:root{color:#182337;font-synthesis:none;text-rendering:optimizelegibility;-webkit-font-smoothing:antialiased;--brand:#245bdb;--brand-hover:#1947b4;--blue-soft:#eef4ff;--text:#182337;--muted:#526178;--surface:#f5f7fb;--line:#e6ebf2;--green:#17805c;--red:#c83f49;background:#fff;font-family:Inter,system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,PingFang SC,Microsoft YaHei,sans-serif}*{box-sizing:border-box}body{margin:0}button,input,select,textarea{font:inherit}button,a,input,select,textarea{-webkit-tap-highlight-color:transparent}button,a{touch-action:manipulation}button{cursor:pointer}button:disabled{cursor:not-allowed;opacity:.55}a{color:inherit;text-decoration:none}button{color:inherit}button,input,select,textarea{outline-offset:4px}a:focus-visible,button:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible{outline-offset:3px;outline:3px solid #83a8f4}button{background:0 0;border:none}img{max-width:100%;display:block}h1,h2,h3,p{margin:0}h1,h2,h3{line-height:1.4}p{line-height:1.7}svg{flex-shrink:0}input,select,textarea{min-width:0}input,textarea{color:var(--text);background:#fff;border:1px solid #cfd7e3;border-radius:8px;padding:12px 14px;font-size:15px}input::placeholder,textarea::placeholder{color:#758197}input:focus,textarea:focus{border-color:var(--brand)}textarea{resize:vertical;line-height:1.6}input[readonly]{background:var(--surface);color:var(--muted)}fieldset{min-width:0}main{min-height:65vh}#main:focus{outline:none}.container{width:min(1240px,100% - 64px);margin:0 auto}.site-header{border-bottom:1px solid var(--line);z-index:10;background:#fff;height:76px;position:relative}.header-inner{align-items:center;gap:42px;max-width:1376px;height:100%;margin:auto;padding:0 32px;display:flex}.brand{letter-spacing:1px;white-space:nowrap;align-items:center;gap:10px;font-size:23px;font-weight:750;display:flex}.brand-mark{background:var(--brand);color:#fff;border-radius:11px;place-items:center;width:41px;height:41px;display:grid}.brand small{letter-spacing:2px;color:var(--muted);margin-top:1px;font-size:9px;display:block}.main-nav{white-space:nowrap;align-items:center;gap:32px;height:100%;font-size:15px;display:flex}.main-nav a{height:100%;color:var(--muted);align-items:center;display:flex;position:relative}.main-nav a.active{color:var(--brand);font-weight:650}.main-nav a.active:after{content:"";background:var(--brand);height:3px;position:absolute;bottom:0;left:0;right:0}.header-search{background:var(--surface);width:245px;height:40px;color:var(--muted);border-radius:8px;align-items:center;gap:8px;margin-left:auto;padding:0 10px;display:flex}.header-search input{background:0 0;border:0;outline:0;width:100%;padding:0;font-size:13px}.header-search .icon-btn{width:26px;height:32px;min-height:32px}.user-link{align-items:center;gap:9px;max-width:155px;font-size:14px;display:flex}.user-link>span:last-child{white-space:nowrap;text-overflow:ellipsis;overflow:hidden}.avatar{width:42px;height:42px;color:var(--brand);background:#e9effc;border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;font-weight:650;display:inline-flex}.avatar.small{width:33px;height:33px;font-size:14px}.avatar.large{width:78px;height:78px;font-size:32px}.button{white-space:nowrap;border:1px solid #0000;border-radius:8px;justify-content:center;align-items:center;gap:9px;min-height:46px;padding:11px 22px;font-size:14px;font-weight:600;line-height:1.5;transition:background .18s,border-color .18s;display:inline-flex}.primary{background:var(--brand);color:#fff}.primary:hover:not(:disabled){background:var(--brand-hover)}.secondary{color:var(--text);background:#fff;border-color:#dbe2ed}.secondary:hover:not(:disabled){background:var(--surface);border-color:#afbed4}.small-button{min-height:38px;padding:8px 14px;font-size:13px}.full{width:100%}.fit{align-self:flex-start}.icon-btn{border-radius:7px;justify-content:center;align-items:center;width:38px;height:38px;min-height:38px;display:inline-flex}.icon-btn:hover:not(:disabled){background:var(--blue-soft);color:var(--brand)}.text-link,.back-link,.text-button{color:var(--brand);align-items:center;gap:8px;font-size:14px;display:inline-flex}.text-button{padding:2px 5px;text-decoration:underline}.muted{color:var(--muted)}.small-text{font-size:13px}.success{color:var(--green)}.eyebrow{letter-spacing:1.5px;color:var(--brand);font-size:12px;font-weight:650;line-height:1.5}.tag-row{flex-wrap:wrap;align-items:center;gap:8px;display:flex}.tag,.badge{background:var(--surface);color:var(--muted);border-radius:5px;padding:4px 9px;font-size:12px;display:inline-block}.badge{background:var(--blue-soft);color:var(--brand)}.green{color:var(--green);background:#edf8f2}.page-heading{padding:42px 0 30px}.page-heading h1{letter-spacing:-.7px;margin:8px 0 10px;font-size:34px}.page-heading>p:last-child{color:var(--muted);font-size:15px}.state-panel{text-align:center;min-height:280px;color:var(--muted);flex-direction:column;align-items:center;gap:16px;padding:64px 20px;display:flex}.state-panel h3{color:var(--text);font-size:20px}.state-panel p{max-width:550px;font-size:14px}.spin{animation:1s linear infinite spin}@keyframes spin{to{transform:rotate(360deg)}}.inline-error,.inline-success{white-space:pre-line;border-radius:7px;padding:12px 