/* ── Base ── */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; -webkit-font-smoothing: antialiased; }

/* ── Scroll Reveal (progressive enhancement) ── */
@media (prefers-reduced-motion: no-preference) {
    .reveal {
        opacity: 0;
        transform: translateY(30px);
        transition: opacity 0.7s cubic-bezier(0.22, 1, 0.36, 1), transform 0.7s cubic-bezier(0.22, 1, 0.36, 1);
    }
    .reveal.revealed {
        opacity: 1;
        transform: translateY(0);
    }
    .reveal-delay-1 { transition-delay: 0.1s; }
    .reveal-delay-2 { transition-delay: 0.2s; }
    .reveal-delay-3 { transition-delay: 0.3s; }
    .reveal-delay-4 { transition-delay: 0.4s; }
    .reveal-delay-5 { transition-delay: 0.5s; }
}

/* ── Navbar scroll state ── */
#navbar.scrolled {
    background: rgba(255, 255, 255, 0.97);
    backdrop-filter: blur(10px);
    box-shadow: 0 1px 20px rgba(0, 0, 0, 0.08);
}

/* ── Mobile menu transition ── */
#mobile-menu {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
}
#mobile-menu.open {
    max-height: 300px;
}

/* ── Feature card stagger ── */
@media (prefers-reduced-motion: no-preference) {
    .feature-card {
        opacity: 0;
        transform: translateY(20px);
        transition: opacity 0.5s ease, transform 0.5s ease;
    }
    .feature-card.revealed {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ── Selection color ── */
::selection {
    background: #99f6e4;
    color: #134e4a;
}