/**
 * Loading Animation CSS
 * 
 * Grid-style loading spinner animation for the puzzle generation screen.
 * Source: CSS Loading.io (https://loading.io/css/)
 */

.lds-grid {
    display: inline-block;
    position: relative;
    width: 64px;
    height: 64px;
}

.lds-grid div {
    position: absolute;
    width: 13px;
    height: 13px;
    border-radius: 50%;
    background: #fff;
    animation: lds-grid 1.2s linear infinite;
}

/* Grid positions - 3x3 layout */
.lds-grid div:nth-child(1) {
    top: 6px;
    left: 6px;
    animation-delay: 0s;
}

.lds-grid div:nth-child(2) {
    top: 6px;
    left: 26px;
    animation-delay: -0.4s;
}

.lds-grid div:nth-child(3) {
    top: 6px;
    left: 45px;
    animation-delay: -0.8s;
}

.lds-grid div:nth-child(4) {
    top: 26px;
    left: 6px;
    animation-delay: -0.4s;
}

.lds-grid div:nth-child(5) {
    top: 26px;
    left: 26px;
    animation-delay: -0.8s;
}

.lds-grid div:nth-child(6) {
    top: 26px;
    left: 45px;
    animation-delay: -1.2s;
}

.lds-grid div:nth-child(7) {
    top: 45px;
    left: 6px;
    animation-delay: -0.8s;
}

.lds-grid div:nth-child(8) {
    top: 45px;
    left: 26px;
    animation-delay: -1.2s;
}

.lds-grid div:nth-child(9) {
    top: 45px;
    left: 45px;
    animation-delay: -1.6s;
}

/* Pulsing opacity animation */
@keyframes lds-grid {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}