/* Botão START com barra de progresso */
#startBtn {
    position: relative;
    overflow: hidden;
    color: white;
    font-weight: bold;
    border-radius: 0.3rem;
}

#startBtn .progress-bar {
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 0%;
    background-color: #4caf50;
    z-index: 0;
    transition: width 0.2s ease;
    border-radius: 0.3rem;
}

#startBtn .progress-text {
    position: relative;
    z-index: 1;
    font-weight: bold;
    pointer-events: none;
}

.selected-cell {
  background-color: #d1e7dd !important; /* verde claro do Bootstrap */
  border: 2px solid #0f5132;
}