:root {
    --negro: #1a1a1a;
    --azul: #2c7da0;
    --verde: #52b788;
    --turquesa: #48cae4;
    --blanco: #ffffff;
    --gris-claro: #f8f9fa;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, var(--gris-claro) 0%, #e9ecef 100%);
    min-height: 100vh;
}

/* Navbar personalizado */
.navbar {
    background: var(--negro) !important;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.navbar-brand {
    color: var(--turquesa) !important;
    font-weight: bold;
    font-size: 1.5rem;
}

.navbar-brand:hover {
    color: var(--verde) !important;
}

.nav-link {
    color: var(--blanco) !important;
    transition: all 0.3s ease;
}

.nav-link:hover {
    color: var(--turquesa) !important;
    transform: translateY(-2px);
}

/* Botones */
.btn-primary {
    background: var(--azul);
    border: none;
    transition: all 0.3s ease;
}

.btn-primary:hover {
    background: var(--turquesa);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(44,125,160,0.3);
}

.btn-success {
    background: var(--verde);
    border: none;
}

.btn-success:hover {
    background: #409c6e;
    transform: translateY(-2px);
}

/* Tarjetas */
.card {
    border: none;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    transition: all 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0,0,0,0.15);
}

.card-header {
    background: linear-gradient(135deg, var(--azul), var(--turquesa));
    color: var(--blanco);
    border-radius: 15px 15px 0 0 !important;
    padding: 1.5rem;
    font-weight: bold;
}

/* Formularios */
.form-control, .form-select {
    border-radius: 10px;
    border: 2px solid #e0e0e0;
    transition: all 0.3s ease;
}

.form-control:focus, .form-select:focus {
    border-color: var(--turquesa);
    box-shadow: 0 0 0 0.2rem rgba(72,202,228,0.25);
}

/* Alertas */
.alert {
    border-radius: 10px;
    border: none;
}

/* Footer */
.footer {
    background: var(--negro);
    color: var(--blanco);
    padding: 2rem 0;
    margin-top: 4rem;
}

/* Responsive */
@media (max-width: 768px) {
    .card-header {
        padding: 1rem;
    }

    .btn {
        width: 100%;
        margin-bottom: 0.5rem;
    }
}

/* Animaciones */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    animation: fadeIn 0.5s ease-out;
}
/* Footer fijo abajo */
html, body {
    height: 100%;
    margin: 0;
    display: flex;
    flex-direction: column;
}

body {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

main.container {
    flex: 1 0 auto;
}

.footer {
    margin-top: auto;
    background: var(--negro);
    color: var(--blanco);
    padding: 2rem 0;
    flex-shrink: 0;
}