/* ===================================
   CONTENT HUB / SEO ARTICLES
   =================================== */
.content-hub-section {
    background: radial-gradient(ellipse at center top, rgba(0, 212, 255, 0.02) 0%, transparent 60%);
}

.content-articles {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.content-article {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    overflow: hidden;
    transition: var(--transition-smooth);
}

.content-article:hover {
    border-color: var(--border-highlight);
    box-shadow: 0 8px 40px rgba(0, 0, 0, 0.25);
}

.content-article-warning {
    border-color: rgba(255, 140, 0, 0.15);
}

.content-article-warning:hover {
    border-color: rgba(255, 140, 0, 0.3);
    box-shadow: 0 8px 40px rgba(255, 140, 0, 0.08);
}

.content-article-featured {
    border-color: rgba(255, 215, 0, 0.15);
    background: linear-gradient(135deg, rgba(255, 215, 0, 0.03) 0%, var(--bg-card) 30%);
}

.content-article-featured:hover {
    border-color: rgba(255, 215, 0, 0.3);
    box-shadow: 0 8px 40px rgba(255, 215, 0, 0.08);
}

.content-article-inner {
    padding: 40px 44px;
}

.content-article-icon {
    width: 52px;
    height: 52px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--accent-blue-dim);
    border: 1px solid rgba(0, 212, 255, 0.15);
    border-radius: var(--radius-md);
    color: var(--accent-blue);
    margin-bottom: 20px;
    transition: var(--transition-smooth);
}

.content-article:hover .content-article-icon {
    background: rgba(0, 212, 255, 0.12);
    transform: scale(1.05);
}

.content-icon-warning {
    background: rgba(255, 140, 0, 0.1);
    border-color: rgba(255, 140, 0, 0.2);
    color: #ff8c00;
}

.content-icon-featured {
    background: var(--accent-gold-dim);
    border-color: rgba(255, 215, 0, 0.2);
    color: var(--accent-gold);
}

.content-article-title {
    font-size: 1.4rem;
    font-weight: 800;
    letter-spacing: 0;
    margin-bottom: 20px;
    line-height: 1.3;
}

.content-article-body {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.85;
}

.content-article-body p {
    margin-bottom: 16px;
}

.content-article-body p:last-child {
    margin-bottom: 0;
}

.content-article-body strong {
    color: var(--text-primary);
    font-weight: 600;
}

.content-list {
    list-style: none;
    padding: 0;
    margin: 0 0 16px 0;
}

.content-list li {
    position: relative;
    padding: 8px 0 8px 24px;
    line-height: 1.7;
}

.content-list li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 16px;
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--gradient-primary);
    opacity: 0.7;
}

.content-formula-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 16px;
    margin: 20px 0;
}

.content-formula-item {
    padding: 24px;
    background: rgba(0, 0, 0, 0.2);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    transition: var(--transition-fast);
}

.content-formula-item:hover {
    border-color: var(--border-highlight);
    background: rgba(0, 212, 255, 0.03);
}

.content-formula-item .content-formula-expression {
    font-family: 'JetBrains Mono', monospace;
    font-size: 1.5rem;
    font-weight: 800;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 6px;
}

.content-formula-item .content-formula-name {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: none;
    letter-spacing: 0;
    color: var(--text-muted);
    margin-bottom: 12px;
}

.content-formula-item p {
    font-size: 0.88rem;
    margin-bottom: 12px;
}

.content-formula-item .content-formula-example {
    padding: 10px 14px;
    background: rgba(0, 0, 0, 0.2);
    border-radius: var(--radius-sm);
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.82rem;
    color: var(--text-secondary);
}

.content-formula-item .content-formula-example strong {
    color: var(--accent-blue);
}

.content-formula-highlight {
    padding: 28px 32px;
    background: linear-gradient(135deg, rgba(0, 212, 255, 0.06) 0%, rgba(124, 58, 237, 0.04) 100%);
    border: 1px solid rgba(0, 212, 255, 0.12);
    border-radius: var(--radius-lg);
    margin: 20px 0;
    text-align: center;
}

.content-formula-highlight .content-formula-expression {
    font-family: 'JetBrains Mono', monospace;
    font-size: 1.8rem;
    font-weight: 800;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 10px;
}

.content-formula-highlight p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 0;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.content-table-wrap {
    margin: 20px 0;
    overflow-x: auto;
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    backdrop-filter: blur(10px);
}

.content-table {
    width: 100%;
    border-collapse: collapse;
    min-width: 500px;
}

.content-table thead {
    background: rgba(0, 0, 0, 0.2);
}

.content-table th {
    padding: 14px 20px;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: none;
    letter-spacing: 0;
    color: var(--text-muted);
    text-align: left;
    border-bottom: 1px solid var(--border-color);
    white-space: nowrap;
}

.content-table td {
    padding: 12px 20px;
    font-size: 0.9rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.03);
    transition: var(--transition-fast);
}

