:root{font-family:system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;color:#202622;background:#f7f8fa;font-synthesis:none;line-height:1.5;letter-spacing:0}*{box-sizing:border-box}body{margin:0}button,input,summary,a{ -webkit-tap-highlight-color:transparent}button,input{font:inherit}button{border:1px solid #ccd3d2;background:#fff;border-radius:6px;padding:11px 18px;cursor:pointer;color:inherit;font-weight:600}button:hover{background:#edf2ef}button:disabled{opacity:.45;cursor:not-allowed}button:focus-visible,a:focus-visible,summary:focus-visible,input:focus-visible{outline:3px solid #b27919;outline-offset:4px}a{color:#14664e}input{accent-color:#17634f}input[type=checkbox]{width:18px;height:18px;flex-shrink:0}.topbar{height:60px;border-bottom:1px solid #dde2e0;background:white;padding:0 5%;display:flex;align-items:center;justify-content:space-between;gap:20px}.brand{display:flex;align-items:center;gap:14px;text-decoration:none;color:#262f2b;font-size:12px;font-weight:750}.brandmark{background:#185f4b;color:#fff;padding:5px 7px;font-size:18px;border-radius:4px}.local-label,.muted,.total{color:#737c78;font-size:14px}main{max-width:1200px;margin:auto;padding:24px 32px 64px}.page-heading{display:flex;align-items:end;justify-content:space-between;gap:20px;margin-bottom:20px}.eyebrow{font-size:11px;font-weight:750;color:#707b76;margin:0 0 6px}h1{font-size:32px;line-height:1.2;margin:0;font-weight:650}h2{font-size:20px;line-height:1.3;margin:0 0 26px}.setup-layout{display:grid;grid-template-columns:minmax(0,1fr) 310px;gap:48px}.library{border-top:1px solid #cdd7d1}details{border-bottom:1px solid #d8dfdc}summary{display:flex;align-items:center;gap:18px;cursor:pointer;padding:22px 0;list-style:none}summary::-webkit-details-marker{display:none}.section-number{font-size:12px;color:#88918b;min-width:24px}.section-name{font-size:17px;font-weight:600;flex:1}.section-name small,.topic small{display:block;font-size:12px;color:#7d8580;font-weight:400;margin-top:4px}.expand{font-size:22px;font-weight:300;color:#4e685c}details[open] .expand{transform:rotate(45deg)}.topic-list{padding:0 0 18px 40px}.topic,.select-all{display:flex;align-items:center;gap:12px;padding:10px 8px;cursor:pointer;font-size:14px}.topic:hover{background:#eaf0ec}.select-all{font-weight:600;border-bottom:1px solid #e2e7e4;margin-bottom:5px}.settings{border-top:3px solid #236b53;padding-top:14px;align-self:start;position:sticky;top:28px}fieldset{border:0;margin:0;padding:0}legend{font-size:13px;margin-bottom:10px}.segmented{display:flex;border:1px solid #cbd5cf;border-radius:6px;padding:3px;background:#e9eeeb}.segmented label{flex:1;text-align:center;position:relative;cursor:pointer}.segmented input{position:absolute;opacity:0}.segmented span{display:block;padding:9px 4px;font-size:13px;border-radius:3px}.segmented input:checked+span{background:#fff;box-shadow:0 1px 3px #0001}.segmented input:focus-visible+span{outline:2px solid #b27919}.answer-filter{display:flex;align-items:center;gap:10px;font-size:14px;margin:24px 0}.selection-count{border-top:1px solid #dce3df;padding:24px 0;display:flex;align-items:baseline;gap:10px}.selection-count strong{font-size:32px;font-weight:600}.selection-count span{font-size:13px;color:#6a766f}.primary{background:#19654e;color:#fff;border-color:#19654e}.primary:hover{background:#124c3b}.settings .primary{width:100%}.resume{display:flex;justify-content:space-between;align-items:center;gap:16px;background:#e8efe9;border-left:3px solid #246f52;padding:14px 20px;margin-bottom:28px;font-size:14px}.study-top,.question-nav{display:flex;align-items:center;justify-content:space-between;gap:16px;max-width:850px;margin:auto}.text-button{border:0;background:none;padding-left:0}.study-top