.container.learn-overview{max-width:928px;padding-top:72px;padding-bottom:96px}.learn-hero h1{margin:0;font-size:clamp(36px,6vw,56px);font-weight:var(--display-weight);letter-spacing:var(--display-tracking);line-height:1.05;color:var(--fg-strong);text-wrap:balance}.learn-lede{margin:20px 0 0;max-width:640px;font-size:18px;line-height:1.6;color:var(--muted)}.learn-cta{display:flex;margin-top:32px;height:40px}.learn-meta{margin:14px 0 0;font-size:13px;color:var(--subtle)}.learn-meter{margin-top:32px;max-width:320px}.learn-meter-label{display:flex;justify-content:space-between;font-size:12.5px;color:var(--subtle);margin-bottom:8px}.learn-meter-track{height:4px;border-radius:999px;background:var(--bg-3);overflow:hidden}.learn-meter-track>span{display:block;height:100%;background:var(--green);transform-origin:left center;transition:transform .4s ease}[dir=rtl] .learn-meter-track>span{transform-origin:right center}.learn-chapters{list-style:none;margin:56px 0 0;padding:0;border:1px solid var(--line);border-radius:var(--radius-lg);overflow:hidden}.learn-chapters li+li{border-top:1px solid var(--line)}.learn-chapter-card{display:flex;align-items:center;gap:16px;padding:18px 20px;background:var(--bg);transition:background .15s ease}.learn-chapter-card:hover{background:var(--bg-1)}.learn-chapter-text{display:flex;flex-direction:column;gap:2px;min-width:0;flex:1}.learn-chapter-title{font-size:15px;font-weight:500;color:var(--fg)}.learn-chapter-summary{font-size:14px;color:var(--muted)}.learn-chapter-min{flex-shrink:0;font-size:13px;color:var(--subtle);font-variant-numeric:tabular-nums}.learn-check{flex-shrink:0;display:inline-flex;align-items:center;justify-content:center;width:28px;height:28px;border-radius:999px;border:1px solid var(--line-2);font-family:var(--mono);font-size:11.5px;color:var(--subtle);transition:background .2s ease,border-color .2s ease,color .2s ease}.learn-check.done{border-color:#45a55780;background:#45a5571f;color:var(--green-2);font-size:13px}.learn-section{margin-top:64px}.learn-section h2{margin:0 0 8px;font-size:24px;font-weight:600;letter-spacing:-.03em;color:var(--fg-strong);scroll-margin-top:calc(var(--header-h) + 24px)}.learn-section-lede{margin:0 0 20px;font-size:15px;color:var(--muted)}.learn-video{margin:0 0 40px}.learn-video-frame{position:relative;aspect-ratio:16 / 9;overflow:hidden;border:1px solid var(--line);border-radius:var(--radius-lg);background:#000}.learn-video-frame:focus{outline:none}.learn-video-player{width:100%;height:100%}.learn-video-player video{display:block;width:100%;height:100%;background:#000}.learn-video-player.floating{position:fixed;inset-inline-end:20px;bottom:72px;z-index:58;display:flex;flex-direction:column;width:min(clamp(320px,26vw,400px),calc(100vw - 40px));height:auto;overflow:hidden;border:1px solid var(--line-2);border-radius:var(--radius-lg);background:var(--bg-1);box-shadow:0 16px 48px -12px #000000d9;animation:learn-mini-in .2s cubic-bezier(.2,.8,.2,1)}.learn-video-player.floating video{height:auto;aspect-ratio:16 / 9}.learn-video-player.docking{visibility:hidden}.learn-video-player.docked{animation:learn-dock-in .18s ease-out}@keyframes learn-dock-in{0%{opacity:0}}@keyframes learn-mini-in{0%{opacity:0;transform:translateY(12px)}}.learn-mini-bar{display:flex;align-items:center;gap:2px;height:36px;padding-block:0;padding-inline:2px 4px;border-bottom:1px solid var(--line)}.learn-mini-back{display:inline-flex;flex:1;align-items:center;gap:8px;min-width:0;height:28px;padding:0 8px;border:0;border-radius:6px;background:none;color:var(--muted);font-size:13px;text-align:start;cursor:pointer}.learn-mini-back span{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.learn-mini-back svg{flex:none}.learn-mini-btn{display:inline-flex;flex:none;align-items:center;justify-content:center;min-width:28px;height:28px;padding:0;border:1px solid transparent;border-radius:6px;background:none;color:var(--muted);cursor:pointer}.learn-mini-back:hover,.learn-mini-btn:hover{color:var(--fg);background:var(--bg-2)}.learn-mini-cc{padding:0 6px;font-family:var(--mono);font-size:11px;font-weight:600}.learn-mini-cc[aria-pressed=true]{color:var(--fg);border-color:var(--line-2);background:var(--bg-2)}@media(max-width:640px),(hover:none)and (pointer:coarse){.learn-video-player.floating{bottom:16px}}.learn-video-player.floating.compact{inset-inline-start:8px;inset-inline-end:8px;bottom:calc(8px + env(safe-area-inset-bottom));flex-direction:row;align-items:center;width:auto}.learn-video-player.floating.compact video{flex:none;width:112px;cursor:pointer}.learn-video-player.floating.compact .learn-mini-bar{order:1;flex:1;min-width:0;height:63px;padding-block:0;padding-inline:4px 6px;border-bottom:0}.learn-video-player.floating.compact .learn-mini-btn{min-width:36px;height:36px}@media(prefers-reduced-motion:reduce){.learn-video-player.floating,.learn-video-player.docked{animation:none}}.learn-video figcaption{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-top:10px;font-size:13px;color:var(--muted)}.learn-video-meta{display:inline-flex;align-items:center;gap:10px;font-family:var(--mono);font-size:12.5px;color:var(--subtle);font-variant-numeric:tabular-nums}.learn-video-cc{height:22px;margin:-1px 0;padding:0 8px;border:1px solid var(--line);border-radius:999px;background:none;color:var(--subtle);font:inherit;cursor:pointer;transition:color .15s ease,border-color .15s ease,background-color .15s ease}.learn-video-cc:hover{color:var(--fg);border-color:var(--line-2)}.learn-video-cc[aria-pressed=true]{color:var(--fg);border-color:var(--line-3);background:var(--bg-2)}.learn-section-lede kbd,.learn-live-note kbd{height:20px;vertical-align:1px}.learn-pad .pad{background:radial-gradient(ellipse 60% 45% at 50% 0%,rgba(255,255,255,.035),transparent 70%),var(--bg-1)!important}.learn-layout{display:grid;grid-template-columns:248px minmax(0,1fr);max-width:1200px;margin:0 auto}.learn-sidebar{position:sticky;top:var(--header-h);height:calc(100vh - var(--header-h));overflow-y:auto;padding-block:28px 48px;padding-inline:24px 16px;border-inline-end:1px solid var(--line);scrollbar-width:thin}.learn-sidebar-head{display:block;padding:0 10px;font-size:13px;font-weight:600;color:var(--fg)}.learn-sidebar .learn-meter{margin:14px 10px 18px}.learn-sidebar ol{list-style:none;margin:0;padding:0}.learn-sidebar li a{display:flex;align-items:center;gap:10px;padding:6px 10px;border-radius:6px;font-size:14px;color:var(--muted);transition:color .15s ease,background .15s ease}.learn-sidebar li a:hover{color:var(--fg)}.learn-sidebar li a[aria-current=page]{color:var(--fg-strong);background:var(--bg-3);font-weight:500}.learn-sidebar .learn-check{width:20px;height:20px;font-size:10.5px}.learn-body{display:flex;flex-direction:column;min-width:0}.learn-body .learn-main{flex:1}.learn-body .footer .container{padding:0 56px}.learn-main{width:100%;padding:40px 56px 96px;min-width:0;max-width:820px}.learn-live-note{display:flex;align-items:center;gap:10px;margin:0 0 32px;padding:10px 14px;border:1px solid var(--line);border-radius:var(--radius);background:var(--bg-1);font-size:14px;color:var(--muted)}.learn-live-note .dot{flex-shrink:0;width:7px;height:7px;border-radius:999px;background:var(--green)}.learn-live-note a{color:var(--fg);text-decoration:underline;text-decoration-color:var(--line-3);text-underline-offset:3px}.learn-outline{margin:0 0 40px}.learn-outline h2{margin:0 0 8px;font-size:13px;font-weight:500;color:var(--fg)}.learn-outline ul{margin:0;padding-inline-start:18px;font-size:14.5px;color:var(--muted)}.learn-body>.prose+.prose{margin-top:16px}.learn-diff-stat{display:inline-flex;gap:6px;margin-inline-start:4px;font-size:11.5px}.learn-diff-stat .add{color:var(--green-2)}.learn-diff-stat .del{color:var(--red)}.learn-diff .code code{display:inline-block;min-width:100%}.learn-diff .code .line{padding-inline-start:0}.learn-diff .code .mark{display:inline-block;width:28px;text-align:center;color:var(--faint);user-select:none}.learn-diff .code .line.add{background:#45a5571a;box-shadow:inset 2px 0 0 var(--green)}.learn-diff .code .line.add .mark{color:var(--green-2)}.learn-diff .code .line.del{background:#e5484d14;box-shadow:inset 2px 0 0 var(--red)}.learn-diff .code .line.del .mark{color:var(--red)}.learn-diff .code .line.del>:not(.mark){opacity:.65}.learn-quiz{margin-top:64px;padding-top:40px;border-top:1px solid var(--line)}.learn-quiz-head{display:flex;align-items:baseline;justify-content:space-between;gap:16px}.learn-quiz-head h2{margin:0;font-size:24px;font-weight:600;letter-spacing:-.03em;color:var(--fg-strong);scroll-margin-top:calc(var(--header-h) + 24px)}.learn-status{font-size:13px;color:var(--subtle);white-space:nowrap}.learn-status.done{color:var(--green-2)}.learn-quiz-lede{margin:6px 0 