15px;font-size:14px;line-height:1.65}.inline-error{color:#a42b37;background:#fff2f3}.inline-success{color:#126844;background:#eff9f4}.soft-notice{background:var(--surface);color:var(--muted);border-radius:8px;padding:15px;font-size:14px}.site-footer{border-top:1px solid var(--line);background:#fafbfd;margin-top:72px}.footer-inner{align-items:center;gap:60px;padding-top:34px;padding-bottom:34px;display:flex}.footer-inner strong{font-size:20px}.footer-inner p{color:var(--muted);margin-top:8px;font-size:12px}.footer-links{color:var(--muted);gap:25px;font-size:13px;display:flex}.footer-links a{align-items:center;gap:4px;display:flex}.footer-note{color:var(--muted);margin-left:auto;font-size:12px}.welcome-row{justify-content:space-between;align-items:center;padding:27px 0 22px;font-size:13px;display:flex}.welcome-row p{font-weight:550}.welcome-row p span{color:var(--muted);margin-left:14px;font-weight:400}.welcome-row>a{color:var(--muted);align-items:center;gap:7px;display:flex}.welcome-row>a svg{width:15px}.home-feature{background:#f0f4fc;border:1px solid #e6edf8;border-radius:14px;grid-template-columns:1fr 47%;min-height:325px;display:grid;overflow:hidden}.feature-copy{padding:32px 40px}.feature-copy h1{letter-spacing:-.8px;max-width:590px;margin:13px 0 14px;font-size:34px;line-height:1.4}.feature-subtitle{color:var(--muted);max-width:470px;font-size:15px}.feature-meta{color:var(--muted);gap:22px;margin:18px 0 24px;font-size:12px;display:flex}.feature-image{background:#e3ebfa;border-radius:9px;justify-content:center;align-items:center;margin:24px 24px 24px 0;display:flex;position:relative;overflow:hidden}.feature-image img{object-fit:cover;width:100%;height:100%}.feature-play{color:var(--brand);background:#fffffff0;border-radius:7px;align-items:center;gap:8px;padding:10px 15px;font-size:13px;font-weight:650;display:flex;position:absolute;bottom:18px;right:18px;box-shadow:0 3px 15px #16284812}.category-strip{border-bottom:1px solid var(--line);flex-wrap:wrap;align-items:center;gap:28px;padding:25px 5px;font-size:14px;display:flex}.category-strip a{color:var(--muted);align-items:center;gap:8px;min-height:32px;display:flex}.category-strip a:hover{color:var(--brand)}.category-strip .category-all{color:var(--text);border-right:1px solid var(--line);padding-right:26px;font-weight:600}.category-strip small{color:#687992;font-size:11px}.continue-banner{border:1px solid var(--line);background:#f7f9fd;border-radius:10px;align-items:center;gap:20px;margin-top:26px;padding:20px 24px;display:flex}.continue-icon{width:46px;height:46px;color:var(--brand);background:#e9efff;border-radius:50%;place-items:center;display:grid}.continue-text{flex:1;min-width:0}.continue-text .eyebrow{letter-spacing:.5px;font-size:11px}.continue-text h3{white-space:nowrap;text-overflow:ellipsis;margin-top:5px;font-size:17px;overflow:hidden}.continue-progress{width:165px;color:var(--muted);margin-right:20px;font-size:11px}.continue-progress .progress-track{margin-top:9px}.section{margin-top:39px}.section-heading{justify-content:space-between;align-items:flex-end;gap:20px;margin-bottom:26px;display:flex}.section-heading .eyebrow{letter-spacing:1.8px;font-size:10px}.section-heading h2{margin:6px 0 7px;font-size:26px}.section-heading p:not(.eyebrow){color:var(--muted);font-size:14px}.section-heading .text-link{padding-bottom:6px}.course-grid{grid-template-columns:repeat(4,minmax(0,1fr));gap:25px 22px;display:grid}.course-card{border:1px solid var(--line);background:#fff;border-radius:11px;flex-direction:column;min-width:0;transition:box-shadow .18s,transform .18s,border-color .18s;display:flex;overflow:hidden}.course-card:hover{border-color:#cdd9ed;transform:translateY(-3px);box-shadow:0 8px 24px #1a355312}.course-cover{aspect-ratio:16/9;background:var(--blue-soft);position:relative;overflow:hidden}.course-cover img{object-fit:cover;width:100%;height:100%}.cover-empty{height:100%;color:var(--brand);justify-content:center;align-items:center;gap:15px;display:flex}.cover-level{color:#2c3e5a;background:#fffffff2;border-radius:4px;padding:3px 7px;font-size:10px;position:absolute;top:12px;left:12px}.course-card-content{flex-direction:column;flex:1;padding:17px 18px 15px;display:flex}.course-card-content .eyebrow{letter-spacing:.4px;font-size:10px}.course-card h3{-webkit-line-clamp:2;-webkit-box-orient:vertical;min-height:48px;margin-top:7px;font-size:17px;font-weight:650;display:-webkit-box;overflow:hidden}.course-subtitle{color:var(--muted);text-overflow:ellipsis;white-space:nowrap;margin-top:9px;font-size:12px;overflow:hidden}.course-meta{color:var(--muted);align-items:center;gap:15px;margin:17px 0;font-size:11px;display:flex}.course-meta span{align-items:center;gap:5px;display:flex}.card-bottom{border-top:1px solid var(--line);color:var(--muted);justify-content:space-between;align-items:center;gap:6px;margin-top:auto;padding-top:13px;font-size:11px;display:flex}.card-bottom>span{text-overflow:ellipsis;white-space:nowrap;max-width:50%;overflow:hidden}.card-bottom strong{color:var(--brand);white-space:nowrap;align-items:center;gap:5px;font-size:12px;font-weight:600;display:flex}.progress-track{background:#e5eaf3;border-radius:10px;height:5px;overflow:hidden}.progress-track i{background:var(--brand);border-radius:10px;height:100%;display:block}.progress-label{color:var(--muted);justify-content:space-between;align-items:center;gap:10px;margin:0 