:root {
  --fond: #f6f5f2;
  --texte: #1c1b19;
  --doux: #6b6862;
  --carte: #ffffff;
  --bord: #e3e0da;
  --accent: #1c1b19;
  --sur-accent: #ffffff;
  --ok: #2f7d4f;
  --erreur: #b3261e;
}
@media (prefers-color-scheme: dark) {
  :root {
    --fond: #121211;
    --texte: #f2f0eb;
    --doux: #a19d95;
    --carte: #1c1b19;
    --bord: #2e2c29;
    --accent: #f2f0eb;
    --sur-accent: #121211;
    --ok: #6cc391;
    --erreur: #f2867e;
  }
}
* { box-sizing: border-box; }
html, body { margin: 0; background: var(--fond); color: var(--texte); }
body {
  font: 17px/1.5 -apple-system, BlinkMacSystemFont, "SF Pro Text", system-ui, sans-serif;
  min-height: 100dvh; display: grid; place-items: center; padding: 24px 16px;
}
main { width: 100%; max-width: 380px; text-align: center; }
h1 { font-size: 28px; font-weight: 650; letter-spacing: -0.02em; margin: 18px 0 6px; }
.texte { color: var(--doux); margin: 0 0 24px; }
.texte b { color: var(--texte); font-weight: 600; }
.cadenas {
  width: 64px; height: 64px; margin: 0 auto; border-radius: 20px;
  background: var(--carte); border: 1px solid var(--bord); position: relative;
}
.cadenas::after {
  content: ""; position: absolute; inset: 0; margin: auto; width: 22px; height: 18px;
  border-radius: 5px; background: var(--texte); top: 14px;
}
.cadenas::before {
  content: ""; position: absolute; left: 50%; top: 14px; width: 14px; height: 14px; transform: translateX(-50%);
  border: 3px solid var(--texte); border-bottom: 0; border-radius: 9px 9px 0 0;
}
.cadenas.ouvert::before { transform: translateX(-2px); }
.cadenas.ouvert::after { background: var(--ok); }
.bouton {
  appearance: none; border: 0; width: 100%; padding: 15px 18px; border-radius: 14px;
  background: var(--accent); color: var(--sur-accent); font: inherit; font-weight: 600; cursor: pointer;
}
.bouton:disabled { opacity: .5; }
.bouton.secondaire { background: transparent; color: var(--texte); border: 1px solid var(--bord); margin-top: 10px; }
.cle {
  font: 600 18px/1.6 ui-monospace, "SF Mono", Menlo, monospace; letter-spacing: .04em;
  background: var(--carte); border: 1px solid var(--bord); border-radius: 14px; padding: 14px; word-break: break-all;
  user-select: all; -webkit-user-select: all;
}
.champ { display: block; text-align: left; color: var(--doux); font-size: 15px; margin: 18px 0 12px; }
input {
  display: block; width: 100%; margin-top: 6px; padding: 13px 14px; border-radius: 12px;
  border: 1px solid var(--bord); background: var(--carte); color: var(--texte);
  font: 600 17px ui-monospace, "SF Mono", Menlo, monospace; text-transform: uppercase;
}
details { margin-top: 28px; text-align: left; color: var(--doux); font-size: 15px; }
summary { cursor: pointer; text-align: center; }
details input { margin-top: 12px; }
.erreur { color: var(--erreur); min-height: 1.5em; margin-top: 18px; font-size: 15px; }

#arret .bouton + .bouton { margin-top: 10px; }
.bouton.danger { background: var(--erreur); color: #fff; }
.texte.petit { font-size: 14px; margin-top: 18px; }