.expand-content:where(.astro-5lfx4xea){grid-template-rows:0fr}.expanded:where(.astro-5lfx4xea) .expand-content:where(.astro-5lfx4xea){grid-template-rows:1fr}svg:where(.astro-hn7k2gay){color:var(--sl-icon-color);font-size:var(--sl-icon-size, 1em);width:1.5em;height:1.5em}.sl-steps{--bullet-size: 1.75rem ;--bullet-margin: .375rem;list-style:none!important;counter-reset:steps-counter var(--sl-steps-start, 0);padding-inline-start:0!important}.sl-steps>li{counter-increment:steps-counter;position:relative;padding-inline-start:calc(var(--bullet-size) + 1rem);padding-bottom:1px;min-height:calc(var(--bullet-size) + var(--bullet-margin))}.sl-steps>li+li{margin-top:0}.sl-steps>li:before{content:counter(steps-counter);position:absolute;top:0;inset-inline-start:0;width:var(--bullet-size);height:var(--bullet-size);line-height:var(--bullet-size);font-size:.8125rem;font-weight:600;text-align:center;color:hsl(var(--foreground) / var(--un-text-opacity, 1));background-color:hsl(var(--card) / var(--un-bg-opacity, 1));border-radius:99rem;box-shadow:inset 0 0 0 1px hsl(var(--border) / var(--un-border-opacity, 1))}.sl-steps>li:after{--guide-width: 1px;content:"";position:absolute;top:calc(var(--bullet-size) + var(--bullet-margin));bottom:var(--bullet-margin);inset-inline-start:calc((var(--bullet-size) - var(--guide-width)) / 2);width:var(--guide-width);background-color:hsl(var(--border) / var(--un-border-opacity, 1))}.sl-steps>li>:first-child{--lh: 1.75em ;--shift-y: calc(.5 * (var(--bullet-size) - var(--lh)));margin-top:0;transform:translateY(var(--shift-y));margin-bottom:var(--shift-y);color:hsl(var(--foreground) / var(--un-text-opacity, 1))}.sl-steps>li>:first-child:where(h1,h2,h3,h4,h5,h6){--lh: 1.2em }footer:where(.astro-dojmed5u) a:where(.astro-dojmed5u){color:hsl(var(--foreground) / var(--un-text-opacity, 1));text-decoration:underline;font-weight:500}#toggleDarkMode:where(.astro-3ef6ksr2)[data-theme=dark] .system:where(.astro-3ef6ksr2),#toggleDarkMode:where(.astro-3ef6ksr2)[data-theme=light] .system:where(.astro-3ef6ksr2){display:none}#toggleDarkMode:where(.astro-3ef6ksr2)[data-theme=dark] .dark:where(.astro-3ef6ksr2){display:block}#toggleDarkMode:where(.astro-3ef6ksr2)[data-theme=light] .light:where(.astro-3ef6ksr2){display:block}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,PingFang SC,Hiragino Sans GB,Microsoft YaHei,sans-serif}@keyframes fade-in-up{0%{transform:translateY(2rem);opacity:0}to{transform:translateY(0);opacity:1}}.animate{opacity:0;animation:.3s fade-in-up;animation-fill-mode:forwards}@media(prefers-reduced-motion){.animate{opacity:0;animation:.1s fade-in-up;animation-fill-mode:forwards}}#content-header{animation-delay:50ms}#content{animation-delay:.1s}#sidebar{animation-delay:.15s}span.katex-display{overflow-y:scroll;padding:.5rem}.katex-html{overflow:auto hidden;padding:3px}.katex-html .base{margin-block:0;margin-inline:auto}.katex-html .tag{position:relative!important;display:inline-block;padding-inline-start:.5rem}.astro-code{margin-top:.5rem;margin-bottom:.5rem;border-radius:.75rem;background-color:hsl(var(--muted) / var(--un-bg-opacity, 1))!important;display:flex;flex-direction:column;& pre{margin:0;padding-top:.85rem;padding-bottom:.85rem;padding-inline:0;background:none;overflow-x:scroll;& code{display:block;width:fit-content;min-width:100%;min-height:1.5rem;counter-reset:step;counter-increment:step 0;&:before{position:absolute;inset-inline-start:0;width:2.75rem;top:.8571429em;bottom:0;content:"";display:block;background-color:hsl(var(--muted) / var(--un-bg-opacity, 