/* Header & Navigation Styles */

.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: var(--z-fixed);
    background: var(--bg-overlay);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-primary);
    transition: all var(--transition-base);
}

.header.scrolled {
    box-shadow: var(--shadow-md);
}

/* Navigation Container */
.nav-container {
    max-width: 1600px;
    margin: 0 auto;
    padding: var(--spacing-lg) var(--spacing-xl);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--spacing-xl);
}

/* Logo */
.logo {
    flex-shrink: 0;
}

.logo-link {
    display: flex;
    align-items: center;
    transition: all var(--transition-base);
}

.logo-link:hover {
    opacity: 0.8;
}

.logo-image {
    height: 40px;
    width: auto;
    display: block;
}

.logo-text {
    color: var(--text-primary);
}

.logo-accent {
    background: var(--gradient-purple-pink);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.logo-link:hover {
    transform: translateY(-2px);
}

/* Navigation Menu */
.nav-menu {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    flex: 1;
    justify-content: center;
}

.nav-item {
    position: relative;
}

.nav-link {
    display: flex;
    align-items: center;
    padding: var(--spacing-sm) var(--spacing-lg);
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-semibold);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-secondary);
    transition: all var(--transition-base);
    border-radius: var(--radius-md);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%) scaleX(0);
    width: 80%;
    height: 2px;
    background: var(--gradient-purple-pink);
    transition: transform var(--transition-base);
}

.nav-link:hover {
    color: var(--text-primary);
}

.nav-link:hover::after {
    transform: translateX(-50%) scaleX(1);
}

.nav-link.active {
    color: var(--text-primary);
}

.nav-link.active::after {
    transform: translateX(-50%) scaleX(1);
    background: var(--gradient-green-cyan);
}

.nav-link.disabled {
    opacity: 0.4;
    cursor: not-allowed;
    pointer-events: none;
}

/* Navigation Actions */
.nav-actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    flex-shrink: 0;
}

/* Theme Toggle */
.theme-toggle {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    background: var(--bg-secondary);
    border: 1px solid var(--border-primary);
    transition: all var(--transition-base);
    position: relative;
}

.theme-toggle:hover {
    color: var(--text-primary);
    border-color: var(--color-cyan);
    box-shadow: var(--glow-cyan);
}

.theme-icon {
    position: absolute;
    transition: all var(--transition-base);
}

.sun-icon {
    opacity: 0;
    transform: rotate(-90deg) scale(0.8);
}

.moon-icon {
    opacity: 1;
    transform: rotate(0deg) scale(1);
}

[data-theme="light"] .sun-icon {
    opacity: 1;
    transform: rotate(0deg) scale(1);
}

[data-theme="light"] .moon-icon {
    opacity: 0;
    transform: rotate(90deg) scale(0.8);
}

/* Mobile Toggle */
.mobile-toggle {
    display: none;
    width: 40px;
    height: 40px;
    border-radius: var(--radius-md);
    align-items: center;
    justify-content: center;
    background: var(--bg-secondary);
    border: 1px solid var(--border-primary);
    transition: all var(--transition-base);
}

.mobile-toggle:hover {
    border-color: var(--color-cyan);
}

.hamburger {
    width: 20px;
    height: 2px;
    background: var(--text-primary);
    position: relative;
    transition: all var(--transition-base);
}

.hamburger::before,
.hamburger::after {
    content: '';
    position: absolute;
    width: 20px;
    height: 2px;
    background: var(--text-primary);
    transition: all var(--transition-base);
}

.hamburger::before {
    top: -6px;
}

.hamburger::after {
    bottom: -6px;
}

.mobile-toggle.active .hamburger {
    background: transparent;
}

.mobile-toggle.active .hamburger::before {
    top: 0;
    transform: rotate(45deg);
}

.mobile-toggle.active .hamburger::after {
    bottom: 0;
    transform: rotate(-45deg);
}

/* Mobile Menu */
@media (max-width: 1024px) {
    .nav-menu {
        position: fixed;
        top: 80px;
        left: 0;
        right: 0;
        flex-direction: column;
        background: var(--bg-overlay);
        backdrop-filter: blur(20px);
        -webkit-backdrop-filter: blur(20px);
        border-bottom: 1px solid var(--border-primary);
        padding: var(--spacing-xl);
        gap: var(--spacing-md);
        opacity: 0;
        visibility: hidden;
        transform: translateY(-20px);
        transition: all var(--transition-base);
        box-shadow: var(--shadow-lg);
    }
    
    .nav-menu.active {
        opacity: 1;
        visibility: visible;
        transform: translateY(0);
    }
    
    .nav-link {
        width: 100%;
        justify-content: center;
        padding: var(--spacing-md) var(--spacing-lg);
    }
    
    .mobile-toggle {
        display: flex;
    }
}

@media (max-width: 768px) {
    .nav-container {
        padding: var(--spacing-md) var(--spacing-md);
    }
    
    .logo-link {
        font-size: var(--font-size-xl);
    }

    .theme-toggle,
    .mobile-toggle {
        width: 44px;
        height: 44px;
    }
}

/* Header Gradient Divider */
.header .gradient-divider {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
}