Claude Haiku 5.5
by AnthropicReasoningClean
Running live in a sandboxed frame. Click inside it before using the keyboard.
How it went
- Total time
- 47.1 s
- Cost
- $0.0064
- Output tokens
- 12,664
- Spent thinking
- 3,214 tokens
- Speed
- 278.4 tok/s
- Console errors
- 0
- First token after
- 1.6 s
- First visible text after
- 19.2 s
- Prompt tokens
- 745
- Code size
- 21.7 KB
- Finish reason
- stop
- Served by
- Claude Platform on AWS
- Model id
anthropic/claude-haiku-5.5- Reasoning sent
{"effort":"medium"}- Max output
- 32,000 tokens
- Generated
- Nov 10, 2026
What it was asked
The prompt
Build an interactive Kanban board in vanilla HTML, CSS and JavaScript (no framework, no library). Requirements: - Three columns: "To do", "In progress", "Done", each showing its card count. - Pre-populate the board with 6 realistic cards spread across the columns so the first screenshot looks alive. - Each card has a title and a priority (low / medium / high) shown as a colored badge. - Add a card through a small modal form (title required), and delete a card with a button on it. - Drag and drop cards between columns with the mouse, with a clear visual drop indicator. - A search field that filters cards live by title. - A light / dark theme toggle. - State lives in memory only (no storage APIs).
System prompt, sent with every prompt
You are generating a self-contained web demo. It will be rendered automatically in a sandboxed iframe and compared side by side with the output of other AI models given the exact same task. Output rules: - Reply with exactly ONE fenced code block containing the complete file: ```html (or ```svg when the task asks for an SVG). No text before or after the code block. - Everything must be inline: CSS in <style>, JavaScript in <script>. No external files, images, fonts or network requests, except the CDN URLs explicitly allowed by the task. - Do not use localStorage, sessionStorage, cookies, IndexedDB, alert(), confirm(), prompt() or window.open(): they are blocked in the sandbox and will throw. - The page must look right in a 1280×800 viewport and adapt gracefully down to 375px wide. No horizontal scrollbar. - Something meaningful must be visible on first paint: a screenshot is taken automatically about 3 seconds after load, without any interaction. - Everything that makes the demo interesting must be visible within the first seconds: nothing hidden behind a high score, a later level or a long play session. - Games must start in a self-playing demo mode (a simple AI plays) behind a "Click or press a key to start" message, so the game can be judged in action without playing. - The iframe only receives keyboard events after the user clicks it: if the demo uses the keyboard, display a clear "Click or press a key to start" message. - The code must run with zero errors in the console of the latest Chrome.
Code run-1.html · 729 lines
<!DOCTYPE html>
<html lang="en" data-theme="light">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Kanban Board</title>
<style>
:root {
--bg: #f3f5f9;
--surface: #ffffff;
--column: #eaeef5;
--text: #1d2433;
--muted: #6b7587;
--border: #d8dee9;
--accent: #4f6ef7;
--accent-text: #ffffff;
--card-shadow: 0 1px 2px rgba(16,24,40,.08), 0 1px 3px rgba(16,24,40,.06);
--indicator: #4f6ef7;
--overlay: rgba(15,20,32,.45);
--input-bg: #ffffff;
--low-bg: #dcf5e6; --low-fg: #17703f;
--med-bg: #fdf0cf; --med-fg: #8a5a00;
--high-bg: #fde0dd; --high-fg: #b42318;
--danger: #d92d20;
}
html[data-theme="dark"] {
--bg: #0f1420;
--surface: #1a2130;
--column: #151b2a;
--text: #e6eaf3;
--muted: #8a94a8;
--border: #2a3345;
--accent: #7b93ff;
--accent-text: #0f1420;
--card-shadow: 0 1px 2px rgba(0,0,0,.4);
--indicator: #7b93ff;
--overlay: rgba(0,0,0,.6);
--input-bg: #111826;
--low-bg: #123a27; --low-fg: #6fe3a0;
--med-bg: #3d2f10; --med-fg: #f5c968;
--high-bg: #441a18; --high-fg: #ff9b92;
--danger: #ff6b61;
}
* { box-sizing: border-box; }
html, body { margin: 0; height: 100%; }
body {
font-family: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
background: var(--bg);
color: var(--text);
display: flex;
flex-direction: column;
min-height: 100vh;
overflow-x: hidden;
transition: background .2s, color .2s;
}
/* Top bar */
.topbar {
display: flex;
align-items: center;
justify-content: space-between;
