/* Enhanced Header Styles for Vietnamese Historical Game */

/* Special Vietnamese Cultural Elements */
.nav-container::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, 
        transparent 0%,
        rgba(212, 175, 55, 0.3) 20%,
        rgba(255, 107, 53, 0.5) 50%,
        rgba(212, 175, 55, 0.3) 80%,
        transparent 100%);
    animation: borderFlow 4s ease-in-out infinite;
}

/* Vietnamese Pattern Background */
.nav-content::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        radial-gradient(circle at 25% 25%, rgba(212, 175, 55, 0.03) 0%, transparent 50%),
        radial-gradient(circle at 75% 75%, rgba(255, 107, 53, 0.03) 0%, transparent 50%);
    pointer-events: none;
    z-index: -1;
}

/* Enhanced Logo with Vietnamese Characteristics */
.logo {
    position: relative;
}

.logo::before {
    content: '';
    position: absolute;
    top: 50%;
    left: -50px;
    width: 30px;
    height: 2px;
    background: linear-gradient(90deg, transparent, var(--primary-color), transparent);
    transform: translateY(-50%);
    opacity: 0.6;
    animation: logoAccent 3s ease-in-out infinite alternate;
}

.logo::after {
    content: '';
    position: absolute;
    top: 50%;
    right: -50px;
    width: 30px;
    height: 2px;
    background: linear-gradient(90deg, transparent, var(--accent-color), transparent);
    transform: translateY(-50%);
    opacity: 0.6;
    animation: logoAccent 3s ease-in-out infinite alternate-reverse;
}

/* Enhanced Typography */
.logo h2 {
    position: relative;
    letter-spacing: 1px;
    font-family: 'Playfair Display', serif;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    line-height: 1;
}

.logo-main {
    font-size: 1.8rem;
    font-weight: 700;
    background: linear-gradient(45deg, 
        var(--primary-color) 0%,
        #f4d03f 50%,
        var(--accent-color) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-shadow: 0 0 20px rgba(212, 175, 55, 0.3);
    margin-bottom: 2px;
}

.logo-subtitle {
    font-size: 0.7rem;
    font-weight: 400;
    color: var(--text-muted);
    letter-spacing: 2px;
    text-transform: uppercase;
    opacity: 0.8;
    animation: subtitleGlow 3s ease-in-out infinite alternate;
}

.logo h2::before {
    content: '⚔️';
    position: absolute;
    left: -40px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 1.2rem;
    opacity: 0.8;
    animation: logoSymbol 2s ease-in-out infinite alternate;
    filter: drop-shadow(0 0 8px rgba(212, 175, 55, 0.5));
}

.logo h2::after {
    content: '🏛️';
    position: absolute;
    right: -40px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 1.2rem;
    opacity: 0.8;
    animation: logoSymbol 2s ease-in-out infinite alternate-reverse;
    filter: drop-shadow(0 0 8px rgba(255, 107, 53, 0.5));
}

/* Navigation Links Enhancement */
.nav-link {
    position: relative;
    overflow: hidden;
}

.nav-link::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, 
        transparent, 
        rgba(212, 175, 55, 0.1), 
        transparent);
    transition: left 0.6s ease;
    z-index: -1;
}

.nav-link:hover::before {
    left: 100%;
}

/* Vietnamese Cultural Patterns */
.nav-link:hover {
    position: relative;
}

.nav-link:hover::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 50%;
    width: 0;
    height: 0;
    border-left: 4px solid transparent;
    border-right: 4px solid transparent;
    border-bottom: 4px solid var(--primary-color);
    transform: translateX(-50%);
    animation: arrowPulse 0.6s ease-out;
}

/* Mobile Menu Enhancements */
@media (max-width: 768px) {
    .nav-menu.active {
        background: linear-gradient(135deg, 
            rgba(15, 15, 15, 0.98) 0%,
            rgba(26, 26, 26, 0.96) 30%,
            rgba(42, 24, 16, 0.94) 60%,
            rgba(15, 15, 15, 0.98) 100%);
    }

    .nav-menu.active::before {
        content: '';
        position: absolute;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        background-image: 
            linear-gradient(45deg, transparent 25%, rgba(212, 175, 55, 0.02) 25%),
            linear-gradient(-45deg, transparent 25%, rgba(255, 107, 53, 0.02) 25%);
        background-size: 30px 30px;
        pointer-events: none;
        animation: mobilePattern 10s linear infinite;
    }

    .nav-link {
        position: relative;
        border-left: 3px solid transparent;
        transition: all var(--transition-smooth);
    }

