.particle-container {
    position: absolute;
    bottom: 0; /* start from bottom of the section */
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    overflow: visible;
    z-index: 0; /* behind text */
}

.particle {
    position: absolute;
    background: #00c8ff; /* fire-blue color */
    pointer-events: none;
    border-radius: 20%; /* ember-like shape */
    width: 10px;  /* default size, can be overridden by JS */
    height: 6px;
    transform: translateY(0) rotate(0deg);
    opacity: 1;
    animation-name: particleUp;
    animation-timing-function: linear;
    animation-fill-mode: forwards; /* keep final state */
}

@keyframes particleUp {
    0% {
        transform: translateY(0) rotate(0deg) scale(1);
        opacity: 1;
    }
    50% {
        transform: translateY(-50vh) rotate(180deg) scale(0.8);
        opacity: 1;
    }
    100% {
        transform: translateY(-100vh) rotate(360deg) scale(0.6);
        opacity: 0;
    }
}