.loader {
    position: fixed;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
    display: flex;
    justify-content: center;
    align-items: center;
}

.loader .loader-inner {
    position: relative;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.3);
    display: flex;
    justify-content: center;
    align-items: center;
    -webkit-transition:
      width 0.5s,
      height 1s; /* For Safari 3.1 to 6.0 */
    transition:
      width 0.5s,
      height 1s;
}
.loader .loader-inner .loading-box {
    text-align: center;
    width: 100%;
    padding: 2em;
}
.loader .loader-inner .loading-box .circular-loader {
    border: 3px solid #f3f3f3; /* Light grey */
    border-top: 3px solid #444; /* Blue */
    border-radius: 50%;
    width: 50px;
    height: 50px;
    animation: spin 2s linear infinite;
    margin: 0 auto;
    transition: all 0.5s ease-out;
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
    animation: spin 3s linear infinite;
}
@keyframes spin {
    0% {
      transform: rotate(0deg);
    }
    100% {
      transform: rotate(360deg);
    }
}