.back-to-top{position:fixed;bottom:30px;right:30px;width:56px;height:56px;background:linear-gradient(135deg,#1b6ca8,#2d9cdb);color:white;border:none;border-radius:50%;display:flex;align-items:center;justify-content:center;cursor:pointer;box-shadow:0 8px 25px rgba(27,108,168,.4);transition:all .3s ease;opacity:0;visibility:hidden;z-index:1000}.back-to-top.visible{opacity:1;visibility:visible}.back-to-top:hover{transform:translateY(-5px) scale(1.1);box-shadow:0 12px 35px rgba(27,108,168,.5)}.back-to-top:active{transform:translateY(-3px) scale(1.05)}@media (max-width:768px){.back-to-top{bottom:20px;right:20px;width:48px;height:48px}}