.hidden {
  display: none;
}
body {
  background-color: #0C0C0C;
  color: white;
  font-family: 'IBM Plex Sans', sans-serif;
  margin: 0;
  padding: 0;
}
header {
  background: #1A1A1A;
  padding: 1rem;
  text-align: center;
}
nav ul {
  list-style: none;
  display: flex;
  justify-content: center;
  gap: 1rem;
  padding: 0;
}
nav button {
  background-color: transparent;
  color: #00FFFF;
  border: 1px solid #00FFFF;
  padding: 0.5rem 1rem;
  cursor: pointer;
  border-radius: 4px;
}
main {
  padding: 2rem;
}
.panel {
  display: none;
}
.panel.active {
  display: block;
}
input, button {
  margin: 0.5rem 0;
  padding: 0.5rem;
  background-color: #1F1F1F;
  color: white;
  border: 1px solid #39FF14;
  border-radius: 4px;
}
pre {
  background-color: #1A1A1A;
  padding: 1rem;
  border-radius: 6px;
  overflow: auto;
}
footer {
  text-align: center;
  padding: 1rem;
  background: #1A1A1A;
}