.scroll-to-top {
    position: fixed;
    bottom: 50px;
    right: 50px;
    width: 50px;
    height: 80px;
    background: linear-gradient(135deg, rgba(0, 18, 26, 0.9), rgba(4, 22, 35, 0.9));
    border: 2px solid var(--line_color);
    border-radius: 7px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 1px;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transform: translateY(100px);
    transition: all 0.4s ease;
    z-index: 9998;
    box-shadow: 0 0 20px rgba(193, 239, 251, 0.3),
        inset 0 0 15px rgba(193, 239, 251, 0.1);
    overflow: hidden;
}
.scroll-to-top::before {
    content: '';
    position: absolute;
    top: -40%;
    left: -80%;
    width: 120px;
    height: 120px;
    background: linear-gradient(45deg,
            transparent,
            rgba(193, 239, 251, 0.1),
            transparent);
    transform: rotate(45deg);
    animation: scan 3s linear infinite;
}
.scroll-to-top::after {
    content: '';
    position: absolute;
    inset: 3px;
    border-radius: 7px;
    border: 1px solid var(--line_color);
    opacity: 0.5;
}
.scroll-to-top.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}
.scroll-to-top:hover {
    background: linear-gradient(135deg, rgba(4, 22, 35, 0.95), rgba(0, 18, 26, 0.95));
    border-color: var(--border_color);
    box-shadow: 0 0 12px rgba(193, 239, 251, 0.6),
        0 0 60px rgba(193, 239, 251, 0.3),
        inset 0 0 20px rgba(193, 239, 251, 0.2);
    transform: translateY(-5px);
}
.scroll-to-top i {
    color: var(--txt_color);
    font-size: 1rem;
    transition: all 0.3s ease;
    text-shadow: 0 0 10px rgba(193, 239, 251, 0.8),
        0 0 20px rgba(193, 239, 251, 0.5);
    z-index: 1;
}
.scroll-to-top i:nth-child(1) {opacity: 0.4;}
.scroll-to-top i:nth-child(2) {opacity: 0.7;}
.scroll-to-top i:nth-child(3) {opacity: 1;}
.scroll-to-top:hover i {
    transform: scale(1.1);
    text-shadow: 0 0 15px rgba(193, 239, 251, 1),
        0 0 30px rgba(193, 239, 251, 0.7),
        0 0 45px rgba(193, 239, 251, 0.4);
}

@keyframes scan {
    0% { transform: translateY(100%) rotate(45deg);}
    100% { transform: translateY(-100%) rotate(45deg);}
}

/* Responsive */
@media (max-width: 768px) {
    .scroll-to-top {
        width: 45px;
        height: 70px;
        bottom: 20px;
        right: 5%;
    }
    .scroll-to-top::before { left: -95%;}
    .scroll-to-top i {font-size: 0.9rem;}
}