body {
    margin: 0;
    font-family: Arial, Helvetica, sans-serif;
    background: var(--color-fondo, #f4f4f4);
    color: var(--color-texto, #212121);
    font-size: var(--tamano-letra-base, 16px);
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100vh;
}

.login-box {
    background: #fff;
    padding: 40px;
    border-radius: 10px;
    box-shadow: 0 2px 12px rgba(0,0,0,0.1);
    width: 320px;
}

.login-box h1 {
    color: var(--color-primario, #1565C0);
    text-align: center;
    margin-bottom: 24px;
    font-size: 1.4em;
}

.login-box label {
    display: block;
    margin-top: 14px;
    margin-bottom: 4px;
    font-size: 0.9em;
}

.login-box input {
    width: 100%;
    padding: 10px;
    border: 1px solid #ccc;
    border-radius: 6px;
    box-sizing: border-box;
}

.login-box button {
    width: 100%;
    margin-top: 22px;
    padding: 12px;
    border: none;
    border-radius: 6px;
    background: var(--color-primario, #1565C0);
    color: #fff;
    font-weight: bold;
    cursor: pointer;
}

.login-box button:hover {
    opacity: 0.9;
}

.alert-error {
    background: #fdecea;
    color: #b71c1c;
    padding: 10px;
    border-radius: 6px;
    margin-bottom: 10px;
    font-size: 0.9em;
}