span{font-size:13px;color:#6d7771}progress{display:block;width:100%;max-width:850px;height:4px;margin:8px auto 20px;border:0;background:#dce5df}progress::-webkit-progress-bar{background:#dce5df}progress::-webkit-progress-value{background:#27795c}.question{max-width:850px;margin:auto;overflow-wrap:anywhere}.group{font-size:13px;color:#976c27;margin:12px 0}.question-title{font-size:26px;font-weight:600;line-height:1.45;margin-bottom:28px}.question-title p{margin-top:0}.reveal{background:#e5eee8;border-color:#cadbcf;color:#175b43;margin-bottom:22px}.answer{border-top:1px solid #d4ded7;padding-top:20px;font-size:16px}.answer p{margin:0 0 18px}.answer pre{background:#252c29;color:#edf3ef;padding:10px 12px;border-radius:5px;overflow:auto;font-size:13px;line-height:1.7}.answer code{font-family:ui-monospace,SFMono-Regular,Consolas,monospace}.answer :not(pre)>code,.question-title code{background:#e8ecea;padding:2px 5px;border-radius:3px;font-size:.9em}.answer img{max-width:100%}.answer table{display:block;overflow:auto}.source-link{display:block;font-size:12px;margin:20px 0 32px;color:#758279}.question-nav{border-top:1px solid #d6ddd8;padding-top:24px}.no-answer{padding:16px;border-left:3px solid #c3a365;background:#f1eee5;color:#775f34;font-size:14px}.empty-section{font-size:14px;color:#777;padding-left:42px}.completion{max-width:700px;margin:80px auto}.completion h1{font-size:36px}.completion>div{display:flex;gap:12px;margin-top:30px;flex-wrap:wrap}#storage-warning{position:fixed;bottom:0;background:#fff0ca;padding:12px;width:100%;margin:0;font-size:13px}@media(max-width:760px){.topbar{height:52px;padding:0 20px}.local-label{display:none}main{padding:16px 20px 40px}.page-heading{display:block}h1{font-size:27px}.total{display:block;margin-top:6px}.setup-layout{display:flex;flex-direction:column;gap:20px}.settings{position:static;order:-1;width:100%}.settings h2{font-size:18px;margin-bottom:12px}.selection-count{padding:8px 0}.selection-count strong{font-size:26px}.answer-filter{margin:10px 0;min-height:28px}.section-name{font-size:15px}.topic-list{padding-left:20px}.question-title{font-size:22px}.resume{padding:12px;flex-wrap:wrap}.question-nav button{padding:11px 14px}.brand{font-size:10px}.completion{margin:40px auto}}
:root body{min-height:100vh;display:flex;flex-direction:column}
body>main{width:100%;flex:1}
.site-footer{border-top:1px solid #dde2e0;padding:12px 32px;background:#fff}
.site-footer nav{max-width:1136px;margin:0 auto;display:flex;flex-wrap:wrap;gap:8px 12px;align-items:center}
.site-footer a{font-size:13px;padding:8px 0;text-decoration:none;text-underline-offset:4px}
.site-footer a:hover{text-decoration:underline}
@media(max-width:760px){.site-footer{padding:8px 20px}.site-footer nav{gap:4px 8px}}
.topic[hidden],.select-all[hidden]{display:none}
.topic-search{padding:12px 0;border-bottom:1px solid #dde2e0}
.topic-search label{display:block;font-size:13px;margin-bottom:8px}
.topic-search input{width:100%;padding:12px;border:1px solid #cbd5cf;border-radius:5px;background:white;color:inherit}
.question-rating{margin:24px 0;display:flex;flex-wrap:wrap;gap:10px}
.question-rating legend{margin-bottom:10px}
.question-rating [data-mark=known][aria-pressed=true]{background:#19654e;color:white;border-color:#19654e}
.question-rating [data-mark=review][aria-pressed=true]{background:#f4e4bb;color:#674711;border-color:#b89550}
.progress-tools{border-top:1px solid #dce3df;margin-top:24px;padding-top:16px}
.progress-tools h3{font-size:14px;font-weight:600;margin:0 0 12px}
.progress-tools button{font-size:13px;margin:0 8px 8px 0}
.katex-display{overflow-x:auto;overflow-y:hidden;padding:2px 0}

