:root{--paper:#f6f8f5;--white:#fff;--ink:#142e29;--muted:#6e7d77;--line:#dfebe4;--green:#176b5b;--green2:#e4f3ed;--blue:#3d77d3;--blue2:#eaf1ff;--orange:#f08b18;--orange2:#fff0da;--purple:#7d69c7;--purple2:#f0ecff;--red:#c45364;--red2:#fce8ec;--shadow:0 8px 24px rgba(24,67,54,.07)}*{box-sizing:border-box}html,body{margin:0;background:var(--paper);color:var(--ink);font-family:"Noto Sans SC","Microsoft YaHei",system-ui,sans-serif;line-height:1.55}button,input{font:inherit}button{cursor:pointer}.brand{display:flex;align-items:center;gap:9px;color:var(--ink)}.brand-mark{width:31px;height:31px;border:3px solid var(--green);display:grid;place-items:center;color:var(--green);font-size:25px;line-height:1}.brand b{display:block;font-size:20px;letter-spacing:.08em}.brand small{display:block;color:var(--muted);font-size:10px;font-weight:500}.primary{background:var(--green);color:#fff;border:0;border-radius:9px;padding:11px 20px;font-weight:800}.primary:disabled{opacity:.45}.wide{width:100%}.activate{min-height:100vh;display:grid;grid-template-columns:1.2fr .8fr;background:#fbfcfa}.activate-visual{position:relative;overflow:hidden;background:linear-gradient(140deg,#eef7f3,#dcece5 58%,#e6f1f5);min-height:100vh}.activate-visual img{position:absolute;width:100%;bottom:7%;left:0}.visual-copy{position:absolute;top:42px;left:8%;z-index:1}.visual-copy .brand b{font-size:27px}.visual-copy p{margin:120px 0 0 38px;color:var(--green);font-family:serif;font-size:24px;line-height:1.4}.visual-copy p b{font-size:30px}.activate-panel{background:#fff;padding:70px max(42px,8vw);display:flex;flex-direction:column;justify-content:center}.panel-brand{display:none}.course-pill{background:var(--green2);color:var(--green);border-radius:999px;padding:6px 12px;font-size:12px;font-weight:800;width:max-content;margin:48px 0 19px}.activate-panel h1{font-size:40px;line-height:1.25;letter-spacing:-.045em;margin:0 0 12px}.activate-panel>p{color:var(--muted);margin:0 0 24px;line-height:1.8}.activate-panel label{font-size:12px;font-weight:800;margin-bottom:6px}.activate-panel input{border:1px solid var(--line);border-radius:9px;padding:12px 13px;outline:0}.form-error{height:22px;color:var(--red);font-size:12px}.hint{display:block;text-align:center;color:#94a39c;margin-top:12px;line-height:1.8}.hint b{color:var(--green)}.quote{text-align:center;color:#7d8a83;font-family:serif;font-size:13px;margin-top:40px}.quote span{font-size:11px}.app-shell{min-height:100vh}.topbar{height:72px;background:#fff;border-bottom:1px solid var(--line);display:flex;align-items:center;padding:0 34px;position:sticky;top:0;z-index:10}.top-actions{display:flex;gap:10px;margin-left:auto}.top-actions button,.back{border:0;background:transparent;color:var(--muted);padding:8px 10px}.body-layout{display:flex;max-width:1440px;margin:auto}.sidebar{width:245px;min-height:calc(100vh - 72px);background:#fff;border-right:1px solid var(--line);padding:26px 18px;flex:0 0 245px}.side-label{font-size:11px;color:#9aa8a1;margin:0 10px 9px}.side-item,.side-chapter{border:0;background:transparent;width:100%;text-align:left;border-radius:9px;padding:10px 12px;color:var(--muted);margin-bottom:3px}.side-item{font-weight:700;display:flex;gap:10px;align-items:center}.side-item span{flex:1}.side-item em{font-size:11px;font-style:normal;color:var(--orange)}.side-item.active,.side-item:hover,.side-chapter.active,.side-chapter:hover{background:var(--green2);color:var(--green)}.side-chapter{font-size:13px}.side-chapter i{font-style:normal;margin-right:8px}.chapters-label{margin-top:28px}.content{max-width:1130px;flex:1;padding:35px 46px 80px;min-width:0}.page-head,.practice-head{display:flex;align-items:flex-end;justify-content:space-between;margin-bottom:20px}.crumb,.practice-head p{font-size:12px;color:#93a09a;margin:0 0 5px}.page-head h1,.practice-head h1{font-size:32px;margin:0;letter-spacing:-.04em}.page-head>div>p:last-child{color:var(--muted);margin:5px 0 0}.user-chip{font-size:13px;color:var(--muted)}.course-hero{height:190px;border-radius:18px;background:linear-gradient(100deg,#e4f2ed,#eef4ff);position:relative;overflow:hidden;padding:25px 30px;margin-bottom:14px}.hero-tag{font-size:11px;color:var(--green);font-weight:800}.course-hero h2{font-size:28px;margin:6px 0 4px}.course-hero p{color:var(--muted);font-size:13px;margin:0;max-width:310px}.course-hero img{position:absolute;width:57%;right:-2%;bottom:-35px}.continue{background:#fff;border:1px solid var(--line);border-radius:14px;padding:17px 20px;display:flex;align-items:center;justify-content:space-between;gap:15px;margin-bottom:25px}.label{font-size:11px;color:var(--green);font-weight:800}.continue h2{font-size:17px;margin:3px 0}.continue p{font-size:12px;color:var(--muted);margin:0 0 8px}.bar,.practice-progress{height:6px;border-radius:5px;background:#e7eee9;overflow:hidden}.bar{width:240px}.bar i,.practice-progress i{display:block;height:100%;background:var(--green);border-radius:5px}.continue small{display:block;color:var(--muted);font-size:11px;margin-top:4px}.continue .primary{white-space:nowrap}.section-line{display:flex;align-items:baseline;justify-content:space-between;margin:22px 0 10px}.section-line h2{font-size:18px;margin:0}.section-line span{color:var(--muted);font-size:11px}.map-grid{display:grid;grid-template-columns:repeat(5,1fr);gap:10px}.map-card{position:relative;min-height:132px;text-align:left;border:1px solid var(--line);background:#fff;border-radius:14px;padding:14px 13px;overflow:hidden;color:var(--ink)}.map-card.selected{border-color:#8fc6b2;background:#f2faf6}.map-card:hover{transform:translateY(-2px);box-shadow:var(--shadow)}.map-number{display:block;color:var(--muted);font-size:10px}.map-card strong{display:block;font-size:16px;margin-top:5px}.map-card em{position:absolute;right:8px;top:29px;font-style:normal;font-size:31px;opacity:.22}.map-card small{display:block;color:var(--muted);font-size:11px;line-height:1.45;margin-top:35px}.map-card>b{position:absolute;right:12px;bottom:11px;color:var(--green);font-size:20px;font-weight:400}.path-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:10px}.path{border-radius:14px;padding:14px 15px;min-height:85px}.path b{display:block;font-size:10px;opacity:.55}.path strong{display:block;margin:5px 0 1px;font-size:14px}.path small{font-size:11px;color:var(--muted)}.path.pre{background:var(--green2)}.path.key{background:var(--blue2)}.path.up{background:var(--orange2)}.path.ext{background:var(--purple2)}.lesson-cover{height:205px;background:linear-gradient(100deg,#e7f4ef,#edf4ff);border-radius:18px;position:relative;overflow:hidden;padding:24px 28px}.lesson-cover span{font-size:11px;color:var(--green);font-weight:800}.lesson-cover h1{font-size:30px;margin:7px 0}.lesson-cover p{color:var(--muted);margin:0}.lesson-cover img{position:absolute;width:48%;right:0;bottom:-30px}.stage-nav{display:grid;grid-template-columns:repeat(4,1fr);gap:6px;background:#fff;border:1px solid var(--line);border-radius:13px;padding:5px;margin:14px 0}.stage-nav button{border:0;background:#fff;border-radius:9px;padding:8px;color:var(--muted);text-align:left}.stage-nav button.active{background:var(--green);color:#fff}.stage-nav b{display:inline-grid;place-items:center;width:21px;height:21px;border-radius:50%;background:var(--green2);color:var(--green);font-size:11px;margin-right:5px}.stage-nav .active