0 10px;font-size:11px;display:flex}.progress-label>span:last-child{color:var(--brand);align-items:center;gap:4px;display:flex}.catalog-search{background:var(--surface);border:1px solid var(--line);max-width:720px;color:var(--muted);border-radius:9px;align-items:center;gap:15px;padding:7px 8px 7px 20px;display:flex}.catalog-search input{background:0 0;border:0;outline:0;flex:1;padding:8px 0}.filter-panel{border:1px solid var(--line);background:#fafbfd;border-radius:10px;margin-top:30px;padding:9px 22px}.filter-line{align-items:flex-start;gap:28px;padding:12px 0;font-size:13px;display:flex}.filter-line+.filter-line{border-top:1px solid var(--line)}.filter-title{white-space:nowrap;color:var(--muted);padding-top:8px}.filter-options{flex-wrap:wrap;gap:10px;display:flex}.filter-options button{border-radius:6px;min-height:34px;padding:7px 15px}.filter-options button:hover{background:var(--surface)}.filter-options .selected{background:var(--blue-soft);color:var(--brand);font-weight:650}.results-heading{justify-content:space-between;align-items:center;margin:29px 0 23px;display:flex}.results-heading p{align-items:center;gap:10px;font-size:15px;display:flex}.results-heading p>strong{color:var(--muted);font-size:13px;font-weight:400}.search-tag{background:var(--blue-soft);color:var(--brand);border-radius:5px;align-items:center;gap:6px;padding:1px 0 1px 10px;font-size:12px;display:flex}.search-tag .icon-btn{width:29px;height:29px;min-height:29px}.sort-control{color:var(--muted);align-items:center;gap:7px;display:flex}.sort-control select{color:var(--muted);background:0 0;border:0;padding:8px;font-size:13px}.pagination{color:var(--muted);justify-content:center;align-items:center;gap:20px;padding-top:35px;font-size:13px;display:flex}.pagination .icon-btn{border:1px solid var(--line)}.auth-page{grid-template-columns:1fr 440px;align-items:center;gap:80px;max-width:1100px;padding-top:70px;padding-bottom:45px;display:grid}.auth-story{padding:20px}.auth-symbol{width:85px;height:85px;color:var(--brand);background:var(--blue-soft);border-radius:20px;place-items:center;margin-bottom:34px;display:grid}.auth-story h1{letter-spacing:-1px;margin:15px 0 20px;font-size:35px;line-height:1.6}.auth-story>p:not(.eyebrow){color:var(--muted);font-size:15px}.auth-benefits{color:var(--muted);flex-direction:column;gap:15px;margin-top:38px;font-size:13px;display:flex}.auth-benefits span{align-items:center;gap:10px;display:flex}.auth-benefits svg{color:var(--brand)}.auth-card{border:1px solid var(--line);border-radius:15px;padding:32px 35px 30px;box-shadow:0 10px 35px #21355208}.auth-tabs{border-bottom:1px solid var(--line);gap:28px;margin-bottom:27px;display:flex}.auth-tabs button{color:var(--muted);padding:0 0 15px;font-size:14px;position:relative}.auth-tabs button.active{color:var(--brand);font-weight:650}.auth-tabs button.active:after{content:"";background:var(--brand);height:3px;position:absolute;bottom:-1px;left:0;right:0}.auth-card h2{margin-bottom:9px;font-size:25px}.auth-card>p{color:var(--muted);margin-bottom:26px;font-size:13px}.auth-card .form-stack{margin-top:25px}.auth-help{color:var(--muted);text-align:center;margin-top:26px;font-size:12px;display:block}.form-stack{flex-direction:column;gap:20px;display:flex}.form-stack label{flex-direction:column;gap:8px;font-size:14px;font-weight:550;display:flex}.form-stack label small{color:var(--muted);font-size:12px;font-weight:400}.password-input{border:1px solid #cfd7e3;border-radius:8px;align-items:center;padding-right:6px;display:flex}.password-input input{background:0 0;border:0;width:100%}.form-columns{grid-template-columns:1fr 1fr;gap:20px;display:grid}.my-heading{justify-content:space-between;align-items:center;padding:43px 0 37px;display:flex}.my-heading h1{margin:10px 0;font-size:32px}.my-heading p:last-child{color:var(--muted);font-size:14px}.my-count{background:var(--blue-soft);color:var(--brand);border-radius:12px;align-items:center;gap:14px;padding:23px 28px;display:flex}.my-count strong{font-size:30px}.my-count span{color:var(--muted);font-size:13px}.my-toolbar{border-bottom:1px solid var(--line);justify-content:space-between;align-items:center;gap:20px;margin-bottom:27px;display:flex}.line-tabs{align-items:center;gap:30px;min-height:62px;display:flex}.line-tabs>button,.line-tabs>a{color:var(--muted);white-space:nowrap;align-items:center;gap:7px;padding:20px 0;font-size:14px;display:flex;position:relative}.line-tabs>button.active{color:var(--brand);font-weight:650}.line-tabs>button.active:after{content:"";background:var(--brand);height:3px;position:absolute;bottom:0;left:0;right:0}.compact-search{background:var(--surface);border-radius:7px;align-items:center;margin-bottom:8px;display:flex}.compact-search input{background:0 0;border:0;width:190px;padding:9px 12px;font-size:13px}.breadcrumbs{color:var(--muted);align-items:center;gap:10px;padding:26px 0;font-size:12px;display:flex}.course-hero{grid-template-columns:46% 1fr;gap:40px;padding:5px 0 36px;display:grid}.detail-cover{aspect-ratio:16/9;background:var(--blue-soft);border-radius:12px;justify-content:center;align-self:start;align-items:center;display:flex;overflow:hidden}.detail-cover img{object-fit:cover;width:100%;height:100%}.course-info h1{margin:14px 0 