gap: 16px;
padding: 16px 24px;
background: var(--surface);
border-bottom: 1px solid var(--border);
flex-wrap: wrap;
position: sticky;
top: 0;
z-index: 5;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 18px; }
.brand-mark {
width: 28px; height: 28px; border-radius: 8px;
background: linear-gradient(135deg, #4f6ef7, #9b6bff);
display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 2px; padding: 6px;
}
.brand-mark span { background: rgba(255,255,255,.9); border-radius: 1px; }
.tools { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.search {
position: relative;
}
.search svg {
position: absolute; left: 10px; top: 50%; transform: translateY(-50%);
width: 16px; height: 16px; color: var(--muted); pointer-events: none;
}
.search input {
width: 240px;
padding: 9px 12px 9px 34px;
border-radius: 8px;
border: 1px solid var(--border);
background: var(--input-bg);
color: var(--text);
font: inherit;
font-size: 14px;
outline: none;
}
.search input:focus, .field input:focus, .field select:focus, .field textarea:focus {
border-color: var(--accent);
box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 25%, transparent);
}
button {
font: inherit;
cursor: pointer;
}
.btn {
padding: 9px 14px;
border-radius: 8px;
border: 1px solid var(--border);
background: var(--surface);
color: var(--text);
font-size: 14px;
font-weight: 500;
transition: background .15s, border-color .15s, transform .05s;
white-space: nowrap;
}
.btn:hover { border-color: var(--accent); }
.btn:active { transform: translateY(1px); }
.btn.primary {
background: var(--accent);
color: var(--accent-text);
border-color: transparent;
}
.btn.primary:hover { filter: brightness(1.08); }
.btn:focus-visible, .icon-btn:focus-visible, .col-add:focus-visible {
outline: 2px solid var(--accent); outline-offset: 2px;
}
/* Board */
.board {
flex: 1;
display: grid;
grid-template-columns: repeat(3, minmax(0, 1fr));
gap: 18px;
padding: 22px 24px 32px;
align-items: start;
}
.column {
background: var(--column);
border: 1px solid var(--border);
border-radius: 14px;
display: flex;
flex-direction: column;
min-height: 380px;
min-width: 0;
}
.col-head {
display: flex;
align-items: center;
gap: 10px;
padding: 14px 14px 10px 16px;
}
.col-head h2 {
margin: 0;
font-size: 15px;
font-weight: 650;
letter-spacing: .01em;
}
.col-dot {
width: 9px; height: 9px; border-radius: 50%;
}
.count {
margin-left: 2px;
min-width: 24px;
padding: 2px 8px;
border-radius: 999px;
background: var(--surface);
border: 1px solid var(--border);
font-size: 12px;
font-weight: 600;
color: var(--muted);
text-align: center;
font-variant-numeric: tabular-nums;
}
.col-add {
margin-left: auto;
width: 28px; height: 28px;
border-radius: 8px;
border: 1px dashed var(--border);
background: transparent;
color: var(--muted);
font-size: 18px;
line-height: 1;
display: grid; place-items: center;
}
.col-add:hover { color: var(--accent); border-color: var(--accent); }
.list {
flex: 1;
display: flex;
flex-direction: column;
gap: 10px;
padding: 4px 12px 14px;
min-height: 120px;
border-radius: 10px;
transition: background .15s;
}
.list.drag-over { background: color-mix(in srgb, var(--accent) 6%, transparent); }
.empty {
margin: auto;
color: var(--muted);
font-size: 13px;
padding: 24px 8px;
text-align: center;
border: 1px dashed var(--border);
border-radius: 10px;
width: 100%;
}
body.is-dragging .empty { display: none; }
.card {
background: var(--surface);
border: 1px solid var(--border);
border-radius: 10px;
padding: 12px 12px 10px;
box-shadow: var(--card-shadow);
cursor: grab;
user-select: none;
animation: pop .25s ease;
transition: opacity .15s, transform .15s;
}
.card:hover { border-color: color-mix(in srgb, var(--accent) 45%, var(--border)); }
.card:active { cursor: grabbing; }
.card.dragging { opacity: .4; transform: rotate(1.5deg); }
.card-title {
margin: 0 0 10px;
font-size: 14px;
line-height: 1.4;
font-weight: 500;
word-break: break-word;
}
.card-foot {
display: flex;
align-items: center;
justify-content: space-between;
gap: 8px;
}
.badge {
font-size: 11px;
font-weight: 700;
letter-spacing: .04em;
text-transform: uppercase;
padding: 3px 8px;
border-radius: 6px;
}
.prio-low { background: var(--low-bg); color: var(--low-fg); }
.prio-medium { background: var(--med-bg); color: var(--med-fg); }
.prio-high { background: var(--high-bg); color: var(--high-fg); }