1));z-index:1}.line{padding-inline-end:3rem;&:before{position:sticky;content:counter(step);counter-increment:step;color:hsl(var(--muted-foreground) / .6);background-color:hsl(var(--muted) / var(--un-bg-opacity, 1));inset-inline-start:0;justify-content:end;display:inline-flex;width:2rem;padding-inline-end:.75rem;box-sizing:content-box;z-index:2}&:last-child:empty,&:last-child:has(>span:empty:only-child){display:none}}}}}.dark{.astro-code pre span{color:var(--shiki-dark)!important}}.astro-code{&:has(code){position:relative}&:has(div.title){padding-top:2rem;& code:before{top:calc(2rem + .8571429em)}}.title{position:absolute;top:0;left:0;margin:.5rem}.language{transition:opacity .3s;position:absolute;top:.75rem;right:0}& button.copy{transition:opacity .3s;opacity:0;position:absolute;top:.75rem;right:.75rem;user-select:none;.success:before{content:"Copied!";position:absolute;right:100%;top:0;bottom:0;display:flex;justify-content:center;align-items:center;font-size:.75rem;padding:.5rem;margin-right:.5rem;border-radius:.25rem;color:hsl(var(--muted-foreground) / var(--un-text-opacity, 1));background-color:hsl(var(--card) / var(--un-bg-opacity, 1));border:1px solid hsl(var(--border) / var(--un-border-opacity, 1))}&.copied{.success{display:block}.ready{display:none}}}&:hover,&:focus-within{& button.copy{opacity:1}.language{opacity:0}}.highlighted,.diff{min-width:100%;display:inline-block}.highlighted,.highlighted:before{background-color:#95a6b752!important}.diff{&.remove{background-color:#f43f5e29;&:before{background-color:#f43f5e29;content:"-"}}&.add{background-color:#10b98129;&:before{background-color:#10b98129;content:"+"}}}.collapse-toggle{z-index:3;padding:.25rem;user-select:none;display:flex;justify-content:center;align-items:center;column-gap:.3rem;box-sizing:border-box;margin:0;border-top:1px solid hsl(var(--border) / var(--un-border-opacity, 1));.desc:before{content:"Collapse"}& svg{transition:transform .2s ease;transform:rotate(180deg)}}&.collapsed{& pre{max-height:15rem;overflow:hidden}.collapse-toggle{margin:.5rem;border:1px solid hsl(var(--border) / var(--un-border-opacity, 1));.desc:before{content:"Show all"}& svg{transform:rotate(0)}}.collapse-fade{z-index:2;user-select:none;pointer-events:none;position:absolute;bottom:0;left:0;right:0;height:8rem;background:linear-gradient(to bottom,transparent 0%,hsl(var(--muted) / var(--un-bg-opacity, 1)) 60%)}}}:root{--scrollbar-thumb: hsl(var(--muted-foreground) / var(--un-bg-opacity, .3))}:not(html){::-webkit-scrollbar{width:5px;height:5px}::-webkit-scrollbar-thumb{background-color:var(--scrollbar-thumb);border-radius:999px}}:root{--primary: 198 32% 46%;--foreground: 240 10% 3.9%;--muted-foreground: 240 3.8% 28.1%;--background: 210 33% 99%;--muted: 240 4.8% 96%;--card: 0 0% 90%;--border: 240 5.9% 88%;--input: 240 5.9% 90%;--ring: 198 32% 46%;--radius: .75rem;--space-unit: .5rem}.dark{--primary: 198 52% 76%;--foreground: 0 0% 98%;--muted-foreground: 240 5% 74.9%;--background: 240 20.54% 5.2%;--muted: 240 5.9% 13%;--card: 240 3.7% 24.9%;--border: 240 3.7% 22.9%;--input: 240 3.7% 17.9%;--ring: 240 4.9% 83.9%}:root{--un-default-border-color: hsl(var(--border) / 1)}html.dark{color-scheme:dark}html{-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;scroll-behavior:smooth}::selection{background-color:hsl(var(--primary) / .25);color:hsl(var(--foreground))}a{transition:color .2s ease;&:hover{color:hsl(var(--primary) / var(--un-text-opacity, 