:root { --fundo: #f7f6f3; --texto: #1d1d1b; --suave: #6b6a66; --link: #1f4e79; }
@media (prefers-color-scheme: dark) {
  :root { --fundo: #161615; --texto: #ecebe7; --suave: #9b9a95; --link: #8ab4e0; }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--fundo); color: var(--texto);
       font: 17px/1.6 Georgia, "Times New Roman", serif; }
main { max-width: 680px; margin: 0 auto; padding: 48px 16px 64px; }
h1 { font: 700 2rem/1.2 "Helvetica Neue", Arial, sans-serif; letter-spacing: -0.01em; margin: 0 0 4px; }
h2 { font: 700 1.1rem/1.3 "Helvetica Neue", Arial, sans-serif; margin: 32px 0 8px; }
.sub { color: var(--suave); font-family: "Helvetica Neue", Arial, sans-serif; margin-top: 0; }
a { color: var(--link); }
nav { margin-top: 40px; font-family: "Helvetica Neue", Arial, sans-serif; font-size: 0.95rem; }
hr { border: 0; border-top: 1px solid var(--suave); opacity: .3; margin: 48px 0; }