/* ==========================================================================
   Library — Nav Divider & Tree
   ========================================================================== */
.nav-divider {
    height: 1px;
    background: var(--border-color);
    margin: 0.5rem 1.5rem;
    list-style: none;
}

.nav-item-library {
    display: flex;
    flex-direction: column;
}

.nav-item-library .nav-link {
    cursor: pointer;
    display: flex;
    align-items: center;
    padding: 0.875rem 1.5rem;
}

.library-toggle-arrow {
    margin-left: auto;
    transition: transform 0.3s ease;
    font-size: 0.7rem;
    color: var(--text-secondary);
}

.library-toggle-arrow.open {
    transform: rotate(90deg);
}

.library-nav-tree {
    display: none;
    padding: 0 0.75rem 0.5rem;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease, padding 0.3s ease;
}

.nav-item-library.library-expanded .library-nav-tree {
    display: block;
    max-height: 2000px;
    padding: 0 0.75rem 0.75rem;
}

.lib-nav-section {
    margin-bottom: 0.25rem;
}

.lib-nav-section-header {
    padding: 0.5rem 0.75rem;
    cursor: pointer;
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--primary-color);
    border-radius: var(--border-radius-sm);
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 0.35rem;
}

.lib-nav-section-header:hover {
    background: var(--glass-bg);
}

.lib-nav-groups {
    display: none;
    padding-left: 0.75rem;
}

.lib-nav-groups.open {
    display: block;
}

.lib-nav-group {
    margin: 0.15rem 0;
}

.lib-nav-group-header {
    padding: 0.35rem 0.5rem;
    cursor: pointer;
    font-size: 0.75rem;
    color: var(--text-secondary);
    border-radius: var(--border-radius-sm);
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 0.3rem;
}

.lib-nav-group-header:hover {
    color: var(--text-color);
    background: var(--glass-bg);
}

.lib-count {
    margin-left: auto;
    font-size: 0.65rem;
    color: var(--text-secondary);
    opacity: 0.6;
}

.lib-nav-items {
    display: none;
    padding: 0;
    margin: 0;
    list-style: none;
    padding-left: 1rem;
}

.lib-nav-items.open {
    display: block;
}

.lib-nav-item {
    padding: 0;
    margin: 0;
}

.lib-nav-item a {
    display: block;
    padding: 0.3rem 0.5rem;
    font-size: 0.75rem;
    color: var(--text-secondary);
    text-decoration: none;
    border-radius: var(--border-radius-sm);
    transition: var(--transition);
    word-break: break-word;
}

.lib-nav-item a:hover {
    color: var(--text-color);
    background: var(--glass-bg);
}

.lib-nav-item a.active {
    color: white;
    background: var(--primary-color);
}

.lib-arrow {
    font-size: 0.55rem;
    transition: transform 0.3s ease;
    display: inline-block;
}

.lib-arrow.open {
    transform: rotate(90deg);
}

/* ==========================================================================
   Library — Content Area
   ========================================================================== */
.library-content h1,
.library-content h2,
.library-content h3,
.library-content h4 {
    color: var(--text-color);
    line-height: 1.4;
}

.library-content h1 { font-size: 1.75rem; margin: 0 0 0.5rem; }
.library-content h2 {
    font-size: 1.35rem;
    margin: 2rem 0 0.75rem;
    padding-left: 0.75rem;
    border-left: 3px solid var(--primary-color);
    color: var(--text-color);
    font-weight: 700;
}
.library-content h3 {
    font-size: 1rem;
    margin: 1.25rem 0 0.5rem;
    color: var(--text-color);
    font-weight: 600;
}

.library-content p {
    font-size: 0.9375rem;
    line-height: 1.7;
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.library-content ul,
.library-content ol {
    color: var(--text-secondary);
    font-size: 0.9375rem;
    line-height: 1.7;
    padding-left: 1.5rem;
    margin-bottom: 1rem;
}

.library-content li {
    margin-bottom: 0.25rem;
}

.library-content code {
    font-family: 'Cascadia Code', 'Fira Code', 'Consolas', monospace;
}

.library-content p code,
.library-content li code,
.library-content h2 code,
.library-content h3 code {
    background: rgba(255, 255, 255, 0.08);
    padding: 0.15rem 0.35rem;
    border-radius: 4px;
    font-size: 0.85em;
    color: var(--accent-color);
}