b{background:#fff}.stage-nav span{font-size:12px;font-weight:800}.stage-nav small{display:block;margin:3px 0 0 28px;font-size:10px;opacity:.72}.lesson-card,.quiz-card{background:#fff;border:1px solid var(--line);border-radius:15px;padding:20px;margin-bottom:12px}.lesson-card header{display:flex;gap:9px;align-items:center}.lesson-card header>span{display:grid;place-items:center;width:28px;height:28px;border-radius:9px;background:var(--orange2);color:var(--orange)}.lesson-card.core header>span{background:var(--blue2);color:var(--blue)}.lesson-card.extension header>span{background:var(--purple2);color:var(--purple)}.lesson-card header b{display:block}.lesson-card header small{display:block;font-size:11px;color:var(--muted)}.lesson-card h2{font-size:18px;margin:16px 0 8px}.lesson-card p{color:var(--muted);font-size:14px}.lesson-card.think{background:var(--orange2);border-color:#f6d8aa}.lesson-card.think h2{font-size:19px;max-width:620px}.lesson-card.think img{display:block;width:45%;max-height:75px;object-fit:contain;margin:12px auto -10px}.lesson-card ul{padding-left:20px}.lesson-card li{margin:8px 0;font-size:14px}.prompt,.formula{background:var(--blue2);padding:12px 14px;border-radius:10px;color:#315a9c;font-size:13px}.warning{background:var(--orange2);color:#8f5a15;border-radius:10px;padding:11px 13px;font-size:13px;margin-top:12px}.quiz-teaser{width:100%;border:0;border-radius:11px;background:var(--blue2);color:var(--blue);padding:13px;text-align:left;font-weight:800}.quiz-teaser span{float:right;font-weight:500;font-size:12px}.challenge{background:var(--purple2)}.hint-button{border:1px solid var(--purple);color:var(--purple);background:#fff;border-radius:9px;padding:8px 12px}.quiz-card{position:relative}.quiz-meta{display:flex;justify-content:space-between;align-items:center;color:var(--muted);font-size:12px}.quiz-meta span{background:var(--blue2);color:var(--blue);padding:4px 9px;border-radius:999px}.quiz-card h2{font-size:17px;margin:14px 0}.options{display:grid;gap:8px}.option{border:1px solid var(--line);background:#fff;border-radius:10px;text-align:left;padding:11px;color:var(--ink);display:flex;gap:10px;align-items:center}.option i{width:23px;height:23px;border-radius:50%;display:grid;place-items:center;background:#f1f5f2;color:var(--green);font-style:normal;font-weight:800;font-size:11px}.option.correct{border-color:var(--green);background:var(--green2)}.option.wrong{border-color:#e0a0aa;background:var(--red2)}.answer{border-radius:10px;margin-top:10px;padding:10px 12px;font-size:13px}.answer p{margin:3px 0 0}.answer.ok{background:var(--green2);color:var(--green)}.answer.bad{background:var(--orange2);color:#8f5a15}.submit{margin-top:12px;width:100%}.finish{width:100%;border:0;border-radius:10px;background:var(--green);color:#fff;padding:13px;font-weight:800}.practice-head b{color:var(--muted);font-size:13px}.practice-progress{margin:-8px 0 15px}.mistake-tabs{display:flex;gap:7px;margin-bottom:14px}.mistake-tabs button{border:0;background:#fff;border-radius:999px;padding:7px 12px;color:var(--muted);font-size:12px}.mistake-tabs button.active{background:var(--blue2);color:var(--blue);font-weight:800}.review-banner{background:var(--orange2);border-radius:14px;padding:16px;margin-bottom:13px}.review-banner b,.review-banner small{display:block}.review-banner small{color:var(--muted);font-size:12px;margin:3px 0 12px}.orange{background:var(--orange);color:#fff;border:0;border-radius:8px;padding:8px 15px;font-weight:800}.mistake-row{background:#fff;border:1px solid var(--line);border-radius:12px;padding:14px;margin-bottom:9px}.mistake-row>b{font-size:11px;color:var(--muted)}.mistake-row p{margin:5px 0;font-size:14px}.mistake-row span{color:var(--red);font-size:11px}.mistake-row button{float:right;background:var(--blue2);color:var(--blue);border:0;border-radius:7px;padding:5px 9px;font-size:11px}.empty-state{text-align:center;color:var(--muted);padding:55px}.mobile-nav{display:none}@media(max-width:900px){.activate{display:block}.activate-visual{min-height:245px}.visual-copy{top:20px;left:22px}.visual-copy p{display:none}.activate-visual img{bottom:-8px}.activate-panel{margin:-20px 14px 0;position:relative;border-radius:18px;padding:24px 20px 28px;box-shadow:var(--shadow)}.panel-brand{display:block;margin-bottom:14px}.panel-brand .brand b{font-size:23px}.activate-panel .course-pill{margin:0 0 16px}.activate-panel h1{font-size:29px}.activate-panel>p{font-size:13px}.quote{margin-top:25px}.topbar{height:58px;padding:0 16px}.topbar .brand small{display:none}.topbar .brand b{font-size:18px}.top-actions button{font-size:12px;padding:5px}.top-actions button:last-child{display:none}.sidebar{display:none}.body-layout{display:block}.content{padding:20px 14px 84px}.page-head h1,.practice-head h1{font-size:25px}.page-head{align-items:flex-start}.user-chip{font-size:11px}.course-hero{height:205px;padding:20px 17px}.course-hero h2{font-size:24px}.course-hero img{width:90%;right:-12%;bottom:-24px}.continue{display:block;padding:16px}.continue .primary{width:100%;margin-top:13px}.bar{width:100%}.section-line{margin-top:22px}.section-line span{font-size:10px}.map-grid{grid-template-columns:1fr;gap:8px}.map-card{min-height:84px;padding:12px 13px}.map-card em{top:17px;right:39px}.map-card small{margin-top:6px;max-width:75%;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.map-card>b{right:14px;top:33px}.path-grid{grid-template-columns:1fr 1fr}.path{min-height:77px;padding:12px}.lesson-cover{height:185px;padding:19px 18px}.lesson-cover h1{font-size:25px}.lesson-cover img{width:90%;right:-15%;bottom:-18px;opacity:.7}.stage-nav{position:sticky;top:58px;z-index:5;margin:10px -1px 13px}.stage-nav button{padding:7px 2px;text-align:center}.stage-nav b{display:block;margin:0 auto 4px}.stage-nav span{font-size:11px;display:block}.stage-nav small{display:none}.lesson-card,.quiz-card{padding:16px}.lesson-card.think img{width:85%}.practice-head{align-items:flex-end}.mobile-nav{display:flex;position:fixed;z-index:20;bottom:0;left:0;right:0;height:64px;background:#fff;border-top:1px solid var(--line);justify-content:space-around;padding-bottom:env(safe-area-inset-bottom)}.mobile-nav button{border:0;background:transparent;color:var(--muted);font-size:10px;padding:7px 12px}.mobile-nav button span{display:block;font-size:21px;line-height:1.1;margin-bottom:3px}.mobile-nav button.active{color:var(--green);font-weight:800}}
:root{--gold:#f2a445}
.brand-mark{width:35px;height:31px;border:0;font-size:0}.brand-mark svg{width:35px;height:31px}