24px;font-size:15px;color:var(--muted)}.learn-question{margin:0 0 20px;padding:0;border:0;min-width:0}.learn-question legend{padding:0;margin-bottom:12px;font-size:15.5px;font-weight:500;color:var(--fg)}.learn-options{display:grid;gap:8px}.learn-option{display:flex;align-items:center;gap:12px;width:100%;min-height:44px;padding:8px 14px;border:1px solid var(--line-2);border-radius:var(--radius);background:var(--bg);font-size:14.5px;text-align:start;color:var(--muted);cursor:pointer;transition:border-color .15s ease,background .15s ease,color .15s ease}.learn-option:hover{border-color:var(--line-3);color:var(--fg)}.learn-option-key{flex-shrink:0;display:inline-flex;align-items:center;justify-content:center;width:22px;height:22px;border-radius:5px;border:1px solid var(--line-2);font-family:var(--mono);font-size:11px;color:var(--subtle)}.learn-option.right{border-color:#45a55799;background:#45a55714;color:var(--fg)}.learn-option.right .learn-option-key{border-color:var(--green);color:var(--green-2)}.learn-option.wrong{border-color:#e5484d8c;background:#e5484d0f;color:var(--fg)}.learn-option.wrong .learn-option-key{border-color:var(--red);color:var(--red)}.learn-feedback{margin:10px 0 0;min-height:1.6em;font-size:14px;color:var(--subtle)}.learn-feedback.right{color:var(--green-2)}.learn-feedback.wrong{color:var(--red)}.learn-cert-status{margin:-16px 0 28px;font-size:14px;color:var(--subtle);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.learn-cert-status.done{color:var(--green-2)}.learn-name{display:flex;flex-direction:column;gap:8px;max-width:360px;margin-bottom:24px;font-size:13px;color:var(--muted)}.learn-name input{height:40px;padding:0 12px;border:1px solid var(--line-2);border-radius:var(--radius);background:var(--bg-1);color:var(--fg);font:inherit;font-size:15px}.learn-name input:focus{outline:none;border-color:var(--line-3);box-shadow:0 0 0 3px #ffffff0f}.learn-cert{overflow-x:auto;padding:28px 0;border:1px solid var(--line);border-radius:var(--radius-lg);background:radial-gradient(ellipse 70% 60% at 50% 0%,rgba(255,255,255,.04),transparent 70%),var(--bg-1);text-align:center}.learn-cert pre{display:inline-block;margin:0;font-size:min(13px,2.55vw);line-height:1.25;color:var(--fg);text-align:start}.learn-cert.pending pre{color:var(--subtle)}.learn-reset{margin-top:48px;font-size:13px}.learn-reset .text-link{background:none;border:0;padding:0;cursor:pointer;color:var(--subtle)}.learn-reset a{margin-inline-start:20px}@media(max-width:960px){.learn-layout{grid-template-columns:minmax(0,1fr)}.learn-body .footer .container{padding:0 20px}.learn-sidebar{display:none}.learn-main{margin:0 auto;padding:28px 20px 80px}}@media(max-width:640px){.container.learn-overview{padding-top:40px}.learn-lede{font-size:16px}.learn-chapter-card{align-items:flex-start;padding:16px;gap:12px}.learn-chapter-min{display:none}.learn-cert{padding:20px 0}}@media(hover:none)and (pointer:coarse){.learn-live-note{display:none}}.learn-main .breadcrumbs{display:flex}@media print{@page{margin:.5in}html:has(.learn-cert),html:has(.learn-cert) body{height:auto!important;min-height:0!important;overflow:visible!important;background:#fff!important;color:#000!important}html:has(.learn-cert) body *:not(:has(.learn-cert)):not(.learn-cert):not(.learn-cert *){display:none!important}html:has(.learn-cert) body *:has(.learn-cert){display:block!important;position:static!important;width:auto!important;max-width:none!important;height:auto!important;min-height:0!important;margin:0!important;padding:0!important;border:0!important;overflow:visible!important;background:none!important;box-shadow:none!important;transform:none!important;filter:none!important;backdrop-filter:none!important;contain:none!important;container-type:normal!important;will-change:auto!important}html:has(.learn-cert) body:before,html:has(.learn-cert) body:after,html:has(.learn-cert) body *:has(.learn-cert):before,html:has(.learn-cert) body *:has(.learn-cert):after{content:none!important;display:none!important}html:has(.learn-cert) .learn-cert{position:fixed!important;inset:0!important;display:flex!important;align-items:center;justify-content:center;margin:0!important;padding:0!important;overflow:visible!important;border:0!important;border-radius:0!important;background:none!important;box-shadow:none!important}html:has(.learn-cert) .learn-cert pre{font-family:var(--mono);font-size:12pt;line-height:1.25;color:#000!important}}