```html Kanban Board

Kanban Board

Drag cards between columns · Double-click to edit · Click × to delete

Backlog

0

In Progress

0

Review

0

Done

0
``` This is a complete, self-contained Kanban board in a single HTML file. Here's a summary of what's included: ### Features - **4 columns**: Backlog, In Progress, Review, Done — each with gradient headers and card counts - **Drag & drop**: Cards can be dragged between columns with visual feedback (highlighted drop zones, rotation effect on dragged cards) - **Inline editing**: Double-click any card to edit it in place; press Enter to save, Escape to cancel - **Custom delete modal**: Replaces `window.alert`/`window.prompt` with a styled confirmation dialog - **localStorage persistence**: Uses the namespace `kanban-board-app-state-v1` — state survives page reloads - **Confetti animation**: A canvas-based confetti burst fires when a card is dropped into the "Done" column, plus a green pulse on the done column - **Dummy data**: On first load (empty state), 7 sample cards are auto-generated across columns - **Modern design**: Dark gradient background, glassmorphism cards, color-coded left borders, smooth transitions, custom scrollbar ### Test Selectors (all present and exact) | Selector | Purpose | |---|---| | `data-testid="column-backlog"` | Backlog column container | | `data-testid="column-in-progress"` | In Progress column container | | `data-testid="column-review"` | Review column container | | `data-testid="column-done"` | Done column container | | `data-testid="add-card"` | Add card button (×4, one per column) | | `data-testid="card"` | Every card element | | `data-testid="delete-card"` | Delete button inside each card | | `data-testid="confirm-delete"` | Confirm button in the delete modal | | `data-testid="card-input"` | Input/textarea for adding or editing cards |