body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: linear-gradient(135deg, #0f172a 0%, #1e3a5f 60%, #0c4a6e 100%);
}
main {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 2rem 1rem;
}
.login-card {
  width: 100%;
  max-width: 420px;
  border-radius: 16px;
  overflow: hidden;
}
.form-control:focus {
  border-color: #0ea5e9;
  box-shadow: 0 0 0 3px rgba(14, 165, 233, 0.15);
}
.input-group-text {
  background: #f8fafc;
  border-right: 0;
  color: #94a3b8;
}
.form-control {
  border-left: 0;
}
.btn-login {
  background: linear-gradient(135deg, #0ea5e9, #0284c7);
  border: none;
  transition: opacity 0.2s;
}
.btn-login:hover {
  opacity: 0.9;
}