.masthead{height:104px;position:relative;overflow:hidden;background:#f4f7f3;margin:-35px -46px 0;padding:17px 46px;border-bottom:1px solid var(--line)}.masthead img{position:absolute;width:63%;right:0;top:-66px;opacity:.78}.mast-copy{position:relative;z-index:1;margin-left:31%;color:var(--green);font-family:serif;font-size:20px;line-height:1.25}.mast-copy span,.mast-copy b{display:block}.mast-copy b{font-size:24px}.feature-strip{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;margin:14px 0 28px}.feature-strip>div{background:#fff;border:1px solid var(--line);border-radius:10px;padding:10px 12px;display:grid;grid-template-columns:28px 1fr;column-gap:8px}.feature-strip b{grid-row:span 2;width:28px;height:28px;border-radius:50%;display:grid;place-items:center;background:var(--green2);color:var(--green);font-size:17px}.feature-strip strong{font-size:12px}.feature-strip small{font-size:10px;color:var(--muted)}.continue>img{width:102px;height:72px;object-fit:cover;border-radius:9px;order:0}.continue>div{flex:1}.continue{justify-content:flex-start}.continue .primary{margin-left:auto}.map-card em{font-family:Georgia,serif;font-weight:400;color:var(--green)}@media(max-width:900px){.masthead{margin:-20px -14px 14px;height:112px;padding:16px 18px}.masthead img{width:100%;right:-31%;top:-30px}.mast-copy{margin-left:0;font-size:15px}.mast-copy b{font-size:18px}.feature-strip{grid-template-columns:repeat(2,1fr);gap:7px;margin:10px 0 20px}.feature-strip>div{padding:8px}.feature-strip strong{font-size:11px}.feature-strip small{font-size:9px}.continue>img{width:100%;height:90px;order:0;margin-bottom:10px}.continue>div{width:100%}.continue .primary{margin-left:0}.continue{display:flex;flex-wrap:wrap}.continue .primary{width:100%}}
.masthead{display:block}
@media(max-width:900px){.masthead,.feature-strip{display:none}.continue{display:grid;grid-template-columns:86px 1fr;gap:12px;align-items:center}.continue>img{width:86px;height:74px;margin:0;grid-row:span 2}.continue>div{width:auto}.continue .primary{grid-column:1/-1;width:100%;margin:4px 0 0}.continue h2{font-size:15px}.continue p{font-size:11px}.continue small{font-size:10px}.continue .bar{width:100%}}
.topic-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:9px}.topic{background:#f7faf8;border:1px solid var(--line);border-radius:10px;padding:12px}.topic b{font-size:14px;color:var(--green)}.topic p{font-size:12px;margin:5px 0 0;color:var(--muted)}.solution{padding-left:21px}.solution li{margin:7px 0;font-size:13px}.warning b{display:block;margin-bottom:5px}.warning ul{margin:0;padding-left:18px}.warning li{font-size:12px;margin:4px 0}.pre-task{background:#f6f8ff}.pre-task ol{padding-left:20px;color:var(--muted);font-size:13px}.explore-task{background:var(--purple2);border-radius:10px;margin-top:12px;padding:12px;color:#6453a9}.explore-task p{margin:4px 0 0;color:#6453a9;font-size:13px}@media(max-width:900px){.topic-grid{grid-template-columns:1fr}.topic{padding:10px}.topic p{font-size:11px}}
/* final acceptance layout overrides */
:root{--navy:#183b56;--teal:#176b5b;--paper:#fbfaf7;--blue:#e7f1f7;--orange:#f5a65b;--green:#dcefe5}
body{background:var(--paper);color:var(--navy);font-family:"Noto Sans SC","Microsoft YaHei",sans-serif}
.activate{min-height:100vh;display:grid;place-items:center;background:#fbfaf7;padding:32px}.activate-visual{display:none}.activate-panel{width:min(460px,100%);padding:42px 44px;background:#fff;border:1px solid #e4eceb;border-radius:24px;box-shadow:0 18px 50px #183b5614}.panel-brand{margin-bottom:24px}.activate-panel h1{font-size:32px;line-height:1.3;margin:18px 0 10px}.activate-panel>p{color:#61737f;line-height:1.8}.quote{display:none}.app-shell{max-width:1240px;margin:auto}.masthead,.feature-strip,.course-hero{display:none}.content{padding:34px 42px 80px}.page-head{margin:0 0 22px}.page-head h1{font-size:32px;margin:8px 0}.continue{display:grid;grid-template-columns:180px 1fr auto;gap:24px;align-items:center;background:#fff;border-radius:20px;padding:18px;border:1px solid #e1ecec;box-shadow:0 8px 24px #183b560c}.continue>img{width:180px;height:120px;object-fit:cover;border-radius:14px;background:#e5f0f2}.continue h2{margin:7px 0}.map-grid{display:grid;grid-template-columns:repeat(5,1fr);gap:12px}.map-card{min-height:170px;background:#fff;border:1px solid #e4eceb;border-radius:16px;padding:18px;text-align:left;position:relative}.map-card em{display:block;font-size:42px;color:var(--teal);font-style:normal;margin:16px 0}.map-card small{display:block;color:#72818a;line-height:1.5}.path-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:14px}.path{padding:20px;border-radius:16px;min-height:100px}.lesson-cover{background:#e7f1f7;border-radius:20px;padding:26px 32px;margin-bottom:20px}.lesson-cover img{display:none}.stage-nav{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;margin-bottom:18px}.stage-nav button{background:#fff;border:1px solid #e3eaea;border-radius:14px;padding:14px;text-align:left}.lesson-card{background:#fff;border-radius:18px;border:1px solid #e4eceb;padding:28px;margin-bottom:16px}.topic-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:14px}.topic{background:#f4f8f8;padding:16px;border-radius:12px}.quiz-card{background:#fff;border:1px solid #e2ecec;border-radius:18px;padding:26px}.mobile-nav{display:none}
@media(max-width:700px){.activate{padding:18px}.activate-panel{padding:30px 24px}.activate-panel h1{font-size:27px}.content{padding:20px 16px 84px}.topbar{padding:14px 16px}.top-actions{display:none}.page-head h1{font-size:26px}.continue{grid-template-columns:92px 1fr;gap:14px;padding:12px}.continue>img{width:92px;height:92px}.continue .primary{grid-column:1/-1;width:100%}.continue p{font-size:13px}.map-grid{grid-template-columns:1fr;gap:8px}.map-card{min-height:0;height:72px;padding:12px 14px;display:grid;grid-template-columns:52px 1fr auto;align-items:center}.map-card em{font-size:28px;margin:0}.map-card small{display:none}.path-grid{grid-template-columns:repeat(2,1fr)}.stage-nav{grid-template-columns:repeat(4,1fr);gap:5px}.stage-nav button{padding:9px 4px;text-align:center}.stage-nav small{display:none}.stage-nav span{font-size:12px;display:block}.lesson-cover{padding:20px}.lesson-cover h1{font-size:26px}.topic-grid{grid-template-columns:1fr}.lesson-card{padding:20px}.mobile-nav{display:flex;position:fixed;bottom:0;left:0;right:0;background:#fff;border-top:1px solid #e1e8e8;z-index:5;justify-content:space-around;padding:8px}.mobile-nav button{background:none;border:0;color:#70808a;font-size:12px}.mobile-nav button.active{color:var(--teal);font-weight:700}.practice-head{display:flex;align-items:center;gap:12px}.practice-head h1{font-size:24px}}
.textbook-points{margin-top:22px;padding:18px 20px;background:#eef6f6;border-radius:14px}.textbook-points h3{margin:0 0 10px;font-size:17px}.textbook-points li{margin:8px 0;line-height:1.7}.method-box{margin-top:14px;padding:16px 18px;background:#fff4e8;border-left:4px solid #f2a35b;border-radius:10px}.method-box p{margin:8px 0 0;line-height:1.7;color:#536873}
.practice-head small{display:block;color:#71818b;margin-top:3px}.quiz-meta span{background:#edf6f5;color:#176b5b;border-radius:99px;padding:5px 9px;font-size:12px}

/* Activation screen follows the approved centered brand and illustration. */
.activate{background:#fff;padding:24px;min-height:100dvh}
.activate-panel{width:360px;max-width:100%;padding:32px 20px;border:0;box-shadow:none;border-radius:0}
.activate-panel .panel-brand{display:block;margin:0 0 24px}
.activate-panel .brand{display:flex;flex-direction:column;align-items:center;text-align:center;gap:10px}
.activate-panel .brand-mark{color:#17665d;background:transparent;width:52px;height:48px}
.activate-panel .brand-mark svg{width:52px;height:48px}
.activate-panel .brand b{font-size:30px;color:#102f49}
.activate-panel .brand small{font-size:13px;color:#486176;margin-top:8px}
.activation-art{display:block;width:100%;height:170px;object-fit:contain;margin:22px 0}
.activate-panel .activation-course{font-size:12px;text-align:center;color:#536b7a;margin-bottom:24px}
.activate-panel label{color:#29485c}
