/* ========================================
   AI Cluster Interactive Diagram
   Pure CSS — no frameworks
   ======================================== */

.cluster-section {
    padding: 4rem 0;
    background: linear-gradient(135deg, #0a0e27 0%, #1a1f3a 50%, #0d1117 100%);
    color: #e6e6e6;
    position: relative;
    overflow: hidden;
}

.cluster-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(circle at 20% 50%, rgba(108,99,255,0.08) 0%, transparent 50%),
                radial-gradient(circle at 80% 20%, rgba(0,201,167,0.06) 0%, transparent 50%);
    pointer-events: none;
}

.cluster-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
    position: relative;
    z-index: 1;
}

.cluster-header {
    text-align: center;
    margin-bottom: 3rem;
}

.cluster-header h2 {
    font-size: 2.2rem;
    font-weight: 800;
    background: linear-gradient(135deg, #6C63FF, #00C9A7);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 0.75rem;
}

.cluster-header p {
    font-size: 1.1rem;
    color: #8892b0;
    max-width: 700px;
    margin: 0 auto;
    line-height: 1.6;
}

/* ---- Stats Bar ---- */
.cluster-stats {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 1.5rem;
    margin-bottom: 3rem;
}

.stat-pill {
    background: rgba(255,255,255,0.05);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: 50px;
    padding: 0.5rem 1.25rem;
    font-size: 0.85rem;
    color: #ccd6f6;
    backdrop-filter: blur(10px);
    transition: all 0.3s ease;
}

.stat-pill:hover {
    background: rgba(108,99,255,0.15);
    border-color: rgba(108,99,255,0.3);
    transform: translateY(-2px);
}

.stat-pill strong {
    color: #6C63FF;
}

/* ---- Diagram Canvas ---- */
.cluster-diagram {
    position: relative;
    width: 100%;
    max-width: 900px;
    margin: 0 auto 3rem;
    aspect-ratio: 4 / 3;
}

.cluster-svg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 1;
}

.cluster-svg line {
    stroke-width: 2;
    opacity: 0.4;
    transition: opacity 0.3s ease, stroke-width 0.3s ease;
}

.cluster-svg line.highlight {
    opacity: 0.9;
    stroke-width: 3;
}

.conn-control { stroke: #6C63FF; stroke-dasharray: 8 4; }
.conn-management { stroke: #00C9A7; }
.conn-storage { stroke: #FFA62B; stroke-dasharray: 4 4; }

/* ---- Node Cards ---- */
.node-card {
    position: absolute;
    width: 180px;
    background: rgba(22, 27, 44, 0.95);
    border: 2px solid rgba(255,255,255,0.1);
    border-radius: 16px;
    padding: 1.25rem;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: 2;
    backdrop-filter: blur(12px);
    text-align: center;
}

.node-card:hover,
.node-card:focus-visible {
    transform: scale(1.08);
    border-color: var(--node-color);
    box-shadow: 0 0 30px rgba(var(--node-color-rgb), 0.3),
                0 8px 32px rgba(0,0,0,0.4);
    z-index: 10;
}

.node-card.active {
    transform: scale(1.08);
    border-color: var(--node-color);
    box-shadow: 0 0 30px rgba(var(--node-color-rgb), 0.3),
                0 8px 32px rgba(0,0,0,0.4);
    z-index: 10;
}

.node-card:focus-visible {
    outline: 2px solid #6C63FF;
    outline-offset: 4px;
}

.node-icon {
    width: 48px;
    height: 48px;
    margin: 0 auto 0.75rem;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    background: linear-gradient(135deg, var(--node-color), rgba(var(--node-color-rgb), 0.5));
}

.node-card h3 {
    font-size: 1rem;
    font-weight: 700;
    color: #fff;
    margin: 0 0 0.25rem;
}

.node-role {
    font-size: 0.7rem;
    color: #8892b0;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin: 0;
}

.node-specs {
    margin-top: 0.5rem;
    font-size: 0.75rem;
    color: #a8b2d1;
    line-height: 1.4;
}

.node-specs span {
    display: block;
}

/* ---- Hover Tooltip ---- */
.node-tooltip {
    position: absolute;
    bottom: calc(100% + 12px);
    left: 50%;
    transform: translateX(-50%);
    background: #1a1f3a;
    border: 1px solid rgba(255,255,255,0.15);
    border-radius: 10px;
    padding: 0.75rem 1rem;
    width: 220px;
    font-size: 0.78rem;
    color: #ccd6f6;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.2s ease;
    z-index: 20;
    box-shadow: 0 8px 24px rgba(0,0,0,0.5);
}

