body {
  font-family: sans-serif;
  background: #f4f4f4;
  color: #333;
  display: flex;
  justify-content: center;
  padding: 2rem;
  transition: background 0.3s ease, color 0.3s ease;
}

body.dark {
  background: #121212;
  color: #eee;
}

.app {
  background: #fff;
  padding: 2rem;
  border-radius: 10px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
  width: 100%;
  max-width: 400px;
  transition: background 0.3s ease, color 0.3s ease;
}

body.dark .app {
  background: #1e1e1e;
}

form {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 1rem;
}

input {
  flex: 1;
  padding: 0.5rem;
}

button {
  padding: 0.5rem 1rem;
  background: #007bff;
  color: #fff;
  border: none;
  cursor: pointer;
}

.hidden {
  display: none;
}

img {
  width: 80px;
}