.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: var(--color-background);
    z-index: var(--z-navigation);
    padding: var(--space-sm) 0;
    transition: transform 0.3s ease; /* Add smooth transition */
}

.site-header.hidden {
    transform: translateY(-100%);
}

.nav-container {
    display: flex;
    align-items: center;
    padding: 0 var(--space-sm);
}

.nav-logo {
    font-size: var(--font-size-3xl);
    font-weight: var(--font-weight-light);
    text-decoration: none;
    color: var(--color-primary);
    position: relative;
    padding-left: var(--space-sm);
    padding-right: var(--space-xl);
    transition: opacity var(--transition-fast);
}

.nav-logo::after {
    content: "";
    position: absolute;
    right: 0;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--color-primary);
    border-radius: 1px;
}

.nav-logo:hover {
    opacity: 0.7;
}

.nav-menu {
    display: flex;
    gap: var(--space-xl);
    list-style: none;
    flex-wrap: wrap;
    align-items: center;
    margin: 0;
    padding-left: var(--space-xl);
}

.nav-link {
    text-decoration: none;
    color: var(--color-primary);
    font-size: var(--font-size-lg);
    padding: 0;
    transition: opacity var(--transition-fast);
    white-space: nowrap;
    font-weight: var(--font-weight-light);
    line-height: 1;
}

.nav-link:hover,
.nav-link:focus {
    opacity: 0.7;
    color: var(--color-accent);
}

.nav-link.active {
    font-weight: var(--font-weight-light);
}

.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    padding: var(--space-sm);
    margin-left: auto;
}

.hamburger {
    width: 24px;
    height: 2px;
    background: var(--color-primary);
    position: relative;
    transition: background var(--transition-fast);
}

.hamburger::before,
.hamburger::after {
    content: "";
    position: absolute;
    width: 100%;
    height: 2px;
    background: var(--color-primary);
    left: 0;
    transition: transform var(--transition-fast);
}

.hamburger::before {
    top: -8px;
}

.hamburger::after {
    bottom: -8px;
}

.mobile-menu-toggle[aria-expanded="true"] .hamburger {
    background: transparent;
}

.mobile-menu-toggle[aria-expanded="true"] .hamburger::before {
    transform: rotate(45deg) translate(6px, 6px);
}

.mobile-menu-toggle[aria-expanded="true"] .hamburger::after {
    transform: rotate(-45deg) translate(6px, -6px);
}

.github-link {
    position: fixed;
    top: var(--space-sm);
    right: var(--space-md);
    z-index: var(--z-fixed);
    display: flex;
    align-items: center;
    padding: var(--space-xs);
    transition: opacity var(--transition-fast);
}

.github-link:hover,
.github-link:focus {
    opacity: 0.7;
}

.github-link svg {
    width: 28px;
    height: 28px;
}

.main-content {
    min-height: 100vh;
    padding-top: 70px;
}

.page-container {
    max-width: var(--max-width-content);
    margin: 0 auto;
    padding: var(--space-sm) var(--space-2xl) var(--space-5xl);
}

.page-title {
    font-size: var(--font-size-4xl);
    color: var(--color-primary);
    margin-bottom: var(--space-2xl);
    font-weight: var(--font-weight-light);
}

.content-card {
    background-color: var(--color-white);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    box-shadow: var(--shadow-sm);
    margin-bottom: var(--space-xl);
}

.content-card h2 {
    font-size: var(--font-size-xl);
    color: var(--color-primary);
    margin: 0 0 var(--space-lg) 0;
    font-weight: var(--font-weight-light);
}

.two-column-layout {
    display: grid;
    grid-template-columns: 400px 1fr;
    gap: var(--space-xl);
    align-items: start;
}

@media (max-width: 968px) {
    .two-column-layout {
        grid-template-columns: 1fr;
    }

    .page-container {
        padding: var(--space-xl) var(--space-lg);
    }
}

@media (max-width: 768px) {
    .site-header {
        padding: var(--space-sm);
    }

    .nav-container {
        flex-wrap: wrap;
        position: relative;
    }

    .mobile-menu-toggle {
        display: block;
        position: absolute;
        right: 0;
        top: 0;
    }

    .nav-logo {
        font-size: var(--font-size-2xl);
    }

    .nav-menu {
        display: none;
        width: 100%;
        flex-direction: column;
        padding: var(--space-lg) 0 0 0;
        gap: var(--space-md);
        margin-top: var(--space-lg);
        align-items: flex-start;
    }

    .nav-menu.open {
        display: flex;
    }

    .main-content {
        padding-top: 60px;
    }

    .page-container {
        padding: var(--space-lg) var(--space-md);
    }

    .page-title {
        font-size: var(--font-size-3xl);
    }
}

@media (max-width: 480px) {
    .github-link {
        top: var(--space-xs);
        right: var(--space-sm);
    }

    .github-link svg {
        width: 24px;
        height: 24px;
    }

    .nav-logo {
        font-size: var(--font-size-xl);
    }
}