;line-height:1.4}.brand-mark{display:flex;align-items:center;justify-content:center;background:var(--wine);width:45px;height:48px;color:#fff;font-size:28px;flex-shrink:0;border-radius:4px 4px 11px 4px;font-family:serif}.brand strong{display:block;font-size:18px;letter-spacing:-.4px;font-family:var(--heading)}.brand small{display:block;font-size:12px;color:var(--muted);margin-top:2px}
.intro{display:grid;grid-template-columns:1.3fr 1fr;align-items:center;gap:72px;padding:60px 0 62px}.eyebrow{font-size:10px;letter-spacing:1.9px;font-weight:750;color:var(--wine);margin:0 0 14px}.intro .eyebrow{display:flex;align-items:center;gap:10px}.small-rule{width:26px;height:2px;background:var(--wine)}h1,h2,h3,p{margin-top:0}h1,h2,h3{font-family:var(--heading);line-height:1.22}h1{font-size:clamp(33px,3.8vw,48px);letter-spacing:-1.8px;margin-bottom:20px}h1 span{color:var(--wine)}.lead{font-size:15px;color:var(--muted);max-width:455px;line-height:1.8;margin-bottom:22px}.intro-link{display:inline-flex;align-items:center;gap:34px;text-decoration:none;border-bottom:1px solid var(--wine);padding-bottom:5px;font-size:13px;font-weight:700;color:var(--wine)}.intro-link:hover{gap:43px}.first-word{background:var(--white);border:1px solid #e7e3da;border-radius:4px;box-shadow:6px 7px 0 #f0ece4;transform:rotate(1deg);padding:22px 26px;position:relative}.first-word:before{content:"";position:absolute;left:17px;top:69px;bottom:46px;border-left:1px solid #ebc6cc}.paper-top,.paper-bottom{display:flex;justify-content:space-between;align-items:center;gap:12px;font-size:9px;letter-spacing:1px;color:var(--muted)}.paper-stamp{border:1px solid var(--rose);background:var(--rose-light);color:var(--wine);padding:3px 8px;font-size:8px;font-weight:700}.word-lines{display:flex;flex-direction:column;align-items:center;padding:23px 0 24px;background:repeating-linear-gradient(transparent,transparent 37px,#eeede8 37px,#eeede8 38px);margin:15px 0}.word-pinyin{color:var(--wine);font-size:23px;letter-spacing:5px}.word-hanzi{font-family:"Microsoft YaHei","PingFang SC",sans-serif;font-size:69px;line-height:1.3;color:var(--wine);font-weight:700;letter-spacing:7px}.word-hanzi>span{font-size:50px}.paper-bottom{letter-spacing:0;font-size:11px}.paper-bottom>span:first-child{font-family:var(--heading);font-size:18px;color:var(--ink)}
.classroom{scroll-margin-top:24px}.section-heading{display:flex;align-items:end;justify-content:space-between;gap:20px;margin-bottom:23px}.section-heading .eyebrow{margin-bottom:9px}.section-heading h2{font-size:29px;letter-spacing:-.8px;margin:0}.section-note{font-size:12px;color:var(--muted);text-align:right;margin:0}.library-toolbar{display:flex;gap:20px;align-items:center;padding:16px 0 22px;border-top:1px solid var(--line)}.search-field{display:flex;align-items:center;background:var(--white);border:1px solid var(--line);border-radius:6px;gap:10px;flex:1;max-width:490px;padding:10px 13px;color:var(--muted)}.search-field input{border:0;background:transparent;color:var(--ink);width:100%;min-width:0;outline:none;font-size:13px;line-height:24px}.search-field:focus-within{border-color:var(--wine);box-shadow:0 0 0 2px var(--rose)}.search-field input:focus-visible{outline:0}.search-field svg{width:18px;height:18px;flex-shrink:0}.filter-group{display:flex;gap:7px;flex-wrap:wrap;margin-left:auto}.filter{background:transparent;border:1px solid transparent;border-radius:30px;color:var(--muted);font-size:12px;padding:8px 13px;line-height:1.4}.filter.active{background:var(--wine);color:#fff}.filter:not(.active):hover{background:var(--rose)}#ready-count:not(:empty){display:inline-block;margin-left:4px;font-family:var(--utility);font-size:10px}
