:root {
  --papel: #f5f0e6;
  --papel-2: #ebe3d3;
  --tinta: #1f1b16;
  --tinta-2: #5a5045;
  --linha: #d6cbb6;
  --acento: #8a3b12;
  --foco: #0b5cad;
  --erro: #a1260d;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --papel: #16130f;
    --papel-2: #211c16;
    --tinta: #efe7d8;
    --tinta-2: #b9ad9a;
    --linha: #3b332a;
    --acento: #f0a36b;
    --foco: #7cb8ff;
    --erro: #ff9b85;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
  background: var(--papel);
  color: var(--tinta);
  font: 1rem/1.5 system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
}

.porta {
  width: min(24rem, calc(100% - 2.5rem));
  border-top: 2px solid var(--tinta);
  padding-top: 1.5rem;
}

.selo {
  margin: 0 0 .35rem;
  font-size: .78rem;
  font-weight: 600;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--acento);
}

h1 {
  margin: 0 0 1.5rem;
  font: 600 2.2rem/1.1 "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, serif;
}

form { display: flex; flex-direction: column; gap: .6rem; }

label {
  font-size: .8rem;
  font-weight: 600;
  letter-spacing: .06em;
  text-transform: uppercase;
  color: var(--tinta-2);
}

input, button {
  font: inherit;
  min-height: 44px;
  border-radius: 0;
}

input {
  color: var(--tinta);
  background: var(--papel-2);
  border: 1px solid var(--linha);
  border-bottom: 2px solid var(--tinta);
  padding: .7rem .8rem;
}

button {
  margin-top: .4rem;
  border: 0;
  background: var(--tinta);
  color: var(--papel);
  font-weight: 600;
  cursor: pointer;
}

:focus-visible { outline: 3px solid var(--foco); outline-offset: 2px; }

.erro { margin: 0; color: var(--erro); font-size: .92rem; }

.aviso { margin: 0; color: var(--acento); font-size: .92rem; font-weight: 600; }