Experiment

/* Initial loading screen */
.loading-screen {
position: fixed;
top: 0;
left: 0;
width: 100%;
height: 100%;
background-color: white;
display: flex;
align-items: center;
justify-content: center;
z-index: 1000;
transition: opacity 1s ease-out;
}

.loading-screen.hidden {
opacity: 0;
visibility: hidden;
}

/* Smooth underline effect */
.main_center_itm_block_line_active {
width: 0;
height: 2px;
background-color: xxx;
transition: width 0.4s ease;
}

.main_center_itm_block:hover .main_center_itm_block_line_active {
width: 100%;
}

/* Text hover effect */
.main_center_itm_block:hover .main_center_itm {
color: xxx;
}