:root{--ink:#172b47;--muted:#65748a;--line:#dce3ec;--paper:#f5f7fb;--white:#fff;--navy:#172b47;--lime:#d4f593;--blue:#365bdc;--radius:19px;font-family:Inter,"Segoe UI",Arial,sans-serif;font-size:16px;color:var(--ink);background:var(--paper);color-scheme:light}*{box-sizing:border-box}body{margin:0}button,input,select,textarea{font:inherit}button,a,input,select,textarea{touch-action:manipulation}a{color:inherit}button{cursor:pointer}button:disabled{cursor:default;opacity:.6}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible,summary:focus-visible{outline:3px solid 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@media(max-width:740px){.sidebar{position:static;width:100%;padding:16px 18px;border-right:0;border-bottom:1px solid var(--line)}.brand{font-size:1.65rem}.brand-mark{width:34px;height:34px;font-size:1.3rem}.sidebar-label,.sidebar-bottom{display:none}nav{position:fixed;bottom:0;left:0;right:0;display:grid;grid-template-columns:repeat(5,minmax(0,1fr));background:#fffffff5;backdrop-filter:blur(14px);border-top:1px solid var(--line);padding:7px 5px calc(7px + env(safe-area-inset-bottom));gap:2px;z-index:10}nav a{flex-direction:column;justify-content:center;gap:5px;padding:8px 1px;font-size:.75rem;min-width:0;border-radius:9px;min-height:54px;line-height:1.3}nav .nav-icon{font-size:1.25rem;height:20px}nav .code-icon{font-size:.875rem;line-height:20px}nav b{display:none!important}.shell{margin-left:0;padding-bottom:calc(80px + env(safe-area-inset-bottom))}header{padding:14px 20px;min-height:45px;font-size:.8125rem}main{padding:26px 20px;min-height:60vh}.page-heading{gap:15px;margin-bottom:22px}.page-heading h1{font-size:2.1rem}.page-heading .eyebrow{font-size:.75rem}.dashboard-grid{grid-template-columns:1fr;gap:18px}.feature{min-height:310px;padding:26px}.feature h2{font-size:2rem}.practice-card{padding:24px}.stats{gap:9px;margin:18px 0 26px}.stat{padding:16px 11px}.stat strong{font-size:1.4rem}.stat span{font-size:.8125rem;line-height:1.5;display:block}.lesson-row{padding:15px 14px;gap:12px}.row-end{font-size:.8125rem;max-width:55px}.lesson-row p{font-size:.8125rem}.lesson-number{width:34px;height:34px}.module-summary{grid-template-columns:1fr;gap:10px}.panel{padding:23px}.grid-two{grid-template-columns:1fr}.tabs{gap:7px}.tab{padding:10px 12px}.lesson-layout h1{font-size:2rem}.flashcard h2{font-size:1.6rem}.btn-row .btn{flex-grow:1}.section-head{align-items:start}.section-head h2{font-size:1.25rem}footer{padding-inline:20px}.activity-grid{gap:4px}.skip{left:10px}.code-editor{padding:14px;font-size:1rem;min-height:310px}.editor-bar{padding:12px 14px}.lesson-layout{gap:0}.terminal{margin-bottom:20px}#toast{bottom:calc(92px + env(safe-area-inset-bottom));width:max-content;max-width:calc(100% - 32px)}pre{padding:16px;font-size:.875rem}.level-pill{font-size:.8125rem}.lesson-header{flex-wrap:wrap}.practice-card .btn{width:100%}}
@media(max-width:370px){main{padding-inline:15px}nav a{font-size:.6875rem}.stats{grid-template-columns:1fr}.stat{display:flex;gap:15px;align-items:center}.stat strong{margin:0}.lesson-row{gap:8px}}
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.tab{text-decoration:none}label.btn:focus-visible{outline:3px solid #365bdc;outline-offset:4px}
.school-link{display:flex;align-items:center;gap:8px;min-height:44px;margin-top:12px;font-size:.875rem;font-weight:650;line-height:1.5;text-decoration:none;color:var(--blue)}.school-link:hover{text-decoration:underline}