/* ==========================================================================
   CLUSTER PAGES - Design system for article/guide pages
   Lightweight, no frameworks. Uses vars from styles.css
   ========================================================================== */

/* ---- Hero ---- */
.cluster-hero {
    position: relative;
    padding: calc(100px + var(--spacing-3xl)) 0 var(--spacing-3xl);
    overflow: hidden;
}

.cluster-hero-bg {
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse at 30% 0%, rgba(255,140,66,0.12) 0%, transparent 60%),
        radial-gradient(ellipse at 80% 100%, rgba(255,107,107,0.06) 0%, transparent 50%),
        var(--bg-secondary);
    z-index: 0;
}

.cluster-hero .container {
    position: relative;
    z-index: 1;
}

.cluster-hero-content {
    max-width: 780px;
}

.cluster-badge {
    display: inline-block;
    padding: 6px 16px;
    font-size: var(--font-size-sm);
    font-weight: 600;
    color: var(--primary-color);
    background: rgba(255,140,66,0.1);
    border: 1px solid rgba(255,140,66,0.2);
    border-radius: var(--radius-full);
    margin-bottom: var(--spacing-lg);
}

.cluster-hero h1 {
    font-size: var(--font-size-4xl);
    font-weight: 700;
    line-height: 1.2;
    color: var(--text-primary);
    margin-bottom: var(--spacing-lg);
}

.cluster-hero p {
    font-size: var(--font-size-lg);
    color: var(--text-secondary);
    line-height: 1.7;
    max-width: 640px;
}

.cluster-hero-meta {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
    font-size: var(--font-size-sm);
    color: var(--text-muted);
}

.cluster-hero-meta span {
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.cluster-hero-meta svg {
    color: var(--primary-color);
}

/* ---- Breadcrumb ---- */
.breadcrumb {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: var(--font-size-sm);
    color: var(--text-muted);
    margin-bottom: var(--spacing-xl);
}

.breadcrumb a {
    color: var(--primary-color);
    text-decoration: none;
}

.breadcrumb a:hover {
    text-decoration: underline;
}

.breadcrumb svg {
    opacity: 0.4;
    flex-shrink: 0;
}

/* ---- Layout: Article + Sidebar ---- */
.cluster-content {
    padding: var(--spacing-3xl) 0;
}

.cluster-layout {
    display: grid;
    grid-template-columns: 220px 1fr;
    gap: var(--spacing-3xl);
    align-items: start;
}

/* ---- Sidebar TOC ---- */
.cluster-sidebar {
    position: sticky;
    top: 100px;
}

.toc {
    background: var(--gradient-card);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    backdrop-filter: var(--glass-blur);
}

.toc-title {
    font-size: var(--font-size-sm);
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--spacing-md);
}

.toc-list {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.toc-link {
    display: block;
    padding: 8px 12px;
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    text-decoration: none;
    border-radius: var(--radius-sm);
    border-left: 2px solid transparent;
    transition: var(--transition-fast);
}

.toc-link:hover,
.toc-link.active {
    color: var(--primary-color);
    background: rgba(255,140,66,0.06);
    border-left-color: var(--primary-color);
}

/* ---- Article ---- */
.cluster-article {
    min-width: 0;
}

.article-section {
    margin-bottom: var(--spacing-3xl);
}

.article-section h2 {
    font-size: var(--font-size-3xl);
    color: var(--text-primary);
    margin-bottom: var(--spacing-lg);
    line-height: 1.3;
}

.article-section p {
    font-size: var(--font-size-lg);
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: var(--spacing-md);
}

.article-section a {
    color: var(--primary-color);
    text-decoration: none;
}

.article-section a:hover {
    text-decoration: underline;
}

.section-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    border-radius: var(--radius-md);
    background: rgba(255,140,66,0.1);
    color: var(--primary-color);
    margin-bottom: var(--spacing-md);
}

/* ---- Feature Cards (Top 5) ---- */
.feature-cards {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    margin: var(--spacing-xl) 0;
}

.feature-card {
    display: flex;
    gap: var(--spacing-lg);
    background: var(--gradient-card);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    backdrop-filter: var(--glass-blur);
}

.feature-card--gold {
    border-color: rgba(255,140,66,0.3);
    background: linear-gradient(135deg, rgba(255,140,66,0.08) 0%, rgba(26,27,36,0.8) 100%);
}

.feature-card-rank {
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--gradient-primary);
    font-size: var(--font-size-lg);
    font-weight: 700;
    color: #fff;
}

.feature-card--gold .feature-card-rank {
    width: 56px;
    height: 56px;
    font-size: var(--font-size-xl);
    box-shadow: 0 0 24px rgba(255,140,66,0.3);
}

.feature-card-body {
    flex: 1;
    min-width: 0;
}

.feature-card h3 {
    font-size: var(--font-size-xl);
    color: var(--text-primary);
    margin-bottom: 4px;
}

.feature-card-label {
    display: inline-block;
    font-size: var(--font-size-sm);
    color: var(--primary-color);
    font-weight: 500;
    margin-bottom: var(--spacing-sm);
}

.feature-card p {
    font-size: var(--font-size-base);
    color: var(--text-secondary);
    line-height: 1.7;
    margin: 0;
}

.feature-card a {
    color: var(--primary-color);
    text-decoration: none;
}

.feature-card a:hover {
    text-decoration: underline;
}

/* ---- CTA Inline ---- */
.cluster-cta {
    margin: var(--spacing-3xl) 0;
}

.cluster-cta-inner {
    background: linear-gradient(135deg, rgba(255,140,66,0.1) 0%, rgba(255,107,107,0.05) 100%);
    border: 1px solid rgba(255,140,66,0.2);
    border-radius: var(--radius-xl);
    padding: var(--spacing-2xl);
    text-align: center;
}