1))}}.hover-card-lift{transition:transform .25s cubic-bezier(.16,1,.3,1),box-shadow .25s cubic-bezier(.16,1,.3,1),border-color .2s ease,background-color .2s ease}.hover-card-lift:hover{transform:translateY(-2px);border-color:hsl(var(--primary) / .45);box-shadow:0 10px 25px -5px #0000000d,0 8px 10px -6px #00000008}.dark .hover-card-lift:hover{border-color:hsl(var(--primary) / .55);box-shadow:0 10px 25px -5px #00000080,0 0 20px -3px #54889c2e}:not(pre)>code{padding:.22rem .55rem!important;margin:0 .2rem!important;font-size:.85em!important;font-family:ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace!important;background-color:hsl(var(--muted) / .85)!important;border:1px solid hsl(var(--border) / .85)!important;border-radius:.375rem!important;line-height:1.6!important;box-decoration-break:clone;-webkit-box-decoration-break:clone}.dark :not(pre)>code{background-color:hsl(var(--muted) / .9)!important;border-color:hsl(var(--border) / .9)!important}.astro-code,pre.astro-code{margin-top:1.25rem!important;margin-bottom:1.25rem!important;border:1px solid hsl(var(--border) / .85)!important;border-radius:6px!important;box-shadow:0 2px 10px -2px #0000000a!important}.astro-code pre,pre.astro-code{padding:1.25rem!important;line-height:1.65!important;font-size:.875rem!important}blockquote{padding:.875rem 1.25rem!important;border-left-width:3.5px!important;background-color:hsl(var(--muted) / .35)!important;border-radius:0 4px 4px 0!important;line-height:1.65!important}.tag-badge,[data-badge]{padding:.25rem .625rem!important;border-radius:.375rem!important}a.group:has(>svg polyline[points="12 19 5 12 12 5"]),button.group:has(>svg polyline[points="12 19 5 12 12 5"]),a[variant=back],button[variant=back],.btn-back{background-color:transparent!important;border-color:transparent!important;border-width:0!important;box-shadow:none!important;padding:.375rem .75rem .375rem 0!important;color:hsl(var(--muted-foreground))!important;font-weight:500!important;transition:all .2s cubic-bezier(.16,1,.3,1)!important}a.group:has(>svg polyline[points="12 19 5 12 12 5"]):hover,button.group:has(>svg polyline[points="12 19 5 12 12 5"]):hover,a[variant=back]:hover,button[variant=back]:hover,.btn-back:hover{background-color:transparent!important;color:hsl(var(--foreground))!important;transform:translate(-4px)!important}a.group:has(>svg polyline[points="12 19 5 12 12 5"]):hover svg,button.group:has(>svg polyline[points="12 19 5 12 12 5"]):hover svg{stroke:hsl(var(--primary))!important}a.group:has(>svg polyline[points="12 5 19 12 12 19"]),button.group:has(>svg polyline[points="12 5 19 12 12 19"]),a[variant=ahead],button[variant=ahead],.btn-ahead{background-color:transparent!important;border-color:transparent!important;border-width:0!important;box-shadow:none!important;padding:.375rem 0!important;color:hsl(var(--primary))!important;font-weight:500!important;transition:all .2s cubic-bezier(.16,1,.3,1)!important}a.group:has(>svg polyline[points="12 5 19 12 12 19"]):hover,button.group:has(>svg polyline[points="12 5 19 12 12 19"]):hover,a[variant=ahead]:hover,button[variant=ahead]:hover,.btn-ahead:hover{background-color:transparent!important;color:hsl(var(--primary))!important;transform:translate(4px)!important}.site-header{display:flex!important;background:linear-gradient(180deg,#ffffffa6,#fff6)!important;backdrop-filter:blur(24px) saturate(190%)!important;-webkit-backdrop-filter:blur(24px) saturate(190%)!important;border:1px solid rgba(255,255,255,.6)!important;box-shadow:inset 