* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: 'Segoe UI', system-ui, -apple-system, sans-serif; background: #f5f7fa; color: #1e4b69; }
.container { max-width: 900px; margin: 0 auto; padding: 16px; }
h2 { text-align: center; font-size: 1.3rem; margin-bottom: 8px; color: #1e4b69; }
.curve-container { margin-bottom: 12px; }
#revenue-curve { width: 100%; height: auto; }
.curve-label { font-size: 13px; fill: #64748b; }
.phases { display: flex; align-items: flex-start; gap: 6px; justify-content: center; flex-wrap: nowrap; }
.phase-arrow { font-size: 1.2rem; color: #94a3b8; align-self: center; margin-top: 20px; flex-shrink: 0; }
.phase-card { flex: 1; min-width: 0; border-radius: 10px; background: #fff; box-shadow: 0 2px 8px rgba(0,0,0,0.08); cursor: pointer; transition: transform 0.2s, box-shadow 0.2s; position: relative; overflow: visible; }
.phase-card:hover { transform: translateY(-4px); box-shadow: 0 6px 20px rgba(0,0,0,0.12); }
.phase-card.selected { transform: translateY(-4px); box-shadow: 0 6px 20px rgba(0,0,0,0.18); }
.phase-header { padding: 10px 12px; border-radius: 10px 10px 0 0; display: flex; align-items: center; gap: 8px; }
.phase-header h3 { font-size: 0.85rem; color: #fff; }
.phase-number { width: 22px; height: 22px; border-radius: 50%; background: rgba(255,255,255,0.3); display: flex; align-items: center; justify-content: center; font-size: 0.75rem; font-weight: 700; color: #fff; flex-shrink: 0; }
.introduction { background: #3b82f6; }
.growth { background: #22c55e; }
.maturity { background: #f59e0b; }
.decline { background: #9ca3af; }
.phase-body { padding: 10px 12px; }
.focus { font-style: italic; font-size: 0.8rem; color: #475569; margin-bottom: 8px; text-align: center; }
.phase-details { display: none; }
.phase-card.selected .phase-details { display: block; }
.detail-section { margin-bottom: 8px; }
.detail-section strong { font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.5px; color: #1e4b69; }
.detail-section ul { list-style: none; padding: 0; margin: 4px 0 0; }
.detail-section li { font-size: 0.78rem; color: #475569; padding: 1px 0; padding-left: 12px; position: relative; }
.detail-section li::before { content: '•'; position: absolute; left: 0; color: #94a3b8; }
.detail-section p { font-size: 0.78rem; color: #475569; margin-top: 4px; }
.tooltip { display: none; position: absolute; bottom: calc(100% + 8px); left: 50%; transform: translateX(-50%); background: #1e293b; color: #f1f5f9; padding: 10px 14px; border-radius: 8px; font-size: 0.75rem; line-height: 1.4; width: 220px; z-index: 10; box-shadow: 0 4px 12px rgba(0,0,0,0.2); }
.tooltip::after { content: ''; position: absolute; top: 100%; left: 50%; transform: translateX(-50%); border: 6px solid transparent; border-top-color: #1e293b; }
.phase-card:hover .tooltip { display: block; }
@media (max-width: 700px) {
    .phases { flex-direction: column; align-items: stretch; }
    .phase-arrow { transform: rotate(90deg); text-align: center; margin: 4px 0; }
    .tooltip { width: 180px; }
}