:root {
    --primary-color: #4a90e2;
    --primary-hover: #357abd;
    --bg-color: #f4f7f6;
    --text-color: #333;
    --white: #ffffff;
    --error-color: #e74c3c;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: var(--bg-color);
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

.login-container {
    background-color: var(--white);
    padding: 2.5rem;
    border-radius: 10px;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
    width: 100%;
    max-width: 400px;
}

.login-container h2 {
    margin-bottom: 1.5rem;
    color: var(--text-color);
    text-align: center;
    font-weight: 600;
}

.form-group {
    margin-bottom: 1.2rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    color: #666;
    font-size: 0.9rem;
}

.form-group input {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary-color);
}

button {
    width: 100%;
    padding: 0.75rem;
    background-color: var(--primary-color);
    color: var(--white);
    border: none;
    border-radius: 5px;
    font-size: 1rem;
    font-weight: bold;
    cursor: pointer;
    transition: background-color 0.3s ease;
    margin-top: 1rem;
}

button:hover {
    background-color: var(--primary-hover);
}

.footer-text {
    text-align: center;
    margin-top: 1.5rem;
    font-size: 0.85rem;
    color: #888;
}

.error-alert {
    background-color: #DC143C;
    color: #DC143C;
    border: 1px solid var(--error-color);
    color: var(--error-color);
    padding: 0.8rem;
    border-radius: 5px;
    margin-bottom: 1.5rem;
    font-size: 0.85rem;
    text-align: center;
    animation: shake 0.4s ease-in-out; /* Efecto de vibración opcional */
}

/* Pequeña animación para llamar la atención sobre el error */
@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-5px); }
    75% { transform: translateX(5px); }
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(74, 144, 226, 0.2);
    transition: all 0.3s ease;
}