/* Base & Reset */
*, *::before, *::after {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}

body {
    overflow-x: hidden;
}

/* Navigation */
.nav-fixed {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: transparent;
    transition: background-color 0.4s ease, box-shadow 0.4s ease;
}

.nav-fixed.scrolled {
    background: rgba(255, 255, 255, 0.97);
    box-shadow: 0 1px 20px rgba(0, 0, 0, 0.08);
    backdrop-filter: blur(12px);
}

.nav-link {
    color: rgba(255, 255, 255, 0.85);
    font-size: 0.9rem;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: #2dd4bf;
    transition: width 0.3s ease;
}

.nav-link:hover {
    color: #ffffff;
}

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

.nav-fixed.scrolled .nav-link {
    color: #334155;
}

.nav-fixed.scrolled .nav-link:hover {
    color: #0d9488;
}

.nav-fixed.scrolled .nav-link::after {
    background: #0d9488;
}

.nav-light,
.nav-dark {
    transition: opacity 0.4s ease;
}

.nav-light.hidden,
.nav-dark.hidden {
    opacity: 0;
    pointer-events: none;
    position: absolute;
}

.nav-dark {
    display: none;
}

.nav-fixed.scrolled .nav-dark {
    display: block;
}

.nav-fixed.scrolled .nav-light {
    display: none;
}

/* Scroll reveal animations (progressive enhancement) */
@media (prefers-reduced-motion: no-preference) {
    .reveal {
        opacity: 0;
        transform: translateY(30px);
        transition: opacity 0.7s ease, transform 0.7s 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; }
    .reveal-delay-6 { transition-delay: 0.6s; }
}

/* Mobile menu */
#mobile-menu {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease, padding 0.4s ease;
}

#mobile-menu.open {
    max-height: 400px;
    padding-bottom: 0.5rem;
}

.mobile-link {
    position: relative;
}

.mobile-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 1px;
    background: #0d9488;
    transition: width 0.3s ease;
}

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

/* Form styles */
input:focus,
select:focus,
textarea:focus {
    outline: none;
    box-shadow: 0 0 0 3px rgba(13, 148, 136, 0.15);
}

/* Custom scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: #f1f5f9;
}

::-webkit-scrollbar-thumb {
    background: #94a3b8;
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: #64748b;
}

/* Selection */
::selection {
    background: rgba(13, 148, 136, 0.2);
    color: #134e4a;
}