.concept-box { background: linear-gradient(135deg, #f0f7ff 0%, #e8f4fd 100%); border-left: 4px solid #3b82f6; border-radius: 8px; padding: 1.25rem 1.5rem; margin: 1.5rem 0; }
.concept-box h4 { margin: 0 0 0.5rem 0; font-size: 1rem; font-weight: 600; color: #1e40af; }
.concept-box p { margin: 0; color: #334155; line-height: 1.6; }
.concept-box ul { margin: 0.5rem 0 0 0; padding-left: 1.25rem; color: #334155; }
.math-block { background: #f8fafc; border-radius: 8px; padding: 1.25rem; margin: 1rem 0; text-align: center; overflow-x: auto; }
.hierarchy-grid { display: grid; gap: 1rem; margin: 1.5rem 0; }
@media (min-width: 700px) { .hierarchy-grid { grid-template-columns: repeat(3, 1fr); } }
.hierarchy-card { background: var(--panel, #fff); border: 1px solid var(--border, #e5e7eb); border-radius: 10px; padding: 1.25rem; text-align: center; }
.hierarchy-card .level { font-size: 0.7rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.05em; color: #6366f1; margin-bottom: 0.5rem; }
.hierarchy-card h4 { margin: 0 0 0.5rem 0; font-size: 1.05rem; }
.hierarchy-card p { margin: 0; font-size: 0.9rem; color: #6b7280; line-height: 1.4; }
.compare-grid { display: grid; gap: 1.25rem; margin: 1.5rem 0; }
@media (min-width: 600px) { .compare-grid { grid-template-columns: repeat(2, 1fr); } }
.compare-card { background: var(--panel, #fff); border: 1px solid var(--border, #e5e7eb); border-radius: 12px; padding: 1.5rem; }
.compare-card h4 { margin: 0 0 0.75rem 0; font-size: 1.1rem; }
.compare-card ul { margin: 0; padding-left: 1.25rem; font-size: 0.95rem; color: #4b5563; }
.compare-card ul li { margin-bottom: 0.4rem; }
.compare-card.mcmc { border-top: 3px solid #f59e0b; }
.compare-card.inla { border-top: 3px solid #10b981; }
.note-box { background: linear-gradient(135deg, #fffbeb 0%, #fef3c7 100%); border-left: 4px solid #f59e0b; border-radius: 8px; padding: 1rem 1.25rem; margin: 1.5rem 0; font-size: 0.95rem; color: #78350f; }
.note-box strong { color: #92400e; }
.step-list { counter-reset: step-counter; list-style: none; padding: 0; margin: 1.5rem 0; }
.step-list li { counter-increment: step-counter; position: relative; padding-left: 3rem; margin-bottom: 1.25rem; }
.step-list li::before { content: counter(step-counter); position: absolute; left: 0; top: 0; width: 2rem; height: 2rem; background: linear-gradient(135deg, #6366f1, #8b5cf6); color: white; font-weight: 600; font-size: 0.9rem; border-radius: 50%; display: flex; align-items: center; justify-content: center; }
.step-list li strong { color: #1e293b; }
.model-examples { display: grid; gap: 0.75rem; margin: 1rem 0; }
@media (min-width: 500px) { .model-examples { grid-template-columns: repeat(2, 1fr); } }
.model-tag { background: #f1f5f9; border-radius: 6px; padding: 0.5rem 0.75rem; font-size: 0.9rem; color: #475569; }
.section-divider { border-top: 1px solid #e5e7eb; margin: 2.5rem 0; padding-top: 2rem; }