*, *::before, *::after { box-sizing: border-box; }
body {
  font-family: sans-serif;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  margin: 0;
  background: #1a1a2e;
  color: #e0e0e0;
}
h1 { font-size: 2rem; margin-bottom: 0.25rem; }
p.subtitle { color: #aaa; margin-bottom: 2rem; }
form {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  width: 100%;
  max-width: 360px;
}
label { font-size: 0.9rem; color: #ccc; margin-bottom: 0.25rem; display: block; }
input[type="text"], input[type="password"] {
  width: 100%;
  padding: 0.6rem 0.8rem;
  border: 1px solid #444;
  border-radius: 6px;
  background: #16213e;
  color: #e0e0e0;
  font-size: 1rem;
}
input:focus { outline: 2px solid #7b5ea7; border-color: transparent; }
button {
  padding: 0.7rem;
  border: none;
  border-radius: 6px;
  background: #7b5ea7;
  color: #fff;
  font-size: 1rem;
  cursor: pointer;
  margin-top: 0.5rem;
}
button:hover { background: #9370c8; }
.error {
  background: #4a1a1a;
  border: 1px solid #a33;
  border-radius: 6px;
  padding: 0.6rem 0.8rem;
  color: #f88;
  font-size: 0.9rem;
  display: none;
}
.error.visible { display: block; }