.particle {
    $side: 20px;

    // background: url('../res/seahorse.svg') no-repeat center center #aaa;
    background-color: #555;
    background-size: $side $side;
    border-radius: $side / 2;
    color: #fff;
    font-size: 11px;
    height: $side;
    line-height: $side;
    margin: #{-$side / 2} 0 0 #{-$side / 2};
    position: absolute;
    text-align: center;
    width: $side;
    z-index: 1;

    // &.has-vision::after {
    //     border: 50px solid;
    //     border-color: lightgreen transparent transparent turquoise;
    //     border-radius: 50px;
    //     content: ' ';
    //     height: 0;
    //     left: -50px;
    //     margin: #{$side / 2} 0 0 #{$side / 2};
    //     opacity: 0.5;
    //     position: absolute;
    //     transform: rotate(45deg);
    //     top: -50px;
    //     width: 0;
    //     z-index: 0;
    // }
}

.particle-movement-circle {
    border: 3px dotted darkturquoise;
    margin-left: 10px;
    margin-top: 10px;
    position: absolute;
    z-index: 0;
}

.particle-vision-grid {
    height: 100px;
    // margin-top: 50px;
    // margin-left: 50px;
    position: absolute;
    transform-origin: left top;
    width: 100px;
    z-index: 99;
}

.particle-vision-dot {
    $s: 2px;

    background: red;
    // border-radius: 2px;
    height: $s;
    position: absolute;
    width: $s;
    z-index: 99;

    &.removed {
        // background: purple;
        background: green;
    }

    &.touching {
        outline: 2px solid yellow;
    }
}