:root{color-scheme:light;--fundo:#f6f7fb;--cartao:#fff;--texto:#172033;--suave:#526079;--linha:#dce1eb;--cor:#3157d5}*{box-sizing:border-box}body{margin:0;background:var(--fundo);color:var(--texto);font-family:system-ui,sans-serif;line-height:1.6}body.escuro{color-scheme:dark;--fundo:#111827;--cartao:#1c2638;--texto:#f3f5fc;--suave:#b3bfd4;--linha:#354158}header,main,footer{max-width:1100px;margin:auto;padding:24px}header{display:flex;justify-content:space-between;align-items:center;border-bottom:1px solid var(--linha);gap:16px}main{padding-top:70px}h1{font-size:clamp(3.5rem,10vw,6rem);line-height:1.1;letter-spacing:-.06em;margin:20px 0}p,main>span,footer{color:var(--suave)}section{display:grid;grid-template-columns:repeat(3,1fr);gap:20px;margin-top:50px}article{background:var(--cartao);padding:26px;border:1px solid var(--linha);border-radius:18px}h2{font-size:1.2rem}button{background:var(--cor);color:white;border:0;border-radius:10px;padding:12px 16px;min-height:44px;font:inherit;cursor:pointer}button:hover{filter:brightness(.9)}button:focus-visible{outline:3px solid var(--texto);outline-offset:4px}footer{margin-top:50px;font-size:.85rem}@media(max-width:780px){section{grid-template-columns:1fr}main{padding-top:40px}}