:root {
            --primary-color: #005a9c;
            --secondary-color: #00a9e0;
            --accent-color: #f5a623;
            --success-color: #2e7d32;
            --error-color: #c62828;
            --light-gray: #f0f2f5;
            --text-color: #4f4f4f;
            --bg-color: #ffffff;
            --border-radius: 8px;
            --shadow: 0 4px 12px rgba(0,0,0,0.1);
        }

        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
            display: flex;
            flex-direction: column;
            align-items: center;
            margin: 0;
            padding: 1rem;
            background-color: var(--light-gray);
            color: var(--text-color);
            font-size: 16px;
        }

        .navbar {
            width: 100%;
            max-width: 1400px;
            padding-bottom: 1rem;
            margin-bottom: 1rem;
            border-bottom: 1px solid #ddd;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        .nav-link {
            color: var(--primary-color);
            text-decoration: none;
            font-weight: 600;
            padding: 8px 12px;
            border-radius: 6px;
            transition: background-color 0.2s ease;
        }

        .nav-link:hover {
            background-color: rgba(0, 90, 156, 0.1);
        }

        .nav-link span {
            margin-right: 4px;
        }

        .main-container { display: flex; flex-direction: column; width: 100%; max-width: 1400px; gap: 1rem; position: relative; }
        header { text-align: center; display: flex; justify-content: space-between; align-items: center; width: 100%; }
        h1 { color: var(--primary-color); font-weight: 700; margin: 0; font-size: 1.75rem; }

        .content-area { display: flex; gap: 1.5rem; width: 100%; flex-direction: column; }
        .plot-column { display: flex; flex-direction: column; gap: 1rem; flex-grow: 1; }
        .canvas-container { position: relative; width: 100%; display: flex; justify-content: center; align-items: flex-start; }
        #plot-canvas { background-color: var(--bg-color); cursor: crosshair; touch-action: none; border-radius: var(--border-radius); box-shadow: var(--shadow); border: 1px solid #ddd; max-width: 100%; height: auto; }
        .controls-container { display: flex; flex-direction: column; gap: 1.5rem; }
        
        @media (min-width: 1024px) {
            .content-area { flex-direction: row; align-items: flex-start; }
            .controls-container { width: 350px; flex-shrink: 0; }
        }

        .panel { background-color: var(--bg-color); border-radius: var(--border-radius); box-shadow: var(--shadow); padding: 1.25rem; display: flex; flex-direction: column; gap: 1rem; }
        .panel h3 { margin: 0; padding-bottom: 0.5rem; border-bottom: 1px solid #eee; color: var(--primary-color); font-size: 1.1rem; }
        .control-group { display: flex; flex-direction: column; gap: 0.5rem; }
        .control-group label { font-weight: 500; color: #555; }

        button, select, input[type="text"] { padding: 12px 15px; border-radius: 6px; border: 1px solid #ccc; font-size: 1rem; width: 100%; box-sizing: border-box; }
        button { background-color: var(--primary-color); color: white; font-weight: 600; cursor: pointer; border-color: var(--primary-color); transition: background-color 0.2s ease; }
        button:hover { background-color: #004a8c; }
        button:disabled { background-color: #e0e0e0; color: #9e9e9e; cursor: not-allowed; border-color: #ccc; }
        
        #reset-btn { background-color: #757575; }
        #slicer-cancel-btn { background-color: var(--error-color); }
        #slicer-confirm-btn { background-color: var(--success-color); }
        #export-pdf-btn { background-color: var(--success-color); }
        #undo-btn { background-color: var(--accent-color); width: auto; flex-shrink: 0; }
        #undo-btn:hover { background-color: #d98e1a; }

        .info-bar { padding: 0.75rem 1rem; border-radius: var(--border-radius); font-weight: 500; text-align: center; background: #e3f2fd; border: 1px solid var(--secondary-color); color: var(--primary-color); }
        .results { padding: 1rem; border-radius: var(--border-radius); font-weight: 500; text-align: left; background: #e8f5e9; border: 1px solid var(--success-color); color: var(--success-color); line-height: 1.6; }
        .hidden { display: none !important; }
        
        .modal { position: absolute; top: 20px; left: 50%; transform: translateX(-50%); background: white; padding: 1rem; border-radius: var(--border-radius); box-shadow: 0 8px 25px rgba(0,0,0,0.2); z-index: 100; border: 1px solid #ccc; display: flex; flex-direction: column; gap: 0.75rem; align-items: center; width: 280px; }
        .modal h3 { margin: 0; color: var(--primary-color); font-size: 1.1rem; }
        .modal p { font-size: 0.85rem; margin: 0; text-align: center; }
        .modal input { text-align: center; }
        .modal-buttons { display: flex; gap: 1rem; width: 100%; }
        .modal-buttons button { flex-grow: 1; }
        #modal-cancel-btn { background-color: #757575; border-color: #757575; }

        #inline-input-box {
            position: absolute;
            transform: translate(-50%, -50%);
            z-index: 100;
            padding: 4px;
            background: var(--bg-color);
            border: 1px solid var(--primary-color);
            border-radius: 6px;
            box-shadow: 0 4px 10px rgba(0,0,0,0.2);
            display: flex;
        }
        #inline-input-box input {
            width: 120px;
            border: 1px solid #ccc;
            padding: 8px;
            font-size: 1rem;
            text-align: center;
        }