:root {
    --color-fondo-claro: #f5f6fa;
    --color-fondo-oscuro: #1e1f25;
    --color-card-claro: #ffffff;
    --color-card-oscuro: #2b2c33;
    --color-texto-claro: #1e1f25;
    --color-texto-oscuro: #f5f6fa;
    --color-acento: #3f8efc;
    --color-acento-hover: #3577e0;
    --color-error: #ff4d4f;
    --borde-radius: 10px;
    --transicion: 0.3s ease;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: "Poppins", sans-serif;
    background-color: var(--color-fondo-claro);
    color: var(--color-texto-claro);
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100vh;
    transition: var(--transicion);
    opacity: 0;
    animation: fadeIn 0.8s forwards;
}

@keyframes fadeIn {
    to {
        opacity: 1;
    }
}

body.dark {
    background-color: var(--color-fondo-oscuro);
    color: var(--color-texto-oscuro);
}

.login-container {
    background-color: var(--color-card-claro);
    padding: 2.5rem;
    border-radius: var(--borde-radius);
    width: 100%;
    max-width: 380px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    transition: var(--transicion);
    position: relative;
}

body.dark .login-container {
    background-color: var(--color-card-oscuro);
    box-shadow: 0 4px 25px rgba(0,0,0,0.3);
}

h2 {
    text-align: center;
    margin-bottom: 1.5rem;
    font-weight: 600;
}

label {
    display: block;
    margin-top: 1rem;
    font-weight: 500;
}

select, input {
    width: 100%;
    padding: 0.75rem 1rem;
    margin-top: 0.5rem;
    border: 1px solid #ccc;
    border-radius: var(--borde-radius);
    outline: none;
    transition: var(--transicion);
    background-color: inherit;
    color: inherit;
    font-size: 1rem;
}

    input:focus, select:focus {
        border-color: var(--color-acento);
        box-shadow: 0 0 5px var(--color-acento);
    }

.password-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.toggle-password {
    position: absolute;
    right: 12px;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1rem;
    color: inherit;
    opacity: 0.7;
    transition: opacity var(--transicion);
}

    .toggle-password:hover {
        opacity: 1;
    }

.btn-login {
    width: 100%;
    margin-top: 1.5rem;
    padding: 0.75rem 1rem;
    background-color: var(--color-acento);
    color: #fff;
    border: none;
    border-radius: var(--borde-radius);
    cursor: pointer;
    font-size: 1rem;
    transition: transform 0.2s ease, background 0.3s ease;
}

    .btn-login:hover {
        background-color: var(--color-acento-hover);
        transform: scale(1.02);
    }

.error {
    color: var(--color-error);
    font-size: 0.85rem;
    margin-top: 0.3rem;
    height: 1em;
}

.theme-toggle {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1.2rem;
    color: inherit;
    transition: transform 0.3s;
}

    .theme-toggle:hover {
        transform: rotate(20deg);
    }

footer {
    position: fixed;
    bottom: 1rem;
    right: 1rem;
    font-size: 0.85rem;
    opacity: 0.6;
}