/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 72px;
    background: rgba(0, 0, 0, 0.85);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    z-index: var(--z-fixed);
    transition: all var(--transition-base);
}

.header.scrolled {
    background: rgba(0, 0, 0, 0.95);
    box-shadow: var(--shadow-lg);
    height: 64px;
}

.header .container {
    height: 100%;
}

/* Navigation */
.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}

.logo {
    display: flex;
    align-items: center;
    font-weight: var(--weight-bold);
    font-size: var(--font-lg);
    transition: opacity var(--transition-base);
}

.logo:hover {
    opacity: 0.8;
}

.logo img {
    height: 42px;
    width: auto;
    transition: height var(--transition-base);
}

.header.scrolled .logo img {
    height: 36px;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: var(--space-32);
}

.nav-link {
    font-size: var(--font-sm);
    font-weight: var(--weight-medium);
    color: var(--text-secondary);
    transition: color var(--transition-base);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--text-primary);
    transition: width var(--transition-base);
}

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

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

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

/* Social Links in Nav */
.nav-social {
    display: flex;
    align-items: center;
    gap: var(--space-8);
    margin-left: var(--space-16);
    padding-left: var(--space-16);
    border-left: 1px solid var(--border);
}

.social-icon {
    width: 38px;
    height: 38px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-md);
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    transition: all var(--transition-base);
    color: var(--text-secondary);
}

.social-icon:hover {
    border-color: var(--border-light);
    background: var(--bg-tertiary);
    color: var(--text-primary);
    transform: translateY(-2px);
}

.social-icon svg {
    width: 20px;
    height: 20px;
}

/* Mobile Toggle */
.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 6px;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--space-8);
    border-radius: var(--radius-md);
    transition: background var(--transition-base);
}

.nav-toggle:hover {
    background: var(--bg-secondary);
}

.nav-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    transition: all var(--transition-base);
    border-radius: var(--radius-full);
}

.nav-toggle.active span:first-child {
    transform: rotate(45deg) translate(6px, 6px);
}

.nav-toggle.active span:last-child {
    transform: rotate(-45deg) translate(6px, -6px);
}

/* Responsive */
@media (max-width: 968px) {
    .nav-social {
        display: none;
    }
    
    .header {
        height: 64px;
    }
}

@media (max-width: 768px) {
    .nav-toggle {
        display: flex;
    }
    
    .nav-menu {
        position: fixed;
        top: 64px;
        left: 0;
        right: 0;
        flex-direction: column;
        gap: 0;
        background: rgba(0, 0, 0, 0.98);
        backdrop-filter: blur(20px);
        border-bottom: 1px solid var(--border);
        padding: var(--space-24) 0;
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all var(--transition-base);
        box-shadow: var(--shadow-xl);
    }
    
    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .nav-link {
        padding: var(--space-16) var(--space-24);
        width: 100%;
        text-align: center;
        border-bottom: 1px solid var(--border);
    }
    
    .nav-link::after {
        display: none;
    }
    
    .nav-menu .button {
        margin: var(--space-16) var(--space-24) 0;
        width: calc(100% - var(--space-48));
    }
}