html{scroll-behavior:smooth}.btn-ghost{border-radius:.6rem;transition:transform .2s ease}.btn-ghost:hover{transform:translateY(-2px)}.err-code{font-size:clamp(5rem,18vw,10rem);font-weight:900;line-height:1;letter-spacing:-.04em}.err-icon{font-size:3.5rem}.back-top{position:fixed;bottom:1.5rem;right:1.5rem;z-index:1050;padding:.5rem .8rem;font-size:1.2rem;border-radius:.5rem;box-shadow:0 4px 14px rgba(239,68,68,0.45);border:none;cursor:pointer;transition:transform .2s ease}.back-top:hover{transform:translateY(-3px)}@keyframes float-orb{0%,100%{transform:translateY(0) scale(1)}50%{transform:translateY(-18px) scale(1.04)}}.hero-orb{position:absolute;width:340px;height:340px;border-radius:50%;background:radial-gradient(circle,var(--btn-bg) 0%,transparent 70%);opacity:.09;top:50%;left:50%;transform:translate(-50%,-50%);pointer-events:none;animation:float-orb 6s ease-in-out infinite}.err-hero{position:relative;overflow:hidden}