* { margin: 0; padding: 0; box-sizing: border-box; }
body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans SC', sans-serif;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}
.nav-scrolled {
    background: rgba(255, 255, 255, 0.85) !important;
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    box-shadow: 0 1px 20px rgba(0, 0, 0, 0.05);
}
.back-to-top {
    position: fixed; bottom: 2rem; right: 2rem;
    width: 44px; height: 44px; border-radius: 50%;
    background: linear-gradient(135deg, #6366f1, #8b5cf6);
    color: white; border: none; cursor: pointer;
    display: flex; align-items: center; justify-content: center;
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
    opacity: 0; transform: translateY(20px);
    transition: all 0.3s ease; z-index: 40;
}
.back-to-top.visible { opacity: 1; transform: translateY(0); }
.back-to-top:hover { transform: translateY(-3px); box-shadow: 0 6px 20px rgba(99, 102, 241, 0.4); }
html { scroll-behavior: smooth; }
.scroll-reveal {
    opacity: 0; transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}
.scroll-reveal.visible { opacity: 1; transform: translateY(0); }
@media (max-width: 768px) {
    .hide-mobile { display: none !important; }
}