.library-content pre {
    background: #1a1a2e;
    border: 1px solid var(--glass-border);
    border-radius: var(--border-radius-sm);
    padding: 0.5rem 1rem;
    margin: 0.75rem 0 1.25rem;
    overflow-x: auto;
    position: relative;
    line-height: 1;
}

.library-content pre code {
    background: none;
    padding: 0;
    border-radius: 0;
    font-size: 0.85rem;
    line-height: inherit;
}

.library-content .breadcrumbs {
    font-size: 0.8rem;
    color: var(--text-secondary);
    margin-bottom: 1.25rem;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid var(--border-color);
}

.library-content .breadcrumbs a {
    color: var(--primary-color);
    text-decoration: none;
}

.library-content .breadcrumbs a:hover {
    text-decoration: underline;
}

.library-content .pattern-header {
    margin-bottom: 1rem;
}

.library-content .pattern-header h1 {
    margin-top: 0.5rem;
}

.library-content .pattern-badge {
    display: inline-block;
    padding: 0.2rem 0.6rem;
    border-radius: 4px;
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    background: var(--glass-bg);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
}

.library-content .pattern-meta {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 0.75rem;
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: var(--border-radius-sm);
    padding: 1rem;
    margin: 1rem 0;
}

.library-content .meta-item {
    font-size: 0.85rem;
    color: var(--text-color);
}

.library-content .meta-label {
    display: block;
    font-size: 0.7rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 0.2rem;
}

.library-content .intent,
.library-content .problem,
.library-content .solution,
.library-content .when-to-use {
    margin-bottom: 1rem;
}

.library-content .example {
    margin-bottom: 1rem;
}

.library-content .pros-cons {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    margin: 1.25rem 0;
}

.library-content .pros,
.library-content .cons {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: var(--border-radius-sm);
    padding: 1rem;
}

.library-content .pros h3,
.library-content .cons h3 {
    margin-top: 0;
    font-size: 1rem;
}

.library-content .pros h3 { color: var(--success-color); }
.library-content .cons h3 { color: var(--warning-color); }

.library-content .pros ul,
.library-content .cons ul {
    margin-bottom: 0;
}

.library-content .related {
    margin: 1.5rem 0;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
}

.library-content .related a {
    color: var(--primary-color);
    text-decoration: none;
}

.library-content .related a:hover {
    text-decoration: underline;
}

.library-content .pattern-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 1.5rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
}

.library-content .pattern-nav a {
    color: var(--primary-color);
    text-decoration: none;
    font-size: 0.9rem;
    padding: 0.4rem 0.75rem;
    border-radius: var(--border-radius-sm);
    transition: var(--transition);
}

.library-content .pattern-nav a:hover {
    background: var(--glass-bg);
}

.library-content .pattern-nav .prev {
    margin-right: auto;
}

.library-content .pattern-nav .next {
    margin-left: auto;
}

.library-welcome {
    text-align: center;
    padding: 1.5rem 0;
}

.library-welcome h2 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    border-left: none;
    padding-left: 0;
}

.library-welcome .lead {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.library-welcome-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.25rem;
    max-width: 700px;
    margin: 0 auto;
}

.library-welcome-card {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    cursor: pointer;
    transition: var(--transition);
    backdrop-filter: blur(10px);
}

.library-welcome-card:hover {
    border-color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: 0 8px 25px var(--shadow-color);
}

.library-welcome-card h3 {
    font-size: 1.15rem;
    margin-bottom: 0.5rem;
    margin-top: 0;
    color: var(--primary-color);
}

.library-welcome-card p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 0;
}

.library-loading {
    text-align: center;
    padding: 3rem;
    color: var(--text-secondary);
}

.lib-home-link {
    display: inline-block;
    margin-top: 1.5rem;
    color: var(--primary-color);
    text-decoration: none;
    padding: 0.5rem 1.25rem;
    border: 1px solid var(--primary-color);
    border-radius: var(--border-radius-sm);
    transition: var(--transition);
}

.lib-home-link:hover {
    background: var(--primary-color);
    color: white;
}

.hljs {
    background: transparent;
}

@media (max-width: 768px) {
    .library-content .pros-cons {
        grid-template-columns: 1fr;
    }
    .library-content .pattern-meta {
        grid-template-columns: 1fr;
    }
}