.deep-dive {
            margin: 1.8rem 0;
        }
        .deep-dive p {
            text-align: justify;
        }
        .unit-note {
            font-size: 0.9rem;
            color: #6c757d;
        }
        .solutions-container {
            max-height: 300px;
            overflow-y: auto;
            background-color: #f9f9f9;
            padding: 1rem;
            border-radius: 8px;
            border: 1px solid #e0e0e0;
            font-family: 'Courier New', monospace;
            font-size: 1.1rem;
            margin-top: 1rem;
        }
        .solution-item {
            padding: 0.3rem 0.5rem;
            border-bottom: 1px dashed #ddd;
        }
        .solution-item:last-child {
            border-bottom: none;
        }
        .no-solution {
            color: #856404;
            background-color: #fff3cd;
            padding: 0.5rem;
            border-radius: 4px;
        }
        .btn-random {
            background-color: #28a745;
            color: white;
        }
        .btn-random:hover {
            background-color: #218838;
        }
        details {
            margin: 1.5rem 0;
            border: 1px solid #e0e0e0;
            border-radius: 8px;
            background-color: #fafafa;
            transition: all 0.2s ease;
        }
        details:hover {
            border-color: var(--primary-color);
        }
        details summary {
            padding: 0.75rem 1rem;
            background-color: #f0f0f0;
            border-radius: 8px 8px 0 0;
            font-weight: 600;
            color: var(--accent-color);
            cursor: pointer;
            list-style: none;
            display: flex;
            align-items: center;
            gap: 0.5rem;
        }
        details summary::-webkit-details-marker {
            display: none;
        }
        details summary::before {
            content: "▶";
            font-size: 0.8rem;
            color: var(--primary-color);
            transition: transform 0.2s;
        }
        details[open] summary::before {
            content: "▼";
        }
        details pre {
            margin: 0;
            padding: 1rem;
            background-color: #2d2d2d;
            color: #f8f8f2;
            border-radius: 0 0 8px 8px;
            overflow-x: auto;
            font-family: 'Courier New', monospace;
            font-size: 0.95rem;
            border: none;
        }