.icon-btn {
border: none;
background: transparent;
color: var(--muted);
width: 28px; height: 28px;
border-radius: 7px;
display: grid; place-items: center;
padding: 0;
}
.icon-btn svg { width: 15px; height: 15px; }
.icon-btn:hover { color: var(--danger); background: color-mix(in srgb, var(--danger) 12%, transparent); }
.drop-indicator {
height: 6px;
border-radius: 6px;
background: var(--indicator);
box-shadow: 0 0 0 3px color-mix(in srgb, var(--indicator) 22%, transparent);
flex-shrink: 0;
animation: grow .15s ease;
}
@keyframes grow { from { transform: scaleX(.6); opacity: .4; } to { transform: none; opacity: 1; } }
@keyframes pop { from { opacity: 0; transform: translateY(4px); } to { opacity: 1; transform: none; } }
/* Modal */
.overlay {
position: fixed; inset: 0;
background: var(--overlay);
display: flex; align-items: center; justify-content: center;
padding: 20px;
z-index: 20;
backdrop-filter: blur(2px);
}
.overlay[hidden] { display: none; }
.modal {
width: 100%;
max-width: 440px;
background: var(--surface);
border: 1px solid var(--border);
border-radius: 14px;
box-shadow: 0 20px 50px rgba(0,0,0,.25);
padding: 22px;
animation: pop .2s ease;
}
.modal h3 { margin: 0 0 16px; font-size: 18px; }
.field { display: flex; flex-direction: column; gap: 6px; margin-bottom: 14px; }
.field label { font-size: 13px; font-weight: 600; color: var(--muted); }
.field input, .field select, .field textarea {
font: inherit;
font-size: 14px;
padding: 10px 12px;
border-radius: 8px;
border: 1px solid var(--border);
background: var(--input-bg);
color: var(--text);
outline: none;
}
.field.invalid input { border-color: var(--danger); }
.error { color: var(--danger); font-size: 12px; min-height: 0; display: none; }
.field.invalid .error { display: block; }
.row { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.modal-actions { display: flex; justify-content: flex-end; gap: 10px; margin-top: 8px; }
.toast {
position: fixed;
bottom: 20px; left: 50%;
transform: translateX(-50%);
background: var(--text);
color: var(--bg);
padding: 10px 16px;
border-radius: 10px;
font-size: 13px;
opacity: 0;
pointer-events: none;
transition: opacity .2s;
z-index: 30;
white-space: nowrap;
}
.toast.show { opacity: .95; }
/* Responsive */
@media (max-width: 1000px) {
.search input { width: 180px; }
}
@media (max-width: 860px) {
.board { grid-template-columns: 1fr; gap: 16px; padding: 16px; }
.column { min-height: 0; }
.list { min-height: 80px; }
}
@media (max-width: 560px) {
.topbar { padding: 12px 14px; }
.tools { width: 100%; }
.search { flex: 1 1 100%; }
.search input { width: 100%; }
.tools .btn { flex: 0 0 auto; }
.board { padding: 12px; }
.row { grid-template-columns: 1fr; }
.modal { padding: 18px; }
}
</style>
</head>
<body>
<header class="topbar">
<div class="brand">
<div class="brand-mark" aria-hidden="true"><span></span><span></span><span></span><span></span><span></span><span></span></div>
<span>Kanban Board</span>
</div>
<div class="tools">
<label class="search">
<svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" aria-hidden="true"><circle cx="11" cy="11" r="7"/><path d="m20 20-3.5-3.5"/></svg>
<span class="sr-only" style="position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0)">Search cards</span>
<input id="search" type="search" placeholder="Search cards by title…" autocomplete="off">
</label>
<button id="themeBtn" class="btn" type="button" aria-label="Toggle color theme">🌙 Dark</button>
<button id="addBtn" class="btn primary" type="button">+ New card</button>
</div>
</header>
<main class="board" id="board">
<section class="column" data-status="todo" aria-labelledby="h-todo">
<div class="col-head">
<span class="col-dot" style="background:#6b87ff"></span>
<h2 id="h-todo">To do</h2>
<span class="count" data-count="todo">0</span>
<button class="col-add" type="button" data-add="todo" aria-label="Add card to To do">+</button>
</div>
<div class="list" data-status="todo"></div>
</section>
<section class="column" data-status="progress" aria-labelledby="h-progress">
<div class="col-head">
<span class="col-dot" style="background:#f5a524"></span>
<h2 id="h-progress">In progress</h2>
<span class="count" data-count="progress">0</span>
<button class="col-add" type="button" data-add="progress" aria-label="Add card to In progress">+</button>
