:root{--navy:#071226;--navy2:#0d2547;--ink:#13203a;--text:#2a3650;--muted:#5d6a82;--line:#e3e8f1;--bg:#f6f8fc;--card:#ffffff;--blue:#2f6fed;--teal:#1fb5c9;--green:#22a06b;--pill:#e8f0ff}
@media (prefers-color-scheme:dark){:root{--ink:#eef3fb;--text:#cdd6e6;--muted:#93a0b8;--line:#22314d;--bg:#0b1324;--card:#121d33;--pill:#1b2b4b}}
*{box-sizing:border-box}html{-webkit-text-size-adjust:100%}
body{margin:0;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;color:var(--text);background:var(--bg);line-height:1.6;font-size:17px}
a{color:var(--blue)}img{max-width:100%;height:auto}
.wrap{max-width:1080px;margin:0 auto;padding:0 20px}.narrow{max-width:760px}
.top{background:var(--navy);position:sticky;top:0;z-index:5}
.nav{display:flex;align-items:center;justify-content:space-between;height:60px}
.logo{display:flex;align-items:center;gap:10px;color:#fff;text-decoration:none;font-weight:800;font-size:20px}
.logo img{border-radius:8px}
.nav nav{display:flex;gap:18px;align-items:center}
.nav nav a{color:#c9d6ee;text-decoration:none;font-weight:600;font-size:15px}
.nav nav a.cta{background:var(--green);color:#fff;padding:8px 14px;border-radius:10px}
@media (max-width:640px){.nav nav a:not(.cta){display:none}}
.hero{background:linear-gradient(160deg,var(--navy),var(--navy2));color:#fff;padding:56px 0 40px;overflow:hidden}
.hero .wrap{display:grid;grid-template-columns:1.1fr .9fr;gap:30px;align-items:center}
@media (max-width:860px){.hero .wrap{grid-template-columns:1fr}.hero-shots{display:none}}
.kicker{color:#7fe3f0;font-weight:700;font-size:14px;letter-spacing:.3px;margin:0 0 10px}
.hero h1{font-size:clamp(32px,5vw,50px);line-height:1.1;margin:0 0 16px;color:#fff}
.lead{font-size:19px;color:inherit;opacity:.92}
.pagehead .lead{color:var(--muted)}
.btns{display:flex;gap:12px;flex-wrap:wrap;margin:22px 0 10px}
.btn{display:inline-block;background:var(--green);color:#fff;font-weight:700;text-decoration:none;padding:13px 22px;border-radius:12px}
.btn.ghost{background:transparent;border:2px solid currentColor;color:var(--blue)}
.hero .btn.ghost{color:#fff}
.small{font-size:14px;opacity:.75}
.hero-shots{position:relative;height:520px}
.hero-shots img{position:absolute;width:250px;border-radius:28px;box-shadow:0 20px 60px rgba(0,0,0,.45);border:6px solid #1d2a44;right:120px;top:0}
.hero-shots img.back{right:0;top:60px;transform:rotate(4deg)}
h1,h2,h3{color:var(--ink);line-height:1.25}
section{padding:36px 0}section h2{font-size:28px;margin:0 0 18px}
.grid3{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}.grid2{display:grid;grid-template-columns:repeat(2,1fr);gap:16px}
@media (max-width:860px){.grid3{grid-template-columns:1fr 1fr}}@media (max-width:600px){.grid3,.grid2{grid-template-columns:1fr}}
.card{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:20px}
.card h3{margin:6px 0 6px;font-size:19px}.card p{margin:0;color:var(--muted);font-size:15.5px}
.card.link{text-decoration:none;display:block;transition:transform .15s,border-color .15s}.card.link:hover{transform:translateY(-2px);border-color:var(--blue)}
.ico{font-size:30px}.ico.big{font-size:46px}
.pill{display:inline-block;background:var(--pill);color:var(--blue);font-weight:700;font-size:12.5px;padding:3px 10px;border-radius:999px}.pill.sm{font-size:11px;padding:1px 8px;vertical-align:middle}
.meta{color:var(--muted);font-size:14px}
.center{text-align:center}.endcta{padding-bottom:60px}
.faq details{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:14px 18px;margin:10px 0}
.faq summary{font-weight:700;cursor:pointer;color:var(--ink)}
.crumbs{font-size:14px;color:var(--muted)}.crumbs a{color:var(--muted)}
.lessons{list-style:none;padding:0;margin:0}
.lessons li a{display:flex;gap:14px;align-items:center;background:var(--card);border:1px solid var(--line);border-radius:14px;padding:14px 16px;margin:10px 0;text-decoration:none;color:var(--ink)}
.lessons .n{flex:0 0 34px;height:34px;border-radius:50%;background:var(--pill);color:var(--blue);font-weight:800;display:flex;align-items:center;justify-content:center}
article h1{font-size:clamp(28px,4.5vw,40px);margin:12px 0 6px}
article .body p{font-size:18px}
.formula,.keys{background:var(--card);border:1px solid var(--line);border-left:5px solid var(--teal);border-radius:14px;padding:6px 20px 14px;margin:26px 0}
.keys{border-left-color:var(--green)}
.formula pre{white-space:pre-wrap;font-size:15px;background:var(--bg);padding:12px;border-radius:8px;overflow-x:auto}
.quiz{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:12px 20px;margin:12px 0}
.quiz .q{font-weight:700;color:var(--ink)}.quiz ul{margin:6px 0}.quiz summary{cursor:pointer;color:var(--blue);font-weight:600}
.links li{margin:6px 0}
.appcta{margin:30px 0;border-color:var(--blue)}.appcta .btn{margin-top:12px}
.pn{display:flex;justify-content:space-between;gap:16px;margin:24px 0;font-weight:600}
.disc{font-size:13px;color:var(--muted)}
.letters a{display:inline-block;margin:3px;padding:4px 10px;border:1px solid var(--line);border-radius:8px;text-decoration:none;font-weight:700}
dl dt{font-weight:800;color:var(--ink);margin-top:16px;scroll-margin-top:80px}dl dd{margin:4px 0 0}
.legal h2{font-size:20px;margin-top:28px}
.foot{background:var(--navy);color:#b8c5dc;padding:36px 0 20px;margin-top:30px}
.foot .cols{display:grid;grid-template-columns:2fr 1fr 1fr;gap:20px}@media (max-width:640px){.foot .cols{grid-template-columns:1fr}}
.foot h4{color:#fff;margin:0 0 8px}.foot a{display:block;color:#b8c5dc;text-decoration:none;margin:4px 0}.foot .disc{color:#8794ad}
.band{background:transparent}