13px;font-size:28px;line-height:1.5}.detail-subtitle{color:var(--muted);font-size:14px}.detail-meta{color:var(--muted);flex-wrap:wrap;gap:20px;margin-top:20px;font-size:12px;display:flex}.detail-meta>span{align-items:center;gap:6px;display:flex}.detail-actions{flex-wrap:wrap;align-items:center;gap:14px;margin-top:25px;display:flex}.detail-actions+.muted{margin-top:12px}.detail-progress{max-width:340px;margin-top:20px}.detail-layout{grid-template-columns:minmax(0,1fr) 295px;align-items:start;gap:34px;display:grid}.detail-body{border:1px solid var(--line);border-radius:12px;overflow:hidden}.detail-tabs{border-bottom:1px solid var(--line);padding:0 28px}.detail-section{padding:30px}.detail-section h2{margin-bottom:22px;font-size:21px}.spaced-heading{margin-top:36px}.detail-section h2 small{color:var(--muted);margin-left:12px;font-size:13px;font-weight:400}.rich-text{color:#34435a;overflow-wrap:anywhere;font-size:15px;line-height:1.9}.rich-text>*{max-width:100%}.rich-text h1,.rich-text h2,.rich-text h3{color:var(--text);margin:26px 0 15px}.rich-text p{margin:12px 0;line-height:1.9}.rich-text ul,.rich-text ol{padding-left:24px}.rich-text li{margin:8px 0}.rich-text img{border-radius:8px;height:auto}.rich-text pre{background:var(--surface);padding:15px;overflow:auto}.rich-text table{border-collapse:collapse;display:block;overflow:auto}.rich-text th,.rich-text td{border:1px solid var(--line);padding:8px}.rich-text a{color:var(--brand);text-decoration:underline}.detail-section>.tag-row{margin-top:24px}.chapter+.chapter{margin-top:20px}.chapter h3{background:var(--surface);border-radius:6px;align-items:center;gap:10px;padding:13px 16px;font-size:14px;line-height:1.6;display:flex}.chapter h3>span{color:var(--muted);font-size:12px;font-weight:400}.chapter h3 small{color:var(--muted);white-space:nowrap;margin-left:auto;font-size:11px;font-weight:400}.lesson-row{text-align:left;border-bottom:1px solid #f0f3f7;align-items:center;gap:11px;width:100%;min-height:57px;padding:14px 15px;font-size:13px;display:flex}.lesson-row:hover{background:var(--surface)}.lesson-row>svg{color:var(--brand)}.lesson-row.locked>svg{color:#7e8ca2}.lesson-row.current{background:var(--blue-soft);color:var(--brand);border-left:3px solid var(--brand);padding-left:12px}.lesson-title{flex-direction:column;flex:1;gap:4px;min-width:0;line-height:1.6;display:flex}.lesson-title small{color:var(--muted);font-size:10px}.lesson-duration{color:var(--muted);white-space:nowrap;font-size:11px}.preview-label{color:var(--green);white-space:nowrap;border:1px solid #bcdccc;border-radius:3px;padding:2px 5px;font-size:10px}.course-aside{flex-direction:column;gap:18px;display:flex}.aside-note{border:1px solid var(--line);background:#f7f9fd;border-radius:12px;padding:26px}.aside-icon{width:45px;height:45px;color:var(--brand);background:#e8effe;border-radius:10px;place-items:center;margin-bottom:17px;display:grid}.aside-note h3{margin-bottom:12px;font-size:17px}.aside-note>p{color:var(--muted);font-size:13px}.aside-note dl{margin-bottom:0;padding-top:8px}.aside-note dl>div{justify-content:space-between;gap:10px;padding-top:14px;font-size:12px;display:flex}.aside-note dt{color:var(--muted)}.aside-note dd{text-align:right;margin:0}.quiz-entry{background:var(--blue-soft);color:var(--brand);border-radius:10px;align-items:center;gap:14px;padding:21px 20px;display:flex}.quiz-entry>span{flex:1}.quiz-entry strong{font-size:15px;display:block}.quiz-entry small{color:var(--muted);margin-top:7px;font-size:11px;display:block}.support-link{text-align:center;color:var(--muted);padding:7px;font-size:12px}.permission-note{background:var(--surface);color:var(--muted);border-radius:8px;align-items:center;gap:7px;padding:12px;font-size:13px;display:flex}.course-info>.inline-error{margin-top:12px}.subheading{align-items:center;gap:10px;margin-bottom:22px;font-size:18px;display:flex}.subheading>span{color:var(--muted);font-size:13px;font-weight:400}.comment-form textarea{width:100%;font-size:13px}.comment-form>div{justify-content:space-between;align-items:center;gap:15px;margin:11px 0 24px;display:flex}.comment-form small{color:var(--muted);font-size:11px}.comment{border-bottom:1px solid var(--line);gap:14px;padding:24px 0;display:flex}.comment>div{flex:1;min-width:0}.comment-author{justify-content:space-between;gap:12px;font-size:13px;display:flex}.comment-author time{color:var(--muted);font-size:11px}.comment p{white-space:pre-wrap;overflow-wrap:anywhere;margin-top:9px;font-size:14px}.empty-comments{text-align:center;color:var(--muted);padding:35px 0;font-size:13px}.attachment-row{border-bottom:1px solid var(--line);align-items:center;gap:14px;padding:19px 0;display:flex}.file-icon{background:var(--blue-soft);width:42px;height:48px;color:var(--brand);border-radius:7px;place-items:center;display:grid}.attachment-row>div{flex:1;min-width:0}.attachment-row strong{overflow-wrap:anywhere;font-size:14px;font-weight:550;display:block}.attachment-row small{color:var(--muted);margin-top:6px;font-size:11px;display:block}.profile-layout{grid-template-columns:275px 1fr;align-items:start;gap:30px;display:grid}.profile-summary{border:1px solid var(--line);text-align:center;background:#fafbfd;border-radius:12px;padding:35px 24px}.profile-summary h2{margin:18px 0 10px;font-size:21px}.profile-summary