0 1px 1.5px #fffffff2,0 10px 28px -4px #54889c29,0 2px 6px -1px #0000000a!important;transition:all .3s cubic-bezier(.16,1,.3,1)!important}.dark .site-header{background:linear-gradient(180deg,#1c1c22a6,#10101473)!important;backdrop-filter:blur(24px) saturate(190%)!important;-webkit-backdrop-filter:blur(24px) saturate(190%)!important;border:1px solid rgba(255,255,255,.14)!important;box-shadow:inset 0 1px 1px #ffffff40,0 12px 36px -4px #000000a6,0 2px 8px -2px #0006!important}.site-header.is-scrolled{background:linear-gradient(180deg,#ffffffb8,#ffffff7a)!important;border-color:#fffc!important;box-shadow:inset 0 1px 2px #fff,0 14px 40px -4px #54889c38,0 4px 12px -2px #0000000f!important}.dark .site-header.is-scrolled{background:linear-gradient(180deg,#1c1c22bf,#1010148c)!important;border-color:#fff3!important;box-shadow:inset 0 1px 1px #ffffff4d,0 16px 44px -4px #000000bf,0 4px 12px -2px #00000080!important}.hover-card-lift,.card-container,article,article[class*=rounded-],div[class*=hover-card-lift],a[class*=hover-card-lift],div[class*=rounded-2xl],a[class*=rounded-2xl],div[class*=rounded-xl],a[class*=rounded-xl],div[class*=rounded-lg],a[class*=rounded-lg],.lesson-courseware .expr,.lesson-courseware .pat,.lesson-courseware .setup-item,.lesson-courseware .my-turn-body,.lesson-courseware header .task,.lesson-courseware .answer,.lesson-courseware .line.is-playing,#lesson-progress-banner,[data-lesson-card]{border-radius:6px!important}.pill-badge,.tag-pill,.badge-pill,.capsule-badge,.btn-pill,[data-lesson-badge],.tag-badge,span[class*=rounded-full],span[class*=rounded-md],span[class*=rounded-lg],span[class*=rounded],.lesson-courseware button,.lesson-courseware select,.lesson-courseware .speaker,.lesson-courseware .play-line,.lesson-courseware .reveal,.lesson-courseware-container .mark-complete,.toc-item{border-radius:4px!important}.hero-banner-container{overflow:hidden!important;cursor:pointer!important}.hero-banner-image{transform:scale(1) translateZ(0)!important;transform-origin:center center!important;transition:transform .75s cubic-bezier(.16,1,.3,1),filter .75s cubic-bezier(.16,1,.3,1)!important;will-change:transform,filter!important;-webkit-backface-visibility:hidden!important;backface-visibility:hidden!important}.hero-banner-container:hover .hero-banner-image,.group\/hero:hover .hero-banner-image{transform:scale(1.045) translateZ(0)!important;filter:brightness(1.02) contrast(1.04)!important}.dark .hero-banner-container:hover .hero-banner-image,.dark .group\/hero:hover .hero-banner-image{transform:scale(1.045) translateZ(0)!important;filter:brightness(.82) contrast(1.06)!important}.highlight{--highlight-fg: color-mix( in srgb, var(--highlightColor) 40%, hsl(var(--foreground)/var(--un-text-opacity, 1)) );color:var(--highlight-fg, hsl(var(--primary) / var(--un-text-opacity)))!important}.highlight-bg{background-color:var( --highlightColor, hsl(var(--primary) / var(--un-text-opacity)) )!important}#main-container:where(.astro-37fxchfa){padding-top:env(safe-area-inset-top);padding-left:calc(1rem + env(safe-area-inset-left));padding-right:calc(1rem + env(safe-area-inset-right))}@media(min-width:640px){#main-container:where(.astro-37fxchfa){padding-left:calc(1.75rem + env(safe-area-inset-left));padding-right:calc(1.75rem + env(safe-area-inset-right))}}@media(min-width:1024px){#main-container:where(.astro-37fxchfa){padding-left:calc(2.5rem + env(safe-area-inset-left));padding-right:calc(2.5rem + env(safe-area-inset-right))}}