:root{
  --ink:#1c2433; --muted:#5b6776; --paper:#ffffff; --wash:#f4f6f9;
  --line:#dfe5ec; --accent:#2f6fed; --accent-ink:#ffffff;
  --code-bg:#0f1722; --code-ink:#dce6f2; --good:#1a7f37; --bad:#c0392b; --warn:#b45309;
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{
  margin:0; color:var(--ink); background:var(--paper);
  font:17px/1.7 -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;
  -webkit-font-smoothing:antialiased;
}
main{max-width:720px;margin:0 auto;padding:0 20px 70px}
h1,h2,h3,h4{line-height:1.25}
h1{font-size:clamp(26px,6vw,38px);margin:.2em 0 .3em}
h2{font-size:clamp(20px,4.5vw,26px);margin:2em 0 .5em;padding-top:.4em;border-top:1px solid var(--line)}
h3{font-size:19px;margin:1.5em 0 .4em}
h4{font-size:16px;margin:.2em 0}
p{margin:.7em 0}
a{color:var(--accent);text-decoration:none;border-bottom:1px solid rgba(47,111,237,.35)}
a:hover{border-bottom-color:var(--accent)}
code,kbd{
  font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
  font-size:.9em;background:var(--wash);border:1px solid var(--line);
  border-radius:5px;padding:.06em .35em;color:#234;
}
pre{
  background:var(--code-bg);color:var(--code-ink);border-radius:12px;
  padding:15px 17px;overflow-x:auto;font-size:13.5px;line-height:1.55;
  font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
}
pre code{background:none;border:none;padding:0;color:inherit}
ul,ol{padding-left:1.3em;margin:.6em 0}
li{margin:.35em 0}
.hero{
  background:linear-gradient(150deg,#0f1722 0%,#1e293b 60%,#2f4a73 100%);
  color:#eef2f8;padding:40px 20px 30px;margin:0 -20px 6px;
}
.hero .inner{max-width:680px;margin:0 auto}
.hero .tag{display:inline-block;font-size:12px;letter-spacing:.12em;text-transform:uppercase;
  color:#9fb3d1;border:1px solid #334766;border-radius:999px;padding:3px 12px;margin-bottom:14px}
.hero p.lede{font-size:clamp(16px,2.6vw,19px);color:#c8d3e2}
.hero p.sub{margin:.4em 0 0}
.hero p.sub a{color:#9ec5ff;border-color:rgba(158,197,255,.4);font-size:15px}
.grid{display:grid;gap:12px;margin:14px 0}
@media(min-width:620px){.grid{grid-template-columns:1fr 1fr}.grid.three{grid-template-columns:1fr 1fr 1fr}}
.card{background:var(--wash);border:1px solid var(--line);border-radius:14px;padding:14px 16px}
.card p{font-size:15px;color:var(--muted);margin:0}
.note{border-left:4px solid var(--accent);background:var(--wash);border-radius:0 10px 10px 0;
  padding:10px 14px;margin:16px 0;font-size:16px}
.note code{background:#fff}
.note.good{border-left-color:var(--good)}
.note.warn{border-left-color:var(--warn)}
.muted{color:var(--muted)}
.small{font-size:14.5px}
footer{margin-top:50px;color:var(--muted);font-size:14px;border-top:1px solid var(--line);padding-top:16px}

/* схема шагов */
.steps{list-style:none;counter-reset:step;padding:0;margin:16px 0}
.steps li{counter-increment:step;position:relative;padding:0 0 18px 46px;border-left:2px solid var(--line);margin-left:14px}
.steps li:last-child{border-left:2px solid transparent}
.steps li::before{content:counter(step);position:absolute;left:-18px;top:0;
  width:32px;height:32px;border-radius:50%;background:var(--accent);color:#fff;
  display:flex;align-items:center;justify-content:center;font-weight:700}

/* разбор кода по блокам */
.block{border:1px solid var(--line);border-radius:14px;margin:14px 0;overflow:hidden}
.block > summary{
  cursor:pointer;list-style:none;padding:13px 16px;font-weight:700;font-size:16px;
  display:flex;align-items:center;gap:10px;background:var(--wash);
}
.block > summary::-webkit-details-marker{display:none}
.block > summary::before{content:"+";flex:0 0 auto;width:22px;height:22px;border-radius:50%;
  background:var(--accent);color:#fff;display:flex;align-items:center;justify-content:center;
  font-weight:700;font-size:16px}
.block[open] > summary::before{content:"–"}
.block .b-what{padding:2px 16px 12px;font-size:15.5px}
.block .b-code{background:var(--code-bg);margin:0;border-radius:0}
/* метка "реальный код" под псевдокодом */
.reveal{margin:10px 0}
.reveal summary{cursor:pointer;font-size:13.5px;color:var(--muted);border:1px solid var(--line);
  border-radius:999px;display:inline-block;padding:4px 12px;background:var(--wash)}
.reveal summary:hover{color:var(--accent)}
.reveal pre{margin-top:8px}
/* полоса "куда идём" */
.flag{font-size:13px;letter-spacing:.05em;text-transform:uppercase;color:var(--muted);
  border:1px solid var(--line);border-radius:999px;display:inline-block;padding:2px 10px;margin:2px 6px 2px 0}
.flag.hot{color:var(--accent);border-color:rgba(47,111,237,.4)}
.flag.warn{color:var(--warn);border-color:rgba(180,83,9,.4)}
table{border-collapse:collapse;width:100%;margin:12px 0;font-size:14.5px}
th,td{text-align:left;padding:7px 10px;border-bottom:1px solid var(--line);vertical-align:top}
th{font-size:12.5px;letter-spacing:.06em;text-transform:uppercase;color:var(--muted)}
td code{white-space:normal}