:root{--ink:#19354b;--navy:#0f263d;--teal:#147f87;--aqua:#46c7be;--line:#d9e6ed;--muted:#5f7486;--white:#fff;--surface:#f6f9fb;--shadow:0 8px 26px rgba(12,37,58,.08)}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:white;color:var(--ink);font-family:system-ui,-apple-system,'Segoe UI',sans-serif;line-height:1.65}a{color:#06707d}a:hover{text-decoration-thickness:2px}button,input,textarea{font:inherit}button{cursor:pointer}.container{width:min(1140px,calc(100% - 44px));margin:auto}.skip{position:absolute;top:-100px;left:12px;background:white;padding:12px;z-index:10}.skip:focus{top:12px}.site-head{border-bottom:1px solid var(--line);background:white}.navline{min-height:82px;display:flex;justify-content:space-between;align-items:center;gap:20px}.brand{display:flex;gap:12px;align-items:center;text-decoration:none;color:var(--navy);font-size:.95rem;font-weight:900;letter-spacing:.07em}.brand small{display:block;font-size:.64rem;letter-spacing:.11em;color:var(--muted);font-weight:600}.brandmark{width:44px;height:44px;background:var(--navy);color:var(--aqua);display:grid;place-items:center;border-radius:12px}.navline nav{display:flex;gap:20px;flex-wrap:wrap}.navline nav a{text-decoration:none;font-weight:700;font-size:.83rem;color:#35536a}.hero{background:radial-gradient(ellipse at 93% 10%,#166771 0,transparent 45%),linear-gradient(120deg,#0d263e 10%,#153954 90%);color:white;padding:44px 0 54px}.eyebrow,.kicker{font-size:.75rem;letter-spacing:.14em;font-weight:850;color:#54d8cc}.hero h1{max-width:900px;font-size:clamp(2.15rem,5vw,3.5rem);line-height:1.14;letter-spacing:-.04em;margin:14px 0 18px}.hero h1 span{color:#7bebdc}.lede{max-width:790px;color:#e3f0f4;font-size:1.08rem}.pills{display:flex;flex-wrap:wrap;gap:9px;margin-top:26px}.pills span{border:1px solid #5b8897;border-radius:999px;padding:6px 12px;font-size:.78rem;background:#fff1}.actions{display:flex;gap:10px;flex-wrap:wrap;margin:24px 0 12px}.btn{border:1px solid transparent;border-radius:10px;text-decoration:none;padding:11px 17px;display:inline-flex;align-items:center;justify-content:center;font-size:.89rem;font-weight:750;line-height:1.35}.btn.primary{background:#1b9a9c;color:white}.btn.primary:hover{background:#16777b}.btn.secondary{background:#eaf8f7;color:#074c57;border-color:#b9dedf}.btn.ghost{background:transparent;color:#f1ffff;border-color:#82bcc4}.layout{display:grid;grid-template-columns:230px minmax(0,1fr);gap:47px;padding:46px 0}.layout>main,.layout>aside{min-width:0}.layout .section{min-width:0}.sidebar{position:sticky;top:20px;align-self:start;background:var(--surface);border:1px solid var(--line);border-radius:15px;padding:20px 18px}.sidebar strong{font-size:.9rem}.sidebar nav{display:flex;flex-direction:column;gap:11px;margin-top:15px}.sidebar a{font-size:.83rem;text-decoration:none;color:#35536a}.sidebar a:hover{color:var(--teal)}.side-note{border-top:1px solid var(--line);margin-top:20px;padding-top:16px;font-size:.78rem;color:var(--muted)}.section{border-bottom:1px solid var(--line);padding:5px 0 37px;margin-bottom:25px;scroll-margin-top:20px}.section:last-child{border-bottom:0}.section h2{font-size:clamp(1.5rem,2.6vw,2rem);line-height:1.25;letter-spacing:-.02em;color:var(--navy);margin:8px 0 16px}.section h3{font-size:1.14rem;margin:22px 0 10px;color:var(--navy)}.section p{margin:11px 0 16px}.kicker{color:var(--teal);margin:0!important}.notice,.warning{border-left:4px solid var(--teal);background:#edf8f8;padding:14px 18px;border-radius:0 9px 9px 0;margin:20px 0}.warning{border-left-color:#c67b2b;background:#fff5e8}.notice p,.warning p{margin:5px 0 0}.learning-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin:17px 0}.learning-grid article{border:1px solid var(--line);border-radius:12px;padding:14px;background:var(--surface)}.learning-grid strong{color:var(--teal)}.learning-grid p{font-size:.86rem;margin:5px 0 0}.terminal{border-radius:12px;overflow:hidden;border:1px solid #34556f;margin:14px 0;background:#0d263a;color:#daf5f4}.terminal-top{display:flex;justify-content:space-between;align-items:center;gap:14px;background:#153951;padding:10px 14px;font-size:.76rem;color:#a9e5e3}.copy{border:1px