/* Keep secondary setup controls compact above the topic list on phones. */
#empty-hint:empty,#import-status:empty{display:none}
@media(max-width:760px){.settings .progress-tools{margin-top:16px;padding-top:10px;display:flex;align-items:center;flex-wrap:wrap;gap:8px}.settings .progress-tools h3,.settings .progress-tools button{margin:0}.settings .progress-tools h3{margin-right:auto}.settings #import-status{flex-basis:100%;margin:0}}

.code-example{margin:16px 0;border:1px solid #d4ded7;border-radius:5px;overflow:hidden}
.code-toolbar{display:flex;align-items:center;justify-content:flex-end;gap:12px;padding:4px 8px;background:#edf2ef}
.code-toolbar [role=status]{font-size:12px;color:#536159;overflow-wrap:anywhere}
.copy-code{flex-shrink:0;padding:6px 10px;min-height:36px;font-size:12px;font-weight:600}
.answer .code-example pre{margin:0;border-radius:0}
.answer pre code.hljs{padding:0;background:transparent}

.settings-toggle{display:none}
@media(max-width:760px){
  .settings>h2,.settings>.eyebrow{display:none}
  .settings-toggle{display:block;width:100%;min-height:44px;text-align:left;background:transparent;border:0;padding:8px 0}
  .settings:not(.settings-expanded) .training-options{display:none}
  .settings .selection-count{border-top:0}
  .settings .training-options{padding:8px 0 14px;border-bottom:1px solid #dce3df}
}

.site-footer .footer-icon{display:inline-flex;align-items:center;justify-content:center;width:44px;height:44px;padding:10px;border-radius:6px}
.site-footer .footer-icon:hover{background:#edf2ef}
.footer-icon svg{width:24px;height:24px}
#footer-source{margin-right:auto}
#footer-source[hidden]{display:none}

.page-heading .library-heading{font-size:11px;font-weight:750;line-height:1.5;color:#707b76;text-transform:uppercase}

.page-heading{align-items:center}
.page-heading .total{display:inline-flex;align-items:baseline;gap:6px;padding:5px 10px;margin:0;border:1px solid #d4e2d9;border-radius:20px;background:#eaf2ed;color:#536b5d;font-size:12px;white-space:nowrap}
.total strong{color:#185f4b;font-size:14px;font-weight:650;font-variant-numeric:tabular-nums}
@media(max-width:760px){.page-heading{display:flex;flex-wrap:wrap;gap:8px 12px}}

.learning-start{margin:0 0 28px;padding:20px;border:1px solid #d4e2d9;border-radius:10px;background:#fff}
.learning-start h2{margin-bottom:8px}.learning-start p{color:#536159;margin-top:0}
.track-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;margin:16px 0}
.track-card{text-align:left;display:flex;flex-direction:column;gap:8px;font-size:14px;min-height:110px}
.track-card span{font-size:13px;font-weight:400;color:#536159}
.plan-link{display:inline-block;margin:0 0 16px 40px;font-size:13px}
.learning-page{max-width:1050px;overflow-wrap:anywhere}.learning-page h1{margin:24px 0}.learning-page h2{margin:32px 0 16px}.learning-page table{display:block;overflow-x:auto;border-collapse:collapse;margin:20px 0}.learning-page th,.learning-page td{text-align:left;vertical-align:top;border:1px solid #d4ded7;padding:12px;min-width:150px}.learning-page th{background:#eaf2ed}.learning-page li{margin:10px 0}
select:focus-visible{outline:3px solid #b27919;outline-offset:4px}
@media(max-width:760px){.track-grid{grid-template-columns:1fr}.track-card{min-height:0}.learning-start{padding:16px}.topbar{height:auto;min-height:60px;flex-wrap:wrap;padding:12px 20px;gap:8px}.learning-page table{font-size:14px}.learning-start h2{font-size:20px}}

/* Compact library header; learning routes open from the help button. */
.topbar{flex-wrap:nowrap;min-height:60px;height:60px;padding:0 5%}
.help-button{display:inline-flex;align-items:center;justify-content:center;flex-shrink:0;width:44px;height:44px;padding:0;border-radius:50%;font-size:18px;color:#185f4b}
.help-button[hidden],.learning-start[hidden]{display:none}
.help-button[aria-expanded=true]{background:#e5eee8;border-color:#8faf9b}
.page-heading{justify-content:flex-start;flex-wrap:nowrap;gap:12px;min-height:44px;margin-bottom:16px}
.page-heading .library-heading{white-space:nowrap}
.page-heading .resume{margin:0 0 0 auto;padding:0;background:transparent;border:0;gap:12px;flex-wrap:nowrap;white-space:nowrap;font-size:12px}
.page-heading .resume #resume{display:inline-flex;align-items:center;gap:8px;min-height:44px;width:auto;padding:8px 12px;border:1px solid #d4e2d9;background:#eaf2ed;color:#175b43;font-size:12px}
.page-heading .resume #resume:hover{background:#dce8df}
@media(max-width:900px){.page-heading .resume>span{display:none}}
@media(max-width:600px){
  .topbar{height:56px;min-height:56px;padding:0 20px}
  .page-heading{gap:8px;margin-bottom:12px}
  .page-heading .library-heading{font-size:10px}
  .section-count-label{display:none}
  .page-heading .total{gap:4px;padding:4px 7px;font-size:11px}
  .page-heading .total strong{font-size:12px}
  .page-heading .resume #resume{width:44px;padding:0;justify-content:center;font-size:20px}
  .resume-label{display:none}
}

