:root{--ink:#1d1d1f;--grey:#6e6e73;--ground:#fbfbfd;--soft:#f5f5f7;--blue:#0071e3}
*{margin:0;padding:0;box-sizing:border-box}
body{font-family:Inter,system-ui,-apple-system,sans-serif;background:var(--ground);color:var(--ink);-webkit-font-smoothing:antialiased;line-height:1.5}
.wrap{max-width:720px;margin:0 auto;padding:0 24px}
.nav{position:fixed;top:0;left:0;right:0;background:rgba(251,251,253,.96);z-index:10;height:56px}
.nav .wrap{max-width:1100px;display:flex;justify-content:space-between;align-items:center;height:56px}
.nav a{color:var(--grey);text-decoration:none;font-size:14px;font-weight:500;margin-left:20px}.nav .brand{color:var(--ink);font-weight:600;font-size:16px;margin:0}
.article-wrap{padding-top:112px;padding-bottom:80px}
.back{color:var(--blue);font-size:14px;font-weight:500;text-decoration:none;display:inline-block;margin-bottom:32px}
.kicker{color:var(--grey);font-size:14px;margin-bottom:12px}
h1{font-size:clamp(32px,5vw,48px);line-height:1.12;letter-spacing:-.02em;font-weight:700;margin-bottom:20px}
.meta{color:var(--grey);font-size:14px;margin-bottom:32px}
.body p,.body li{font-size:18px;line-height:1.8}.body p{margin-bottom:1.4em}
.body h2{font-size:28px;letter-spacing:-.02em;margin:2.4em 0 .8em;line-height:1.2}.body h3{font-size:22px;margin:2em 0 .6em}
.body ul,.body ol{padding-left:1.5em;margin-bottom:1.5em}.body li{margin-bottom:.5em}
.body a,.related a{color:var(--blue);text-decoration:none}.body a:hover,.related a:hover{text-decoration:underline}
.body blockquote{background:var(--soft);padding:20px 24px;border-radius:12px;margin:0 0 1.6em;font-size:17px;line-height:1.7}
.body code{background:var(--soft);padding:2px 6px;border-radius:6px;font-size:.92em}
.toc{background:var(--soft);border-radius:12px;padding:20px 24px;margin-bottom:32px}.toc ul{list-style:none;padding:8px 0 0}.toc li{font-size:15px;margin:6px 0}.toc a{color:var(--ink);text-decoration:none}
.callout{background:var(--soft);border-radius:12px;padding:20px 24px;margin:0 0 1.6em}.callout strong{display:block;margin-bottom:6px}.callout p{margin:0}
.takeaway{font-size:21px!important;font-weight:600;line-height:1.5!important;padding:4px 0 4px 20px;border-left:4px solid var(--ink);margin:1.6em 0!important}
.steps{list-style:none;padding:0!important;counter-reset:s}.steps li{counter-increment:s;display:grid;grid-template-columns:36px 1fr;gap:4px 12px;margin-bottom:18px}
.steps li::before{content:counter(s);grid-row:1/3;background:var(--ink);color:#fff;border-radius:50%;width:32px;height:32px;display:grid;place-items:center;font-size:15px;font-weight:600}
.steps span{display:block}
.tablewrap{overflow-x:auto;margin-bottom:1.6em}table{border-collapse:collapse;width:100%;font-size:16px}th,td{padding:10px 12px;text-align:left;border-bottom:1px solid #d2d2d7}th{background:var(--soft)}
.faq details{background:var(--soft);border-radius:12px;padding:16px 20px;margin-bottom:10px}.faq summary{cursor:pointer;font-weight:600;font-size:17px}.faq details p{margin:10px 0 0;font-size:16px}
.cta{background:var(--ink);color:#fff;border-radius:16px;padding:32px;margin-top:56px}.cta h2{font-size:24px;margin-bottom:8px}.cta p{color:#d2d2d7;margin-bottom:20px}
.btn{display:inline-block;background:#fff;color:var(--ink);padding:12px 22px;border-radius:999px;font-weight:600;text-decoration:none;font-size:15px}.btn:focus-visible,a:focus-visible,summary:focus-visible{outline:3px solid var(--blue);outline-offset:3px}
.related{margin-top:48px}.related h2{font-size:22px;margin-bottom:12px}.related ul{list-style:none}.related li{margin:10px 0}
.lesson{margin-bottom:28px}.lesson h3{font-size:20px;margin-bottom:8px}.lesson ul{list-style:none}.lesson li{margin:6px 0}.lesson a,section h3 a{color:var(--ink);text-decoration:none}.lesson li a{color:var(--blue)}
section>h2{font-size:26px;margin:40px 0 16px}
.foot{border-top:1px solid #e5e5ea;padding:32px 0;text-align:center;color:var(--grey);font-size:13px}
@media(max-width:600px){.body p,.body li{font-size:17px}.body h2{font-size:24px}}