/* Site Header */
.site-header {
    background: var(--bg-elevated);
    border-bottom: 1px solid var(--border-color);
    padding: var(--spacing-md) 0;
    position: sticky;
    top: 0;
    z-index: var(--z-header);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}

/* Navigation Container */
.nav-container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 48px;
}

/* Logo */
.logo {
    display: flex;
    align-items: center;
    text-decoration: none;
    color: var(--text-primary);
}

.logo img {
    height: 32px;
    width: auto;
}

/* Navigation Right */
.nav-right {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

/* User Menu */
.user-menu {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-xs) var(--spacing-md);
    background: var(--bg-secondary);
    border-radius: var(--border-radius-full);
    border: 1px solid var(--border-color);
    transition: all var(--transition-normal);
}

.user-menu:hover {
    background: var(--bg-elevated);
    border-color: var(--border-hover);
    box-shadow: var(--shadow-sm);
}

.avatar {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: var(--bg-secondary);
    border: 2px solid var(--border-color);
    transition: border-color var(--transition-normal);
}

.user-menu:hover .avatar {
    border-color: var(--primary-500);
}

.user-name {
    font-weight: var(--font-weight-medium);
    color: var(--text-primary);
    max-width: 150px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* Theme Toggle */
.theme-toggle {
    padding: var(--spacing-xs);
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    border-radius: var(--border-radius);
    transition: all var(--transition-fast);
}

.theme-toggle:hover {
    color: var(--text-primary);
    background: var(--bg-secondary);
}

.theme-toggle .icon {
    width: 20px;
    height: 20px;
}

/* Auth Buttons */
.auth-buttons {
    display: flex;
    gap: var(--spacing-sm);
}

/* Responsive Adjustments */
@media (max-width: 768px) {
    .nav-container {
        padding: 0 var(--spacing-sm);
    }

    .user-name {
        display: none;
    }

    .auth-buttons {
        gap: var(--spacing-xs);
    }

    .auth-buttons .btn {
        padding: var(--spacing-xs) var(--spacing-sm);
    }
}

/* High Contrast Mode */
@media (forced-colors: active) {
    .site-header {
        border-bottom: 2px solid ButtonText;
    }

    .user-menu {
        border: 1px solid ButtonText;
    }

    .avatar {
        border: 2px solid ButtonText;
    }

    .theme-toggle {
        border: 1px solid ButtonText;
    }
}

/* Glass Effect for Elevated Backgrounds */
.site-header::before {
    content: '';
    position: absolute;
    inset: 0;
    background: var(--bg-primary);
    opacity: 0.85;
    z-index: -1;
}

/* Animation for User Menu */
.user-menu {
    animation: slideIn 0.3s ease-out;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Reduced Motion */
@media (prefers-reduced-motion: reduce) {
    .user-menu {
        animation: none;
    }
}