:root{
  color-scheme:dark;
  --bg:#0b1015;
  --surface:#121a21;
  --surface2:#18232b;
  --border:#263640;
  --text:#eef6f7;
  --muted:#9db0b8;
  --teal:#2dd4bf;
  --teal-dark:#0f766e;
  --amber:#f6ad55;
  --code:#071014;
  --max:1120px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:radial-gradient(circle at 80% 0,rgba(45,212,191,.08),transparent 30rem),var(--bg);color:var(--text);font:16px/1.65 Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif}
a{color:inherit}
.site-header{max-width:var(--max);margin:auto;display:flex;align-items:center;justify-content:space-between;gap:24px;padding:24px 28px;border-bottom:1px solid var(--border)}
.brand{display:flex;align-items:center;gap:12px;text-decoration:none}
.brand img{border-radius:12px}
.brand span{display:grid;line-height:1.2}.brand strong{font-size:18px}.brand small{margin-top:4px;color:var(--muted);font-size:12px}
.site-header nav{display:flex;align-items:center;gap:20px}.site-header nav>a:not(.button){color:var(--muted);text-decoration:none}.site-header nav>a:hover{color:var(--text)}.language-link{font-weight:750}
main{max-width:var(--max);margin:auto;padding:0 28px 72px}
.hero{padding:92px 0 70px;max-width:900px}.hero.compact{padding:62px 0 52px}
.eyebrow{margin:0 0 12px;color:var(--teal);font-size:13px;font-weight:750;letter-spacing:.09em;text-transform:uppercase}
h1,h2,h3{line-height:1.15;letter-spacing:-.025em}h1{font-size:clamp(42px,7vw,76px);margin:0 0 24px}.compact h1{font-size:clamp(36px,6vw,62px)}h2{font-size:clamp(28px,4vw,42px);margin:0 0 18px}h3{font-size:20px;margin:0 0 8px}
.lead{max-width:780px;margin:0;color:#c8d7dc;font-size:clamp(19px,2.4vw,25px);line-height:1.55}
.hero-actions{display:flex;align-items:center;flex-wrap:wrap;gap:20px;margin-top:34px}.button{display:inline-flex;align-items:center;justify-content:center;padding:13px 19px;border:1px solid #5eead4;border-radius:10px;background:linear-gradient(180deg,#25c8b4,#119386);color:#04110f;font-weight:800;text-decoration:none;box-shadow:0 12px 32px rgba(45,212,191,.14)}.button:hover{filter:brightness(1.08)}.button.small{padding:9px 14px;font-size:14px}.text-link{color:var(--teal);font-weight:700;text-underline-offset:5px}
.feature-row{display:flex;flex-wrap:wrap;gap:10px;margin:38px 0 0;padding:0;list-style:none}.feature-row li{padding:7px 11px;border:1px solid var(--border);border-radius:999px;background:rgba(18,26,33,.75);color:#b8c9cf;font-size:13px}
.course-intro,.content-grid,.example,.lesson-cta{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1.3fr);gap:54px;align-items:start;padding:54px 0;border-top:1px solid var(--border)}
.course-intro>p,.section-head>p,.example>div>p:not(.eyebrow){color:var(--muted);margin-top:0}
.section-head{display:flex;align-items:end;justify-content:space-between;gap:30px;margin-bottom:24px}.section-head>p{max-width:430px}
.lesson-list{padding:60px 0}.cards{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px;margin:0;padding:0;list-style:none}.cards a{height:100%;display:grid;grid-template-columns:auto 1fr auto;gap:18px;align-items:start;padding:24px;border:1px solid var(--border);border-radius:14px;background:linear-gradient(150deg,rgba(24,35,43,.96),rgba(15,23,29,.96));text-decoration:none}.cards a:hover{border-color:#3a655f;transform:translateY(-1px)}.cards p{margin:0;color:var(--muted);font-size:14px}.lesson-number{display:grid;place-items:center;width:38px;height:38px;border-radius:9px;background:rgba(45,212,191,.11);color:var(--teal);font-weight:800}.arrow{color:var(--teal);font-size:22px}
