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@media(min-width:1600px){.lesson-shell{grid-template-columns:310px 1fr}.lesson-main{padding:0 44px 35px}}
@media(max-width:1100px){.site-header{padding:0 24px;gap:25px}.container{width:calc(100% - 40px)}.hero{gap:25px;grid-template-columns:1.5fr 1fr}.hero h1{font-size:35px}.hero-art{height:220px}.library-layout{grid-template-columns:1fr 240px;gap:18px}.book-card{grid-template-columns:125px 1fr;gap:22px;padding:22px}.book-cover{padding:18px 15px}.book-cover strong{font-size:34px}.book-info h3{font-size:22px}.book-stats{gap:12px}.lesson-shell{grid-template-columns:250px 1fr}.lesson-main{padding:0 20px 25px}.lesson-title h1{font-size:21px}.filter-note{display:none}}
@media(max-width:760px){.site-header{height:65px;padding:0 18px;gap:20px}.brand{font-size:18px;gap:7px}.brand-mark{width:30px;height:30px}.nav{gap:16px;font-size:12px}.nav .optional{display:none}.preview-label{font-size:9px;padding:5px 8px}.container{width:calc(100% - 32px)}.hero{grid-template-columns:1fr;padding:30px 0 25px}.hero h1{font-size:32px;margin:15px 0;letter-spacing:-1.3px}.hero p{font-size:13px}.hero-art{display:none}.feature-strip{gap:16px;font-size:11px}.search{height:52px;margin-top:22px;padding:0 13px}.search input{font-size:12px}.search kbd{display:none}.filters{padding:12px 14px;border-radius:12px}.filter-row{gap:10px;font-size:11px;padding:7px 0}.filter-name{min-width:30px}.chip{padding:7px 10px}.filter-options{gap:3px}.library-layout{grid-template-columns:1fr}.side-note{padding:22px}.side-note .roadmap{grid-template-columns:1fr 1fr;gap:14px}.section-head{margin:25px 0 15px}.section-head h2{font-size:19px}.book-card{grid-template-columns:95px 1fr;gap:17px;padding:19px}.book-cover{align-self:start;min-height:145px;padding:15px 11px}.book-cover strong{font-size:26px;margin-top:12px}.book-cover .cover-top{font-size:6px;letter-spacing:.5px}.book-cover .cover-grade{font-size:8px;letter-spacing:0}.book-cover svg{height:66px;bottom:13px}.book-cover .cover-bottom{font-size:5px;left:10px;bottom:12px;letter-spacing:0}.book-info h3{font-size:18px;margin:12px 0 8px}.badge{font-size:9px;padding:4px 6px}.badge-row{gap:5px}.book-info .subtitle{font-size:10px}.book-stats{font-size:10px;gap:9px;margin:12px 0 15px}.book-stats b{font-size:13px;margin-right:2px}.btn{font-size:11px;padding:9px 12px;min-height:36px;gap:8px}.scope-note{font-size:10px;margin-top:13px}.resume{padding:14px;gap:12px}.resume .resume-copy{font-size:11px}.resume small{font-size:10px}.resume a{font-size:11px;white-space:nowrap}.footer{margin-top:36px;display:block;font-size:10px}.footer span{display:block;margin-bottom:8px}.book-hero{gap:20px;padding:5px 0 26px}.book-hero .book-cover{width:95px}.book-hero h1{font-size:24px;margin:10px 0}.book-hero p{font-size:11px}.book-hero .book-stats{margin:10px 0 15px}.breadcrumb{font-size:11px;padding:21px 0}.book-layout{grid-template-columns:1fr;gap:15px}.book-nav{display:flex;overflow:auto;position:static;gap:5px;padding-bottom:5px}.book-nav h2,.book-nav .small-note{display:none}.book-nav a{white-space:nowrap;border:1px solid var(--line);background:white;border-radius:7px;padding:9px;font-size:11px;gap:5px}.toc-toolbar{margin-bottom:15px;flex-wrap:wrap;gap:8px}.toc-toolbar h2{font-size:18px}.toc-toolbar small{font-size:10px}.chapter-heading{padding:18px 15px}.chapter-heading h3{font-size:16px;gap:8px}.chapter-heading h3 span{font-size:10px}.chapter-heading a{font-size:10px}.toc-section>summary,.section-single{padding:16px 15px;font-size:12px;gap:8px;line-height:1.8}.toc-section>summary a{font-size:10px;white-space:nowrap}.section-label{font-size:10px;min-width:29px}.toc-child{padding:13px 15px 13px 27px;font-size:12px;gap:7px}.toc-child small{font-size:9px;white-space:nowrap}.extras{padding:12px 15px;gap:5px}.extras a{font-size:10px}.result{padding:17px 15px;gap:12px}.result strong{font-size:13px}.result small{font-size:10px}.num-chip{min-width:48px;font-size:10px}.home-hero{padding:42px 0 95px}.home-hero h1{font-size:27px;line-height:1.5}.home-hero p{font-size:13px}.home-feature{grid-template-columns:1fr;padding:28px;margin-top:-55px;gap:0}.home-feature h2{font-size:29px}.home-feature p{font-size:13px}.home-more{grid-template-columns:1fr;gap:12px;margin-top:20px}.lesson-header{height:58px;padding:0 14px;gap:13px}.lesson-header .nav{gap:15px}.lesson-header .brand{font-size:16px}.lesson-header .brand-mark{width:25px;height:25px}.lesson-header .preview-label{display:none}.lesson-shell{display:block;min-height:calc(100vh - 58px)}.lesson-sidebar{display:none;position:fixed;top:0;bottom:0;left:0;width:285px;height:100dvh;z-index:22;box-shadow:15px 0 60px #13271925}.menu-open .lesson-sidebar{display:flex}.menu-open .sidebar-backdrop{display:block;position:fixed;inset:0;background:#132d3599;z-index:21}.sidebar-close{display:block;position:absolute;right:12px;top:14px;font-size:23px;color:var(--muted)}.lesson-main{padding:0 14px 25px}.lesson-main .breadcrumb{padding:17px 0 15px;flex-wrap:wrap;gap:7px;font-size:10px}.mobile-menu{display:inline-flex;color:var(--green);font-size:12px;margin-right:auto;padding:4px 0}.lesson-title{margin-bottom:14px;gap:10px}.lesson-title h1{font-size:20px}.lesson-title p{font-size:10px}.lesson-title .badge{font-size:9px}.player-wrap{border-radius:9px}.player-wrap iframe{aspect-ratio:16/11}.player-caption{font-size:10px;align-items:start;gap:10px}.player-caption button{font-size:10px}.lesson-actions{margin:17px 0;padding-bottom:17px;flex-wrap:wrap;gap:12px}.lesson-actions .btn{font-size:11px;min-height:35px;padding:8px 10px}.lesson-actions .nextprev{margin-left:auto;gap:6px}.part-head h2{font-size:14px}.part-head small{font-size:9px}.part-link{font-size:10px;padding:9px}.lesson-footer{font-size:9px}.source-box{padding:17px;font-size:11px}.home-feature .badge{font-size:10px}}
@media(prefers-reduced-motion:reduce){*,*:before,*:after{animation:none!important;scroll-behavior:auto!important}}

