/* Beginner guide: reading progress, sticky contents, quizzes, worksheets. */
.zh-readbar{position:fixed;top:0;left:0;right:0;height:4px;z-index:80;background:color-mix(in oklab,var(--border) 70%,transparent);pointer-events:none}
.zh-readbar__fill{height:100%;width:0;background:#3538F5}
.zh-crumbs{display:flex;flex-wrap:wrap;gap:.35rem .45rem;justify-content:center;align-items:center;margin:0 auto .8rem;font-size:.82rem;color:var(--muted-foreground)}
.zh-crumbs a{color:inherit;text-decoration:underline;text-underline-offset:.15em}
.zh-crumbs [aria-current="page"]{color:var(--foreground)}
.zh-art .zh-toc-tools{display:grid;gap:.45rem;margin:0 0 .8rem}
.zh-art .zh-count{margin:0;font-weight:700;color:var(--foreground);font-size:.92rem}
.zh-art .zh-resume{font-size:.88rem;line-height:1.4}
.zh-toc-toggle{min-height:2.75rem;border-radius:.75rem;border:1px solid var(--border);background:transparent;color:var(--foreground);font:inherit;font-weight:600;cursor:pointer}
@media (min-width:1024px){
  .zh-toc-toggle{display:none}
  .zh-art .zh-toc-card .mk-list{max-height:calc(100vh - 12rem);overflow:auto;padding-right:.15rem}
}
@media (max-width:1023px){
  .zh-art .mk-aside{position:sticky;top:4px;z-index:40}
  .zh-art .zh-toc-card{background:var(--background);box-shadow:0 10px 28px rgb(0 0 0 / .16)}
  .zh-art .zh-toc-card:not(.is-collapsed) .mk-list{max-height:min(52vh,24rem);overflow:auto}
}
.zh-art .mk-list.zh-toc-on li::before{display:none}
.zh-art .mk-list.zh-toc-on li{align-items:center}
.zh-art .mk-list.zh-toc-on a{flex:1;text-decoration:none;padding:.35rem 0;min-height:2.75rem;display:flex;align-items:center}
.zh-art .mk-list.zh-toc-on a:hover,.zh-art .mk-list.zh-toc-on a[aria-current="true"]{text-decoration:underline}
.zh-art .mk-list.zh-toc-on a[aria-current="true"]{font-weight:700;color:var(--foreground)}
.zh-tick{flex:none;width:2.75rem;height:2.75rem;border-radius:.55rem;border:1.5px solid var(--border);background:transparent;color:transparent;cursor:pointer;display:grid;place-items:center}
.zh-tick[aria-pressed="true"]{background:#3538F5;border-color:#3538F5;color:#fff}
.zh-tick[aria-pressed="true"]::after{content:"";width:.38rem;height:.7rem;border:solid #fff;border-width:0 2px 2px 0;transform:rotate(45deg);margin-top:-.15rem}
.zh-tick:focus-visible,.zh-toc-toggle:focus-visible,.zh-quiz input:focus-visible,.zh-note a:focus-visible{outline:2px solid #3538F5;outline-offset:3px}
.zh-art .mk-prose .zh-fig{margin:0 0 1.4rem}
.zh-art .mk-prose .zh-fig img,.zh-art .mk-prose img{max-width:100%;height:auto;border-radius:1rem;border:1px solid var(--border);background:#f4f6fb}
.zh-art .mk-prose figcaption{margin-top:.45rem;font-size:.88rem;color:var(--muted-foreground)}
.zh-svg{display:block;width:100%;height:auto;margin:0 0 1.2rem;color:var(--foreground)}
.zh-code{overflow:auto;padding:1rem 1.1rem;border-radius:1rem;border:1px solid var(--border);background:color-mix(in oklab,var(--card) 88%,transparent);font-size:.92rem;line-height:1.55}
.zh-note,.zh-close{margin:1.4rem 0 1.6rem;padding:1rem 1.1rem;border-radius:1rem;border:1px solid color-mix(in oklab,var(--accent) 45%,var(--border));background:color-mix(in oklab,var(--accent) 8%,var(--card))}
.zh-note p,.zh-close p{margin:0 0 .7rem}
.zh-note__actions,.zh-close .zh-note__actions{display:flex;flex-wrap:wrap;gap:.6rem;margin:.2rem 0 0}
