html, body {
    height: 100%;
    overflow: hidden;
}

.preloader {
    position: fixed;
    width: 100%;
    height: 100%;
    background-color: #ffffff;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 99;
}

.loader {
    width: 30px;
    height: 30px;
    border: 5px solid #677583;
    border-top: 5px solid #171c24;
    border-radius: 50%;
    animation: spin 2s linear infinite;
}

.preloader.hidden {
    display: none;
}

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