.question-title>p:not(:first-child){font-size:16px;font-weight:400}
.question-title pre{font-size:14px;line-height:1.6;font-weight:400;overflow:auto;padding:12px;background:#252c29;color:#edf3ef;border-radius:5px}
.question-title pre code{font-size:inherit;background:transparent;padding:0;font-family:ui-monospace,SFMono-Regular,Consolas,monospace}
.question-title .code-example pre{margin:0;border-radius:0}
.question-title pre code.hljs{background:transparent;padding:0}

/* Shared interaction and content rules. */
:root{background:#f2f2f7;color:#1c1c1e;--action-bar-height:calc(94px + env(safe-area-inset-bottom,0px))}
[hidden]{display:none!important}
html{scroll-padding-block:20px 130px;-webkit-text-size-adjust:100%}
button,select{min-height:44px;touch-action:manipulation}
button,a,label,summary{touch-action:manipulation}
button{border-color:#dedee3;border-radius:10px}
button:focus-visible,a:focus-visible,summary:focus-visible,input:focus-visible,select:focus-visible{outline-color:#007aff}
.brandmark{border-radius:10px}
.brand>span:last-child{min-width:0;overflow-wrap:anywhere}
.topbar{border-color:#e2e2e7}
.setup-layout{gap:32px}
.library{border:0}
.library details{padding:0 16px;border:1px solid #e2e2e7;border-radius:14px;background:#fff;margin-bottom:10px}
.library summary{padding:18px 0}
.library details[open]>summary{border-bottom:1px solid #eeeef2;margin-bottom:8px}
.library .topic-list{padding-left:0}
.settings{padding:22px;border:1px solid #e2e2e7;border-radius:16px;background:#fff}
.settings h2{font-size:20px}
.selection-count #empty-hint{font-size:12px}
.mobile-heading,.mobile-label,.library-intro{display:none}
.section-name,.topic>span{min-width:0;overflow-wrap:anywhere}
.section-name small,.topic small,.section-number{color:#59675f}
.section-selected{color:#19654e!important;font-weight:650!important}
.topic,.select-all,.answer-filter{min-height:48px}
.topic{border-radius:6px}
.topic.is-selected{background:#e6f0e9}
.topic+.topic{margin-top:3px}
.topic input{margin-left:0}
.plan-link{min-height:44px;display:inline-flex;align-items:center}
.search-heading{display:flex;align-items:center;justify-content:space-between;gap:8px;min-height:44px;margin-bottom:6px}
.search-heading label{margin:0;font-weight:600}
.search-heading button{font-size:12px;padding:8px 0 8px 8px;color:#14664e}
.search-field{display:flex;align-items:center;border:1px solid transparent;border-radius:12px;background:#e8e8ed;padding-left:12px;color:#636366}
.search-field:focus-within{outline:3px solid #007aff;outline-offset:3px}
.search-field svg{flex-shrink:0}
.search-field input{min-width:0;border:0;background:transparent;font-size:16px;padding:13px 10px;outline:0;box-shadow:none}
.search-field input:focus-visible{outline:0}
.search-field input::-webkit-search-cancel-button{-webkit-appearance:none}
#clear-search{flex-shrink:0;width:44px;border:0;background:transparent;font-size:24px;font-weight:400;padding:0}
#search-empty{font-size:14px;margin:12px 0 4px}
.selection-count{display:block}
.selection-total{display:flex;align-items:baseline;flex-wrap:wrap;gap:8px}
.selection-total strong{white-space:nowrap;font-variant-numeric:tabular-nums}
.selection-count #empty-hint{margin:6px 0 0;font-size:13px;color:#59675f}
.question-title:focus,.library-heading:focus,.completion h1:focus{outline:none}
.question-title img{max-width:100%;height:auto}
.question-title table{display:block;overflow-x:auto;font-size:16px;font-weight:400}
.question-title pre,.answer pre{max-width:100%;overscroll-behavior-x:contain}
.copy-code{min-height:44px}
.question-rating button{min-width:112px}
.learning-page> a:first-child{display:inline-flex;align-items:center;min-height:44px}
.learning-page pre{overflow-x:auto;padding:16px;border-radius:8px;background:#e8eeea}
.learning-page img{max-width:100%;height:auto}

