* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    background: #f5f7fa;
    color: #1e293b;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    padding: 20px;
}

.container {
    max-width: 1000px;
    width: 100%;
    position: relative;
}

h1 {
    text-align: center;
    color: #1e4b69;
    font-size: 1.6rem;
    margin-bottom: 4px;
}

.subtitle {
    text-align: center;
    color: #64748b;
    font-size: 0.95rem;
    margin-bottom: 24px;
}

.diagram {
    display: flex;
    align-items: stretch;
    gap: 0;
    background: white;
    border-radius: 16px;
    box-shadow: 0 4px 24px rgba(0, 0, 0, 0.08);
    padding: 32px 24px;
    position: relative;
    min-height: 400px;
}

.column {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 16px;
    padding: 0 12px;
}

.column-title {
    font-size: 0.85rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    margin-bottom: 8px;
    padding: 4px 16px;
    border-radius: 20px;
}

.clients-column .column-title {
    color: #3b82f6;
    background: rgba(59, 130, 246, 0.08);
}

.network-column .column-title {
    color: #94a3b8;
    background: rgba(148, 163, 184, 0.08);
}

.servers-column .column-title {
    color: #22c55e;
    background: rgba(34, 197, 94, 0.08);
}

.component {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
    padding: 16px 20px;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.25s ease;
    width: 160px;
    position: relative;
}

.component:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
}

.client {
    background: rgba(59, 130, 246, 0.06);
    border: 2px solid rgba(59, 130, 246, 0.2);
    color: #3b82f6;
}

.client:hover {
    border-color: #3b82f6;
    background: rgba(59, 130, 246, 0.1);
}

.server {
    background: rgba(34, 197, 94, 0.06);
    border: 2px solid rgba(34, 197, 94, 0.2);
    color: #22c55e;
}

.server:hover {
    border-color: #22c55e;
    background: rgba(34, 197, 94, 0.1);
}

.icon {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.component .label {
    font-size: 0.88rem;
    font-weight: 600;
    color: #1e293b;
}

.role-hint {
    font-size: 0.72rem;
    color: #64748b;
    font-style: italic;
}

.network-column {
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
}

.network-cloud {
    margin-top: 24px;
}

.cloud-label {
    font-size: 16px;
    font-weight: 600;
    fill: #64748b;
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
}

.cloud-sublabel {
    font-size: 11px;
    fill: #94a3b8;
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
}

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

.connections-svg .conn-line {
    pointer-events: stroke;
    cursor: pointer;
}

.connections-svg .conn-line:hover {
    stroke-width: 3;
    filter: drop-shadow(0 0 4px rgba(70, 180, 200, 0.5));
}

.connections-svg .conn-arrow {
    pointer-events: none;
}

/* Tooltip */
.tooltip {
    position: fixed;
    background: #1e293b;
    color: white;
    padding: 12px 16px;
    border-radius: 10px;
    font-size: 0.85rem;
    max-width: 280px;
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.2s ease;
    z-index: 100;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
}

.tooltip.visible {
    opacity: 1;
}

.tooltip-title {
    font-weight: 700;
    margin-bottom: 6px;
    color: rgb(70, 180, 200);
}

.tooltip-body {
    line-height: 1.5;
}

.tooltip-body .tech-label {
    display: block;
    margin-top: 6px;
    color: #94a3b8;
    font-size: 0.78rem;
}

/* Connection detail panel */
.connection-panel {
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%) translateY(100%);
    background: white;
    border: 2px solid rgb(70, 180, 200);
    border-radius: 12px;
    padding: 20px 24px;
    width: 90%;
    max-width: 600px;
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.15);
    z-index: 50;
    display: none;
}

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

.connection-panel h3 {
    color: #1e4b69;
    font-size: 1rem;
    margin-bottom: 12px;
}

.close-btn {
    position: absolute;
    top: 10px;
    right: 14px;
    background: none;
    border: none;
    font-size: 1.4rem;
    color: #94a3b8;
    cursor: pointer;
    line-height: 1;
}

.close-btn:hover {
    color: #1e293b;
}

.request-response {
    display: flex;
    gap: 16px;
}

.request-block,
.response-block {
    flex: 1;
}

.block-label {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-weight: 700;
    margin-bottom: 6px;
}

.request-block .block-label {
    color: #3b82f6;
}

.response-block .block-label {
    color: #22c55e;
}

pre {
    background: #f1f5f9;
    padding: 10px 12px;
    border-radius: 8px;
    font-size: 0.78rem;
    line-height: 1.5;
    overflow-x: auto;
    font-family: 'Cascadia Code', 'Fira Code', monospace;
    white-space: pre-wrap;
    word-break: break-word;
}

/* Animated dots along connection lines */
@keyframes flowDot {
    0% { offset-distance: 0%; opacity: 0; }
    10% { opacity: 1; }
    90% { opacity: 1; }
    100% { offset-distance: 100%; opacity: 0; }
}

.flow-dot {
    width: 6px;
    height: 6px;
    background: rgb(70, 180, 200);
    border-radius: 50%;
    position: absolute;
    offset-rotate: 0deg;
    animation: flowDot 2s linear infinite;
    pointer-events: none;
    z-index: 2;
}

@media (max-width: 700px) {
    .diagram {
        flex-direction: column;
        gap: 24px;
        padding: 20px 16px;
    }

    .component {
        width: 140px;
    }

    .request-response {
        flex-direction: column;
    }

    .connections-svg {
        display: none;
    }
}