body {
    background-color: #f4f6f9;
}

.card-area {
    cursor: pointer;
    transition: transform .15s ease, box-shadow .15s ease;
    border-width: 2px;
}
.card-area:hover {
    transform: translateY(-3px);
    box-shadow: 0 .5rem 1rem rgba(0,0,0,.1);
}
.card-area.seleccionada {
    border-color: #0d6efd;
    background-color: #eaf2ff;
}

#timer-box {
    position: sticky;
    top: 10px;
    z-index: 10;
}
#timer-box.tiempo-critico {
    background-color: #dc3545 !important;
    color: #fff;
    animation: parpadeo 1s infinite;
}
@keyframes parpadeo {
    50% { opacity: .6; }
}

.pregunta-card {
    scroll-margin-top: 90px;
}

.nav-pregunta {
    width: 40px;
    height: 40px;
}
.nav-pregunta.respondida {
    background-color: #198754;
    color: #fff;
    border-color: #198754;
}

.calificacion-circulo {
    width: 180px;
    height: 180px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.5rem;
    font-weight: bold;
    margin: 0 auto;
    border: 10px solid #0d6efd;
}