/* One-column layout and thumb-accessible actions for phones and small tablets. */
@media(max-width:900px){
  html{scroll-padding-top:68px;scroll-padding-bottom:calc(var(--action-bar-height) + 24px)}
  body[data-view=setup],body[data-view=study]{padding-bottom:calc(var(--action-bar-height) + 20px)}
  .topbar{height:auto;min-height:64px;padding:8px max(16px,env(safe-area-inset-right,0px)) 8px max(16px,env(safe-area-inset-left,0px));gap:12px}
  .brand{flex:1;min-width:0;gap:10px;font-size:12px;line-height:1.35}
  .brandmark{flex-shrink:0;min-width:48px;text-align:center;font-size:19px;padding:6px}
  .help-button{width:44px;height:44px}
  main{padding:20px max(16px,env(safe-area-inset-right,0px)) 28px max(16px,env(safe-area-inset-left,0px))}
  .page-heading{display:flex;align-items:center;flex-wrap:wrap;gap:12px 8px;margin-bottom:8px}
  .page-heading .library-heading{flex:1;font-size:clamp(22px,6vw,28px);line-height:1.25;font-weight:700;letter-spacing:-.6px;text-transform:none;white-space:normal;color:#1c1c1e}
  .desktop-heading,.desktop-label{display:none}
  .mobile-heading,.mobile-label{display:inline}
  .page-heading .total{font-size:11px;gap:4px;padding:5px 8px;margin:0}
  .page-heading .total strong{font-size:12px}
  .library-intro{display:block;font-size:14px;line-height:1.6;color:#59675f;margin:0 0 20px}
  .page-heading .resume{flex-basis:100%;display:flex;flex-wrap:wrap;justify-content:space-between;gap:12px;margin:8px 0 4px;padding:14px;border:1px solid #e2e2e7;border-radius:16px;background:#fff;white-space:normal}
  .page-heading .resume>span{display:block;flex:1 1 130px;min-width:0;font-size:12px;color:#636366;overflow-wrap:anywhere}
  .page-heading .resume #resume{flex-shrink:0;justify-content:center;width:auto;max-width:100%;min-height:44px;padding:8px 12px;font-size:13px;gap:8px;white-space:normal;overflow-wrap:anywhere}
  .resume-label{display:inline}
  .setup-layout{display:flex;flex-direction:column;gap:20px}
  .settings{position:static;order:-1;width:100%;border:1px solid #e2e2e7;border-radius:16px;background:#fff;padding:0}
  .settings>h2,.settings>.eyebrow{display:none}
  .settings-toggle{display:flex;align-items:center;justify-content:space-between;gap:12px;width:100%;min-height:72px;text-align:left;padding:14px 16px;border:0;background:transparent;border-radius:16px}
  .settings-toggle>span:first-child{min-width:0}
  .settings-toggle strong{display:block;font-size:14px;font-weight:650}
  .settings-summary{display:block;font-size:12px;line-height:1.5;font-weight:400;color:#59675f;margin-top:3px;overflow-wrap:anywhere}
  .settings-chevron{font-size:22px;line-height:1;color:#19654e;flex-shrink:0;transition:transform .15s ease}
  .settings-expanded .settings-chevron{transform:rotate(180deg)}
  .settings .training-options{padding:4px 16px 16px;border-bottom:0}
  .settings:not(.settings-expanded) .training-options{display:none}
  .segmented span{font-size:14px;min-height:44px;display:flex;align-items:center;justify-content:center}
  .answer-filter{margin:8px 0;font-size:14px;line-height:1.5}
  .settings .progress-tools{display:flex;align-items:center;flex-wrap:wrap;gap:8px;margin-top:12px;padding-top:12px}
  .settings .progress-tools h3{margin:0 auto 0 0}
  .settings .progress-tools button{margin:0}
  .settings #import-status{flex-basis:100%;margin:0}
  .setup-actions,.question-nav{position:fixed;z-index:20;left:0;right:0;bottom:0;width:100%;max-width:none;margin:0;background:#fff;border-top:1px solid #d6e1d9;box-shadow:0 -4px 20px #173c2610;padding:12px max(16px,env(safe-area-inset-right,0px)) calc(12px + env(safe-area-inset-bottom,0px)) max(16px,env(safe-area-inset-left,0px));display:grid;align-items:center;gap:12px}
  .setup-actions{display:flex;flex-wrap:wrap}
  .setup-actions .selection-count{flex:1 1 132px;border:0;padding:0;min-width:min-content}
  .selection-total{gap:6px;flex-wrap:wrap}
  .setup-actions .selection-count strong{font-size:26px;line-height:1.15;color:#203c2c}
  .setup-actions .selection-count span{font-size:12px;color:#53665a}
  .setup-actions .selection-count #empty-hint{font-size:12px;line-height:1.35;margin-top:4px;overflow-wrap:anywhere}