.cluster-cta-inner svg {
    color: var(--primary-color);
    margin-bottom: var(--spacing-md);
}

.cluster-cta-inner h3 {
    font-size: var(--font-size-2xl);
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

.cluster-cta-inner p {
    font-size: var(--font-size-lg);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xl);
    max-width: 480px;
    margin-left: auto;
    margin-right: auto;
}

/* ---- Criteria Grid ---- */
.criteria-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
    margin: var(--spacing-xl) 0;
}

.criteria-card {
    background: var(--gradient-card);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    backdrop-filter: var(--glass-blur);
    text-align: center;
}

.criteria-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 56px;
    height: 56px;
    border-radius: 50%;
    background: rgba(255,140,66,0.1);
    color: var(--primary-color);
    margin-bottom: var(--spacing-md);
}

.criteria-card h3 {
    font-size: var(--font-size-lg);
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

.criteria-card p {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    line-height: 1.6;
    margin: 0;
}

/* ---- Test Links ---- */
.test-links {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    margin: var(--spacing-xl) 0;
}

.test-link {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--gradient-card);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-md);
    text-decoration: none;
    transition: var(--transition-fast);
}

.test-link:hover {
    border-color: rgba(255,140,66,0.3);
    background: rgba(255,140,66,0.04);
}

.test-link svg {
    color: var(--primary-color);
    flex-shrink: 0;
}

.test-link strong {
    display: block;
    font-size: var(--font-size-base);
    color: var(--text-primary);
    font-weight: 600;
}

.test-link span {
    font-size: var(--font-size-sm);
    color: var(--text-muted);
}

/* ---- Category Grid ---- */
.category-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-md);
    margin: var(--spacing-xl) 0;
}

.category-card {
    background: var(--gradient-card);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    backdrop-filter: var(--glass-blur);
}

.category-tag {
    display: inline-block;
    padding: 3px 10px;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--primary-color);
    background: rgba(255,140,66,0.12);
    border-radius: var(--radius-full);
    margin-bottom: var(--spacing-sm);
}

.category-card h3 {
    font-size: var(--font-size-base);
    color: var(--text-primary);
    margin-bottom: 4px;
}

.category-card p {
    font-size: var(--font-size-sm);
    color: var(--text-muted);
    margin: 0;
    line-height: 1.5;
}

/* ---- Related Articles Grid ---- */
.related-section {
    padding: var(--spacing-3xl) 0;
    background: var(--bg-secondary);
}

.related-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
}

.related-card {
    display: flex;
    flex-direction: column;
    background: var(--gradient-card);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    text-decoration: none;
    transition: var(--transition-normal);
    backdrop-filter: var(--glass-blur);
}

.related-card:hover {
    border-color: rgba(255,140,66,0.3);
    transform: translateY(-2px);
}

.related-card-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    border-radius: var(--radius-md);
    background: rgba(255,140,66,0.1);
    color: var(--primary-color);
    margin-bottom: var(--spacing-md);
}

.related-card h3 {
    font-size: var(--font-size-lg);
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

.related-card p {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    line-height: 1.6;
    flex: 1;
}

.related-card-link {
    font-size: var(--font-size-sm);
    font-weight: 600;
    color: var(--primary-color);
    margin-top: var(--spacing-md);
}

/* ---- Final CTA ---- */
.cluster-final-cta {
    padding: var(--spacing-3xl) 0;
}

.cluster-final-cta-inner {
    background:
        radial-gradient(ellipse at 30% 50%, rgba(255,140,66,0.12) 0%, transparent 60%),
        var(--gradient-card);
    border: 1px solid rgba(255,140,66,0.15);
    border-radius: var(--radius-xl);
    padding: var(--spacing-3xl) var(--spacing-2xl);
    text-align: center;
}

.cluster-final-cta h2 {
    font-size: var(--font-size-3xl);
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
}

.cluster-final-cta p {
    font-size: var(--font-size-lg);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xl);
    max-width: 520px;
    margin-left: auto;
    margin-right: auto;
}

/* ---- Responsive ---- */
@media (max-width: 992px) {
    .cluster-layout {
        grid-template-columns: 1fr;
    }

    .cluster-sidebar {
        position: static;
    }

    .toc {
        display: none;
    }

    .criteria-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .category-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .related-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 640px) {
    .cluster-hero h1 {
        font-size: var(--font-size-3xl);
    }

    .cluster-hero-meta {
        flex-direction: column;
        gap: var(--spacing-sm);
    }

    .feature-card {
        flex-direction: column;
        align-items: flex-start;
    }

    .feature-card-rank {
        width: 40px;
        height: 40px;
        font-size: var(--font-size-base);
    }

    .feature-card--gold .feature-card-rank {
        width: 44px;
        height: 44px;
    }

    .criteria-grid {
        grid-template-columns: 1fr;
    }

    .category-grid {
        grid-template-columns: 1fr 1fr;
    }

    .related-grid {
        grid-template-columns: 1fr;
    }

    .cluster-final-cta-inner {
        padding: var(--spacing-2xl) var(--spacing-lg);
    }
}

@media (max-width: 400px) {
    .category-grid {
        grid-template-columns: 1fr;
    }
}

/* ---- Reduced Motion ---- */
@media (prefers-reduced-motion: reduce) {
    .related-card:hover {
        transform: none;
    }
}