</div>
<div class="list" data-status="progress"></div>
</section>
<section class="column" data-status="done" aria-labelledby="h-done">
<div class="col-head">
<span class="col-dot" style="background:#17b26a"></span>
<h2 id="h-done">Done</h2>
<span class="count" data-count="done">0</span>
<button class="col-add" type="button" data-add="done" aria-label="Add card to Done">+</button>
</div>
<div class="list" data-status="done"></div>
</section>
</main>
<div class="overlay" id="modal" hidden>
<form class="modal" id="cardForm" novalidate role="dialog" aria-modal="true" aria-labelledby="modalTitle">
<h3 id="modalTitle">New card</h3>
<div class="field" id="titleField">
<label for="fTitle">Title</label>
<input id="fTitle" name="title" type="text" maxlength="120" placeholder="e.g. Write release notes" autocomplete="off">
<span class="error">A title is required.</span>
</div>
<div class="row">
<div class="field">
<label for="fPriority">Priority</label>
<select id="fPriority" name="priority">
<option value="low">Low</option>
<option value="medium" selected>Medium</option>
<option value="high">High</option>
</select>
</div>
<div class="field">
<label for="fStatus">Column</label>
<select id="fStatus" name="status">
<option value="todo">To do</option>
<option value="progress">In progress</option>
<option value="done">Done</option>
</select>
</div>
</div>
<div class="modal-actions">
<button type="button" class="btn" id="cancelBtn">Cancel</button>
<button type="submit" class="btn primary">Add card</button>
</div>
</form>
</div>
<div class="toast" id="toast" role="status" aria-live="polite"></div>
<script>
(function () {
'use strict';
const COLUMNS = [
{ id: 'todo', label: 'To do' },
{ id: 'progress', label: 'In progress' },
{ id: 'done', label: 'Done' }
];
// In-memory state only
let cards = [
{ id: 1, title: 'Write onboarding docs for new contributors', priority: 'low', status: 'todo' },
{ id: 2, title: 'Fix login redirect loop on Safari', priority: 'high', status: 'todo' },
{ id: 3, title: 'Redesign pricing page layout', priority: 'medium', status: 'progress' },
{ id: 4, title: 'Set up CI pipeline for staging', priority: 'high', status: 'progress' },
{ id: 5, title: 'Migrate icons to the new SVG set', priority: 'low', status: 'done' },
{ id: 6, title: 'Draft Q3 product roadmap', priority: 'medium', status: 'done' }
];
let nextId = 7;
let query = '';
let dragId = null;
let indicator = null;
const $ = (sel, root = document) => root.querySelector(sel);
const $$ = (sel, root = document) => Array.from(root.querySelectorAll(sel));
const searchInput = $('#search');
const themeBtn = $('#themeBtn');
const addBtn = $('#addBtn');
const modal = $('#modal');
const form = $('#cardForm');
const fTitle = $('#fTitle');
const fPriority = $('#fPriority');
const fStatus = $('#fStatus');
const titleField = $('#titleField');
const toastEl = $('#toast');
let toastTimer = null;
const TRASH_SVG = '<svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true"><path d="M3 6h18"/><path d="M8 6V4h8v2"/><path d="M19 6l-1 14H6L5 6"/></svg>';
function matches(card) {
return !query || card.title.toLowerCase().includes(query);
}
function makeCard(card) {
const el = document.createElement('article');
el.className = 'card';
el.draggable = true;
el.dataset.id = String(card.id);
const title = document.createElement('p');
title.className = 'card-title';
title.textContent = card.title;
const foot = document.createElement('div');
foot.className = 'card-foot';
const badge = document.createElement('span');
badge.className = 'badge prio-' + card.priority;
badge.textContent = card.priority;
const del = document.createElement('button');
del.type = 'button';
del.className = 'icon-btn';
del.setAttribute('aria-label', 'Delete card: ' + card.title);
del.title = 'Delete card';
del.innerHTML = TRASH_SVG;
del.addEventListener('click', (e) => {
e.stopPropagation();
deleteCard(card.id);
});
foot.append(badge, del);
el.append(title, foot);
el.addEventListener('dragstart', onDragStart);
el.addEventListener('dragend', onDragEnd);
return el;
}
function render() {
COLUMNS.forEach(col => {
const list = $('.list[data-status="' + col.id + '"]');
const visible = cards.filter(c => c.status === col.id && matches(c));
list.innerHTML = '';
visible.forEach(c => list.appendChild(makeCard(c)));
