*, *::before, *::after {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    overflow-x: hidden;
}

::selection {
    background: rgba(78, 205, 196, 0.2);
    color: #e8f7f4;
}

/* Mobile menu */
#mobile-menu.open {
    pointer-events: all;
    opacity: 1;
}

#mobile-menu.open .mobile-link {
    animation: fadeUp 0.4s ease forwards;
    opacity: 0;
}

#mobile-menu.open .mobile-link:nth-child(1) { animation-delay: 0.05s; }
#mobile-menu.open .mobile-link:nth-child(2) { animation-delay: 0.1s; }
#mobile-menu.open .mobile-link:nth-child(3) { animation-delay: 0.15s; }
#mobile-menu.open .mobile-link:nth-child(4) { animation-delay: 0.2s; }

@keyframes fadeUp {
    from { opacity: 0; transform: translateY(12px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Hamburger animation */
.menu-line {
    transform-origin: center;
}

#menu-toggle[aria-expanded="true"] .menu-line:nth-child(1) {
    transform: translateY(4px) rotate(45deg);
}

#menu-toggle[aria-expanded="true"] .menu-line:nth-child(2) {
    opacity: 0;
    transform: scaleX(0);
}

#menu-toggle[aria-expanded="true"] .menu-line:nth-child(3) {
    transform: translateY(-4px) rotate(-45deg);
    width: 1.5rem;
}

/* Scroll reveal — progressive enhancement */
@media (prefers-reduced-motion: no-preference) {
    .reveal {
        opacity: 0;
        transform: translateY(24px);
        transition: opacity 0.7s cubic-bezier(0.25, 0.46, 0.45, 0.94),
                    transform 0.7s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    }

    .reveal.revealed {
        opacity: 1;
        transform: translateY(0);
    }

    .reveal:nth-child(2) { transition-delay: 0.1s; }
    .reveal:nth-child(3) { transition-delay: 0.2s; }
}

/* Header scroll state */
header.scrolled {
    background: rgba(10, 35, 66, 0.92);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(78, 205, 196, 0.08);
}

/* Focus styles */
a:focus-visible,
button:focus-visible,
input:focus-visible,
textarea:focus-visible {
    outline: 1px solid rgba(78, 205, 196, 0.5);
    outline-offset: 4px;
}

/* Subtle image hover */
section img {
    transition: transform 0.8s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

/* Smooth image loading */
img {
    image-rendering: -webkit-optimize-contrast;
    image-rendering: crisp-edges;
}