.rechner { border: 1px solid #555; padding: 1rem; margin: 2rem 0; }
.rechner form { display: grid; gap: 1rem; max-width: 36rem; }
.rechner label { display: block; font-weight: bold; }
.rechner input { box-sizing: border-box; width: 100%; padding: .65rem; font: inherit; border: 1px solid #555; border-radius: 0; }
.rechner input[aria-invalid="true"] { border: 3px solid #a00000; }
.rechner button { justify-self: start; padding: .65rem 1rem; font: inherit; color: white; background: #004a8f; border: 1px solid #004a8f; cursor: pointer; }
.rechner small { display: block; }
.rechner-fehler { color: #980000; font-weight: bold; margin: 0; }
.rechner-ergebnis { margin-top: 1.5rem; border-top: 1px solid #777; }
.rechner-ergebnis dt { font-weight: bold; }
.rechner-ergebnis dd { margin: 0 0 .75rem; }