:root { --fg: #1a1a1a; --bg: #fdfdfc; --acento: #2b5f9e; }
* { box-sizing: border-box; }
body { margin: 0; font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
       color: var(--fg); background: var(--bg); line-height: 1.6; }
.cabecera { display: flex; justify-content: space-between; align-items: center;
            padding: 1rem 2rem; border-bottom: 1px solid #e3e3e0; }
.marca { font-weight: 700; letter-spacing: .12em; text-decoration: none; color: var(--acento); }
nav a { margin-left: 1rem; color: var(--acento); }
main { max-width: 60rem; margin: 0 auto; padding: 2rem; }
nav { display: flex; align-items: center; gap: 1rem; }
.salir { display: inline; margin: 0; }
.formulario { max-width: 24rem; }
.formulario p { display: flex; flex-direction: column; gap: .25rem; }
.formulario input { padding: .5rem; border: 1px solid #ccc; border-radius: 4px; }
button { padding: .5rem 1rem; background: var(--acento); color: #fff;
         border: 0; border-radius: 4px; cursor: pointer; font: inherit; }
.error { color: #b3261e; }