  .setup-actions #start{flex:1 1 132px;width:auto;min-height:50px;padding:12px;font-size:16px;border-radius:12px;overflow-wrap:anywhere}
  .library{border-top:0;min-width:0}
  .topic-search{padding:0 0 16px;border-bottom:0}
  summary{padding:18px 0;gap:12px;min-height:76px}
  .section-number{min-width:20px;font-size:11px}
  .section-name{font-size:16px;line-height:1.4}
  .section-name small,.topic small{font-size:12px;line-height:1.5}
  .expand{flex-shrink:0;min-width:24px;text-align:center}
  .topic-list{padding:0 0 12px}
  .topic,.select-all{padding:13px 10px;font-size:15px;gap:12px;line-height:1.4;min-height:52px}
  .topic{align-items:flex-start}
  .topic input{margin-top:3px}
  .select-all{margin-bottom:8px}
  .plan-link{margin:0 0 8px 32px;font-size:14px}
  .empty-section{padding-left:32px;font-size:14px}
  .learning-start{padding:16px;margin-bottom:20px}
  .learning-start h2{font-size:20px;margin-bottom:8px}
  .track-grid{grid-template-columns:1fr}
  .track-card{min-height:0;padding:14px}
  .learning-start>a{display:inline-flex;align-items:center;min-height:44px;font-size:14px}
  body[data-view=study]{background:#fff}
  .study-top{position:sticky;top:0;z-index:5;background:#fff;padding:4px 0;gap:12px}
  .study-top .text-button{padding:10px 6px;font-size:14px}
  .study-top>span{flex-shrink:0;padding:5px 10px;border-radius:20px;background:#eaf2ed;color:#3c5e48;font-variant-numeric:tabular-nums}
  progress{margin:4px auto 20px}
  .question .eyebrow{font-size:11px;line-height:1.7;color:#59675f}
  .group{margin:12px 0 8px;font-size:13px}
  .question-title{font-size:22px;line-height:1.5;margin-bottom:20px}
  .question-title>p:not(:first-child){font-size:16px;line-height:1.7}
  .question-title pre,.answer pre{font-size:13px;line-height:1.7}
  .reveal{display:block;width:100%;min-height:48px;margin-bottom:20px;border-radius:12px}
  .answer{font-size:16px;line-height:1.75;padding-top:20px}
  .answer ul,.answer ol,.question-title ul,.question-title ol{padding-left:24px}
  .answer h2{font-size:20px;margin:24px 0 12px}
  .answer h3{font-size:18px;margin:20px 0 12px}
  .source-link{display:inline-flex;align-items:center;min-height:44px;margin:12px 0 8px;font-size:13px}
  .question-rating{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin:24px 0 8px}
  .question-rating legend{font-size:14px}
  .question-rating button{width:100%;min-width:0;min-height:48px}
  .question-nav{grid-template-columns:minmax(0,1fr) minmax(0,1fr)}
  .question-nav button{width:100%;min-width:0;min-height:50px;padding:12px 8px;font-size:15px;border-radius:12px;overflow-wrap:anywhere}
  .site-footer{padding:8px max(16px,env(safe-area-inset-right,0px)) 12px max(16px,env(safe-area-inset-left,0px))}
  .site-footer nav{gap:4px 8px}
  .site-footer a{min-height:44px;display:inline-flex;align-items:center;font-size:12px}
  #storage-warning{z-index:30;bottom:calc(var(--action-bar-height) + 8px);border-top:1px solid #dcc38a}
  body[data-view=done] #storage-warning{bottom:0}
  .completion{margin:28px auto}
  .completion h1{font-size:30px}
  .completion>div{display:grid;grid-template-columns:1fr;gap:10px;margin-top:24px}
  .completion button{width:100%;min-height:48px}
  .learning-page h1{font-size:27px;line-height:1.3;margin:16px 0 24px}
  .learning-page h2{font-size:21px;margin:28px 0 16px}
  .learning-page ul,.learning-page ol{padding-left:24px}
  .learning-page table,.learning-page tbody,.learning-page tr,.learning-page td{display:block;width:100%;min-width:0}
  .learning-page table{overflow:visible;border:0;font-size:15px;margin:20px 0}
  .learning-page thead{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip-path:inset(50%);white-space:nowrap}
  .learning-page tr{border:1px solid #e2e2e7;border-radius:16px;overflow:hidden;background:#fff;margin-bottom:16px}
  .learning-page td{border:0;padding:12px 14px;overflow-wrap:anywhere}
  .learning-page td+td{border-top:1px solid #e5ece7}
  .learning-page td:first-child{background:#eaf2ed}
  .learning-page td::before{content:attr(data-label);display:block;font-size:12px;font-weight:650;color:#53665a;margin-bottom:6px}
}