.library-layout{display:grid;grid-template-columns:272px minmax(0,1fr);gap:28px;align-items:start}.lesson-shelf{position:sticky;top:20px;align-self:start;border:1px solid var(--line);border-radius:7px;background:#f6f5f0;overflow:hidden}.shelf-top{display:flex;justify-content:space-between;gap:10px;font-size:9px;letter-spacing:1.4px;color:var(--muted);padding:15px 17px 12px;font-weight:700}.shelf-top #result-count{letter-spacing:0;font-family:var(--utility);font-weight:400}.lesson-list{padding:0 8px 8px}.lesson-button{width:100%;border:0;border-radius:5px;background:transparent;text-align:left;padding:12px 11px;display:grid;grid-template-columns:24px minmax(0,1fr) 8px;gap:11px;align-items:center;color:var(--ink);position:relative}.lesson-button+.lesson-button{margin-top:2px}.lesson-button:hover{background:#efeee7}.lesson-button[aria-pressed="true"]{background:var(--white);box-shadow:0 1px 5px #25332f0b}.lesson-button[aria-pressed="true"]:before{content:"";position:absolute;left:-8px;top:10px;bottom:10px;width:3px;border-radius:3px;background:var(--wine)}.lesson-order{font-family:var(--utility);font-size:12px;color:#a4aba4}.lesson-button[aria-pressed="true"] .lesson-order{color:var(--wine)}.lesson-button strong{font-size:13px;font-weight:650;display:block}.lesson-button small{display:block;color:var(--muted);font-size:10px;line-height:1.4;margin-top:2px}.lesson-button .lesson-dot{width:6px;height:6px;border-radius:50%;background:#ccd0c8}.lesson-button .lesson-dot.ready{background:var(--green)}.shelf-foot{font-size:11px;color:var(--muted);padding:12px 18px 17px;margin:0;border-top:1px solid #e5e7df;line-height:1.7}
.lesson-detail{min-width:0}.lesson-heading-card{display:grid;grid-template-columns:minmax(0,1.1fr) minmax(220px,1fr);gap:24px;background:var(--white);border:1px solid var(--line);border-radius:7px;padding:22px}.lesson-heading-copy{min-width:0}.lesson-label-line{display:flex;align-items:center;gap:8px;flex-wrap:wrap;margin-bottom:10px}.course-label{font-size:10px;letter-spacing:1.2px;color:var(--wine);font-weight:750}.material-badge{display:inline-flex;align-items:center;gap:5px;padding:3px 7px;background:var(--green-light);border-radius:3px;font-size:9px;color:var(--green);font-weight:600}.material-badge.pending{background:#f1f1ed;color:var(--muted)}.lesson-heading-card h2{font-size:24px;letter-spacing:-.5px;margin-bottom:10px;overflow-wrap:anywhere}.lesson-summary{font-size:12px;color:var(--muted);line-height:1.75;margin-bottom:17px}.lesson-heading-actions{display:flex;align-items:center;gap:12px;flex-wrap:wrap}.copy-link{display:flex;align-items:center;gap:5px;font-size:10px;color:var(--muted);background:transparent;border:0;padding:5px 0}.copy-link svg{height:13px;width:13px}
.material-tabs{display:flex;gap:23px;border-bottom:1px solid var(--line);margin:25px 0 0}.material-tab{border:0;border-bottom:2px solid transparent;background:transparent;padding:0 0 12px;display:flex;align-items:center;gap:7px;color:var(--muted);font-size:13px}.material-tab svg{height:16px;width:16px}.material-tab[aria-selected="true"]{border-color:var(--wine);color:var(--wine);font-weight:650}.tab-state{height:5px;width:5px;background:var(--green);border-radius:50%;margin-left:1px}.material-panel{background:var(--white);border:1px solid var(--line);border-top:0;border-radius:0 0 6px 6px}.material-top{display:flex;justify-content:space-between;align-items:flex-start;gap:18px;padding:23px 23px 20px;border-bottom:1px solid #eceee7}.material-title{font-size:16px;margin-bottom:4px}.material-meta{color:var(--muted);font-size:10px;margin:0}.file-actions{display:flex;gap:8px;align-items:center;flex-wrap:wrap;justify-content:flex-end}.button{display:inline-flex;align-items:center;justify-content:center;gap:9px;font-size:12px;line-height:1.4;padding:10px 