#start-loader {
    position: fixed;
    top: 0;
    left: 0;
    height: 100%;
    width: 100%;
    background-color: #1a1a1a;
    z-index: 99;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 1;
    transition: opacity 0.5s ease;
}

.hidden {
    opacity: 0 !important;
}

.loader {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    display: inline-block;
    border-top: 3px solid rgba(255, 255, 255, 0.5);
    border-right: 3px solid transparent;
    box-sizing: border-box;
    animation: rotation 1s linear infinite;
}

@keyframes rotation {
    0% {
        transform: rotate(0deg);
    }
    100% {
        transform: rotate(360deg);
    }
}