:root{color-scheme:dark;--bg:#04070b;--panel:#0a1119;--panel2:#0e1722;--line:rgba(255,255,255,.09);--text:#e8ecf1;--muted:#8d99a6;--dim:#617080;--blue:#2f95f4;--green:#22b07f;--gold:#d8b45a;--red:#ea5a58}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--text);font:16px/1.7 Inter,"Segoe UI",system-ui,sans-serif;-webkit-font-smoothing:antialiased}
a{color:var(--blue);text-decoration:none}a:hover{text-decoration:underline}
.wrap{width:min(1020px,100%);margin:0 auto;padding-left:max(18px,env(safe-area-inset-left,0px));padding-right:max(18px,env(safe-area-inset-right,0px))}
.top{border-bottom:1px solid var(--line);background:rgba(4,7,11,.92);position:sticky;top:0;z-index:5;backdrop-filter:blur(8px)}
.top .in{display:flex;align-items:center;gap:18px;min-height:60px;flex-wrap:wrap;padding-top:6px;padding-bottom:6px}
.brand{display:flex;align-items:center;gap:10px;color:var(--text);font:800 17px Syne,"Segoe UI",sans-serif;letter-spacing:-.4px}
.brand img{width:34px;height:34px;border-radius:8px;display:block}.brand b{color:var(--blue)}
.top nav{margin-left:auto;display:flex;gap:6px;align-items:center;flex-wrap:wrap}
.top nav a{color:#b8c2cd;font-size:14px;font-weight:600;padding:8px 10px;border-radius:7px}
.top nav a:hover{background:rgba(255,255,255,.05);text-decoration:none}
.top nav a.cta{background:var(--blue);color:#fff}
@media(max-width:560px){.top .in{flex-wrap:nowrap;min-height:54px;gap:10px}.top nav{flex-wrap:nowrap;margin-left:auto}.top nav a:not(.cta):not(:first-child){display:none}.brand span{font-size:15px}}
main{padding-top:26px;padding-bottom:56px}
.crumbs{font-size:13px;color:var(--dim);margin:0 0 14px}.crumbs a{color:var(--muted)}
h1{font:800 clamp(30px,5vw,46px)/1.1 Syne,"Segoe UI",sans-serif;letter-spacing:-1.4px;margin:0 0 12px;text-wrap:balance}
h2{font:700 13px "JetBrains Mono",Consolas,monospace;letter-spacing:1.4px;text-transform:uppercase;color:var(--blue);margin:30px 0 8px}
.lead{font-size:19px;line-height:1.55;color:#c7d0da;margin:0 0 16px;max-width:62ch}
.meta{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:6px}
.pill{font:700 11px "JetBrains Mono",Consolas,monospace;letter-spacing:.6px;text-transform:uppercase;border:1px solid var(--line);color:var(--muted);padding:4px 10px;border-radius:999px;background:var(--panel)}
a.pill:hover{text-decoration:none;border-color:rgba(255,255,255,.25);color:var(--text)}
.cols{display:grid;grid-template-columns:minmax(0,1.35fr) minmax(0,1fr);gap:34px;align-items:start}
@media(max-width:820px){.cols{grid-template-columns:minmax(0,1fr)}}
p{margin:0 0 12px}.body p{max-width:64ch}
.formula{font:600 14px "JetBrains Mono",Consolas,monospace;background:var(--panel);border:1px solid var(--line);border-radius:9px;padding:12px 14px;color:#cfe2f7;overflow-x:auto}
.note{border-left:3px solid var(--gold);background:rgba(216,180,90,.07);padding:10px 14px;border-radius:0 9px 9px 0;max-width:64ch}
.ex{border:1px solid var(--line);background:var(--panel);border-radius:10px;padding:12px 14px;max-width:64ch}
.ex small{display:block;font:700 10px "JetBrains Mono",Consolas,monospace;letter-spacing:1px;text-transform:uppercase;color:var(--dim);margin-bottom:4px}
aside .card,.card{border:1px solid var(--line);background:var(--panel);border-radius:12px;padding:14px;margin-bottom:14px}
figure{margin:0}figcaption{font-size:12px;color:var(--dim);margin-top:8px}
.chips{display:flex;flex-wrap:wrap;gap:8px}
.chip{border:1px solid var(--line);background:var(--panel2);color:#cfd8e2;padding:6px 12px;border-radius:999px;font-size:14px}
.chip:hover{border-color:rgba(47,149,244,.55);text-decoration:none;color:#fff}
.tool{display:flex;gap:10px;align-items:center;justify-content:space-between;border:1px solid var(--line);background:var(--panel2);border-radius:10px;padding:10px 12px;color:var(--text)}
.tool:hover{border-color:rgba(47,149,244,.55);text-decoration:none}.tool span{color:var(--blue);font-size:13px;font-weight:700}
.cta-card{margin-top:34px;border:1px solid rgba(47,149,244,.4);background:linear-gradient(135deg,rgba(47,149,244,.1),var(--panel) 60%);border-radius:14px;padding:22px}
.cta-card h3{font:800 22px Syne,"Segoe UI",sans-serif;letter-spacing:-.6px;margin:0 0 6px}
.cta-card p{color:var(--muted);margin:0 0 14px;max-width:56ch}
.btn{display:inline-block;padding:11px 18px;border-radius:9px;font-weight:700;font-size:14px;margin-right:8px;margin-bottom:6px}
.btn.pri{background:var(--blue);color:#fff}.btn.sec{border:1px solid var(--line);color:var(--text);background:rgba(255,255,255,.03)}.btn:hover{text-decoration:none;filter:brightness(1.1)}
.pn{display:flex;justify-content:space-between;gap:12px;margin-top:24px;flex-wrap:wrap}.pn a{font-size:14px}
footer{border-top:1px solid var(--line);color:var(--dim);font-size:13px;padding:22px 0 40px}
.az{display:flex;flex-wrap:wrap;gap:4px;margin:14px 0 8px}.az a{display:grid;place-items:center;width:32px;height:32px;border:1px solid var(--line);border-radius:7px;color:#b8c2cd;font:700 13px "JetBrains Mono",Consolas,monospace;background:var(--panel)}
.az a:hover{border-color:var(--blue);text-decoration:none}
.list{list-style:none;padding:0;margin:0;display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:8px 22px}
.list li{padding:8px 0;border-bottom:1px solid var(--line)}.list a{font-weight:700;color:var(--text)}.list a:hover{color:var(--blue);text-decoration:none}
.list small{display:block;color:var(--muted);font-size:13.5px;line-height:1.45;margin-top:1px}
.cats{display:grid;grid-template-columns:repeat(auto-fill,minmax(230px,1fr));gap:10px;margin:14px 0 4px}
.cat{border:1px solid var(--line);background:var(--panel);border-radius:11px;padding:12px 14px;color:var(--text);display:block}
.cat:hover{border-color:rgba(47,149,244,.55);text-decoration:none}.cat b{display:block;font-size:15px}.cat span{font-size:12.5px;color:var(--muted);line-height:1.4;display:block;margin-top:2px}
.letter{font:800 26px Syne,"Segoe UI",sans-serif;color:var(--blue);margin:26px 0 4px;scroll-margin-top:76px}
.video{position:relative;aspect-ratio:16/9;border-radius:12px;overflow:hidden;border:1px solid var(--line);background:#000;margin:14px 0}.video iframe{position:absolute;inset:0;width:100%;height:100%;border:0}
ul.outline{padding-left:20px;margin:0 0 10px}ul.outline li{margin:4px 0;color:#c7d0da}