:root{color-scheme:light;--bg:#f6f8fc;--ink:#222c40;--muted:#5e6b80;--blue:#3759c7;--line:#dce2ed;--white:#fff}
*{box-sizing:border-box}
html{scroll-padding-top:2rem}
body{margin:0;background:var(--bg);color:var(--ink);font-family:system-ui,-apple-system,"Segoe UI",sans-serif;font-size:1rem;line-height:1.65;-webkit-font-smoothing:antialiased}
a{color:inherit}
a:focus-visible{outline:3px solid var(--blue);outline-offset:5px}
.page{width:min(100% - 3rem,960px);margin-inline:auto}
.header{display:flex;justify-content:space-between;align-items:center;gap:1rem;padding-block:1.75rem;border-bottom:1px solid var(--line)}
.brand{display:inline-flex;align-items:center;font-weight:700;font-size:1.05rem;letter-spacing:-.025em;text-decoration:none;white-space:nowrap}
.mark{display:grid;place-items:center;width:2.25rem;height:2.25rem;margin-right:.65rem;background:var(--blue);color:white;border-radius:.6rem;font:700 .9rem ui-monospace,Consolas,monospace;letter-spacing:-.1em}
.brand-dot{color:var(--blue)}
.header-note{font-size:.875rem;color:var(--muted)}
.intro{padding-top:4.5rem;padding-bottom:2.5rem}
.eyebrow{margin:0 0 1rem;color:var(--blue);font-size:.75rem;font-weight:700;letter-spacing:.16em}
h1{margin:0 0 1.25rem;font-size:clamp(2.75rem,8vw,5rem);line-height:1.08;letter-spacing:-.055em;font-weight:750}
h1 span{color:var(--blue)}
.lead{max-width:43rem;margin:0;color:var(--muted);font-size:1.125rem;line-height:1.8}
.button{display:inline-flex;justify-content:center;align-items:center;gap:1.2rem;margin-top:1.75rem;padding:.65rem 1.1rem;background:var(--blue);color:white;border:1px solid var(--blue);border-radius:.5rem;text-decoration:none;font-size:.9375rem;font-weight:600;min-height:46px}
.button:hover{background:#2847ae;border-color:#2847ae}
.code-window{margin:0;background:var(--white);border:1px solid var(--line);border-radius:.8rem;overflow:hidden;box-shadow:0 6px 22px #263e7310}
.code-heading{display:flex;justify-content:space-between;gap:1rem;background:#eff3fa;border-bottom:1px solid var(--line);padding:.7rem 1.25rem;color:var(--muted);font: .8125rem/1.6 ui-monospace,Consolas,monospace}
.code-body{display:flex;gap:1.4rem;align-items:baseline;padding:1.6rem 1.25rem;font-size:1rem}
code,samp{font-family:ui-monospace,SFMono-Regular,Consolas,monospace}
code{overflow-wrap:anywhere}
.line-number{font: .8125rem ui-monospace,Consolas,monospace;color:#6c778a;user-select:none}
.code-object{color:#3d5eb4}
.code-string{color:#24704e}
.code-result{display:flex;gap:1.2rem;align-items:baseline;flex-wrap:wrap;padding:1rem 1.25rem;border-top:1px dashed var(--line);font-size:.875rem}
.result-label{color:var(--muted);font-family:system-ui,sans-serif;font-size:.8125rem}
.notes{margin-top:3.5rem}
.section-heading{display:flex;align-items:baseline;justify-content:space-between;gap:1rem;margin-bottom:1.1rem}
h2{margin:0;font-size:1.25rem;letter-spacing:-.025em}
.section-heading>span{font-size:.8125rem;color:var(--muted)}
.cards{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:1rem}
.card{padding:1.4rem;background:var(--white);border:1px solid var(--line);border-radius:.65rem}
.card-number{font-size:.75rem;font-weight:600;letter-spacing:.055em;color:var(--blue)}
h3{margin:.75rem 0 .5rem;font-size:1.05rem;line-height:1.45;letter-spacing:-.02em}
.card p{margin:0;color:var(--muted);font-size:1rem;line-height:1.7}
.next-note{display:flex;gap:1rem;margin-block:1.5rem 3.5rem;padding:1rem 1.3rem;border-left:2px solid #a6b7ec;color:var(--muted)}
.next-note>span{color:var(--blue);font-size:1.3rem}
.next-note p{margin:0;font-size:.9375rem}
.next-note strong{color:var(--ink);font-weight:600}
.footer{display:flex;justify-content:space-between;gap:1rem;padding-block:1.5rem;border-top:1px solid var(--line);color:var(--muted);font-size:.8125rem}
.error-page{min-height:100svh;display:flex;flex-direction:column}
.error-main{flex:1;padding-block:5rem}
.error-main h1{font-size:clamp(2.3rem,7vw,4.4rem);overflow-wrap:anywhere}
@media(max-width:700px){.cards{grid-template-columns:1fr}.section-heading{display:block}.section-heading>span{display:block;margin-top:.35rem}.intro{padding-top:3rem}.notes{margin-top:2.5rem}.card{padding:1.2rem}.next-note{margin-bottom:2.5rem}.desktop-break{display:none}}
@media(max-width:420px){.page{width:calc(100% - 2rem)}.header{align-items:flex-start;flex-direction:column;gap:.6rem;padding-block:1.2rem}.header-note{font-size:.8125rem}.intro{padding-top:2.5rem}.lead{font-size:1rem}.code-body{gap:.65rem;padding:1.3rem .9rem;font-size:.875rem}.code-heading,.code-result{padding-inline:.9rem}.footer{flex-direction:column;gap:.25rem}.error-main{padding-block:3rem}}
@media(prefers-reduced-motion:no-preference){html{scroll-behavior:smooth}}