/* Desktop layout: readable library, compact setup and persistent study controls. */
@media(min-width:901px){
  html{scroll-padding-top:80px;scroll-padding-bottom:calc(var(--action-bar-height) + 40px)}
  .topbar{height:72px;padding:0 max(32px,calc((100% - 1216px)/2))}
  .brand{font-size:14px;gap:12px}
  .brandmark{font-size:20px;padding:6px 9px}
  main{max-width:1280px;padding:32px 32px 56px}
  .site-footer nav{max-width:1216px}
  .page-heading{flex-wrap:wrap;gap:12px 16px;margin-bottom:10px}
  .page-heading .library-heading{min-width:0;font-size:32px;line-height:1.25;font-weight:700;letter-spacing:-.8px;white-space:normal;text-transform:none;color:#1c1c1e}
  .page-heading .total{padding:6px 10px;font-size:12px}
  .page-heading .resume{flex-wrap:wrap;gap:8px 12px;min-width:0;white-space:normal}
  .page-heading .resume>span{color:#636366;overflow-wrap:anywhere}
  .page-heading .resume #resume{flex-shrink:0;border-radius:10px;font-size:13px}
  .library-intro{display:block;color:#636366;font-size:15px;line-height:1.6;margin:0 0 28px}
  .setup-layout{grid-template-columns:minmax(0,1fr) 320px;gap:28px;align-items:start}
  .library{min-width:0}
  .topic-search{border:1px solid #e2e2e7;border-radius:16px;background:#fff;padding:16px;margin-bottom:16px}
  .search-heading{min-height:28px;margin-bottom:10px;gap:12px}
  .search-heading label{font-size:13px}
  .search-heading button{min-height:28px;padding:2px 0 2px 8px;font-size:12px}
  .search-field input{font-size:16px;padding:12px 10px}
  .library details{padding:0 20px;margin-bottom:12px;border-radius:16px}
  .library summary{gap:16px;padding:18px 0;min-height:78px}
  .section-name{font-size:17px;line-height:1.4}
  .section-name small,.topic small{font-size:12px;line-height:1.5}
  .library .topic-list{padding:0 0 16px}
  .topic{min-height:62px;padding:11px 12px;border-radius:10px;font-size:14px;line-height:1.45;align-items:flex-start}
  .topic input{margin-top:3px}
  .select-all{min-height:44px;font-size:13px;padding:10px 12px;margin-bottom:8px}
  .plan-link{margin:0 0 8px 40px;font-size:13px}
  .settings{top:16px;min-width:0;max-height:calc(100vh - 32px);max-height:calc(100dvh - 32px);overflow-y:auto;overscroll-behavior-y:contain;scrollbar-width:thin;scroll-padding-block:16px;padding:20px;border-radius:18px}
  .settings>.eyebrow{font-size:11px;margin-bottom:6px}
  .settings>h2{font-size:21px;line-height:1.3;letter-spacing:-.4px;margin-bottom:18px}
  .settings .training-options{padding:0}
  .settings legend{font-size:12px;color:#636366;margin-bottom:8px}
  .settings .segmented{border:0;border-radius:10px;background:#ededf1;padding:3px}
  .settings .segmented span{font-size:13px;min-height:38px;display:flex;align-items:center;justify-content:center;border-radius:8px;padding:7px 4px}
  .settings .answer-filter{min-height:44px;font-size:13px;margin:6px 0;gap:10px}
  .setup-actions{margin-top:16px;padding-top:16px;border-top:1px solid #e8e8ed}
  .setup-actions .selection-count{display:block;border:0;padding:0;margin-bottom:14px}
  .setup-actions .selection-count strong{font-size:32px;line-height:1.2;color:#203c2c}
  .setup-actions .selection-count #empty-hint{min-width:0;margin:4px 0 0;font-size:12px;line-height:1.45;overflow-wrap:anywhere}
  .setup-actions #start{min-height:48px;font-size:14px;border-radius:12px}
  .settings .progress-tools{display:flex;align-items:center;flex-wrap:wrap;gap:6px;margin-top:16px;padding-top:16px;border-color:#e8e8ed}
  .settings .progress-tools h3{margin:0 auto 0 0;font-size:12px;color:#636366}
  .settings .progress-tools button{min-height:36px;padding:7px 10px;margin:0;font-size:12px;border-radius:8px}
  .settings #import-status{flex-basis:100%;margin:4px 0 0;font-size:12px}
  .learning-start{padding:24px;border-color:#e2e2e7;border-radius:18px}
  .learning-start h2{font-size:23px;letter-spacing:-.4px}
