gantt chart open source javascript

       <div class="container">
        <div class="header">
            <h1>Project Timeline</h1>
            <p>Gantt Chart Overview</p>
        </div>

        <div class="gantt-container">
            <div class="gantt-chart" id="ganttChart"></div>
        </div>

        <div class="legend">
            <div class="legend-item">
                <div class="legend-color"></div>
                <span>Project Tasks</span>
            </div>
        </div>
    </div>

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

        body {
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Arial, sans-serif;
            background: linear-gradient(135deg, #f5f5f5 0%, #e8e8e8 100%);
            padding: 40px 20px;
            min-height: 100vh;
        }

        .container {
            max-width: 1400px;
            margin: 0 auto;
            background: white;
            border-radius: 12px;
            box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
            overflow: hidden;
        }

        .header {
            background: linear-gradient(135deg, #CD5700 0%, #FF7B1C 100%);
            color: white;
            padding: 30px;
        }

        .header h1 {
            font-size: 28px;
            font-weight: 600;
            margin-bottom: 8px;
        }

        .header p {
            opacity: 0.95;
            font-size: 14px;
        }

        .gantt-container {
            padding: 30px;
            overflow-x: auto;
        }

        .gantt-chart {
            display: flex;
            min-width: 900px;
        }

        .task-list {
            width: 200px;
            border-right: 2px solid #e0e0e0;
            padding-right: 20px;
        }

        .task-item {
            height: 50px;
            display: flex;
            align-items: center;
            padding: 0 10px;
            font-size: 14px;
            font-weight: 500;
            color: #333;
            border-bottom: 1px solid #f0f0f0;
        }

        .timeline {
            flex: 1;
            padding-left: 20px;
        }

        .timeline-header {
            display: flex;
            height: 40px;
            border-bottom: 2px solid #e0e0e0;
            margin-bottom: 10px;
        }

        .month {
            flex: 1;
            text-align: center;
            font-size: 12px;
            font-weight: 600;
            color: #666;
            display: flex;
            align-items: center;
            justify-content: center;
            border-left: 1px solid #f0f0f0;
        }

        .bars-container {
            position: relative;
        }

        .bar-row {
            height: 50px;
            display: flex;
            align-items: center;
            position: relative;
            border-bottom: 1px solid #f0f0f0;
        }

        .timeline-grid {
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            display: flex;
        }

        .grid-line {
            flex: 1;
            border-left: 1px solid #f5f5f5;
        }

        .bar {
            position: absolute;
            height: 28px;
            background: linear-gradient(135deg, #CD5700 0%, #FF8C3A 100%);
            border-radius: 6px;
            display: flex;
            align-items: center;
            padding: 0 12px;
            color: white;
            font-size: 12px;
            font-weight: 500;
            box-shadow: 0 2px 8px rgba(205, 87, 0, 0.3);
            cursor: pointer;
            transition: all 0.3s ease;
        }

        .bar:hover {
            transform: translateY(-2px);
            box-shadow: 0 4px 12px rgba(205, 87, 0, 0.4);
        }

        .bar-label {
            white-space: nowrap;
            overflow: hidden;
            text-overflow: ellipsis;
        }

        .legend {
            display: flex;
            gap: 20px;
            padding: 20px 30px;
            background: #fafafa;
            border-top: 1px solid #e0e0e0;
            font-size: 13px;
        }

        .legend-item {
            display: flex;
            align-items: center;
            gap: 8px;
        }

        .legend-color {
            width: 20px;
            height: 12px;
            border-radius: 3px;
            background: linear-gradient(135deg, #CD5700 0%, #FF8C3A 100%);
        }

        @media (max-width: 768px) {
            .gantt-container {
                padding: 20px;
            }
            
            .task-list {
                width: 150px;
            }
        }

        const tasks = [
            { name: 'Planning', start: 0, duration: 2 },
            { name: 'Design', start: 1.5, duration: 3 },
            { name: 'Development', start: 4, duration: 4 },
            { name: 'Testing', start: 7, duration: 2 },
            { name: 'Deployment', start: 8.5, duration: 1.5 },
            { name: 'Documentation', start: 6, duration: 4 }
        ];

        const months = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'];

        function createGanttChart() {
            const chartContainer = document.getElementById('ganttChart');
            
            // Create task list
            const taskList = document.createElement('div');
            taskList.className = 'task-list';
            tasks.forEach(task => {
                const taskItem = document.createElement('div');
                taskItem.className = 'task-item';
                taskItem.textContent = task.name;
                taskList.appendChild(taskItem);
            });

            // Create timeline
            const timeline = document.createElement('div');
            timeline.className = 'timeline';

            // Create timeline header
            const timelineHeader = document.createElement('div');
            timelineHeader.className = 'timeline-header';
            for (let i = 0; i < 12; i++) {
                const month = document.createElement('div');
                month.className = 'month';
                month.textContent = months[i];
                timelineHeader.appendChild(month);
            }

            // Create bars container
            const barsContainer = document.createElement('div');
            barsContainer.className = 'bars-container';

            // Create grid
            const grid = document.createElement('div');
            grid.className = 'timeline-grid';
            for (let i = 0; i < 12; i++) {
                const gridLine = document.createElement('div');
                gridLine.className = 'grid-line';
                grid.appendChild(gridLine);
            }
            barsContainer.appendChild(grid);

            // Create bars
            tasks.forEach((task, index) => {
                const barRow = document.createElement('div');
                barRow.className = 'bar-row';

                const bar = document.createElement('div');
                bar.className = 'bar';
                
                const leftPercent = (task.start / 12) * 100;
                const widthPercent = (task.duration / 12) * 100;
                
                bar.style.left = leftPercent + '%';
                bar.style.width = widthPercent + '%';
                
                const label = document.createElement('span');
                label.className = 'bar-label';
                label.textContent = task.name;
                bar.appendChild(label);
                
                bar.addEventListener('click', () => {
                    alert(`${task.name}\nDuration: ${task.duration} months`);
                });

                barRow.appendChild(bar);
                barsContainer.appendChild(barRow);
            });

            timeline.appendChild(timelineHeader);
            timeline.appendChild(barsContainer);

            chartContainer.appendChild(taskList);
            chartContainer.appendChild(timeline);
        }

        createGanttChart();