.activate-panel input{width:100%;box-sizing:border-box;border:1px solid #d7e2e8;border-radius:7px;min-height:46px;background:#fff}
.activate-panel .primary{background:#17665d;color:white;border:0;border-radius:7px;min-height:46px}
.activate-panel .primary:disabled{opacity:.6}
.activate-panel .hint{color:#536b7a;line-height:1.8}
.activate-panel .form-error{color:#ad3434;min-height:20px}
@media(max-width:700px){.activate{padding:20px 16px}.activate-panel{padding:16px 8px;width:100%;max-width:340px}.activation-art{height:150px}}
.activate{grid-template-columns:1fr;grid-template-rows:auto;justify-items:center;align-items:center;gap:0}
.activate-panel{grid-column:1;grid-row:1;justify-self:center}

.screen-lesson .lesson-cover{min-height:0;height:auto;padding:14px 18px;margin:8px 0 16px;background:#f1f7fa}
.screen-lesson .lesson-cover h1{margin:8px 0;font-size:26px}
.screen-lesson .lesson-cover p{margin:6px 0;font-size:14px}
.screen-lesson .stage-nav{padding:0;background:transparent;border:0;box-shadow:none}
.screen-lesson .stage-nav button{background:transparent;border:0;text-align:center;color:#50677a;padding:8px 4px}
.screen-lesson .stage-nav button b{display:block;border-radius:50%;width:26px;height:26px;line-height:26px;padding:0;margin:0 auto 6px;background:#e8eff5;color:#29485c}
.screen-lesson .stage-nav button.active b{background:#17665d;color:white}
.screen-lesson .stage-nav button.active span{color:#17665d}
.screen-lesson .think{background:#fff3e5;border-color:#ffe1b7}
.screen-lesson .core{background:#edf5ff;border-color:#dcecff}
.screen-lesson .example{background:#edf8f1;border-color:#dfefe5}
.screen-lesson .think h2{font-size:18px;line-height:1.65;margin:12px 0}
.screen-lesson .think img{width:100%;height:110px;object-fit:contain;margin:0;float:none}
.motion-diagram{margin:10px 0 0;background:#fff;border-radius:6px}
.motion-diagram svg{display:block;width:100%;height:auto}
@media(max-width:700px){
 .screen-lesson .topbar{display:none}
 .screen-lesson .lesson-cover{padding:8px 0;background:transparent;margin-bottom:8px}
 .screen-lesson .lesson-cover>div>span{display:none}
 .screen-lesson .lesson-cover h1{font-size:21px;margin:4px 0}
 .screen-lesson .stage-nav{position:static;gap:0;margin-bottom:12px}
 .screen-lesson .stage-nav button{border-radius:0}
 .screen-lesson .stage-nav button span{font-size:12px}
 .screen-lesson .lesson-card{padding:14px;margin-bottom:12px}
 .screen-lesson .lesson-card h2{font-size:17px;margin:10px 0}
 .screen-lesson .lesson-card p{font-size:14px;line-height:1.8;margin:8px 0}
 .screen-lesson .mobile-nav{display:none}
 .screen-lesson .content{padding-bottom:100px}
 .screen-lesson .finish{position:fixed;left:14px;right:14px;bottom:calc(14px + env(safe-area-inset-bottom));width:calc(100% - 28px);margin:0;z-index:4;min-height:46px;box-shadow:0 0 0 12px #fbfaf7}
}

/* Semantic action color must not share the pale example-card surface color. */
:root{--green:#17665d;--blue:#2469a8;--orange:#bb540a}
.mistake-tabs{display:flex;flex-wrap:wrap;gap:8px}
.mistake-tabs button{flex:none;white-space:nowrap;padding:9px 12px;min-height:40px;border-radius:7px;color:#405c70;background:#fff}
.mistake-tabs button.active{background:#e8f2fc;color:#175c94}
.mistake-row>button{position:static;display:block;width:100%;margin-top:12px;color:#175c94;background:#e8f2fc;min-height:40px;padding:8px 16px}
.review-banner .orange{background:#c65b0b;color:#fff}
.chapter-icon{display:block;width:48px;height:48px}
.side-chapter .chapter-icon{width:22px;height:22px}
@media(max-width:700px){.map-card .chapter-icon{width:30px;height:30px}.map-card em{grid-column:1;grid-row:1}.map-card .map-number{display:none}.map-card strong{grid-column:2;grid-row:1}.map-card strong::before{content:'第' attr(data-number) '章 '}}
.primary,.finish{background:#17665d;color:#fff}
.brand-mark,.continue .label,.map-card em{color:#17665d}
.option i{color:#29485c;background:#fff;border:1px solid #9db4c3}
.option.selected{border-color:#17665d;background:#edf7f2}
.primary:disabled{background:#e1e8e7;color:#526864;opacity:1}
.lesson-card li{line-height:1.85;margin:10px 0}
.lesson-card summary{cursor:pointer;padding:8px 0;line-height:1.6}
.lesson-card table{border-collapse:collapse;font-size:14px;width:100%}
.lesson-card th,.lesson-card td{border:1px solid #dce5eb;padding:10px;text-align:left}
@media(max-width:700px){
 .content{padding:16px 14px 84px}
 .page-head{margin-bottom:14px}.page-head h1{font-size:23px;margin:4px 0}
 .page-head .crumb,.page-head .user-chip{display:none}
 .page-head p{font-size:13px;margin:6px 0}
 .continue{grid-template-columns:86px 1fr;gap:8px 12px;padding:12px;box-shadow:none;border-radius:10px}
 .continue>img{grid-row:1 / 3;width:86px;height:104px;object-fit:cover}
 .continue h2{font-size:16px;margin:4px 0}
 .continue p{font-size:12px;line-height:1.5;margin:4px 0}
 .continue .primary{grid-column:2;min-height:34px;padding:6px 10px;font-size:13px}
 .continue small{font-size:11px}
 .section-line{margin:20px 0 10px}.section-line h2{font-size:17px}.section-line>span{display:none}
 .map-grid{gap:0;border:1px solid #e1e8eb;border-radius:10px;overflow:hidden;background:#fff}
 .map-card{height:52px;border:0;border-bottom:1px solid #eef2f3;border-radius:0;box-shadow:none;padding:8px 14px;grid-template-columns:42px 1fr 30px}
 .map-card strong{font-size:15px}.map-card em{font-size:23px}.map-card>b{display:none}
 .path-grid{gap:8px}.path{min-height:68px;padding:12px}.path small{display:none}
 .quiz-card{padding:18px;border-radius:10px;box-shadow:none}
 .practice-head{gap:10px}.practice-head h1{font-size:21px}.practice-head>div{flex:1}
 .option{min-height:50px;padding:12px}.quiz-card h2{font-size:17px}
 .lesson-cover{padding:16px;border-radius:10px}.lesson-card{border-radius:10px;padding:18px;box-shadow:none}
}
.map-card em{position:static;opacity:1;transform:none;align-self:center;justify-self:start}
.side-chapter{display:flex;align-items:center;gap:10px}
.side-chapter i{display:block;flex:none}
.screen-practice .sidebar,.screen-mistakes .sidebar{display:none}
.screen-practice .body-layout,.screen-mistakes .body-layout{display:block}
.screen-practice .content,.screen-mistakes .content{max-width:760px;margin:0 auto}
.screen-practice .practice-head,.screen-mistakes .practice-head{display:flex;align-items:center;gap:20px;text-align:left}
.screen-practice .practice-head>div,.screen-mistakes .practice-head>div{flex:1}
@media(min-width:701px){
 .continue{grid-template-columns:180px 1fr;gap:8px 24px}
 .continue>img{grid-row:1 / 3;height:150px}
 .continue .primary{grid-column:2;justify-self:start;min-width:180px}
 .map-card{box-shadow:none}
 .screen-home .page-head{padding:10px 0 20px;border-bottom:1px solid #e4edf0}
}
@media(max-width:700px){.map-card em{margin:0;grid-column:1;grid-row:1}.map-card .chapter-icon{opacity:1}}
/* Confirmed board: focused reading column and compact course map. */
.screen-lesson .sidebar{display:none}
.screen-lesson .body-layout{display:block}
.screen-lesson .content{max-width:760px;margin:auto}
.screen-lesson .lesson-cover{background:transparent;padding:0;margin:8px 0 12px;border-radius:0}
.screen-lesson .stage-nav small{display:none}
.screen-lesson .lesson-card{padding:18px;border-radius:9px;margin-bottom:12px}
.screen-lesson .lesson-card header{margin-bottom:8px}
.screen-lesson .lesson-card h2{font-size:18px;margin:8px 0}
.screen-lesson .lesson-card p{color:#365168;line-height:1.8;margin:8px 0}
