body {
  margin: 0;
  font-family: 'Segoe UI', sans-serif;
  background: radial-gradient(circle at top left, #3a2c6d, #1b1730);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100vh;
  transition: background 0.3s, color 0.3s;
}
body.light {
  background: linear-gradient(to bottom right, #ffffff, #e8e8f1);
  color: #111;
}
.login-container {
  background: #1e1e1e;
  padding: 2rem;
  border-radius: 1.2rem;
  width: 90%;
  max-width: 400px;
  text-align: center;
  box-shadow: 0 0 30px rgba(255, 255, 255, 0.05);
}
body.light .login-container {
  background: white;
  box-shadow: 0 0 20px rgba(0,0,0,0.1);
}
.logo {
  width: 80px;
  margin-bottom: 1rem;
}
input, select {
  width: 100%;
  padding: 0.8rem;
  margin-top: 1rem;
  border: none;
  border-radius: 0.6rem;
  background: #222;
  color: white;
}
body.light input, body.light select {
  background: #f0f0f0;
  color: #111;
}
.login-btn {
  background: #00cc66;
  color: white;
  font-weight: bold;
  padding: 0.8rem;
  margin-top: 1rem;
  width: 100%;
  border: none;
  border-radius: 0.6rem;
  cursor: pointer;
}
.login-btn:hover {
  background: #00b359;
}
.spinner, .error-box {
  margin-top: 1rem;
}
.options {
  margin-top: 1rem;
  display: flex;
  gap: 0.5rem;
  justify-content: center;
}
button#themeToggle {
  background: #333;
  color: white;
  padding: 0.6rem 1rem;
  border: none;
  border-radius: 0.6rem;
  cursor: pointer;
}
body.light button#themeToggle {
  background: #ccc;
  color: #111;
}