/* Base & Utilities */
html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}

body {
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Header scroll state */
#site-header.scrolled {
    background: rgba(10, 31, 53, 0.97);
    backdrop-filter: blur(12px);
    box-shadow: 0 1px 20px rgba(0, 0, 0, 0.2);
}

/* Navigation links */
.nav-link {
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: #38b79d;
    transition: width 0.25s ease;
}

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

/* Mobile menu */
#mobile-menu {
    animation: slideDown 0.25s ease-out;
}

@keyframes slideDown {
    from { opacity: 0; transform: translateY(-8px); }
    to { opacity: 1; transform: translateY(0); }
}

.mobile-link {
    display: block;
    padding: 0.5rem 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.mobile-link:last-child {
    border-bottom: none;
}

/* Problem cards */
.problem-card {
    background: #fff;
    transition: transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
}

.problem-card:hover {
    transform: translateY(-4px);
}

/* Process steps */
.process-step {
    background: #fff;
    border: 1px solid #f0f0f0;
    border-radius: 1rem;
    padding: 2rem 1.5rem;
    transition: box-shadow 0.3s ease, transform 0.3s ease;
}

.process-step:hover {
    box-shadow: 0 20px 40px rgba(15, 43, 76, 0.1);
    transform: translateY(-4px);
}

/* FAQ */
.faq-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.35s ease, padding 0.35s ease;
}

.faq-content.open {
    max-height: 200px;
    padding-top: 0;
}

.faq-item.active .faq-icon {
    transform: rotate(45deg);
}

/* Scroll reveal animations (progressive enhancement) */
@media (prefers-reduced-motion: no-preference) {
    .reveal {
        opacity: 0;
        transform: translateY(24px);
        transition: opacity 0.6s ease, transform 0.6s ease;
    }

    .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; }
}

/* Focus visible styles */
*:focus-visible {
    outline: 2px solid #38b79d;
    outline-offset: 2px;
}

/* Button ripple / active */
button:active, a:active {
    transform: scale(0.98);
}