* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: sans-serif;
  background: #0f0f0f;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
}
.box {
  background: #1a1a1a;
  padding: 40px;
  border-radius: 12px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  width: 320px;
  color: white;
}
input {
  padding: 10px;
  border-radius: 6px;
  border: 1px solid #333;
  background: #111;
  color: white;
  font-size: 14px;
}
button {
  padding: 10px;
  border-radius: 6px;
  border: none;
  cursor: pointer;
  font-weight: bold;
}
#loginBtn { background: #4f46e5; color: white; }
#registerBtn { background: #333; color: white; }
#msg { font-size: 13px; color: #f87171; }