p{color:var(--muted);overflow-wrap:anywhere;font-size:13px}.profile-summary small{color:var(--muted);margin:15px 0 26px;font-size:11px;display:block}.profile-sections{flex-direction:column;gap:24px;display:flex}.white-panel{border:1px solid var(--line);border-radius:12px;padding:28px}.white-panel h2{align-items:center;gap:10px;margin-bottom:26px;font-size:19px;display:flex}.white-panel h2 svg{color:var(--brand)}.activity-row{border-bottom:1px solid var(--line);align-items:center;gap:12px;padding:15px 0;display:flex}.activity-row>span{flex:1}.activity-row strong{font-size:14px;font-weight:500;display:block}.activity-row small{color:var(--muted);margin-top:6px;font-size:12px;display:block}.activity-row time{color:var(--muted);font-size:11px}.quiz-page{max-width:900px;padding-top:28px}.quiz-page .page-heading{padding-top:25px}.quiz-notice{border:1px solid var(--line);background:var(--surface);border-radius:9px;margin-bottom:28px;padding:20px 24px}.quiz-notice p{font-size:14px}.quiz-notice span{color:var(--muted);margin-top:8px;font-size:12px;display:block}.question{border:1px solid var(--line);border-radius:11px;margin:0 0 25px;padding:23px 25px 25px}.question legend{padding:0 10px;font-size:17px;font-weight:550;line-height:1.8}.question legend>span{color:var(--brand);margin-right:12px;font-weight:700}.question-option{border:1px solid var(--line);cursor:pointer;border-radius:7px;align-items:center;gap:12px;margin-top:12px;padding:13px 16px;font-size:14px;display:flex}.question-option input{accent-color:var(--brand);width:16px;height:16px;margin:0;padding:0}.question-option>span:last-child{flex:1}.question-option.chosen{background:var(--blue-soft);border-color:#a5bceb}.question-option.correct{background:#f0faf4;border-color:#a6d6b9}.question-option.wrong{background:#fff3f4;border-color:#e7adb6}.option-letter{color:var(--muted);font-weight:600}.question-option>svg{color:var(--green);margin-left:auto}.question-explanation{color:var(--muted);gap:10px;padding:16px 0 0;font-size:13px;display:flex}.question-explanation strong{color:var(--text);margin-bottom:4px;display:block}.question-explanation svg{margin-top:4px}.quiz-submit{border:1px solid var(--line);background:#fffffff2;border-radius:10px;justify-content:space-between;align-items:center;padding:20px;font-size:14px;display:flex;position:sticky;bottom:14px;box-shadow:0 3px 20px #12304509}.quiz-result{background:#fff8ed;border:1px solid #f0dfc3;border-radius:12px;align-items:center;gap:24px;margin-bottom:30px;padding:28px;display:flex}.quiz-result.passed{background:#eef9f3;border-color:#c6e7d2}.quiz-result>svg{color:var(--brand)}.quiz-result>div{flex:1}.quiz-result h2{margin:4px 0;font-size:42px}.quiz-result h2 small{margin-left:6px;font-size:14px}.quiz-result p:last-child{color:var(--muted);font-size:13px}.learning-main{background:#f5f7fb}.learning-shell{max-width:1600px;margin:auto;padding:0 28px 35px}.learning-topbar{justify-content:space-between;align-items:center;gap:20px;min-height:66px;display:flex}.learning-topbar .back-link{color:var(--text);min-width:0}.learning-topbar .back-link span{white-space:nowrap;text-overflow:ellipsis;overflow:hidden}.learning-layout{grid-template-columns:minmax(0,1fr) 320px;align-items:start;gap:22px;display:grid}.learning-layout.expanded{grid-template-columns:minmax(0,1fr);max-width:1150px;margin:auto}.learning-content{border:1px solid var(--line);background:#fff;border-radius:10px;min-width:0;overflow:hidden}.video-stage{aspect-ratio:16/9;background:#0d1626;position:relative}.video-stage video{object-fit:contain;width:100%;height:100%;display:block}.media-error{color:#fff;text-align:center;background:#132035e8;flex-direction:column;justify-content:center;align-items:center;gap:20px;padding:20px;font-size:14px;display:flex;position:absolute;inset:0}.audio-stage{text-align:center;background:linear-gradient(135deg,#edf3fe,#f9fbff);flex-direction:column;align-items:center;gap:15px;min-height:415px;padding:35px;display:flex}.audio-art{background:var(--brand);color:#fff;border-radius:50%;place-items:center;width:150px;height:150px;display:grid;position:relative;overflow:hidden}.audio-art img{object-fit:cover;filter:brightness(.5);width:100%;height:100%}.audio-art svg{position:absolute}.audio-stage h2{font-size:21px}.audio-stage audio{width:min(100%,650px);margin-top:15px}.article-stage{max-width:850px;min-height:420px;margin:auto;padding:45px 50px}.article-stage>h1{margin:12px 0 30px;font-size:27px}.pdf-stage iframe{border:0;width:100%;height:650px;display:block}.pdf-heading{background:var(--surface);justify-content:space-between;align-items:center;gap:12px;padding:14px 20px;font-size:14px;display:flex}.lesson-info-bar{border-top:1px solid var(--line);justify-content:space-between;align-items:center;gap:15px;padding:25px 26px;display:flex}.lesson-info-bar>div:first-child{flex:1;min-width:0}.lesson-info-bar .eyebrow{letter-spacing:.4px;font-size:10px}.lesson-info-bar h1{margin:6px 0 10px;font-size:20px}.lesson-actions{flex-wrap:wrap;align-items:center;gap:9px;display:flex}.save-status{color:var(--muted);flex-wrap:wrap;align-items:center;gap:5px;font-size:11px;display:flex}.save-status.success{color:var(--green)}.learning-bottom{padding:0 26px}.learning-bottom .line-tabs{border-bottom:1px solid var(--line);gap:25px}.learning-bottom .line-tabs>a{margin-left:auto}.learning-panel{padding:24px 0}.learning-sidebar{border:1px solid var(--line);background:#fff;border-radius:10px;max-height:calc(100vh - 100px);position:sticky;top:20px;overflow:auto}.learning-sidebar-title{border-bottom:1px solid var(--line);padding:22px 20px}.learning-sidebar-title h2{font-size:18px}.learning-sidebar-title p{color:var(--muted);margin:9px 0 12px;font-size:12px}.learning-sidebar .chapter+.chapter{margin-top:0}.learning-sidebar .chapter h3{border-radius:0;gap:7px;padding:14px 16px;font-size:12px}.learning-sidebar .chapter h3 small{font-size:10px}.learning-sidebar .lesson-row{gap:9px;min-height:68px;padding:15px;font-size:12px}.learning-sidebar .lesson-row.current{padding-left:12px}.learning-sidebar .lesson-duration{font-size:10px}.learning-sidebar .lesson-title{line-height:1.6}.skip-link{background:var(--brand);color:#fff;z-index:100;border-radius:6px;padding:10px 15px;position:fixed;top:-60px;left:15px}.skip-link:focus{top:10px}.sr-only{clip:rect(0, 0, 0, 0);white-space:nowrap;border:0;width:1px;height:1px;margin:-1px;padding:0;position:absolute;overflow:hidden}@media (width>=1600px){.feature-copy{padding:38px 42px}.feature-copy h1{font-size:37px}}@media (width<=1200px){.header-inner{gap:26px}.main-nav{gap:23px}.header-search{width:210px}.course-grid{grid-template-columns:repeat(3,minmax(0,1fr))}.feature-copy{padding:28px}.feature-copy h1{font-size:28px}.course-hero{gap:28px}.detail-layout{grid-template-columns:minmax(0,1fr) 265px;gap:24px}.learning-layout{grid-template-columns:minmax(0,1fr) 290px;gap:16px}.learning-shell{padding:0 20px 28px}.lesson-info-bar{flex-direction:column;align-items:flex-start}.auth-page{gap:40px}.footer-inner{gap:30px}.continue-progress{margin-right:0}}@media (width<=1000px){.header-search{display:none}.user-link,.header-inner>.button{margin-left:auto}.header-inner{gap:35px}.detail-layout{grid-template-columns:minmax(0,1fr) 240px;gap:20px}.course-hero{grid-template-columns:43% 1fr}.course-info h1{font-size:24px}.detail-meta{gap:12px}.detail-section{padding:22px}.detail-tabs{gap:24px;padding:0 22px}.learning-layout{grid-template-columns:minmax(0,1fr) 265px;gap:12px}.learning-sidebar .lesson-duration{display:none}.feature-image{margin:20px 20px 20px 0}.feature-copy h1{font-size:26px}.home-feature{grid-template-columns:1fr 45%;min-height:310px}.auth-page{grid-template-columns:1fr 410px;gap:20px}.auth-story{padding:0}.auth-story h1{font-size:29px}.profile-layout{grid-template-columns:230px 1fr;gap:22px}.profile-summary{padding:30px 18px}.profile-summary p{font-size:12px}.footer-note{display:none}}@media (width<=800px){.container{width:calc(100% - 40px)}.header-inner{gap:25px;padding:0 20px}.brand{gap:8px;font-size:20px}.brand-mark{width:36px;height:36px}.main-nav{gap:20px;font-size:14px}.user-link>span:last-child{display:none}.course-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:20px}.home-feature{grid-template-columns:1fr 44%;min-height:0}.feature-copy{padding:24px}.feature-copy h1{font-size:25px}.feature-copy .feature-subtitle{font-size:13px}.feature-meta{flex-wrap:wrap;gap:9px;font-size:11px}.feature-image{margin:20px 20px 20px 0}.feature-play{padding:8px;font-size:11px;bottom:12px;right:12px}.category-strip{gap:19px;font-size:13px}.continue-banner{gap:13px;padding:18px}.continue-progress{display:none}.continue-text h3{font-size:15px}.detail-layout{grid-template-columns:1fr}.course-aside{grid-template-columns:1fr 1fr;align-items:start;display:grid}.course-aside .aside-note{grid-row:span 2}.course-hero{grid-template-columns:1fr 1.05fr;gap:24px}.course-info h1{font-size:22px}.detail-meta{font-size:11px}.detail-cover{aspect-ratio:16/9}.detail-actions{gap:10px}.detail-actions .button{padding:10px 14px;font-size:13px}.course-info .detail-subtitle{font-size:13px}.detail-section{padding:25px}.learning-layout{grid-template-columns:1fr}.learning-sidebar{grid-row:2;max-height:480px;position:static}.learning-sidebar .lesson-duration{display:inline}.learning-sidebar .lesson-row{min-height:56px}.video-stage{aspect-ratio:16/9}.lesson-info-bar{flex-direction:row;align-items:center}.learning-sidebar-title{padding:18px}.learning-topbar .back-link{max-width:70%;font-size:13px}.auth-page{grid-template-columns:1fr;max-width:500px;padding-top:35px}.auth-story{display:none}.profile-layout{grid-template-columns:1fr}.profile-summary{text-align:left;grid-template-columns:65px 1fr;gap:8px 20px;padding:22px;display:grid}.profile-summary .avatar{grid-row:span 3;width:65px;height:65px}.profile-summary h2{margin:0;font-size:19px}.profile-summary small{margin:0}.profile-summary .button{grid-column:1/-1;justify-self:start;width:auto;margin-top:12px}.form-columns{grid-template-columns:1fr}.my-count{gap:9px;padding:15px 20px}.my-count strong{font-size:25px}.my-heading h1{font-size:27px}.my-heading{gap:15px}.footer-inner{justify-content:space-between;gap:25px}.footer-links{gap:18px}.pdf-stage iframe{height:550px}.article-stage{padding:30px}.white-panel{padding:25px}}@media (width<=560px){.site-header{height:auto;min-height:115px}.header-inner{flex-wrap:wrap;justify-content:space-between;gap:0;padding-top:14px;padding-bottom:0;position:relative}.brand{font-size:21px}.brand small{font-size:8px}.header-inner>.button{min-height:36px;padding:8px 