.screen-lesson .motion-diagram{max-width:420px;margin:12px auto 0}
.screen-lesson .think img{height:126px;max-width:360px;margin:0 auto}
.screen-home .map-card{border-radius:8px}
@media(max-width:700px){
 .screen-home .topbar{display:none}
 .screen-home .page-head{padding:12px 0 10px;margin-bottom:10px}
 .screen-home .continue{border-radius:8px}
 .screen-home .map-card>b{display:block;color:#7e9cac;font-weight:400}
 .screen-lesson .content{padding-top:14px}
 .screen-lesson .lesson-card{padding:12px}
 .screen-lesson .lesson-card h2{font-size:16px}
 .screen-lesson .lesson-cover h1{font-size:20px}
 .screen-lesson .think img{height:100px}
 .screen-lesson .stage-nav button{min-height:54px}
}
@media(min-width:701px){
 .screen-home .continue .primary{margin-left:0;width:240px;justify-self:start}
 .screen-home .continue{box-shadow:none;border-radius:9px}
 .screen-home .map-card{min-height:190px}
}
@media(max-width:700px){
 .screen-home .map-card{border-radius:0}
 .screen-home .map-card>b{position:static;grid-column:3;grid-row:1;align-self:center;justify-self:end;transform:none}
}

/* Subject bookshelf home */
.screen-home .content{background:#fff;padding-top:30px}
.shelf-intro{display:flex;align-items:end;justify-content:space-between;margin-bottom:18px}
.shelf-intro h1{font-family:"SimSun","Songti SC",serif;font-size:32px;letter-spacing:0;margin:0 0 6px}
.shelf-intro p:last-child{color:#71817a;margin:0}
.shelf-intro input{width:250px;border:0;border-bottom:1px solid #bccbc3;padding:9px 4px;background:transparent;outline:0;color:var(--ink)}
.shelf-toolbar{display:flex;gap:24px;align-items:center;border-bottom:1px solid #e3eae5;margin-bottom:24px}
.shelf-toolbar button{border:0;background:transparent;color:#7a8981;padding:10px 0;font-size:13px}
.shelf-toolbar button.active{color:#17665d;border-bottom:2px solid #17665d;font-weight:800}
.shelf-toolbar span{margin-left:auto;color:#66776f;font-size:12px;padding-bottom:10px}
.subject-shelf{display:grid;grid-template-columns:repeat(5,1fr);gap:18px}
.subject-book{min-width:0;position:relative}
.book-cover{height:210px;padding:22px 18px;position:relative;overflow:hidden;border-radius:3px 7px 7px 3px;border:1px solid #64746c44;box-shadow:2px 3px 0 #e5e7df,4px 5px 0 #ccd0c8,7px 11px 16px #263b3224;background-image:repeating-linear-gradient(0deg,#fff3 0,#fff3 1px,transparent 1px,transparent 3px),repeating-linear-gradient(90deg,#243c3810 0,#243c3810 1px,transparent 1px,transparent 3px)}
.book-cover:before{content:"";position:absolute;inset:0 0 0 9px;border-left:1px solid #ffffff99;box-shadow:-1px 0 #31483b33}
.book-cover h2{position:relative;z-index:1;display:table;margin:7px 0;padding:7px 12px;background:#fffdf5;color:#334c42;font:28px/1.2 "SimSun",serif;border:1px solid #72807444;box-shadow:0 2px 4px #31483b25;transform:rotate(-2deg)}
.subject-book:nth-child(even) .book-cover h2{transform:rotate(1deg)}
.book-cover small,.book-cover b,.book-cover em{position:absolute;z-index:1}
.book-cover small{top:76px;left:18px;color:#365c4f;font-size:10px}
.book-cover b{right:16px;bottom:47px;color:#3f6e60;font:italic 34px Georgia;opacity:.65;transform:rotate(-7deg)}
.book-cover em{left:18px;bottom:13px;color:#456156;font-size:9px;font-style:normal}
.subject-0{background-color:#dfe8dc}.subject-1{background-color:#dce7ef}.subject-2{background-color:#eddfdc}.subject-3{background-color:#cfe0d8}.subject-4{background-color:#e7e1ec}.subject-5{background-color:#e8dfcf}.subject-6{background-color:#dce8d8}.subject-7{background-color:#e4dce8}
.subject-book h3{font-size:14px;margin:13px 0 2px}.subject-book p{font-size:11px;color:#7c8983;margin:0}.subject-book.activated p{color:#17665d}.book-link{border:0;background:transparent;color:#17665d;padding:4px 0;font-size:12px;text-decoration:underline;text-underline-offset:3px}
.activated:after{content:"已激活";position:absolute;right:8px;top:8px;background:#17665d;color:#fff;padding:3px 7px;border-radius:2px;font-size:10px}
.continue-shelf{display:grid;grid-template-columns:1fr 1.2fr auto;align-items:center;gap:24px;margin-top:32px;padding:18px 24px;background:#eff5f1;border-radius:6px}
.continue-shelf h2{font-size:17px;margin:0 0 2px}.continue-shelf p{font-size:12px;margin:0;color:#6d8274}
.continue-lesson{display:flex;align-items:center;gap:12px}.continue-lesson img{width:80px;height:58px;object-fit:cover;border-radius:4px}.continue-lesson b,.continue-lesson small{display:block}.continue-lesson small{font-size:11px;color:#6d8274;margin-top:3px}
.shelf-footer{display:flex;justify-content:space-between;border-top:1px solid #e3eae5;margin-top:24px;padding-top:16px;font-size:12px;color:#6d8178}.shelf-footer button{border:0;background:transparent;color:#17665d}
@media(max-width:700px){
 .screen-home .content{padding:20px 14px 82px}.shelf-intro{display:block;margin-bottom:12px}.shelf-intro h1{font-size:26px}.shelf-intro p:last-child{font-size:12px}.shelf-intro input{width:100%;margin-top:12px;padding:7px 3px;font-size:12px}
 .shelf-toolbar{gap:18px;margin-bottom:16px}.shelf-toolbar button{font-size:12px}.shelf-toolbar span{font-size:11px}
 .subject-shelf{grid-template-columns:repeat(2,minmax(0,1fr));gap:16px 12px}.book-cover{height:146px;padding:13px 14px}.book-cover h2{font-size:23px;padding:5px 9px;margin:4px 0}.book-cover small{top:61px;left:14px;font-size:8px}.book-cover b{right:11px;bottom:30px;font-size:25px}.book-cover em{left:14px;bottom:9px;font-size:7px}.subject-book h3{font-size:13px;margin:8px 0 2px}.subject-book p{font-size:10px}.activated:after{right:6px;top:6px;font-size:9px;padding:2px 5px}.book-link{font-size:11px;padding:2px 0}
 .continue-shelf{grid-template-columns:1fr;gap:12px;margin-top:22px;padding:15px}.continue-shelf .primary{width:100%}.continue-lesson img{width:68px;height:50px}.shelf-footer{display:block;font-size:11px;margin-top:18px}.shelf-footer button{display:block;margin-top:8px;padding:0}
}

/* Learning-space home: a shared subject-neutral entry point with a deliberate desktop layout. */
.screen-home .content{padding-top:28px}
.home-welcome{display:grid;grid-template-columns:minmax(0,1.15fr) minmax(260px,.85fr);min-height:250px;align-items:stretch;overflow:hidden;background:#eaf4f1;border:1px solid #d9e9e5;border-radius:18px;margin-bottom:16px}
.home-welcome>div:first-child{padding:30px 32px}
.home-welcome .crumb{margin:0 0 14px;color:#628078;font-size:12px}
.home-welcome h1{margin:0;font-size:38px;line-height:1.18;letter-spacing:-.04em;color:#183b56}
.home-welcome p:not(.crumb){max-width:34em;margin:10px 0 20px;color:#506b73;font-size:15px}
.home-actions{display:flex;align-items:center;gap:14px}
.home-actions .primary{min-height:42px}
.quiet-action{border:0;background:transparent;color:#17665d;font-weight:700;padding:10px 0}
.welcome-figure{position:relative;min-height:250px;overflow:hidden;background:#dcece7}
.welcome-figure img{position:absolute;width:135%;max-width:none;right:-19%;bottom:-29%;opacity:.84}
.welcome-figure span{position:absolute;left:22px;bottom:18px;color:#17665d;font-size:12px;font-weight:800;background:#ffffffc9;border-radius:999px;padding:7px 11px}
.home-summary{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin:0 0 28px}
.home-summary div{display:flex;align-items:baseline;gap:9px;padding:14px 16px;background:#fff;border:1px solid #e1ebed;border-radius:12px}
