/* Основа: reset, типографика, шапка, hero, раскладка, оглавление, текст статьи */
*,*::before,*::after{box-sizing:inherit}
html{font-size:112.5%;-webkit-text-size-adjust:100%;scroll-padding-top:5rem}
html[data-size="2"]{font-size:125%}
html[data-size="3"]{font-size:142%}
@media (prefers-reduced-motion:no-preference){html{scroll-behavior:smooth}}
body{margin:0;background:var(--bg);color:var(--text);font-family:var(--font);font-size:1rem;line-height:1.65}
html[data-space="wide"] body{line-height:1.9;letter-spacing:.035em;word-spacing:.1em}
img,svg{max-width:100%;height:auto}
a{color:var(--link);text-underline-offset:.2em;text-decoration-thickness:.08em}
a:hover{text-decoration-thickness:.16em}
:focus-visible{outline:3px solid var(--focus);outline-offset:3px;border-radius:2px}
.visually-hidden{position:absolute!important;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
.wrap{width:min(100% - 2rem,62rem);margin-inline:auto}

/* Фирменный знак: жёлтый круг с контрастным кольцом — как маркировка на стеклянных дверях */
.disc{display:inline-block;flex:none;width:.62em;height:.62em;border-radius:50%;background:var(--yellow);box-shadow:0 0 0 .1em var(--surface),0 0 0 .17em var(--ink)}

/* ---------- Skip-link и демо-плашка ---------- */
.skip{position:absolute;left:1rem;top:-6rem;z-index:100;background:var(--yellow);color:var(--on-yellow);padding:.7rem 1rem;font-weight:600;border-radius:.4rem}
.skip:focus{top:calc(.5rem + env(safe-area-inset-top,0px))}
.demo{background:var(--yellow);color:var(--on-yellow);font-size:.82rem;line-height:1.4;padding:.45rem 0}
.demo p{margin:0}

/* ---------- Шапка ---------- */
.site-header{position:sticky;top:env(safe-area-inset-top,0px);z-index:50;background:var(--band);color:var(--band-text);--focus:var(--yellow)}
.site-header .wrap{display:flex;align-items:center;gap:1rem 1.5rem;flex-wrap:wrap;padding-block:.6rem}
.brand{display:flex;align-items:center;gap:.65rem;color:var(--band-text);text-decoration:none;font-weight:800;font-size:1.1rem;margin-right:auto}
.brand .disc{width:1.1rem;height:1.1rem;box-shadow:0 0 0 .14rem var(--band),0 0 0 .22rem var(--band-text)}
.nav ul{display:flex;flex-wrap:wrap;gap:.2rem 1.2rem;list-style:none;margin:0;padding:0}
.nav a{color:var(--band-text);text-decoration:none;font-size:.9rem;padding:.5rem 0;display:inline-block;min-height:1.6rem}
.nav a:hover,.nav a[aria-current="page"]{text-decoration:underline;text-decoration-thickness:.12em}
.btn{font:inherit;font-size:.9rem;font-weight:600;cursor:pointer;display:inline-flex;align-items:center;gap:.5rem;min-height:2.75rem;padding:.4rem .95rem;border-radius:.5rem;border:2px solid currentColor;background:transparent;color:inherit}
.btn:hover{background:var(--yellow);color:var(--on-yellow);border-color:var(--yellow)}
.btn-sr{}
@media (min-width:64rem){.btn-sr{display:none!important}}
.btn-primary{background:var(--yellow);color:var(--on-yellow);border-color:var(--yellow)}
.btn-primary:hover{background:var(--ink);color:var(--surface);border-color:var(--ink)}
.progress{position:fixed;left:0;right:0;top:env(safe-area-inset-top,0px);height:4px;z-index:60;pointer-events:none}
.progress i{display:block;height:100%;background:var(--yellow);transform-origin:left;transform:scaleX(var(--p,0))}

@media (max-width:63.99rem){
  .site-header{position:static}
  .site-header .wrap{flex-wrap:wrap;padding-block:.5rem}
  .nav{order:3;width:100%;overflow-x:auto;margin-inline:-1rem;padding-inline:1rem;width:calc(100% + 2rem)}
  .nav ul{flex-wrap:nowrap;white-space:nowrap;gap:0 1.3rem}
  .btn .btn-long{display:none}
}
/* ---------- Hero ---------- */
.hero{position:relative;overflow:hidden;background:var(--band);color:var(--band-text);--focus:var(--yellow);padding:2rem 0 2.75rem}
.hero::after{content:"";position:absolute;pointer-events:none;border-radius:50%;background:var(--yellow);outline:3px solid var(--band-text);outline-offset:.9rem;width:7rem;aspect-ratio:1;top:-2.5rem;right:-2.5rem}
@media (min-width:64rem){.hero::after{width:clamp(18rem,30vw,26rem);top:50%;right:-5rem;transform:translateY(-50%);outline-offset:1.2rem}}
.hero a{color:var(--band-text)}
.crumbs ol{display:flex;flex-wrap:wrap;list-style:none;margin:0 0 1.75rem;padding:0 4.5rem 0 0;font-size:.88rem;color:var(--band-muted)}
@media (min-width:64rem){.crumbs ol{padding-right:0}}
.crumbs li+li::before{content:"/";margin:0 .6rem;opacity:.7}
.crumbs a,.crumbs li[aria-current]{padding:.35rem 0;display:inline-block}
h1{font-size:clamp(2.1rem,6vw,3.6rem);line-height:1.08;font-weight:800;letter-spacing:-.02em;margin:0 0 1.5rem;max-width:15ch;text-wrap:balance}
.meta{display:grid;grid-template-columns:repeat(auto-fit,minmax(8rem,max-content));gap:.9rem 1.6rem;margin:0;font-size:.92rem;max-width:34rem}
.meta div{min-width:0}
.meta dt{color:var(--band-muted);font-size:.8rem;margin-bottom:.1rem}
.meta dd{margin:0;font-weight:600}

