:root{color-scheme:dark;--bg:#10151f;--panel:#171e2b;--ink:#f4f4f0;--muted:#b0b8c7;--accent:#c5ed95;--line:#30394a}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font:16px/1.7 system-ui,-apple-system,"Segoe UI",sans-serif}.seo-header,.seo-footer{padding:18px max(24px,calc((100vw - 960px)/2));border-bottom:1px solid var(--line);display:flex;justify-content:space-between;gap:20px;align-items:center}.seo-footer{border-top:1px solid var(--line);border-bottom:0;color:var(--muted)}.seo-brand{font-weight:750;font-size:1.15rem;text-decoration:none}.seo-brand span{display:block;color:var(--muted);font-size:.75rem;font-weight:400}.seo-header nav{display:flex;gap:22px}.seo-main{max-width:960px;margin:0 auto;padding:30px 24px 72px}.breadcrumbs{display:flex;flex-wrap:wrap;gap:10px;color:var(--muted);font-size:.9rem;margin:4px 0 26px}.eyebrow{color:var(--accent);font-size:.78rem;font-weight:700;letter-spacing:.12em}.lead{font-size:1.23rem;color:#dce3ed;max-width:75ch}h1{font-size:clamp(2rem,5vw,3.4rem);line-height:1.15;max-width:24ch;margin:.25em 0}h2{font-size:1.45rem;margin-top:2em}p,li{max-width:78ch}a{color:var(--accent);text-underline-offset:3px}.lesson-links{padding-left:1.4rem}.lesson-links li{padding:12px 0;border-bottom:1px solid var(--line)}.lesson-links strong{color:var(--ink)}.sim-link{display:inline-block;margin:4px 0}.seo-callout,.simulation{margin:32px 0;padding:24px;border:1px solid var(--line);border-radius:16px;background:var(--panel)}.button{display:inline-block;margin-top:8px;padding:10px 16px;border-radius:8px;background:var(--accent);color:#111827;text-decoration:none;font-weight:700}.simulation iframe{display:block;width:100%;height:min(78vh,760px);min-height:520px;border:1px solid var(--line);border-radius:12px;background:#0b1421}.back-link{margin-top:32px}@media(max-width:620px){.seo-header{align-items:flex-start;flex-direction:column}.seo-main{padding:20px 18px 48px}.simulation{padding:14px}.simulation iframe{min-height:460px}}.footer-topic-links{display:block;margin-top:10px;font-size:.82rem}.footer-topic-links a{margin-right:10px}
.lesson-links li>a{display:inline-block}.lesson-links li>span{display:block;margin-left:1rem}