.content-table tbody tr:hover td {
    background: rgba(0, 212, 255, 0.03);
}

.content-table tbody tr:last-child td {
    border-bottom: none;
}

.content-table td strong {
    color: var(--text-primary);
}

.wire-size-table {
    min-width: 700px;
}

.content-chart-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 18px;
    margin-top: 24px;
}

.content-chart-card {
    min-width: 0;
    padding: 20px;
    background: rgba(0, 0, 0, 0.16);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
}

.content-chart-title {
    font-size: 1rem;
    font-weight: 750;
    color: var(--text-primary);
    line-height: 1.35;
    margin-bottom: 12px;
}

.content-chart-card .content-table-wrap {
    margin: 0;
    border-radius: var(--radius-md);
}

.compact-table {
    min-width: 440px;
}

.compact-table th,
.compact-table td {
    padding: 10px 12px;
    font-size: 0.82rem;
}

.content-steps-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin: 20px 0;
}

.content-step-item {
    display: flex;
    align-items: flex-start;
    gap: 16px;
    padding: 18px 22px;
    background: rgba(0, 0, 0, 0.15);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    transition: var(--transition-fast);
}

.content-step-item:hover {
    border-color: var(--border-highlight);
    background: rgba(0, 212, 255, 0.02);
}

.content-step-num {
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient-primary);
    border-radius: 50%;
    font-family: 'JetBrains Mono', monospace;
    font-weight: 800;
    font-size: 0.85rem;
    color: #fff;
    flex-shrink: 0;
}

.content-step-item div {
    font-size: 0.92rem;
    line-height: 1.7;
    color: var(--text-secondary);
}

.content-step-item div strong {
    color: var(--text-primary);
}

.content-two-col {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
    margin: 20px 0;
}

.content-col-card {
    padding: 24px;
    background: rgba(0, 0, 0, 0.15);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    transition: var(--transition-fast);
}

.content-col-card:hover {
    border-color: var(--border-highlight);
}

.content-col-card h4 {
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 10px;
    color: var(--text-primary);
}

.content-col-card p {
    font-size: 0.88rem;
    margin-bottom: 0;
}

.content-info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 16px;
    margin: 20px 0;
}

.content-info-item {
    padding: 24px;
    background: rgba(0, 0, 0, 0.15);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    transition: var(--transition-fast);
    text-align: center;
}

.content-info-item:hover {
    border-color: var(--border-highlight);
    background: rgba(0, 212, 255, 0.02);
    transform: translateY(-2px);
}

.content-info-label {
    font-size: 0.72rem;
    font-weight: 700;
    text-transform: none;
    letter-spacing: 0;
    color: var(--text-muted);
    margin-bottom: 6px;
}

.content-info-value {
    font-family: 'JetBrains Mono', monospace;
    font-size: 1.8rem;
    font-weight: 800;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 10px;
}

.content-info-item p {
    font-size: 0.82rem;
    line-height: 1.6;
    margin-bottom: 0;
}

/* Content Diagrams */
.content-diagram {
    margin: 24px 0;
    display: flex;
    justify-content: center;
}

.content-diagram img {
    max-width: 100%;
    height: auto;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
}

.content-diagram svg {
    max-width: 100%;
    height: auto;
}

.content-svg-wrap {
    width: 100%;
    max-width: 600px;
    padding: 28px;
    background: rgba(0, 0, 0, 0.25);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    display: flex;
    justify-content: center;
    transition: var(--transition-fast);
}

.content-svg-wrap:hover {
    border-color: var(--border-highlight);
}

.content-svg-wrap.wide {
    max-width: 700px;
}

@keyframes flowPulse {
    0%, 100% { opacity: 0.4; }
    50% { opacity: 1; }
}

@keyframes dashFlow {
    to { stroke-dashoffset: -24; }
}


/* Responsive rules for content hub */
@media (max-width: 768px) {
    .content-article-inner {
        padding: 28px 24px;
    }

    .content-two-col {
        grid-template-columns: 1fr;
    }

    .content-formula-grid {
        grid-template-columns: 1fr;
    }

    .content-info-grid {
        grid-template-columns: 1fr 1fr;
    }

    .content-formula-highlight .content-formula-expression {
        font-size: 1.3rem;
    }

    .content-formula-item .content-formula-expression {
        font-size: 1.2rem;
    }

    .content-table {
        min-width: 400px;
    }

    .content-chart-grid {
        grid-template-columns: 1fr;
    }

    .content-chart-card {
        padding: 16px;
    }

    .wire-size-table {
        min-width: 600px;
    }
}

@media (max-width: 480px) {
    .content-info-grid {
        grid-template-columns: 1fr;
    }

    .content-article-title {
        font-size: 1.2rem;
    }

    .content-info-value {
        font-size: 1.5rem;
    }
}