.zh-sheet{margin:0 0 1.4rem;padding:1rem 1.1rem 1.1rem;border:1px solid var(--border);border-radius:1rem;background:color-mix(in oklab,var(--card) 90%,transparent)}
.zh-faq{margin:0 0 1.1rem}
.zh-quiz{margin:1.2rem 0 1.8rem;padding:1rem 1rem 1.1rem;border:1px solid var(--border);border-radius:1rem;background:color-mix(in oklab,var(--card) 90%,transparent)}
.zh-quiz__hint,.zh-quiz__score{margin:.2rem 0 .7rem;color:var(--muted-foreground);font-size:.92rem}
.zh-quiz__score{font-weight:700;color:var(--foreground)}
.zh-q{border:0;margin:0 0 1rem;padding:0;min-inline-size:0}
.zh-q legend{font-weight:650;padding:0;margin:0 0 .45rem;line-height:1.4}
.zh-opt{display:flex;flex-wrap:wrap;gap:.15rem .65rem;align-items:flex-start;padding:.65rem .75rem;border-radius:.75rem;border:1px solid var(--border);margin:.4rem 0;cursor:pointer}
.zh-opt input{width:1.15rem;height:1.15rem;margin-top:.2rem;accent-color:#3538F5;flex:none}
.zh-opt__t{flex:1;min-width:12rem}
.zh-opt__why{display:none;flex-basis:100%;margin:.35rem 0 0 1.8rem;color:var(--muted-foreground);font-size:.92rem}
.zh-q.is-answered .zh-opt.is-correct{border-color:#15803d}
.zh-q.is-answered .zh-opt.is-picked.is-wrong{border-color:#b91c1c}
.zh-q.is-answered .zh-opt.is-picked .zh-opt__why,.zh-q.is-answered .zh-opt.is-correct .zh-opt__why{display:block}
.zh-scoreboard{margin:1rem 0 1.5rem;padding:1rem 1.1rem;border-radius:1rem;border:1px solid var(--border)}
.zh-scoreboard p{margin:0 0 .4rem}
@media (prefers-reduced-motion:reduce){
  .zh-readbar__fill{transition:none}
}
.zh-anno{margin:0 0 1.4rem}
.zh-anno__stage{position:relative;border-radius:1rem;overflow:hidden;border:1px solid var(--border);background:#111}
.zh-anno__stage img{display:block;width:100%;height:auto}
.zh-hot{position:absolute;z-index:2;width:2.25rem;height:2.25rem;border-radius:999px;border:2px solid #fff;background:#3538F5;color:#fff;font:700 .95rem/1 inherit;cursor:pointer;box-shadow:0 0 0 6px rgb(53 56 245 / .35);transform:translate(-50%,-50%)}
.zh-hot[aria-expanded="true"],.zh-hot:hover{background:#fff;color:#111}
.zh-hot:focus-visible{outline:2px solid #fff;outline-offset:3px}
.zh-tip{position:absolute;z-index:3;left:1rem;right:1rem;bottom:1rem;margin:0;padding:.75rem .85rem;border-radius:.8rem;background:#0b1026;color:#fff;font-size:.92rem;line-height:1.45;box-shadow:0 12px 30px rgb(0 0 0 / .35)}
.zh-tip strong{display:block;margin-bottom:.15rem}
.zh-ba{position:relative;aspect-ratio:1100/688;border-radius:1rem;overflow:hidden;border:1px solid var(--border);background:#111;margin:0 0 .6rem;container-type:inline-size}
.zh-ba img{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;object-position:top center}
.zh-ba__clip{position:absolute;inset:0 auto 0 0;width:var(--p,55%);overflow:hidden;border-right:3px solid #fff}
.zh-ba__clip img{width:100cqi;max-width:none;height:100%}
.zh-ba input[type="range"]{position:absolute;inset:auto 0 .6rem 0;width:calc(100% - 1.5rem);margin:0 auto;z-index:4;accent-color:#3538F5}
.zh-ba__key{display:flex;justify-content:space-between;gap:1rem;font-size:.82rem;color:var(--muted-foreground);margin:0 0 1rem}
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
@media (hover:hover){
  .zh-anno__stage:hover .zh-hot{box-shadow:0 0 0 8px rgb(53 56 245 / .28)}
}
@media print{
  .zh-readbar,.zh-toc-tools,.zh-tick,.zh-hot,.zh-ba input{display:none}
}