12px;font-size:12px}.main-nav{order:4;justify-content:center;gap:32px;width:100%;height:49px;font-size:14px}.main-nav a{height:49px}.user-link{margin-left:auto}.welcome-row{padding:22px 0 16px;font-size:12px}.welcome-row p span{margin:3px 0 0;font-size:11px;display:block}.welcome-row>a{font-size:11px}.home-feature{border-radius:11px;grid-template-columns:1fr}.feature-copy{padding:23px 23px 20px}.feature-copy h1{max-width:100%;margin:12px 0;font-size:26px}.feature-copy .eyebrow{font-size:10px}.feature-subtitle{font-size:13px}.feature-meta{margin:13px 0 18px}.feature-copy .button{min-height:40px;padding:9px 15px;font-size:13px}.feature-image{aspect-ratio:16/8.5;margin:0 16px 16px}.feature-image img{object-fit:cover}.category-strip{gap:12px 20px;padding:18px 0}.category-strip .category-all{padding-right:18px}.category-strip small,.continue-icon{display:none}.continue-banner{align-items:center;gap:13px;margin-top:20px;padding:15px}.continue-banner .button{gap:4px;min-height:38px;padding:9px 11px;font-size:11px}.continue-banner .button svg{width:14px}.continue-text h3{font-size:13px}.continue-text .eyebrow{font-size:10px}.section{margin-top:28px}.section-heading{align-items:center;gap:10px;margin-bottom:20px}.section-heading h2{font-size:21px}.section-heading .eyebrow{font-size:8px}.section-heading p:not(.eyebrow){max-width:210px;font-size:12px}.section-heading .text-link{white-space:nowrap;gap:3px;font-size:11px}.section-heading .text-link svg{width:14px}.course-grid{grid-template-columns:minmax(0,1fr);gap:22px}.course-cover{aspect-ratio:16/8.5}.course-card-content{padding:18px 20px}.course-card h3{min-height:0;font-size:19px}.course-card-content .eyebrow{font-size:11px}.course-subtitle{font-size:13px}.course-meta{margin:15px 0;font-size:12px}.card-bottom{font-size:12px}.card-bottom strong{font-size:13px}.cover-level{font-size:11px}.page-heading{padding:28px 0 24px}.page-heading h1{font-size:28px}.page-heading>p:last-child{font-size:13px}.catalog-search{gap:10px;padding-left:12px}.catalog-search input{width:0;font-size:13px}.catalog-search .button{min-height:39px;padding:9px 11px;font-size:12px}.catalog-search svg{width:18px}.filter-panel{margin-top:22px;padding:8px 15px}.filter-line{flex-direction:column;gap:12px;padding:10px 0;font-size:12px}.filter-title{padding:0;font-size:11px}.filter-options{gap:4px}.filter-options button{min-height:36px;padding:8px 13px}.results-heading{margin:25px 0 19px}.results-heading p{flex-wrap:wrap;font-size:14px}.sort-control select{padding-right:0;font-size:12px}.site-footer{margin-top:48px}.footer-inner{flex-direction:column;align-items:flex-start;gap:20px;padding-top:25px;padding-bottom:25px}.footer-inner strong{font-size:19px}.footer-links{gap:26px;font-size:12px}.auth-card{padding:25px 23px}.auth-page{padding-bottom:10px}.auth-card h2{font-size:23px}.auth-card>p{font-size:12px}.my-heading{align-items:flex-start;padding:29px 0 26px}.my-heading h1{max-width:230px;margin:8px 0;font-size:23px}.my-heading .eyebrow{font-size:10px}.my-heading p:last-child{font-size:12px}.my-count{flex-direction:column;gap:3px;min-width:72px;padding:11px 13px}.my-count svg{display:none}.my-count strong{font-size:24px}.my-count span{font-size:10px}.my-toolbar{flex-wrap:wrap;gap:10px}.my-toolbar .line-tabs{min-height:49px}.my-toolbar .line-tabs button{padding:15px 0}.my-toolbar .compact-search{width:100%;margin:0 0 14px}.my-toolbar .compact-search input{flex:1;width:100%}.line-tabs{gap:24px}.line-tabs>button,.line-tabs>a{font-size:13px}.breadcrumbs{padding:21px 0;font-size:11px}.course-hero{grid-template-columns:1fr;gap:22px;padding-bottom:27px}.detail-cover{aspect-ratio:16/9}.course-info h1{margin:12px 0;font-size:25px}.detail-meta{gap:15px;margin-top:18px;font-size:12px}.detail-actions .button{min-height:44px;padding:11px 18px;font-size:14px}.detail-tabs{justify-content:space-between;gap:0;min-height:55px;padding:0 16px}.detail-tabs button{padding:18px 0;font-size:12px}.detail-section{padding:21px 16px}.detail-section h2{font-size:19px}.rich-text{font-size:14px}.chapter h3{gap:7px;padding:12px 11px;font-size:13px}.chapter h3 small{font-size:10px}.lesson-row{gap:8px;padding:13px 8px;font-size:12px}.lesson-duration{font-size:10px}.lesson-row.current{padding-left:5px}.course-aside{display:flex}.aside-note{padding:22px}.course-aside .aside-note dl{flex-wrap:wrap;gap:16px;padding-top:10px;display:flex}.aside-note dl>div{gap:9px;padding-top:4px}.quiz-entry{padding:19px}.comment-form>div{align-items:flex-start}.comment-form small{max-width:130px;font-size:10px}.comment-form .button{padding:8px 10px;font-size:11px}.comment-author time{font-size:10px}.comment-author{flex-wrap:wrap;gap:4px}.comment .avatar{width:32px;height:32px;font-size:13px}.comment{gap:10px}.comment p{font-size:13px}.attachment-row{flex-wrap:wrap;gap:10px}.attachment-row strong{font-size:13px}.attachment-row .button{padding:8px 10px;font-size:11px}.file-icon{width:34px;height:40px}.white-panel{padding:21px 18px}.white-panel h2{font-size:18px}.profile-sections{gap:20px}.activity-row{gap:8px}.activity-row strong{font-size:12px}.activity-row small,.activity-row time{font-size:10px}.activity-row svg{width:13px}.quiz-page{padding-top:22px}.quiz-notice{padding:17px}.quiz-notice p{font-size:13px}.quiz-notice span{font-size:11px}.question{padding:18px 