:root {
  --L_background: #f3f3f3;
  --L_background_1: #ffffff;
  --L_background_2: #e0e0e0;
  --L_primary_2: #3949ab;
  --L_primary_3: #5c6bc0;
  --L_primary_4: #7986cb;
  --L_text: #222;
  --L_text_2: #555;
  --L_text_3: #777;

  --D_background: #121212;
  --D_background_2: #1f1f1f;
  --D_background_3: #2c2c2c;
  --D_primary_2: #8c9eff;
  --D_primary_3: #536dfe;
  --D_text: #f5f5f5;
  --D_text_1: #cccccc;
  --D_text_2: #aaaaaa;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Poppins', sans-serif;
}

body {
  background-color: var(--L_background);
  color: var(--L_text);
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  transition: background-color 0.3s, color 0.3s;
}

.login-container {
  background-color: var(--L_background_1);
  padding: 40px;
  border-radius: 16px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
  width: 100%;
  max-width: 400px;
}

.login-container h2 {
  margin-bottom: 20px;
  text-align: center;
  color: var(--L_primary_3);
  font-size: 2rem;
}

.login-container form {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.login-container input {
  padding: 12px;
  border: 1px solid var(--L_background_2);
  border-radius: 8px;
  font-size: 1rem;
  background-color: #fff;
  color: var(--L_text);
  transition: border-color 0.3s ease;
}

.login-container input:focus {
  border-color: var(--L_primary_2);
  outline: none;
}

.login-container button {
  padding: 12px;
  background-color: var(--L_primary_2);
  color: white;
  font-size: 1rem;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: background-color 0.3s ease, transform 0.2s ease;
  font-weight: 600;
}

.login-container button:hover {
  background-color: var(--L_primary_3);
  font-weight: 400;
  transform: scale(0.98);
}

.login-container .error-message {
  color: red;
  font-size: 0.9rem;
  text-align: center;
  font-weight: bold;
  animation: shake 0.4s ease;
}

/* Mode sombre */
@media (prefers-color-scheme: dark) {
  body {
    background-color: var(--D_background);
    color: var(--D_text);
  }

  .login-container {
    background-color: var(--D_background_2);
    box-shadow: 0 10px 30px rgba(255, 255, 255, 0.05);
  }

  .login-container h2 {
    color: var(--D_primary_3);
  }

  .login-container input {
    background-color: var(--D_background_3);
    border: 1px solid var(--D_background_3);
    color: var(--D_text);
  }

  .login-container input:focus {
    border-color: var(--D_primary_2);
  }

  .login-container button {
    background-color: var(--D_primary_3);
  }

  .login-container button:hover {
    background-color: var(--D_primary_2);
  }
}

@keyframes shake {
  0% { transform: translateX(0); }
  20% { transform: translateX(-8px); }
  40% { transform: translateX(8px); }
  60% { transform: translateX(-6px); }
  80% { transform: translateX(6px); }
  100% { transform: translateX(0); }
}