/* ===== Base & Utilities ===== */
*, *::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(94, 234, 212, 0.3);
    color: #f0fdfa;
}

/* ===== Scrollbar ===== */
::-webkit-scrollbar {
    width: 8px;
}
::-webkit-scrollbar-track {
    background: #050d1a;
}
::-webkit-scrollbar-thumb {
    background: rgba(94, 234, 212, 0.3);
    border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
    background: rgba(94, 234, 212, 0.5);
}

/* ===== Navigation ===== */
.nav-fixed {
    transition: box-shadow 0.3s ease, background 0.3s ease;
}

.nav-fixed.scrolled {
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.3);
    background: rgba(2, 6, 16, 0.95) !important;
}

.nav-link {
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: #5eead4;
    transition: width 0.3s ease;
}

.nav-link:hover::after {
    width: 100%;
}

.nav-link:hover {
    color: #5eead4 !important;
}

/* ===== Mobile Menu ===== */
.mobile-link {
    position: relative;
    padding-left: 0;
}

/* ===== Hero ===== */
#hero {
    position: relative;
}

/* ===== Product Cards ===== */
.product-card {
    transform: translateY(0);
    transition: transform 0.4s ease, box-shadow 0.4s ease, border-color 0.4s ease;
}

.product-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3), 0 0 40px rgba(94, 234, 212, 0.05);
}

/* ===== Feature Cards ===== */
.feature-card {
    transition: transform 0.4s ease, box-shadow 0.4s ease, border-color 0.4s ease;
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 16px 48px rgba(0, 0, 0, 0.2);
}

/* ===== Scroll Reveal (below-fold only, progressive enhancement) ===== */
@media (prefers-reduced-motion: no-preference) {
    .reveal {
        opacity: 0;
        transform: translateY(30px);
        transition: opacity 0.8s cubic-bezier(0.16, 1, 0.3, 1), transform 0.8s cubic-bezier(0.16, 1, 0.3, 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; }
}

/* ===== Form Elements ===== */
select option {
    background: #050d1a;
    color: #fff;
}

input:focus, textarea:focus, select:focus {
    outline: none;
}

/* ===== Responsive ===== */
@media (max-width: 767px) {
    .font-serif {
        line-height: 1.1;
    }
}

@media (min-width: 768px) and (max-width: 1023px) {
    .product-card {
        /* ensure two-column grid works well */
    }
}