.book-card+.book-card{margin-top:20px}.badge.legacy-version{background:#fff0dd;color:#8c5422;border:1px solid #e1c398}

/* Planned choices remain operable to explain availability. */
.chip.coming-soon{color:#6f797c;background:#f7f8f7}.coming-tag{display:inline-block;margin-left:6px;padding:2px 5px;border:1px solid #dce1dd;border-radius:4px;font-size:10px;font-weight:400;white-space:nowrap;color:#6c7571;background:#fff}.chip.coming-soon.selected{background:#eef0ed;border-color:#aeb9b1;color:#536158}.filter-note{max-width:320px;line-height:1.7}.filter-row[hidden]{display:none}

.model-resource{display:flex;flex-direction:column;align-items:flex-end;gap:8px;margin-left:auto;flex-shrink:0}.model-resource small{color:var(--muted);font-size:11px;line-height:1.6}.model-resource-links{display:flex;gap:10px}.model-resource .btn{font-size:12px;min-height:38px;padding:9px 14px;white-space:nowrap}.lesson-title.has-model>.badge{display:none}.lesson-title.has-model>div:first-child{min-width:0}.lesson-title.has-model{align-items:center}@media(max-width:1100px){.lesson-title.has-model{flex-wrap:wrap;gap:12px}.model-resource{flex-basis:100%;align-items:flex-start;margin-left:0}.model-resource .btn{font-size:11px}}

#model-select{max-width:350px;width:100%;font:inherit;font-size:12px;padding:7px 10px;border:1px solid #cbded3;border-radius:6px;color:var(--green);background:#fff}.model-resource{max-width:100%}@media(max-width:1100px){#model-select{max-width:100%}}