* { box-sizing: border-box; }
body {
  margin: 0;
  min-height: 100vh;
  font-family: Arial, sans-serif;
  background: #101418;
  color: #e8eef2;
  display: grid;
  place-items: center;
}
main { width: min(520px, 92vw); padding: 24px 0 48px; }
.tag { color: #7ee0c8; font-size: 12px; letter-spacing: .12em; text-transform: uppercase; }
h1 { margin: 8px 0; }
.sub { color: #9aa7b2; }
.tabs { display: flex; gap: 8px; margin: 20px 0 12px; }
.tabs button {
  flex: 1;
  padding: 10px;
  border: 0;
  border-radius: 8px;
  background: #1c242c;
  color: #e8eef2;
  cursor: pointer;
}
.tabs button.on { background: #7ee0c8; color: #042422; font-weight: bold; }
textarea, #go {
  width: 100%;
  font-size: 16px;
  padding: 12px;
  border-radius: 8px;
  border: 0;
}
textarea { background: #1c242c; color: white; }
#go { margin-top: 8px; background: #7ee0c8; color: #042422; font-weight: bold; cursor: pointer; }
#out {
  background: #1c242c;
  padding: 16px;
  border-radius: 12px;
  white-space: pre-wrap;
}
.fine { color: #6b7780; font-size: 12px; }