14px;border-radius:4px;border:1px solid transparent;text-decoration:none;font-weight:600;white-space:normal}.button svg{height:15px;width:15px;flex-shrink:0}.button.primary{background:var(--wine);color:white}.button.primary:hover{background:var(--wine-dark)}.button.secondary{border-color:var(--line);background:white;color:var(--ink)}.button.secondary:hover{border-color:var(--wine);color:var(--wine)}.button.small{font-size:10px;padding:7px 10px}.document-directory{display:flex;gap:7px;align-items:center;flex-wrap:wrap;padding:12px 23px;background:#f7f7f2;font-size:10px;color:var(--muted);border-bottom:1px solid var(--line)}.document-directory>span{margin-right:4px}.page-jump{display:inline-flex;justify-content:center;align-items:center;width:25px;height:25px;border:1px solid var(--line);background:white;color:var(--ink);border-radius:3px;font-family:var(--utility);text-decoration:none}.page-jump:hover{border-color:var(--wine);color:var(--wine)}.document-pages{padding:22px;background:#f2f2ec}.document-page{margin:0 0 25px;scroll-margin-top:20px}.document-page:last-child{margin-bottom:0}.document-page figcaption{display:flex;justify-content:space-between;margin-bottom:7px;color:var(--muted);font-size:9px;letter-spacing:.3px}.document-page img{width:100%;height:auto;box-shadow:0 2px 10px #25332f10;background:white;border:1px solid #e3e3dd}.document-footer{font-size:11px;text-align:center;color:var(--muted);padding:18px 22px;margin:0}.empty-material{padding:40px 30px 42px;min-height:260px}.empty-material .empty-icon{width:43px;height:43px;display:flex;align-items:center;justify-content:center;border:1px solid #ddddd3;background:#f6f6f0;color:var(--muted);border-radius:5px;margin-bottom:19px}.empty-material h3{font-size:20px;margin-bottom:10px}.empty-material p{color:var(--muted);font-size:13px;line-height:1.85;max-width:470px;margin-bottom:20px}.empty-footnote{display:flex;align-items:center;gap:8px;font-size:10px;color:var(--muted);margin-top:18px}.empty-footnote:before{content:"";width:6px;height:6px;border-radius:50%;background:#bdc5b8}
.empty-results{text-align:center;border:1px dashed #d5d9ce;border-radius:7px;padding:45px 20px;margin-top:5px}.empty-results h3{font-size:22px}.empty-results p{font-size:13px;color:var(--muted)}.empty-symbol{display:inline-block;font-size:45px;font-weight:650;color:#a7b4a2;margin-bottom:15px}.loading-state{min-height:250px;border:1px solid var(--line);padding:35px;color:var(--muted);font-size:13px}.notice{background:var(--rose-light);border:1px solid var(--rose);border-radius:6px;padding:25px;margin-bottom:20px}.notice h3{font-size:20px}.notice p{font-size:13px}.noscript-note{max-width:800px;margin:30px auto}
.study-guide{display:grid;grid-template-columns:1.2fr 1fr 1fr 1fr;gap:28px;margin-top:65px;padding:35px 0 38px;border-top:1px solid var(--line);border-bottom:1px solid var(--line)}.guide-title .eyebrow{font-size:9px;letter-spacing:1.2px;margin-bottom:12px}.guide-title h2{font-size:24px;letter-spacing:-.6px;margin:0}.guide-step{padding-top:1px}.step-number{color:var(--gold);font-family:var(--utility);font-size:11px;display:block;margin-bottom:15px}.guide-step h3{font-size:15px;margin-bottom:9px}.guide-step p{font-size:11px;line-height:1.8;color:var(--muted);margin:0}.help-note{display:flex;gap:21px;align-items:center;padding:30px 0 38px}.help-mark{font-family:var(--heading);font-size:31px;color:var(--wine);width:36px;flex-shrink:0;align-self:flex-start}.help-note h2{font-size:15px;margin-bottom:6px}.help-note p{font-size:11px;color:var(--muted);line-height:1.8;margin:0;max-width:600px}.help-note>a{margin-left:auto;flex-shrink:0;font-size:11px;color:var(--wine);font-weight:600;text-decoration:none}.site-footer{border-top:1px solid var(--line);padding-top:22px;padding-bottom:25px;display:flex;justify-content:space-between;gap:20px;color:var(--muted);font-size:10px}
