body {
  margin: 0;
  padding: 0;
  font-family: 'Segoe UI', sans-serif;
  background: linear-gradient(135deg, #7b0c0c, #1e1e1e);
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
}

.login-container {
  background-color: rgba(255, 255, 255, 0.08);
  padding: 3rem;
  border-radius: 15px;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.5);
  max-width: 400px;
  width: 100%;
  text-align: center;
  color: white;
}

h2 {
  margin-bottom: 0.5rem;
  color: #ff4d4d;
}

.login-sub {
  font-size: 0.95rem;
  color: #ddd;
  margin-bottom: 2rem;
}

form {
  display: flex;
  flex-direction: column;
  gap: 1.2rem;
}

label {
  text-align: left;
  font-weight: bold;
  color: #f5f5f5;
}

input {
  padding: 0.7rem;
  font-size: 1rem;
  border: 1px solid #aa2e2e;
  border-radius: 8px;
  background-color: #2b2b2b;
  color: white;
}

input::placeholder {
  color: #bbb;
}

button {
  padding: 0.7rem;
  font-size: 1rem;
  background-color: #c62828;
  color: white;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: background-color 0.3s ease;
}

button:hover {
  background-color: #a91d1d;
}

.btn-retroceso {
  display: inline-block;
  margin: 20px 0;
  padding: 10px 18px;
  background: linear-gradient(135deg, #a91d1d, #ff4d4d); 
  color: white;
  text-decoration: none;
  font-weight: bold;
  border-radius: 25px;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.3);
  transition: background 0.3s ease, transform 0.2s ease;
}

.btn-retroceso:hover {
  background: linear-gradient(135deg, #ff4d4d, #7b0c0c);
  transform: translateY(-2px);
}