if (visible.length === 0) {
const empty = document.createElement('div');
empty.className = 'empty';
empty.textContent = query ? 'No cards match “' + query + '”' : 'No cards here yet';
list.appendChild(empty);
}
$('[data-count="' + col.id + '"]').textContent = visible.length;
});
}
function deleteCard(id) {
const card = cards.find(c => c.id === id);
cards = cards.filter(c => c.id !== id);
render();
if (card) showToast('Deleted “' + truncate(card.title, 40) + '”');
}
function truncate(s, n) {
return s.length > n ? s.slice(0, n - 1) + '…' : s;
}
function showToast(msg) {
toastEl.textContent = msg;
toastEl.classList.add('show');
clearTimeout(toastTimer);
toastTimer = setTimeout(() => toastEl.classList.remove('show'), 1800);
}
/* ---------- Drag and drop ---------- */
function ensureIndicator() {
if (!indicator) {
indicator = document.createElement('div');
indicator.className = 'drop-indicator';
indicator.setAttribute('aria-hidden', 'true');
}
return indicator;
}
function clearIndicator() {
if (indicator && indicator.parentNode) indicator.parentNode.removeChild(indicator);
$$('.list.drag-over').forEach(l => l.classList.remove('drag-over'));
}
function onDragStart(e) {
dragId = Number(this.dataset.id);
this.classList.add('dragging');
document.body.classList.add('is-dragging');
e.dataTransfer.effectAllowed = 'move';
try { e.dataTransfer.setData('text/plain', String(dragId)); } catch (_) {}
}
function onDragEnd() {
this.classList.remove('dragging');
document.body.classList.remove('is-dragging');
clearIndicator();
dragId = null;
}
function onListDragOver(e) {
if (dragId === null) return;
e.preventDefault();
e.dataTransfer.dropEffect = 'move';
const list = this;
list.classList.add('drag-over');
const siblings = $$('.card:not(.dragging)', list);
let before = null;
for (const el of siblings) {
const r = el.getBoundingClientRect();
if (e.clientY < r.top + r.height / 2) { before = el; break; }
}
const ind = ensureIndicator();
const alreadyThere = ind.parentNode === list &&
(before ? ind.nextElementSibling === before : ind.nextElementSibling === null);
if (!alreadyThere) {
if (before) list.insertBefore(ind, before);
else list.appendChild(ind);
}
}
function onListDragLeave(e) {
if (!this.contains(e.relatedTarget)) {
this.classList.remove('drag-over');
if (indicator && indicator.parentNode === this) {
indicator.parentNode.removeChild(indicator);
}
}
}
function onListDrop(e) {
if (dragId === null) return;
e.preventDefault();
const list = this;
const status = list.dataset.status;
// Card that should follow the dropped card (reference point)
let refId = null;
if (indicator && indicator.parentNode === list) {
const next = indicator.nextElementSibling;
if (next && next.classList.contains('card')) refId = Number(next.dataset.id);
}
clearIndicator();
const idx = cards.findIndex(c => c.id === dragId);
if (idx === -1) return;
const [item] = cards.splice(idx, 1);
item.status = status;
if (refId !== null) {
const refIdx = cards.findIndex(c => c.id === refId);
cards.splice(refIdx, 0, item);
} else {
// Append after the last card in this column (or at the end of the array)
let lastIdx = -1;
cards.forEach((c, i) => { if (c.status === status) lastIdx = i; });
cards.splice(lastIdx + 1, 0, item);
}
dragId = null;
render();
}
$$('.list').forEach(list => {
list.addEventListener('dragover', onListDragOver);
list.addEventListener('dragleave', onListDragLeave);
list.addEventListener('drop', onListDrop);
});
/* ---------- Modal ---------- */
function openModal(defaultStatus) {
form.reset();
fPriority.value = 'medium';
fStatus.value = defaultStatus || 'todo';
titleField.classList.remove('invalid');
modal.hidden = false;
setTimeout(() => fTitle.focus(), 0);
}
function closeModal() {
modal.hidden = true;
}
addBtn.addEventListener('click', () => openModal('todo'));
$$('[data-add]').forEach(btn => {
btn.addEventListener('click', () => openModal(btn.dataset.add));
});
$('#cancelBtn').addEventListener('click', closeModal);
modal.addEventListener('click', (e) => { if (e.target === modal) closeModal(); });
document.addEventListener('keydown', (e) => {
if (e.key === 'Escape' && !modal.hidden) closeModal();
});
fTitle.addEventListener('input', () => {
if (fTitle.value.trim()) titleField.classList.remove('invalid');
});
form.addEventListener('submit', (e) => {