  .track-card{padding:18px;border-radius:12px}
  body[data-view=study]{padding-bottom:calc(var(--action-bar-height) + 40px)}
  .study-top{position:sticky;top:0;z-index:10;max-width:880px;padding:10px 8px;background:#f2f2f7;gap:16px}
  .study-top .text-button{padding:10px 8px;font-size:14px}
  .study-top>span{font-size:13px;padding:5px 12px;border-radius:20px;background:#e6eee8;color:#395c47;font-variant-numeric:tabular-nums}
  progress{max-width:880px;margin:4px auto 24px;border-radius:3px;overflow:hidden}
  .question{max-width:880px;padding:28px 32px;background:#fff;border:1px solid #e2e2e7;border-radius:20px}
  .question .eyebrow{font-size:12px;line-height:1.6;color:#636366}
  .group{font-size:13px;margin:12px 0 10px}
  .question-title{font-size:28px;line-height:1.4;letter-spacing:-.4px;margin-bottom:24px}
  .question-title>p:not(:first-child){font-size:16px;line-height:1.75;letter-spacing:0}
  .reveal{min-width:180px;min-height:46px;font-size:14px;border-radius:12px;margin-bottom:24px}
  .answer{font-size:16px;line-height:1.8;padding-top:24px;border-color:#e5e5ea}
  .answer h2{font-size:23px;margin:28px 0 16px}
  .answer h3{font-size:19px;margin:24px 0 12px}
  .answer pre,.question-title pre{font-size:14px;line-height:1.75}
  .code-example{border-radius:12px}
  .code-toolbar{padding:6px 10px;background:#f4f5f6}
  .question-rating{gap:10px;margin:24px 0 12px}
  .question-rating legend{font-size:13px;color:#636366}
  .question-rating button{min-width:130px;min-height:44px;font-size:14px;border-radius:10px}
  .source-link{display:inline-flex;align-items:center;min-height:44px;margin:12px 0 0;font-size:12px}
  .question-nav{position:fixed;z-index:20;left:50%;bottom:20px;transform:translateX(-50%);width:calc(100% - 64px);max-width:880px;padding:12px;border:1px solid #dedee5;border-radius:18px;background:#fff;box-shadow:0 8px 32px #1c1c1e14}
  .question-nav button{min-width:140px;min-height:46px;font-size:14px;border-radius:11px}
  .question-nav #next{min-width:180px}
  body[data-view=study] #storage-warning{z-index:30;bottom:calc(var(--action-bar-height) + 32px)}
  .completion{padding:36px 40px;background:#fff;border:1px solid #e2e2e7;border-radius:20px}
  .completion h1{font-size:36px;letter-spacing:-.8px}
  .completion>div{gap:10px;margin-top:28px}
  .completion button{font-size:14px}
  .learning-page{max-width:1120px;padding-top:36px}
  .learning-page h1{font-size:36px;line-height:1.25;letter-spacing:-.8px;max-width:900px}
  .learning-page h2{font-size:25px;letter-spacing:-.4px}
  .learning-page table{display:table;width:100%;table-layout:fixed;border-collapse:separate;border-spacing:0;border:1px solid #e2e2e7;border-radius:16px;overflow:hidden;background:#fff}
  .learning-page th,.learning-page td{min-width:0;border:0;border-right:1px solid #e8e8ed;border-bottom:1px solid #e8e8ed;padding:16px;font-size:14px;line-height:1.65;overflow-wrap:anywhere}
  .learning-page th{font-size:12px;background:#ededf2;color:#53535a}
  .learning-page th:first-child{width:20%}
  .learning-page th:last-child,.learning-page td:last-child{border-right:0}
  .learning-page tbody tr:last-child td{border-bottom:0}
}

@media(min-width:1200px){
  .library .topic-list{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:4px 12px}
  .library .select-all{grid-column:1 / -1;margin-bottom:4px}
  .library .topic+.topic{margin-top:0}
}

@media(min-width:901px) and (max-width:1100px){
  .page-heading .resume>span{display:none}
  .setup-layout{grid-template-columns:minmax(0,1fr) 300px;gap:24px}
}

@media(min-width:901px) and (max-height:740px){
  main{padding-top:24px}
  .library-intro{margin-bottom:20px}
  .settings{padding:16px}
  .settings>h2{margin-bottom:12px}
  .setup-actions{margin-top:12px;padding-top:12px}
  .settings .progress-tools{margin-top:12px;padding-top:12px}
}

@media(prefers-reduced-motion:reduce){
  .settings-chevron{transition:none}
}