/* Paleta de colores: Azules, blancos, plateados y negros */
:root {
    --azul-oscuro: #1a365d;
    --azul-medio: #2c5282;
    --azul-claro: #3182ce;
    --azul-ligero: #63b3ed;
    --blanco: #ffffff;
    --gris-claro: #f7fafc;
    --gris-medio: #e2e8f0;
    --gris-oscuro: #4a5568;
    --negro: #000000;
    --plateado: #cbd5e0;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, var(--azul-oscuro) 0%, var(--azul-medio) 100%);
    min-height: 100vh;
    color: var(--negro);
}

.navbar {
    background: var(--blanco) !important;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

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

.nav-link {
    color: var(--azul-medio) !important;
    font-weight: 500;
    transition: color 0.3s ease;
}

.nav-link:hover {
    color: var(--azul-claro) !important;
}

.card {
    border: none;
    border-radius: 15px;
    box-shadow: 0 5px 20px rgba(0,0,0,0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0,0,0,0.15);
}

.card-header {
    background: linear-gradient(135deg, var(--azul-oscuro), var(--azul-medio));
    color: var(--blanco);
    border-radius: 15px 15px 0 0 !important;
    font-weight: bold;
    text-align: center;
}

.btn-primary {
    background: linear-gradient(135deg, var(--azul-claro), var(--azul-medio));
    border: none;
    border-radius: 25px;
    padding: 10px 25px;
    font-weight: 600;
    transition: all 0.3s ease;
}

.btn-primary:hover {
    background: linear-gradient(135deg, var(--azul-medio), var(--azul-oscuro));
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.2);
}

.btn-secondary {
    background: var(--plateado);
    border: none;
    border-radius: 25px;
    padding: 10px 25px;
    font-weight: 600;
    transition: all 0.3s ease;
}

.btn-secondary:hover {
    background: var(--gris-oscuro);
    color: var(--blanco);
}

.btn-success {
    background: linear-gradient(135deg, #48bb78, #38a169);
    border: none;
    border-radius: 25px;
    padding: 10px 25px;
    font-weight: 600;
}

.btn-danger {
    background: linear-gradient(135deg, #f56565, #e53e3e);
    border: none;
    border-radius: 25px;
    padding: 10px 25px;
    font-weight: 600;
}

.form-control {
    border-radius: 10px;
    border: 2px solid var(--gris-medio);
    padding: 12px 15px;
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

.form-control:focus {
    border-color: var(--azul-claro);
    box-shadow: 0 0 0 0.2rem rgba(49, 130, 206, 0.25);
}

.alert {
    border-radius: 10px;
    border: none;
    font-weight: 500;
}

.badge {
    padding: 8px 12px;
    border-radius: 20px;
    font-weight: 600;
}

/* Estilos para preguntas */
.pregunta-card {
    background: var(--blanco);
    border-radius: 15px;
    padding: 25px;
    margin-bottom: 20px;
    box-shadow: 0 5px 20px rgba(0,0,0,0.1);
}

.opcion-btn {
    width: 100%;
    text-align: left;
    margin-bottom: 10px;
    padding: 15px;
    border-radius: 10px;
    border: 2px solid var(--gris-medio);
    background: var(--blanco);
    transition: all 0.3s ease;
    cursor: pointer;
}

.opcion-btn:hover {
    border-color: var(--azul-claro);
    background: var(--gris-claro);
    transform: translateX(5px);
}

.opcion-btn.selected {
    border-color: var(--azul-claro);
    background: var(--azul-ligero);
    color: var(--blanco);
}

.opcion-btn.correct {
    border-color: #48bb78;
    background: #48bb78;
    color: var(--blanco);
}

.opcion-btn.incorrect {
    border-color: #f56565;
    background: #f56565;
    color: var(--blanco);
}

/* Temporizador */
.temporizador {
    font-size: 2rem;
    font-weight: bold;
    color: var(--azul-oscuro);
    text-align: center;
    padding: 20px;
    background: var(--blanco);
    border-radius: 15px;
    box-shadow: 0 5px 20px rgba(0,0,0,0.1);
}

.temporizador.advertencia {
    color: #f6ad55;
    animation: pulse 1s infinite;
}

.temporizador.peligro {
    color: #f56565;
    animation: pulse 0.5s infinite;
}

@keyframes pulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.05); }
    100% { transform: scale(1); }
}

/* Ranking */
.ranking-table {
    background: var(--blanco);
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 5px 20px rgba(0,0,0,0.1);
}

.ranking-table th {
    background: linear-gradient(135deg, var(--azul-oscuro), var(--azul-medio));
    color: var(--blanco);
    font-weight: 600;
    text-align: center;
}

.ranking-table td {
    padding: 15px;
    text-align: center;
    border-bottom: 1px solid var(--gris-medio);
}

.ranking-table tr:hover {
    background: var(--gris-claro);
}

/* Medallas */
.medalla-oro {
    color: #ffd700;
    font-size: 1.5rem;
}

.medalla-plata {
    color: #c0c0c0;
    font-size: 1.5rem;
}

.medalla-bronce {
    color: #cd7f32;
    font-size: 1.5rem;
}

/* Responsive */
@media (max-width: 768px) {
    .card {
        margin: 10px;
    }
    
    .opcion-btn {
        padding: 12px;
        font-size: 0.9rem;
    }
    
    .temporizador {
        font-size: 1.5rem;
        padding: 15px;
    }
}

/* Animaciones */
.fade-in {
    animation: fadeIn 0.5s ease-in;
}

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

.slide-in {
    animation: slideIn 0.5s ease-out;
}

@keyframes slideIn {
    from { transform: translateX(-100%); }
    to { transform: translateX(0); }
}