.home-summary strong{font-size:25px;color:#17665d;letter-spacing:-.04em}
.home-summary span{color:#627782;font-size:12px}
.home-section-head{margin:0 0 13px!important;padding:0!important;border:0!important;align-items:flex-end}
.home-section-head h2{margin:0;font-size:22px;letter-spacing:-.03em}
.home-section-head p:last-child{margin:4px 0 0!important;color:#71818b!important;font-size:12px}
.course-shelf{margin-bottom:16px}
.course-card{display:grid;grid-template-columns:150px minmax(0,1fr) auto;align-items:center;gap:20px;padding:14px;background:#fff;border:1px solid #e1ebed;border-radius:15px}
.course-card-art{height:126px;overflow:hidden;border-radius:10px;background:#e6f0f0}
.course-card-art img{width:100%;height:100%;object-fit:cover}
.course-card-copy h2{margin:5px 0;font-size:22px;letter-spacing:-.03em}
.course-card-copy p{margin:0;color:#627782;font-size:13px}
.course-card-meta{display:flex;gap:16px;margin-top:13px;color:#17665d;font-size:11px;font-weight:700}
.course-card>.primary{white-space:nowrap;margin-right:8px}
@media(max-width:700px){
 .screen-home .content{padding-top:12px}
 .home-welcome{display:block;min-height:0;margin-bottom:10px;border-radius:12px}
 .home-welcome>div:first-child{padding:18px 16px 16px}
 .home-welcome h1{font-size:27px}
 .home-welcome p:not(.crumb){font-size:13px;margin:7px 0 14px}
 .home-actions{gap:12px}
 .home-actions .primary{min-height:38px;padding:8px 13px}
 .quiet-action{font-size:12px}
 .welcome-figure{height:92px;min-height:0}
 .welcome-figure img{width:105%;right:-7%;bottom:-35%}
 .welcome-figure span{left:12px;bottom:10px;font-size:10px;padding:5px 8px}
 .home-summary{gap:6px;margin-bottom:18px}
 .home-summary div{display:block;padding:9px 10px;border-radius:9px}
 .home-summary strong{display:block;font-size:20px}
 .home-summary span{font-size:10px}
 .home-section-head h2{font-size:18px}
 .home-section-head p:last-child{font-size:11px!important}
 .course-card{grid-template-columns:74px minmax(0,1fr);gap:10px;padding:10px;border-radius:10px}
 .course-card-art{height:92px;grid-row:span 2}
 .course-card-copy h2{font-size:16px;margin:2px 0}
 .course-card-copy p{font-size:11px;line-height:1.5}
 .course-card-meta{gap:8px;margin-top:5px;font-size:9px}
 .course-card>.primary{grid-column:2;width:100%;margin:0;min-height:34px;padding:6px 10px;font-size:12px}
}
/* Approved navigation release: global library, courses, training and review. */
.library-shell .body-layout{display:block;max-width:1280px}
.library-shell .content{width:100%;max-width:none;padding:36px 48px 56px;background:transparent}
.library-shell .topbar{height:88px;padding:0 max(24px,calc((100vw - 1184px)/2));gap:44px;background:#fff;position:relative}
.library-shell .desktop-links{display:flex;gap:24px;margin-left:0;height:100%}
.library-shell .desktop-links button{display:flex;align-items:center;gap:8px;background:none;border:0;border-bottom:3px solid transparent;border-radius:0;padding:0 3px;font-size:14px;color:#556c60;white-space:nowrap}
.library-shell .desktop-links .active{border-color:#285e51;color:#285e51;font-weight:700}
.desktop-links svg,.mobile-nav svg{width:21px;height:21px;fill:none;stroke:currentColor;stroke-width:1.5;flex:none}
.library-shell .top-actions button{font-size:12px;white-space:nowrap}
.library-heading{margin:0 0 24px}.library-heading h1{font:700 34px/1.4 'SimSun','Songti SC',serif;margin:0 0 8px;color:#29433a}.library-heading p{margin:0;color:#596a60;font-size:14px}
.library-resume{display:flex;align-items:center;justify-content:space-between;gap:20px;padding:20px 25px;background:#f3f6ef;border-radius:6px;margin-bottom:26px}.library-resume h2{font-size:18px;margin:4px 0}.library-resume small,.library-resume p{font-size:12px;color:#596a60;margin:0}
.library-shell .primary{background:#285e51;border-radius:5px;box-shadow:0 3px 7px #28433818;white-space:nowrap;font-weight:600}
.library-section-head{display:flex;justify-content:space-between;align-items:center;gap:16px;margin:22px 0 14px}.library-section-head h2{font-size:21px;margin:0}.library-section-head input{background:transparent;border:0;border-bottom:1px solid #a9b7ad;padding:8px 4px;width:250px}
.library-tabs{display:flex;gap:24px;border-bottom:1px solid #dce3da;margin:0 0 22px;overflow:auto}.library-tabs button{color:#596a60;border:0;background:none;border-bottom:2px solid transparent;padding:10px 0;white-space:nowrap}.library-tabs .active{color:#285e51;border-color:#285e51;font-weight:700}
.library-shell .subject-shelf{grid-template-columns:repeat(4,minmax(0,1fr));gap:24px 32px}.library-shell .book-cover{height:175px}.book-hit{display:block;width:100%;padding:0;border:0;background:none;text-align:left;color:inherit}.subject-book{cursor:pointer}.subject-book:focus-visible,.book-hit:focus-visible{outline:2px solid #285e51;outline-offset:5px}
.library-shell .subject-book h3{font-size:14px;margin-top:12px}.library-shell .subject-book p{color:#596a60}.library-shell .book-cover em{font-size:9px}
.library-courses{display:grid;gap:20px}.library-course{display:flex;align-items:center;gap:26px;padding:24px;background:#fff;border-radius:7px;box-shadow:0 4px 14px #263c320c}.library-shell .mini-book{height:151px;width:126px;flex-shrink:0;padding:13px}.mini-book h2{font-size:24px!important}.mini-book small{font-size:9px;left:14px}.mini-book b{font-size:25px;right:12px;bottom:32px}.mini-book em{font-size:7px!important;left:13px;bottom:10px}.course-info{flex:1;min-width:0}.course-info h2{font-size:23px;margin:4px 0 9px}.course-info p{font-size:14px;color:#596a60;margin:0}.course-info small{color:#596a60;font-size:12px}.library-progress{height:5px;max-width:360px;background:#e2e8dc;margin:16px 0 6px}.library-progress i{display:block;height:100%;background:#52866a}.course-actions{display:grid;gap:4px;text-align:center}.course-actions .back{font-size:12px}
.library-empty{padding:32px;background:#f3f6ef;border-radius:6px;color:#596a60;margin:20px 0}.library-empty h2{color:#29433a}.library-empty button{margin-top:12px}.library-empty p{line-height:1.8}
.training-layout{display:grid;grid-template-columns:minmax(0,1.6fr) minmax(250px,1fr);gap:30px}.training-paper{padding:26px 30px;background:#fff;border-radius:6px}.training-paper h2,.training-summary h2{font-size:22px;margin:0}.training-paper h3{font-size:14px;margin:20px 0 10px}.library-chips{display:flex;flex-wrap:wrap;gap:9px;margin-bottom:20px}.library-chips button,.library-chips select{background:#f2f6ef;border:0;padding:8px 14px;border-radius:4px;color:#365747;font:inherit;font-size:13px}.library-chips .active{background:#285e51;color:white}.training-modes{display:grid;grid-template-columns:1fr 1fr;gap:12px}.training-modes button{border:1px solid #d9e1d4;background:#fff;padding:12px;border-radius:5px;color:#29433a;text-align:left}.training-modes button.selected{border-color:#839f88;background:#edf3e8}.training-modes small{display:block;margin-top:5px;color:#596a60}.training-chapters{max-height:350px;overflow:auto}.training-chapters label{display:flex;align-items:center;gap:10px;border:1px solid #dce2d6;padding:13px;margin-bottom:8px;border-radius:4px;cursor:pointer}.training-chapters label:has(input:checked){background:#edf3e8;border-color:#839f88}.training-chapters small{margin-left:auto;white-space:nowrap;color:#596a60}.training-chapters input{accent-color:#285e51}.training-summary{background:#e5eee0;border-radius:6px;align-self:start;padding:28px;position:sticky;top:25px}.paper-symbol{height:110px;display:grid;place-items:center;background:#fafbef;box-shadow:0 4px 9px #3143371a;transform:rotate(-3deg);font:italic 40px Georgia;margin-bottom:28px}.training-summary p{font-size:14px;color:#596a60}.training-summary dl{display:grid;grid-template-columns:1fr 1fr;gap:18px;border-top:1px solid #bfceba;padding-top:22px;margin:22px 0}.training-summary dd{text-align:right;margin:0;font-weight:bold}.training-summary button{width:100%;margin:10px 0}.training-summary small{color:#596a60;font-size:12px;display:block}