e.preventDefault();
const title = fTitle.value.trim();
if (!title) {
titleField.classList.add('invalid');
fTitle.focus();
return;
}
cards.push({
id: nextId++,
title,
priority: fPriority.value,
status: fStatus.value
});
closeModal();
render();
showToast('Added “' + truncate(title, 40) + '”');
});
/* ---------- Search & theme ---------- */
searchInput.addEventListener('input', () => {
query = searchInput.value.trim().toLowerCase();
render();
});
function applyTheme(theme) {
document.documentElement.dataset.theme = theme;
themeBtn.textContent = theme === 'dark' ? '☀️ Light' : '🌙 Dark';
}
themeBtn.addEventListener('click', () => {
const next = document.documentElement.dataset.theme === 'dark' ? 'light' : 'dark';
applyTheme(next);
});
applyTheme('light');
render();
})();
</script>
</body>
</html>Reasoning trace (3,214 tokens)
I need a single HTML file for the kanban board, kept fairly short. It has to cover three columns with counts, six cards with priority badges, an add modal with a required title, delete buttons, drag and drop with a drop indicator, a search filter, and a theme toggle, all with state held in memory only. The "click or press a key to start" message is for games, so I'll leave it out of this board. I'm laying out the board's header with a title, search box, theme toggle, and add button, and using a three-column grid that stacks vertically on narrower screens. For drag and drop I'll use HTML5 events, computing where to place a drop indicator from the mouse position against card midpoints, and letting cards land in empty columns too. Search will match titles case-insensitively, and I'm still deciding whether the column counts should show visible matches only. The drop logic is taking shape: the dragged card gets excluded, and I'm working out where in the column the new position should go. Next I'm wiring up the drop indicator: during dragover I'll find the first card whose midpoint sits below the cursor, record that index and status, and insert the placeholder there without rebuilding the DOM. Dragend will clear the indicator and dragging state, and I'm planning to pre-populate a few starter cards across the columns. I'm setting up the card ids and HTML escaping, and building the column headers with counts and the body lists. I'll attach the drag listeners once on the columns and only clear the indicator when the cursor truly leaves a column or the drop or dragend fires. Priority badges get green, amber, and red colors that work in both themes, and I still need to check how the mobile layout handles this. Still writing the page markup... Still writing the board script: I'm setting up the status list and starter cards, and a render pass that filters by the search text and rebuilds each column's list with a count. Still wiring up the drag-over logic: I'm finding the first card whose midpoint sits below the cursor, and placing the drop indicator before it, or at the end of the list if there is none. The empty-column placeholder needs handling too, so the indicator still lands correctly there. I'm settling how the drop indicator is inserted: an empty-column placeholder gets hidden while dragging, and I'm placing the indicator at the right spot in the list during dragover. Next I'm wiring the drop itself: the target spot comes from whatever card sits right after the indicator, skipping the dragged card since it's not among the candidates. I'll pull the dragged card out of the list, update its status, and splice it in before that reference card, or after the last card in the target column if there isn't one. Then I'll clear the indicator and re-render. Next I'm handling the drop-to-empty-column case and the drag lifecycle: dragstart stores the card id and adds dragging styles, and dragend cleans them up. Delete buttons will remove a card from the array and re-render, and the add modal will open with an optional default status. Still wiring the search and theme logic: the search box will trim and lowercase its value, then re-render, and the empty-column message will read "No cards" or "No matches" depending on whether a query is active. The theme toggle will flip the root theme attribute and update its own label. Still writing the board's column-count and card-footer markup, with priority badges styled per level.