solid #597b8c;background:transparent;color:#f2ffff;border-radius:7px;padding:4px 10px;font-weight:650}.copy:hover{background:#ffffff16}.terminal pre{margin:0;padding:15px 17px;overflow-x:auto;white-space:pre;font-size:.86rem;line-height:1.7}.syntax{padding:16px;border:1px solid #b9dedf;background:#edf8f8;border-radius:12px;overflow:auto;font-size:1rem}.table-wrap{border:1px solid var(--line);border-radius:12px;overflow:auto}table{width:100%;border-collapse:collapse;font-size:.9rem}th{background:#173f61;color:white;text-align:left}th,td{padding:11px 13px;border-bottom:1px solid var(--line);vertical-align:top}tr:last-child td{border-bottom:0}tbody tr:nth-child(even){background:#f6f9fb}code{font-family:ui-monospace,SFMono-Regular,Consolas,'Liberation Mono',monospace;font-size:.94em}.mask-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:10px}.mask-grid div{border:1px solid var(--line);background:var(--surface);border-radius:11px;padding:13px;text-align:center}.mask-grid code{display:block;font-size:1.5rem;font-weight:900;color:var(--teal)}.mask-grid span{display:block;font-size:.79rem}.muted{color:var(--muted)}.example{border:1px solid var(--line);border-radius:14px;padding:18px;margin:20px 0;box-shadow:var(--shadow)}.example-top{display:flex;align-items:flex-start;gap:15px}.example-top>div{flex:1}.example-top h3{margin:0 0 5px}.example-top p{margin:0}.num{border-radius:10px;padding:8px 10px;background:#e4f7f4;color:#106b73;font-weight:900}.tag{color:#0e666f;background:#eaf8f7;padding:6px 9px;font-size:.75rem;font-weight:750;border-radius:999px;white-space:nowrap}.inline-link{font-weight:700;font-size:.9rem}.form-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;margin-top:17px}.form-grid label{display:flex;flex-direction:column;gap:5px;font-size:.85rem;font-weight:700}.form-grid .wide{grid-column:1/-1}.form-grid input,.form-grid textarea{width:100%;min-width:0;padding:11px;border-radius:9px;border:1px solid #c4d5e1;background:white;color:var(--ink);font-weight:400}.form-grid button{align-self:end}.result{border:1px solid #bbdedb;background:#eff9f7;border-radius:12px;padding:17px;margin:16px 0;color:#125d67}.result strong{display:block;font-size:1.42rem}.result span{display:block;font-size:.87rem}.question{border:1px solid var(--line);border-radius:12px;margin:12px 0;padding:14px 18px}.question legend{font-weight:750;padding:0 7px}.question label{display:block;margin:9px 0;font-size:.91rem}.question input{margin-right:9px;accent-color:#0e7d80}.question.correct{border-color:#5aaa89;background:#f1fcf7}.question.incorrect{border-color:#dfa973;background:#fff9f1}.sources{font-size:.86rem}.sources li{margin:9px 0}footer{border-top:1px solid var(--line);background:var(--surface)}.footerline{display:flex;justify-content:space-between;gap:15px;flex-wrap:wrap;padding:26px 0;font-size:.78rem;color:#5f7486}.toast{position:fixed;bottom:20px;right:20px;padding:13px 18px;background:#0d263a;color:white;box-shadow:var(--shadow);border-radius:8px;font-size:.83rem;z-index:5}button:focus-visible,a:focus-visible,input:focus-visible,textarea:focus-visible{outline:3px solid #edbb5d;outline-offset:3px}
@media(max-width:930px){.layout{grid-template-columns:1fr;gap:22px}.sidebar{position:static}.sidebar nav{display:grid;grid-template-columns:repeat(2,1fr)}}@media(max-width:620px){.container{width:min(100% - 28px,1140px)}.navline{align-items:flex-start;flex-direction:column;padding:14px 0;gap:10px;min-height:0}.navline nav{gap:12px}.hero{padding:30px 0 36px}.hero h1{font-size:2.15rem}.mask-grid{grid-template-columns:repeat(2,1fr)}.learning-grid{grid-template-columns:1fr}.form-grid{grid-template-columns:1fr}.sidebar nav{grid-template-columns:1fr}.sidebar nav a{overflow-wrap:anywhere}.example-top{flex-wrap:wrap}.tag{margin-left:47px}.footerline{display:block}.footerline span{display:block;margin:5px 0}}
@media print{.site-head,.sidebar,.actions,.copy,button,.toast{display:none!important}.layout{display:block}.hero{background:#0f263d!important;-webkit-print-color-adjust:exact;print-color-adjust:exact}.section{break-inside:auto}.terminal{break-inside:avoid}.example{break-inside:avoid}}