/* Base & Reset */
    *, *::before, *::after { box-sizing: border-box; }
    html { scroll-behavior: smooth; scroll-padding-top: 80px; }
    body { margin: 0; -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; }
    img { max-width: 100%; height: auto; display: block; }

    /* Scroll Reveal — progressive enhancement, hidden by default for below-fold */
    @media (prefers-reduced-motion: no-preference) {
        .scroll-reveal {
            opacity: 0;
            transform: translateY(24px);
            transition: opacity 0.6s cubic-bezier(0.22, 1, 0.36, 1), transform 0.6s cubic-bezier(0.22, 1, 0.36, 1);
        }
        .scroll-reveal.revealed {
            opacity: 1;
            transform: translateY(0);
        }
        /* Stagger children */
        .grid .scroll-reveal:nth-child(2) { transition-delay: 0.08s; }
        .grid .scroll-reveal:nth-child(3) { transition-delay: 0.16s; }
        .grid .scroll-reveal:nth-child(4) { transition-delay: 0.24s; }
        .grid .scroll-reveal:nth-child(5) { transition-delay: 0.32s; }
        .grid .scroll-reveal:nth-child(6) { transition-delay: 0.40s; }
    }

    /* Mobile Menu */
    #mobile-menu {
        max-height: 0;
        overflow: hidden;
        transition: max-height 0.35s cubic-bezier(0.4, 0, 0.2, 1);
    }
    #mobile-menu.open {
        max-height: 500px;
    }

    /* Navbar transition */
    #navbar.scrolled {
        background: rgba(2, 6, 23, 0.92);
        backdrop-filter: blur(16px);
        -webkit-backdrop-filter: blur(16px);
        box-shadow: 0 1px 0 rgba(255,255,255,0.06), 0 4px 24px rgba(0,0,0,0.3);
    }

    /* Form select arrow */
    select {
        background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%2394a3b8' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
        background-repeat: no-repeat;
        background-position: right 12px center;
        padding-right: 40px;
    }

    /* Focus visible for accessibility */
    :focus-visible {
        outline: 2px solid #0d9488;
        outline-offset: 2px;
    }

    /* Selection color */
    ::selection {
        background: rgba(13, 148, 136, 0.2);
        color: #0f766e;
    }