@media(min-width:1600px){.site-header,main,.site-footer{max-width:1360px}.library-layout{grid-template-columns:285px minmax(0,1fr)}}
@media(max-width:1050px){.site-header,main,.site-footer{padding-left:30px;padding-right:30px}.intro{gap:35px}.intro h1{font-size:37px}.library-layout{grid-template-columns:230px minmax(0,1fr);gap:20px}.lesson-heading-card{grid-template-columns:minmax(0,1fr);gap:20px}.lesson-heading-card h2{font-size:25px}.study-guide{gap:23px}.guide-title h2{font-size:21px}.material-top{flex-direction:column;gap:15px}.file-actions{justify-content:flex-start}.material-title{font-size:18px}}
@media(max-width:760px){.site-header,main,.site-footer{padding-left:22px;padding-right:22px}.site-header{height:86px}.brand{gap:10px}.brand-mark{width:37px;height:40px;font-size:24px}.brand strong{font-size:15px;letter-spacing:-.3px}.brand small{font-size:10px}.intro{grid-template-columns:1fr 0.75fr;gap:20px;padding:39px 0 43px}.intro h1{font-size:29px;letter-spacing:-1.1px}.intro .eyebrow{font-size:8px;letter-spacing:1px}.lead{font-size:12px;line-height:1.8}.first-word{padding:15px;box-shadow:4px 4px 0 #f0ece4}.paper-top{font-size:7px;gap:5px;letter-spacing:.5px}.paper-stamp{font-size:6px;padding:2px 4px;white-space:nowrap}.word-lines{padding:15px 0;margin:10px 0}.word-pinyin{font-size:17px;letter-spacing:3px}.word-hanzi{font-size:43px;letter-spacing:3px}.word-hanzi>span{font-size:29px}.paper-bottom{font-size:8px;gap:4px;line-height:1.5}.paper-bottom>span:first-child{font-size:14px}.first-word:before{left:8px;top:55px;bottom:40px}.section-heading h2{font-size:26px}.section-note{font-size:10px}.library-toolbar{align-items:stretch;gap:12px;flex-wrap:wrap;padding-bottom:18px}.search-field{flex-basis:100%;max-width:none}.filter-group{margin-left:0}.filter{font-size:11px;padding:7px 12px}.library-layout{grid-template-columns:1fr;gap:18px}.lesson-shelf{position:static}.lesson-list{display:grid;grid-template-columns:1fr 1fr;gap:3px}.lesson-button{padding:10px 8px;gap:7px;grid-template-columns:20px minmax(0,1fr) 5px}.lesson-button+.lesson-button{margin:0}.lesson-button strong{font-size:12px}.lesson-button small{font-size:9px}.lesson-button[aria-pressed="true"]:before{display:none}.lesson-button[aria-pressed="true"]{box-shadow:inset 0 0 0 1px #e4cbd0}.lesson-order{font-size:10px}.shelf-top{padding-bottom:9px}.shelf-foot{display:none}.lesson-heading-card{grid-template-columns:1.1fr 1fr;gap:20px;padding:20px}.lesson-heading-card h2{font-size:22px}.lesson-summary{font-size:11px}.material-top{flex-direction:row}.study-guide{grid-template-columns:1fr 1fr;margin-top:43px;gap:29px}.guide-title h2{font-size:23px}.guide-step p{font-size:12px}.help-note{gap:12px;flex-wrap:wrap}.help-note>div{flex:1}.help-note>a{margin-left:48px}.site-footer{font-size:9px}}
@media(max-width:540px){.site-header,main,.site-footer{padding-left:18px;padding-right:18px}.site-header{gap:10px}.brand strong{font-size:14px}.intro{grid-template-columns:1fr;padding:32px 0 36px;gap:25px}.intro h1{font-size:35px;letter-spacing:-1.3px;margin-bottom:15px}.intro .eyebrow{font-size:9px;letter-spacing:1.2px}.lead{font-size:13px;max-width:360px;margin-bottom:16px}.intro-link{font-size:12px}.first-word{display:none}.section-heading{align-items:start;margin-bottom:20px}.section-heading .eyebrow{font-size:9px;margin-bottom:7px}.section-heading h2{font-size:25px;max-width:240px}.section-note{font-size:9px;margin-top:3px;line-height:1.6;max-width:100px}.library-toolbar{padding-top:13px}.search-field{padding:8px 