.node-card:hover .node-tooltip {
    opacity: 1;
}

.node-tooltip strong {
    color: var(--node-color);
}

/* ---- Detail Panel ---- */
.detail-panel {
    background: rgba(22, 27, 44, 0.95);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: 20px;
    padding: 2rem;
    margin: 0 auto 3rem;
    max-width: 900px;
    backdrop-filter: blur(12px);
    display: none;
    animation: slideUp 0.3s ease;
}

.detail-panel.visible {
    display: block;
}

@keyframes slideUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.detail-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid rgba(255,255,255,0.1);
}

.detail-icon {
    width: 56px;
    height: 56px;
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.8rem;
    flex-shrink: 0;
}

.detail-header h3 {
    font-size: 1.5rem;
    font-weight: 700;
    color: #fff;
    margin: 0;
}

.detail-header .detail-role {
    font-size: 0.85rem;
    color: #8892b0;
    margin: 0;
}

.detail-close {
    margin-left: auto;
    background: none;
    border: 1px solid rgba(255,255,255,0.2);
    color: #8892b0;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    cursor: pointer;
    font-size: 1.2rem;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
}

.detail-close:hover {
    background: rgba(255,255,255,0.1);
    color: #fff;
}

.detail-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
}

.detail-block h4 {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: #6C63FF;
    margin: 0 0 0.5rem;
}

.detail-block p,
.detail-block ul {
    font-size: 0.88rem;
    color: #a8b2d1;
    line-height: 1.6;
    margin: 0;
}

.detail-block ul {
    list-style: none;
    padding: 0;
}

.detail-block ul li::before {
    content: '▸ ';
    color: var(--node-color);
}

.detail-why {
    grid-column: 1 / -1;
    background: rgba(108,99,255,0.08);
    border: 1px solid rgba(108,99,255,0.2);
    border-radius: 12px;
    padding: 1rem 1.25rem;
}

.detail-why h4 {
    color: #00C9A7;
}

.detail-why p {
    color: #ccd6f6;
    font-size: 0.9rem;
}

/* ---- Legend ---- */
.cluster-legend {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 1.5rem;
    margin-bottom: 3rem;
    font-size: 0.8rem;
    color: #8892b0;
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.legend-line {
    width: 30px;
    height: 3px;
    border-radius: 2px;
}

.legend-line.control { background: #6C63FF; }
.legend-line.management { background: #00C9A7; }
.legend-line.storage { background: #FFA62B; }

/* ---- Content Sections ---- */
.cluster-content {
    max-width: 900px;
    margin: 0 auto;
}

.cluster-content h3 {
    font-size: 1.3rem;
    font-weight: 700;
    color: #ccd6f6;
    margin: 2rem 0 1rem;
}

.highlight-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.highlight-card {
    background: rgba(255,255,255,0.03);
    border: 1px solid rgba(255,255,255,0.08);
    border-radius: 12px;
    padding: 1.25rem;
    transition: border-color 0.3s;
}

.highlight-card:hover {
    border-color: rgba(108,99,255,0.3);
}

.highlight-card h4 {
    font-size: 0.9rem;
    color: #6C63FF;
    margin: 0 0 0.5rem;
}

.highlight-card p {
    font-size: 0.85rem;
    color: #8892b0;
    line-height: 1.5;
    margin: 0;
}

.github-callout {
    background: rgba(108,99,255,0.1);
    border: 1px solid rgba(108,99,255,0.25);
    border-radius: 12px;
    padding: 1.25rem 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 1rem;
    margin-top: 2rem;
}

.github-callout p {
    margin: 0;
    color: #ccd6f6;
    font-size: 0.9rem;
}

.github-callout a {
    background: #6C63FF;
    color: #fff;
    padding: 0.5rem 1.25rem;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    font-size: 0.85rem;
    transition: background 0.2s;
}

.github-callout a:hover {
    background: #5a52e0;
}

/* ---- Responsive ---- */
@media (max-width: 768px) {
    .cluster-diagram {
        aspect-ratio: 3 / 4;
    }

    .node-card {
        width: 140px;
        padding: 1rem;
    }

    .node-icon {
        width: 40px;
        height: 40px;
        font-size: 1.2rem;
    }

    .node-card h3 { font-size: 0.9rem; }
    .node-tooltip { display: none; }

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

    .cluster-stats {
        gap: 0.75rem;
    }

    .stat-pill {
        font-size: 0.75rem;
        padding: 0.4rem 0.9rem;
    }

    .cluster-header h2 {
        font-size: 1.6rem;
    }
}

@media (max-width: 480px) {
    .node-card {
        width: 110px;
        padding: 0.75rem;
    }

    .node-specs { display: none; }
    .node-role { font-size: 0.6rem; }
}