    .nav-link:hover,
    .nav-link.active {
        border-left-color: var(--primary-color);
        background: linear-gradient(90deg, 
            rgba(212, 175, 55, 0.1) 0%,
            transparent 100%);
        transform: translateX(10px);
    }

    .logo h2::before,
    .logo h2::after {
        display: none;
    }

    .logo-main {
        font-size: 1.4rem;
    }

    .logo-subtitle {
        font-size: 0.6rem;
        letter-spacing: 1px;
    }
}

/* Loading and Transition Effects */
.nav-container.loading {
    opacity: 0;
    transform: translateY(-20px);
}

.nav-container.loaded {
    opacity: 1;
    transform: translateY(0);
    transition: all 1s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Scroll Effects */
.nav-container.scrolled {
    backdrop-filter: blur(25px) saturate(1.8);
}

.nav-container.scrolled::before {
    opacity: 0.9;
    transform: scaleX(1.5);
}

.nav-container.scrolled .logo h2 {
    transform: scale(0.9);
}

/* Special Hover Effects for Vietnamese Theme */
.nav-link:hover {
    text-shadow: 0 0 15px rgba(212, 175, 55, 0.4);
}

.nav-link.active {
    color: var(--primary-color);
    text-shadow: 0 0 10px rgba(212, 175, 55, 0.3);
    position: relative;
}

.nav-link.active::before {
    opacity: 1;
    transform: scale(1);
}

/* Performance Optimizations for Smooth Scrolling */
.nav-container {
    /* Anti-jitter optimizations */
    will-change: transform;
    transform: translateZ(0);
    backface-visibility: hidden;
    perspective: 1000px;
    
    /* Smooth transitions */
    transition: transform 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    
    /* Layer promotion for GPU acceleration */
    contain: layout style paint;
    isolation: isolate;
}

/* Reduce paint and layout thrashing */
.nav-content {
    will-change: auto;
    contain: layout style;
}

.logo h2 {
    will-change: auto;
    text-rendering: optimizeSpeed;
}

.nav-link {
    will-change: auto;
    contain: layout style;
}

/* Animations */
@keyframes navGlow {
    0% {
        opacity: 0.3;
        transform: scaleX(0.8);
    }
    100% {
        opacity: 0.7;
        transform: scaleX(1.2);
    }
}

@keyframes subtitleGlow {
    0% {
        opacity: 0.6;
        text-shadow: 0 0 5px rgba(212, 175, 55, 0.2);
    }
    100% {
        opacity: 1;
        text-shadow: 0 0 12px rgba(212, 175, 55, 0.4);
    }
}

@keyframes logoSymbol {
    0% {
        transform: translateY(-50%) scale(1) rotate(0deg);
        opacity: 0.6;
    }
    100% {
        transform: translateY(-50%) scale(1.1) rotate(5deg);
        opacity: 1;
    }
}

@keyframes logoAccent {
    0% {
        width: 20px;
        opacity: 0.4;
    }
    100% {
        width: 40px;
        opacity: 0.8;
    }
}

@keyframes borderFlow {
    0%, 100% {
        background-position: 0% 50%;
    }
    50% {
        background-position: 100% 50%;
    }
}

@keyframes arrowPulse {
    0% {
        opacity: 0;
        transform: translateX(-50%) translateY(5px);
    }
    100% {
        opacity: 1;
        transform: translateX(-50%) translateY(0);
    }
}

@keyframes mobilePattern {
    0% {
        background-position: 0 0;
    }
    100% {
        background-position: 30px 30px;
    }
}

/* High DPI Support */
@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {
    .logo h2::before,
    .logo h2::after {
        filter: drop-shadow(0 0 4px rgba(212, 175, 55, 0.8));
    }
}

/* Reduced Motion Support */
@media (prefers-reduced-motion: reduce) {
    .nav-container::before,
    .logo h2::before,
    .logo h2::after,
    .nav-link::before {
        animation: none;
    }
    
    .nav-container,
    .nav-link,
    .logo h2 {
        transition: none;
    }
}

/* Dark Mode Enhancements */
@media (prefers-color-scheme: dark) {
    .nav-container {
        background: linear-gradient(135deg, 
            rgba(10, 10, 10, 0.98) 0%,
            rgba(20, 20, 20, 0.96) 50%,
            rgba(10, 10, 10, 0.98) 100%);
    }
}

/* Print Styles */
@media print {
    .nav-container {
        display: none;
    }
}