commit 3cf7cbe8149a30e3465a1e69d7a41ba7d72379bd
Author: admin <admin@eeuse.com>
Date:   Mon Sep 28 20:05:39 2026 +0800

    AI 生成: 一个简洁的待办事项 Web 应用，支持添加、完成、删除任务，并使用 localStorage 在浏览器本地保存数据。

diff --git a/README.md b/README.md
new file mode 100644
index 0000000..475d529
--- /dev/null
+++ b/README.md
@@ -0,0 +1,44 @@
+# Simple Todo App
+
+一个简洁的待办事项 Web 应用，支持添加、完成、删除任务，数据保存在浏览器本地。
+
+## 功能
+
+- 添加任务
+- 标记任务为完成 / 未完成
+- 删除任务
+- 使用 localStorage 自动保存数据
+- 响应式界面，适合桌面和移动端
+
+## 技术栈
+
+- HTML5
+- CSS3
+- 原生 JavaScript
+
+## 目录结构
+
+```
+simple-todo-app/
+├── index.html
+├── style.css
+├── app.js
+└── README.md
+```
+
+## 使用方法
+
+1. 下载或克隆本项目。
+2. 直接在浏览器中打开 `index.html`。
+3. 输入任务内容，点击“添加”或按回车即可创建任务。
+4. 点击任务左侧复选框可切换完成状态。
+5. 点击右侧删除按钮可删除任务。
+
+## 数据存储
+
+所有任务数据保存在浏览器的 `localStorage` 中，键名为 `simple-todo-app.tasks`。
+清除浏览器数据会同时清除任务。
+
+## 许可
+
+MIT
diff --git a/app.js b/app.js
new file mode 100644
index 0000000..2d85b15
--- /dev/null
+++ b/app.js
@@ -0,0 +1,174 @@
+// Simple Todo App
+// 数据保存在 localStorage 中
+
+(function () {
+  "use strict";
+
+  const STORAGE_KEY = "simple-todo-app.tasks";
+
+  // DOM 元素
+  const form = document.getElementById("todo-form");
+  const input = document.getElementById("todo-input");
+  const list = document.getElementById("todo-list");
+  const countEl = document.getElementById("todo-count");
+  const emptyState = document.getElementById("empty-state");
+  const clearCompletedBtn = document.getElementById("clear-completed");
+
+  /**
+   * 从 localStorage 读取任务列表
+   * @returns {Array<{id: string, text: string, completed: boolean}>}
+   */
+  function loadTasks() {
+    try {
+      const raw = localStorage.getItem(STORAGE_KEY);
+      if (!raw) return [];
+      const parsed = JSON.parse(raw);
+      return Array.isArray(parsed) ? parsed : [];
+    } catch (err) {
+      console.error("读取任务失败:", err);
+      return [];
+    }
+  }
+
+  /**
+   * 保存任务列表到 localStorage
+   * @param {Array} tasks
+   */
+  function saveTasks(tasks) {
+    try {
+      localStorage.setItem(STORAGE_KEY, JSON.stringify(tasks));
+    } catch (err) {
+      console.error("保存任务失败:", err);
+    }
+  }
+
+  // 当前任务状态
+  let tasks = loadTasks();
+
+  /**
+   * 生成唯一 ID
+   */
+  function generateId() {
+    return Date.now().toString(36) + Math.random().toString(36).slice(2, 8);
+  }
+
+  /**
+   * 渲染任务列表
+   */
+  function render() {
+    list.innerHTML = "";
+
+    tasks.forEach(function (task) {
+      const li = document.createElement("li");
+      li.className = "todo-item" + (task.completed ? " completed" : "");
+      li.dataset.id = task.id;
+
+      // 复选框
+      const checkbox = document.createElement("input");
+      checkbox.type = "checkbox";
+      checkbox.checked = task.completed;
+      checkbox.addEventListener("change", function () {
+        toggleTask(task.id);
+      });
+
+      // 文本
+      const span = document.createElement("span");
+      span.className = "todo-text";
+      span.textContent = task.text;
+
+      // 删除按钮
+      const delBtn = document.createElement("button");
+      delBtn.className = "delete-btn";
+      delBtn.type = "button";
+      delBtn.setAttribute("aria-label", "删除任务");
+      delBtn.textContent = "✕";
+      delBtn.addEventListener("click", function () {
+        deleteTask(task.id);
+      });
+
+      li.appendChild(checkbox);
+      li.appendChild(span);
+      li.appendChild(delBtn);
+      list.appendChild(li);
+    });
+
+    // 空状态
