html, body {
  height: 100%;
  margin: 0;
}
body {
  background: linear-gradient(135deg, #1a1a1a 0%, #2d2d2d 50%, #1a1a1a 100%);
  display: flex;
  align-items: center;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}
.form-signin {
  max-width: 400px;
  padding: 2rem;
}
.card-login {
  background: #fff;
  border-radius: 12px;
  box-shadow: 0 10px 40px rgba(0,0,0,0.4);
  padding: 2rem;
}
.card-login .logo {
  width: 125px;
  height: 125px;
  object-fit: contain;
  margin-bottom: 0.5rem;
}
.card-login h3 {
  font-weight: 700;
  color: #1a1a1a;
  letter-spacing: 1px;
}
.card-login .subtitle {
  color: #666;
  font-size: 0.85rem;
  margin-bottom: 1.5rem;
}
.card-login .form-control {
  border-radius: 8px;
  padding: 12px 15px;
  border: 2px solid #e0e0e0;
  transition: border-color 0.3s;
}
.card-login .form-control:focus {
  border-color: #1a1a1a;
  box-shadow: none;
}
.card-login .btn-login {
  background: #1a1a1a;
  border: none;
  border-radius: 8px;
  padding: 12px;
  font-weight: 600;
  transition: background 0.3s;
}
.card-login .btn-login:hover {
  background: #000;
}
.card-login .alert {
  border-radius: 8px;
  font-size: 0.9rem;
  padding: 10px 15px;
}
.card-login .footer-text {
  color: #999;
  font-size: 0.8rem;
}