/* ---------- Раскладка ---------- */
.layout{display:grid;gap:2rem;padding-block:2.5rem 3rem;grid-template-columns:minmax(0,1fr)}
@media (min-width:64rem){.layout{grid-template-columns:14.5rem minmax(0,42rem);gap:4rem;align-items:start}}

/* ---------- Оглавление ---------- */
.toc-title{font-size:.95rem;font-weight:600;margin:0 0 .8rem;color:var(--ink)}
.toc ol{list-style:none;margin:0;padding:0;border-left:2px solid var(--border)}
.toc ol ol{border-left:0;margin-left:.9rem}
.toc a{position:relative;display:block;padding:.4rem .5rem .4rem 1.1rem;font-size:.9rem;line-height:1.35;color:var(--muted);text-decoration:none}
.toc ol ol a{padding-left:.9rem}
.toc a:hover{color:var(--ink);text-decoration:underline}
.toc a[aria-current="true"]{color:var(--ink);font-weight:600}
.toc a[aria-current="true"]::before{content:"";position:absolute;left:-.55rem;top:.62rem;width:.9rem;height:.9rem;border-radius:50%;background:var(--yellow);box-shadow:0 0 0 .13rem var(--bg),0 0 0 .22rem var(--ink)}
.toc-mobile{background:var(--surface);border:2px solid var(--ink);border-radius:.6rem;padding:.2rem 1rem}
.toc-mobile summary{cursor:pointer;font-weight:600;min-height:2.75rem;display:flex;align-items:center}
.toc-mobile[open] summary{margin-bottom:.4rem}
.toc-mobile .toc ol{border-left:0}
.toc-mobile .toc a[aria-current="true"]::before{left:0}
@media (min-width:64rem){.toc-mobile{display:none}.toc-side{position:sticky;top:6.2rem;max-height:calc(100vh - 8rem);overflow:auto;padding:.3rem .5rem .3rem .8rem;margin-left:-.8rem}}
@media (max-width:63.99rem){.toc-side{display:none}}

/* ---------- Типографика статьи ---------- */
.article>*+*{margin-top:1.1rem}
.lead{font-size:1.28rem;line-height:1.5;font-weight:500;color:var(--ink)}
h2,h3{color:var(--ink);scroll-margin-top:5.5rem;position:relative}
h2{display:flex;align-items:baseline;gap:.7rem;font-size:1.85rem;line-height:1.2;font-weight:800;letter-spacing:-.01em;margin:3.2rem 0 0!important;text-wrap:balance}
h2 .disc{margin-top:.1em;width:.55em;height:.55em;transform:translateY(-.02em)}
h3{font-size:1.32rem;line-height:1.3;font-weight:600;margin:2.2rem 0 0!important}
.article h2+*,.article h3+*{margin-top:1rem!important}
.anchor{font:inherit;font-size:.7em;margin-left:.3rem;border:0;background:none;color:var(--muted);cursor:pointer;opacity:0;padding:.3rem .5rem;min-width:2rem;min-height:2rem;border-radius:.3rem}
h2:hover .anchor,h3:hover .anchor,.anchor:focus-visible{opacity:1}
@media (hover:none){.anchor{opacity:.6}}
.article ul,.article ol{padding-left:1.3rem}
dfn{font-style:normal}
.article li+li{margin-top:.45rem}
.article li::marker{color:var(--ink)}
strong{color:var(--ink)}
.term{font:inherit;color:var(--ink);background:none;border:0;padding:0;cursor:help;text-decoration:underline dotted;text-decoration-thickness:.12em;text-underline-offset:.22em}
a.term{color:var(--ink)}
.term-wrap{position:relative}
.term-tip{position:absolute;left:0;top:calc(100% + .4rem);z-index:20;width:max-content;max-width:min(20rem,calc(100vw - 2rem));background:var(--ink);color:var(--surface);padding:.7rem .9rem;border-radius:.5rem;font-size:.88rem;line-height:1.45;font-weight:400;text-align:left;letter-spacing:0;word-spacing:0}