15px 20px}.question legend{padding:0 5px;font-size:15px}.question-option{gap:9px;padding:12px 10px;font-size:13px;line-height:1.7}.question legend>span{margin-right:7px}.quiz-result{flex-wrap:wrap;gap:16px;padding:20px 17px}.quiz-result>svg{width:34px}.quiz-result h2{font-size:37px}.quiz-result p:last-child{font-size:11px}.quiz-result .button{width:100%}.quiz-submit{padding:15px;font-size:12px}.quiz-submit .button{padding:11px 14px;font-size:12px}.learning-shell{padding:0 12px 22px}.learning-topbar{gap:12px;min-height:62px}.learning-topbar .button{gap:5px;min-height:36px;padding:8px 10px;font-size:11px}.learning-topbar .back-link{gap:7px;max-width:calc(100% - 105px);font-size:12px}.learning-layout{gap:16px}.lesson-info-bar{flex-direction:column;align-items:flex-start;padding:20px 16px}.lesson-info-bar h1{font-size:18px}.lesson-actions{width:100%}.lesson-actions .button{min-height:40px;padding:9px 13px;font-size:12px}.learning-bottom{padding:0 16px}.learning-bottom .line-tabs{gap:20px;min-height:57px}.learning-bottom .line-tabs>button,.learning-bottom .line-tabs>a{padding:17px 0;font-size:12px}.learning-bottom .line-tabs>a{gap:5px}.learning-bottom .line-tabs>a svg{width:14px}.learning-panel{padding:17px 0}.article-stage{padding:28px 20px}.article-stage>h1{font-size:23px}.pdf-heading{flex-direction:column;align-items:flex-start;padding:13px;font-size:13px}.pdf-stage iframe{height:500px}.audio-stage{gap:12px;min-height:340px;padding:25px 16px}.audio-art{width:110px;height:110px}.audio-stage h2{font-size:18px}.audio-stage .eyebrow,.save-status{font-size:10px}.progress-label{font-size:12px}.state-panel{padding:40px 15px}.state-panel h3{font-size:18px}.state-panel p{font-size:13px}}@media (prefers-reduced-motion:reduce){*,:before,:after{scroll-behavior:auto!important;transition:none!important;animation:none!important}.course-card:hover{transform:none}}.account-controls{align-items:center;gap:8px;margin-left:auto;display:flex}.account-menu{position:relative}.account-menu summary{cursor:pointer;align-items:center;gap:8px;min-height:44px;font-size:13px;list-style:none;display:flex}.account-menu summary::-webkit-details-marker{display:none}.account-menu summary:focus-visible{outline-offset:3px;border-radius:7px;outline:3px solid #83a8f4}.account-name{text-overflow:ellipsis;white-space:nowrap;max-width:92px;overflow:hidden}.account-menu nav{z-index:30;border:1px solid var(--line);background:#fff;border-radius:10px;width:210px;padding:8px;position:absolute;top:50px;right:0;box-shadow:0 10px 30px #18233716}.account-menu nav a{border-radius:6px;padding:12px 14px;font-size:14px;display:block}.account-menu nav a:hover{background:var(--blue-soft);color:var(--brand)}.learner-context{border-bottom:1px solid var(--line);color:var(--muted);background:#fafcff;font-size:12px}.learner-context>.container{align-items:center;gap:20px;min-height:46px;display:flex}.learner-context label{color:var(--text);align-items:center;gap:8px;display:flex}.learner-context select{color:var(--brand);background:#fff;border:1px solid #d8e3f6;border-radius:5px;max-width:190px;padding:5px 8px;font-size:12px}.learner-context a{color:var(--brand);margin-left:auto}.header-inner{gap:28px}.header-search{width:205px}.main-nav{gap:25px}.course-price{align-items:baseline;gap:12px;margin-top:18px;display:flex}.course-price strong{color:var(--brand);font-size:27px}.course-price span{color:var(--muted);font-size:12px}.course-extra-links{flex-wrap:wrap;gap:16px;margin-top:18px;display:flex}.course-extra-links a{color:var(--brand);font-size:13px}.study-links{flex-wrap:wrap;gap:12px;padding-bottom:24px;display:flex}.study-links a{border:1px solid var(--line);color:var(--brand);background:#fafcff;border-radius:8px;padding:12px 18px;font-size:13px}.account-shortcuts{flex-wrap:wrap;gap:12px;margin-bottom:24px;display:flex}.account-shortcuts a{border:1px solid var(--line);color:var(--brand);border-radius:8px;align-items:center;padding:11px 15px;font-size:13px;display:inline-flex}.oauth-login{border-top:1px solid var(--line);margin-top:20px;padding-top:20px}.oauth-login p{color:var(--muted);margin-top:10px;font-size:12px}.auth-secondary-links{color:var(--brand);justify-content:space-between;margin-top:18px;font-size:12px;display:flex}.price-note{color:var(--muted);margin-top:10px;font-size:12px}.form-stack select{color:var(--text);background:#fff;border:1px solid #cfd7e3;border-radius:8px;padding:12px 14px}@media (width<=1240px){.header-search{display:none}.header-inner{gap:28px}.main-nav{gap:24px}}@media (width<=800px){.header-inner{gap:16px}.main-nav{gap:18px;font-size:13px}.account-name{display:none}.learner-context>.container{gap:12px}.learner-context>.container>span{display:none}}@media (width<=560px){.header-inner{gap:0}.main-nav{justify-content:space-between;gap:14px;font-size:13px}.account-controls{margin-left:auto}.learner-context>.container{gap:8px;min-height:49px}.learner-context label{gap:6px;font-size:11px}.learner-context select{max-width:137px;font-size:11px}.learner-context a{font-size:11px}.learner-context label>svg{display:none}.account-menu nav{top:45px}.course-price strong{font-size:25px}.study-links{gap:9px}.study-links a{padding:10px 12px;font-size:12px}.account-shortcuts{gap:9px}.account-shortcuts a{padding:10px 12px;font-size:12px}}