.breadcrumbs{display:flex;flex-wrap:wrap;gap:9px;padding-top:34px;color:var(--muted);font-size:14px}.breadcrumbs a{color:#bdd0d5;text-underline-offset:3px}
.lesson{max-width:940px}.content-grid{grid-template-columns:minmax(0,1.5fr) minmax(250px,.8fr)}.check-list{display:grid;gap:14px;margin:25px 0 0;padding:0;list-style:none}.check-list li{position:relative;padding-left:30px}.check-list li:before{content:"✓";position:absolute;left:0;color:var(--teal);font-weight:900}
.course-note{padding:24px;border:1px solid #28524e;border-radius:14px;background:rgba(45,212,191,.07)}.course-note strong{display:block;font-size:18px}.course-note p{margin:8px 0 0;color:#b8c9cf}
.explanation{max-width:790px;padding:54px 0}.explanation p{color:#c2d1d5;font-size:18px}
.example{grid-template-columns:minmax(230px,.7fr) minmax(0,1.3fr)}pre{max-width:100%;margin:0;overflow:auto;padding:24px;border:1px solid #28424b;border-radius:14px;background:var(--code);box-shadow:inset 0 1px 0 rgba(255,255,255,.04)}code{color:#b9f8eb;font:14px/1.7 "JetBrains Mono",Consolas,monospace;white-space:pre}
.safety-note{margin:34px 0;padding:18px 20px;border-left:4px solid var(--amber);border-radius:0 10px 10px 0;background:rgba(246,173,85,.08);color:#d9c8ac}.safety-note strong{color:#ffd597}
.lesson-cta{align-items:center;margin-top:54px;border:1px solid #28524e;border-radius:16px;padding:30px;background:linear-gradient(120deg,rgba(45,212,191,.08),rgba(18,26,33,.8))}.lesson-cta h2{font-size:30px;margin:0}.lesson-cta .button{justify-self:end}
.lesson-nav{display:grid;grid-template-columns:1fr 1fr;gap:20px;margin-top:44px}.lesson-nav>a{display:grid;padding:18px;border:1px solid var(--border);border-radius:12px;text-decoration:none}.lesson-nav>a:hover{border-color:#3a655f}.lesson-nav span{color:var(--muted);font-size:12px;text-transform:uppercase;letter-spacing:.08em}.lesson-nav .next{text-align:right}
.site-footer{max-width:var(--max);margin:auto;padding:30px 28px 50px;border-top:1px solid var(--border);color:var(--muted);font-size:13px}.site-footer p{margin:4px 0}.site-footer a{color:#c9d9dd;text-underline-offset:3px}
@media(max-width:760px){html,body{width:100%;max-width:100%;overflow-x:hidden}.site-header{width:100%;max-width:100%;padding:18px;gap:12px;flex-wrap:wrap}.brand{flex:0 0 auto;min-width:0;max-width:100%}.brand small,.site-header nav>a.all-lessons{display:none}.site-header nav{flex:0 0 100%;width:100%;max-width:100%;min-width:0;margin-left:0;gap:9px;flex-wrap:wrap;justify-content:flex-end}.site-header .language-link{font-size:13px}.site-header .button.small{padding:8px 10px;font-size:12px}main{width:100%;max-width:100%;min-width:0;padding:0 18px 52px}h1,h2,.eyebrow{max-width:100%;overflow-wrap:anywhere}.hero{padding:64px 0 48px}.hero.compact{padding:45px 0 38px}h1{font-size:42px}.course-intro,.content-grid,.example,.lesson-cta{grid-template-columns:1fr;gap:24px;padding:38px 0}.cards{grid-template-columns:1fr}.section-head{display:block}.section-head>p{margin-top:0}.lesson-cta{padding:24px}.lesson-cta .button{justify-self:stretch}.lesson-nav{grid-template-columns:1fr}.lesson-nav .next{text-align:left}.site-footer{width:100%;max-width:100%;padding:24px 18px 40px}}
@media(prefers-reduced-motion:no-preference){.cards a,.button{transition:.16s ease}}