.library-mistakes{display:grid;gap:18px}.library-mistakes article{background:#fff;padding:24px 28px;border-radius:6px}.library-mistakes article>small{display:inline-block;background:#e0ebdf;color:#345947;padding:4px 10px}.library-mistakes h2{font-size:19px;margin:14px 0}.library-mistakes p{font-size:13px;color:#7a5243}.library-mistakes .back{display:block;margin-left:auto;border:1px solid #b5c5b6;border-radius:4px;color:#285e51}.library-shell .quiz-card{max-width:850px;margin:20px auto}.library-shell button:focus-visible,.library-shell select:focus-visible{outline:2px solid #285e51;outline-offset:3px}
@media(min-width:701px){.mobile-nav{display:none!important}}
@media(max-width:1000px) and (min-width:701px){.library-shell .topbar{gap:18px;padding:0 20px}.library-shell .desktop-links{gap:12px}.library-shell .top-actions{display:none}.library-shell .content{padding:28px}.library-course{gap:18px}}
@media(max-width:700px){.library-shell .topbar{height:66px;padding:0 20px;gap:8px;position:relative}.library-shell .desktop-links{display:none}.library-shell .top-actions button{font-size:11px;padding:4px}.library-shell .brand b{font-size:21px}.library-shell .brand small{font-size:8px}.library-shell .content{padding:24px 20px calc(100px + env(safe-area-inset-bottom))}.library-heading h1{font-size:26px}.library-heading p{font-size:12px}.library-heading{margin-bottom:20px}.library-resume{padding:15px;gap:12px}.library-resume h2{font-size:14px}.library-resume p{font-size:11px}.library-resume .primary{font-size:12px;padding:10px 12px}.library-section-head{flex-wrap:wrap}.library-section-head h2{font-size:20px}.library-section-head input{width:100%;font-size:12px}.library-tabs{gap:17px}.library-tabs button{font-size:11px}.library-shell .subject-shelf{grid-template-columns:repeat(2,minmax(0,1fr));gap:20px 16px}.library-shell .book-cover{height:151px}.library-shell .subject-book h3{font-size:12px;line-height:1.5}.library-shell .book-cover em{font-size:7px}.library-course{padding:16px;gap:16px;flex-wrap:wrap}.library-shell .mini-book{width:100px;height:126px;padding:9px}.mini-book small{font-size:8px}.mini-book h2{font-size:22px!important}.mini-book em{font-size:6px!important}.course-info h2{font-size:18px;line-height:1.4}.course-info p,.course-info small{font-size:10px}.course-actions{display:flex;align-items:center;justify-content:space-between;width:100%;flex-wrap:wrap}.course-actions .primary{font-size:12px;padding:10px 13px}.course-actions .back{font-size:11px;padding:8px 4px}.training-layout{grid-template-columns:1fr;gap:18px}.training-paper{padding:20px 16px}.training-summary{position:static;padding:22px}.paper-symbol{display:none}.training-chapters{max-height:310px}.training-chapters label{padding:11px;font-size:13px}.training-modes small{font-size:11px}.library-chips{gap:7px}.library-chips button,.library-chips select{font-size:12px;padding:7px 10px}.library-mistakes article{padding:18px}.library-mistakes h2{font-size:16px}.library-empty{padding:20px}.library-empty h2{font-size:20px}.mobile-nav{display:flex!important;position:fixed!important;left:0;right:0;bottom:0;top:auto;z-index:1000;height:calc(70px + env(safe-area-inset-bottom));padding:0 10px env(safe-area-inset-bottom);background:#fff;border-top:1px solid #dce3da;justify-content:space-around;align-items:stretch;box-shadow:0 -3px 12px #29433a08}.mobile-nav button{display:flex!important;flex-direction:column;align-items:center;justify-content:center;gap:5px;flex:1;border:0;background:none;color:#5b7165;font-size:11px!important;padding:7px 0;min-height:44px}.mobile-nav button span{font-size:11px!important}.mobile-nav button::after{content:none!important}.mobile-nav button.active{color:#285e51;font-weight:700;background:#f1f6ef}.activate{padding-bottom:calc(80px + env(safe-area-inset-bottom))}}
/* Physics pilot: paper worksheets and interactive scientific diagrams. */
.physics-studio{max-width:1040px;margin:auto;color:#29433a}.physics-studio h2{font:700 25px/1.5 'SimSun','Songti SC',serif;margin:0 0 12px}.physics-studio h3{font-size:18px;line-height:1.5}.physics-studio p,.physics-studio li{line-height:1.85}.phy-cover{display:flex;align-items:center;justify-content:space-between;gap:30px;margin:10px 0 22px;padding:32px 36px;background:#dce9de;border-radius:4px 16px 16px 4px;box-shadow:0 5px 16px #234d3610}.phy-cover>div:first-child{flex:1;min-width:0}.phy-cover p{margin:0 0 12px;color:#375d4d;font-size:13px}.phy-cover h1{font:700 34px/1.45 'SimSun','Songti SC',serif;margin:0 0 15px;max-width:21em;color:#234d3b}.phy-cover small{color:#375d4d}.phy-cover-mark{font:italic 37px Georgia;color:#486e54;background:#f8f7ed;padding:25px 28px;transform:rotate(-5deg);box-shadow:0 5px 10px #285b3520;white-space:nowrap}
.physics-studio .stage-nav{border:0;background:#f1f5ed;border-radius:6px;padding:7px;margin:22px 0 28px;gap:8px}.physics-studio .stage-nav button{padding:13px 10px;background:none;min-width:0}.physics-studio .stage-nav button.active{background:#285e51;color:#fff}.physics-studio .stage-nav small{font-size:11px}.phy-opening{max-width:780px;margin:28px 0}.phy-opening>p{font-size:17px;color:#3c5548}.phy-opening ul{padding:0;list-style:none;display:flex;gap:20px;border-top:1px solid #dce6da;margin:22px 0;padding-top:18px}.phy-opening li{flex:1;font-size:13px;color:#4b6754}.phy-opening li:before{content:'•';color:#9b693e;margin-right:7px}.phy-prediction{margin:28px 0;background:#f8f6ed;padding:28px 32px;border-radius:6px}.phy-prediction>p{font-size:17px}.phy-choices{display:grid;gap:10px;margin:20px 0}.phy-choices button{display:flex;align-items:center;gap:14px;padding:14px 18px;text-align:left;line-height:1.7;border:1px solid #d5decf;background:#fff;color:#304e3c;border-radius:5px}.phy-choices button span{font:italic 23px Georgia;color:#728473}.phy-choices .selected{background:#e4eedf;border-color:#78947b}.phy-prediction>small,.phy-feedback small{color:#5e6e58;font-size:12px}.phy-feedback{padding:19px;background:#edf2e7;border-radius:5px}.phy-feedback p{margin:7px 0;font-size:15px}.phy-reading,.phy-reference{padding:18px 22px;margin:25px 0;background:#f7f8f2;border-radius:5px}.phy-reading summary,.phy-reference>summary{cursor:pointer;color:#285e51;font-weight:600;min-height:30px}.phy-reading pre{font:inherit;line-height:2;white-space:pre-wrap}.phy-reference>p{font-size:13px;color:#596a60}.phy-reference .lesson-card{box-shadow:none}.phy-next{display:flex;align-items:center;justify-content:space-between;margin:28px 0}.phy-next p{color:#596a60;font-size:13px}.phy-lab{background:#f4f7ed;padding:26px 30px;border-radius:8px;margin:26px 0}.phy-lab-head{display:flex;gap:20px;align-items:start;justify-content:space-between}.phy-lab-head h2{margin:0 0 5px}.phy-lab-head