11px}.search-field input{font-size:12px}.lesson-list{gap:2px;padding:0 6px 7px}.lesson-button{padding:10px 6px;grid-template-columns:17px minmax(0,1fr) 5px;gap:5px}.lesson-button strong{font-size:12px}.lesson-button small{font-size:8px}.shelf-top{padding:12px 13px 9px}.lesson-heading-card{grid-template-columns:1fr;gap:18px;padding:19px}.lesson-heading-card h2{font-size:25px;max-width:100%;margin-bottom:9px}.lesson-summary{font-size:12px;margin-bottom:14px}.material-tabs{gap:24px;margin-top:24px}.material-tab{font-size:13px}.material-top{flex-direction:column;padding:20px 18px 18px;gap:14px}.file-actions{width:100%;gap:8px}.file-actions .button{flex:1;font-size:11px;padding:11px 12px}.material-meta{font-size:10px}.document-directory{padding:11px 15px}.document-pages{padding:10px}.document-page{margin-bottom:18px}.document-page figcaption{font-size:8px;padding:0 2px}.document-footer{font-size:10px;padding:17px 14px}.empty-material{padding:29px 21px;min-height:270px}.empty-material h3{font-size:21px}.empty-material p{font-size:12px}.empty-footnote{font-size:9px}.study-guide{grid-template-columns:1fr;padding:29px 0;gap:24px}.guide-title h2{font-size:25px}.guide-title h2 br{display:none}.guide-step{display:grid;grid-template-columns:28px 1fr;column-gap:13px}.step-number{grid-row:1/3;font-size:12px;margin-top:3px;margin-bottom:0}.guide-step h3{font-size:16px;margin-bottom:5px}.guide-step p{font-size:12px}.help-mark{width:25px;font-size:28px}.help-note h2{font-size:14px}.help-note p{font-size:11px}.help-note>a{margin-left:37px;font-size:11px}.site-footer{flex-direction:column;gap:5px;padding-top:19px;padding-bottom:23px;font-size:10px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*:before,*:after{animation:none!important;transition:none!important}}

.detail-back{display:none}@media(max-width:760px){.detail-back{display:inline-flex;margin:0 0 12px;font-size:11px;text-decoration:none;color:var(--muted)}}
@media(max-width:760px){.search-field input{font-size:16px}}

.materials-link{display:inline-flex;align-items:center;gap:18px;text-decoration:none;font-size:13px;font-weight:650;color:var(--wine)}.lesson-heading-card{display:block}.lesson-heading-card h2{font-size:28px;max-width:100%}.lesson-summary{font-size:13px;max-width:620px}.intro{padding-top:46px;padding-bottom:48px}.intro h1{font-size:46px}.materials-link:hover{text-decoration:underline}@media(max-width:760px){.materials-link{font-size:11px;gap:6px}.intro h1{font-size:33px}.lesson-heading-card h2{font-size:24px}.lesson-summary{font-size:12px}}
.button.youtube-link{background:#c4302b;color:#fff}.button.youtube-link:hover{background:#a32621}.button.youtube-link svg{height:17px;width:17px}
.community{display:flex;align-items:center;justify-content:space-between;gap:28px;background:var(--white);border:1px solid var(--line);border-radius:7px;padding:24px 26px;margin:0 0 46px}.community h2{font-size:21px;letter-spacing:-.4px;margin-bottom:8px}.community-copy p:last-child{font-size:12px;color:var(--muted);line-height:1.75;margin:0;max-width:520px}.community-actions{display:flex;gap:10px;flex-wrap:wrap;flex-shrink:0}.button.group-link{color:#fff;font-size:13px;padding:11px 16px}.button.group-link svg{height:18px;width:18px;fill:none;stroke:currentColor;stroke-width:1.8;stroke-linejoin:round;stroke-linecap:round}.button.whatsapp{background:#1f8f4e}.button.whatsapp:hover{background:#18763f}.button.telegram{background:#2481cc}.button.telegram:hover{background:#1d6aa8}.site-footer a{color:inherit}
@media(max-width:760px){.community{flex-direction:column;align-items:stretch;padding:20px 18px;gap:16px;margin-bottom:36px}.community-actions{flex-direction:column}.button.group-link{width:100%}}