p{font-size:13px;color:#53664f;margin:0}.phy-lab-head>span{font-size:11px;white-space:nowrap;background:#e0e9d4;color:#425a37;padding:5px 10px;border-radius:3px}.phy-lab-grid{display:grid;grid-template-columns:minmax(0,1.8fr) minmax(180px,1fr);gap:24px;align-items:center;margin:22px 0}.phy-scene{background:#fffdf5;border-radius:5px;padding:12px;box-shadow:0 4px 11px #4155350b}.phy-scene svg{width:100%;height:auto;display:block}.phy-scene svg text{font:12px 'Microsoft YaHei',sans-serif;fill:#3c5548}.phy-controls label{display:block;font-size:13px;font-weight:600;color:#3c5548;margin:12px 0 22px}.phy-controls select{display:block;width:100%;margin-top:9px;background:#fff;border:1px solid #a6b49c;padding:10px;border-radius:4px;color:#29433a;font:inherit}.phy-controls input{display:block;width:100%;accent-color:#285e51;margin:15px 0 0;min-height:28px}.phy-controls output{float:right;font-weight:400}.phy-controls .back{padding-left:0;color:#285e51}.phy-readout{padding:17px 20px;margin:0 0 12px;background:#e0ead6;color:#304a34;border-radius:4px;font-size:15px}.phy-lab>small{display:block;color:#53664f;font-size:12px;line-height:1.8}.phy-knowledge{margin:34px 0}.phy-route{display:flex;padding:0;list-style:none;gap:10px;margin:20px 0}.phy-route li{flex:1;padding:12px 14px;background:#e9efdf;font-size:14px;position:relative;text-align:center}.phy-route li:not(:last-child):after{content:'→';position:absolute;right:-11px;z-index:1;color:#587247}.phy-rule{padding:23px 27px;background:#f9f4e6;border-radius:5px}.phy-rule strong{font-size:20px;color:#685237}.phy-rule p{font-size:13px;color:#685237;margin:10px 0 0}.phy-knowledge dl{margin-top:26px}.phy-knowledge dl>div{display:grid;grid-template-columns:150px 1fr;gap:20px;padding:17px 0;border-bottom:1px solid #dce4d6}.phy-knowledge dt{font-weight:700}.phy-knowledge dd{margin:0;color:#4b6352;font-size:14px;line-height:1.9}.phy-examples{margin:35px 0}.phy-examples>p{font-size:13px;color:#596a60}.phy-example{display:grid;grid-template-columns:45px minmax(0,1fr);gap:18px;padding:26px 0;border-bottom:1px solid #dce4d6}.phy-example-number{font:italic 32px Georgia;color:#96a889}.phy-example h3{margin:0 0 10px}.phy-example details{margin:10px 0;background:#f5f7f0;padding:12px 16px}.phy-example summary{cursor:pointer;color:#285e51;font-size:14px;min-height:24px}.phy-example details p{margin:10px 0 0;font-size:14px;color:#415c48}.physics-studio .writing-task{padding:25px 28px;border:0;border-radius:6px;background:#f7f5eb;box-shadow:0 4px 14px #38462e08;margin:25px 0}.physics-studio .writing-task textarea{background:#fffef8;line-height:1.9;color:#29433a}.physics-studio .writing-task .task-label{color:#675b40}.physics-studio .lesson-card.challenge,.physics-studio .lesson-card.extension{padding:26px 30px;border:0;border-radius:6px;background:#f4f7ee}.phy-errors{padding:22px 0}.phy-errors p{display:flex;gap:16px;padding:13px 0;border-bottom:1px solid #e1e6d7}.phy-errors p b{color:#886c43}.phy-finish{display:flex;align-items:center;justify-content:space-between;gap:20px;border-top:1px solid #dce4d6;margin-top:32px;padding-top:24px}.phy-finish p{font-size:12px;color:#596a60;margin:6px 0 0}.phy-finish b{font-size:14px}.phy-distractors{margin-top:15px}.phy-distractors summary{cursor:pointer;font-weight:600}.phy-distractors p{line-height:1.85}.phy-records>p{color:#596a60}.physics-studio button:focus-visible,.physics-studio summary:focus-visible,.physics-studio input:focus-visible{outline:2px solid #285e51;outline-offset:3px}
@media(max-width:700px){.phy-cover{display:block;padding:23px 20px;position:relative;overflow:hidden}.phy-cover h1{font-size:25px;max-width:100%}.phy-cover p{font-size:11px}.phy-cover small{font-size:11px}.phy-cover-mark{display:none}.physics-studio h2{font-size:23px}.physics-studio .stage-nav{gap:3px;padding:4px;margin:18px 0 23px}.physics-studio .stage-nav button{padding:8px 3px;text-align:center}.physics-studio .stage-nav b{display:none}.physics-studio .stage-nav span{font-size:12px}.physics-studio .stage-nav small{margin:4px 0 0;font-size:10px}.phy-opening>p{font-size:15px}.phy-opening ul{display:block;margin:15px 0;padding-top:12px}.phy-opening li{margin:9px 0}.phy-prediction{padding:20px 16px}.phy-prediction>p{font-size:15px}.phy-choices button{font-size:13px;padding:11px 13px;gap:10px}.phy-feedback{padding:15px}.phy-feedback p{font-size:13px}.phy-next{display:block}.phy-next button{width:100%;margin-top:10px}.phy-lab{padding:20px 14px}.phy-lab-head{display:block}.phy-lab-head>span{display:inline-block;margin-top:10px}.phy-lab-grid{grid-template-columns:1fr;gap:12px;margin:15px 0}.phy-scene{padding:3px}.phy-controls label{margin:8px 0 17px}.phy-readout{font-size:13px;padding:14px}.phy-route{display:grid;grid-template-columns:1fr 1fr;gap:8px}.phy-route li{font-size:12px;padding:10px 8px}.phy-route li:after{display:none}.phy-rule{padding:17px}.phy-rule strong{font-size:17px}.phy-knowledge dl>div{grid-template-columns:1fr;gap:6px;padding:14px 0}.phy-example{grid-template-columns:26px minmax(0,1fr);gap:10px}.phy-example-number{font-size:23px}.phy-example h3{font-size:17px}.phy-example p{font-size:14px}.phy-example details{padding:12px}.physics-studio .writing-task{padding:20px 15px}.physics-studio .lesson-card.challenge,.physics-studio .lesson-card.extension{padding:22px 16px}.phy-reading,.phy-reference{padding:15px}.phy-finish{display:block}.phy-finish button{width:100%;margin-top:15px}.phy-errors p{font-size:14px}.physics-studio .quiz-teaser{width:100%;font-size:14px}.physics-studio .quiz-teaser span{display:block;float:none;font-size:12px;margin-top:7px}}
.phy-chapter-list{display:grid;gap:16px}.phy-catalog .phy-chapter{display:flex;align-items:start;gap:24px;padding:26px;text-align:left;border:0;border-radius:6px;background:#f1f6ec;min-height:0}.phy-catalog .phy-chapter:nth-child(even){background:#f7f4e9}.phy-chapter-no{font:italic 39px Georgia;color:#74927b;min-width:55px}.phy-catalog .phy-chapter small{margin:0;color:#496850;font-size:12px}.phy-catalog .phy-chapter h2{font-size:24px;margin:7px 0}.phy-catalog .phy-chapter p{font-size:13px;color:#53664f;margin:6px 0 13px}.phy-catalog .phy-chapter div>span{font-size:12px;color:#285e51}.phy-catalog-note{color:#596a60;font-size:12px;margin-top:25px}@media(max-width:700px){.phy-catalog .phy-chapter{padding:19px 15px;gap:12px}.phy-chapter-no{font-size:26px;min-width:30px}.phy-catalog .phy-chapter h2{font-size:20px}.phy-catalog .phy-chapter p{font-size:11px}.phy-catalog .phy-chapter div>span{font-size:11px}}
.screen-lesson .physics-studio .stage-nav{padding:7px;background:#f1f5ed;gap:8px;border-radius:6px}
.screen-lesson .physics-studio .stage-nav button{border-radius:5px;padding:12px 8px;color:#50664e}
.screen-lesson .physics-studio .stage-nav button.active{background:#285e51;color:#fff}
.screen-lesson .physics-studio .stage-nav button.active span{color:#fff}
.screen-lesson .physics-studio .stage-nav button b{display:none}
.screen-lesson .physics-studio .stage-nav small{display:block;margin:5px 0 0;opacity:1}
.screen-catalog .physics-studio .phy-chapter{flex-direction:row;min-height:0;align-items:flex-start}
@media(max-width:700px){.screen-lesson .physics-studio .stage-nav{padding:4px;gap:3px}.screen-lesson .physics-studio .stage-nav button{padding:8px 2px}.screen-lesson .physics-studio .stage-nav small{font-size:10px}}