+    if (tasks.length === 0) {
+      emptyState.classList.remove("hidden");
+    } else {
+      emptyState.classList.add("hidden");
+    }
+
+    // 统计
+    const remaining = tasks.filter(function (t) {
+      return !t.completed;
+    }).length;
+    countEl.textContent = "共 " + tasks.length + " 项 · 未完成 " + remaining + " 项";
+  }
+
+  /**
+   * 添加任务
+   */
+  function addTask(text) {
+    const trimmed = text.trim();
+    if (!trimmed) return;
+
+    tasks.push({
+      id: generateId(),
+      text: trimmed,
+      completed: false
+    });
+
+    saveTasks(tasks);
+    render();
+  }
+
+  /**
+   * 切换任务完成状态
+   */
+  function toggleTask(id) {
+    tasks = tasks.map(function (t) {
+      return t.id === id ? Object.assign({}, t, { completed: !t.completed }) : t;
+    });
+    saveTasks(tasks);
+    render();
+  }
+
+  /**
+   * 删除任务
+   */
+  function deleteTask(id) {
+    tasks = tasks.filter(function (t) {
+      return t.id !== id;
+    });
+    saveTasks(tasks);
+    render();
+  }
+
+  /**
+   * 清除已完成任务
+   */
+  function clearCompleted() {
+    tasks = tasks.filter(function (t) {
+      return !t.completed;
+    });
+    saveTasks(tasks);
+    render();
+  }
+
+  // 事件绑定
+  form.addEventListener("submit", function (e) {
+    e.preventDefault();
+    addTask(input.value);
+    input.value = "";
+    input.focus();
+  });
+
+  clearCompletedBtn.addEventListener("click", clearCompleted);
+
+  // 初始渲染
+  render();
+
+  // 自动聚焦输入框
+  input.focus();
+})();
diff --git a/index.html b/index.html
new file mode 100644
index 0000000..9c2a99d
--- /dev/null
+++ b/index.html
@@ -0,0 +1,40 @@
+<!DOCTYPE html>
+<html lang="zh-CN">
+<head>
+  <meta charset="UTF-8" />
+  <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+  <title>Simple Todo App</title>
+  <link rel="stylesheet" href="style.css" />
+</head>
+<body>
+  <main class="app">
+    <header class="app-header">
+      <h1>待办事项</h1>
+      <p class="subtitle">简单、快速、本地保存</p>
+    </header>
+
+    <form id="todo-form" class="todo-form">
+      <input
+        id="todo-input"
+        class="todo-input"
+        type="text"
+        placeholder="输入一个新任务..."
+        autocomplete="off"
+        maxlength="120"
+      />
+      <button type="submit" class="add-btn">添加</button>
+    </form>
+
+    <section class="todo-stats">
+      <span id="todo-count">共 0 项</span>
+      <button id="clear-completed" class="clear-btn" type="button">清除已完成</button>
+    </section>
+
+    <ul id="todo-list" class="todo-list"></ul>
+
+    <p id="empty-state" class="empty-state">暂无任务，添加一个开始吧！</p>
+  </main>
+
+  <script src="app.js"></script>
+</body>
+</html>
diff --git a/style.css b/style.css
new file mode 100644
index 0000000..c82e6e7
--- /dev/null
+++ b/style.css
@@ -0,0 +1,176 @@
+:root {
+  --bg: #f5f7fb;
+  --card: #ffffff;
+  --text: #1f2937;
+  --muted: #6b7280;
+  --primary: #2563eb;
+  --primary-hover: #1d4ed8;
+  --danger: #ef4444;
+  --border: #e5e7eb;
+  --done: #9ca3af;
+  --shadow: 0 10px 25px rgba(15, 23, 42, 0.08);
+}
+
+* {
+  box-sizing: border-box;
+}
+
+body {
+  margin: 0;
+  min-height: 100vh;
+  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
+  background: linear-gradient(180deg, #eef2ff 0%, var(--bg) 100%);
+  color: var(--text);
+  display: flex;
+  justify-content: center;
+  padding: 40px 16px;
+}
+
+.app {
+  width: 100%;
+  max-width: 560px;
+  background: var(--card);
+  border-radius: 16px;
+  box-shadow: var(--shadow);
+  padding: 28px;
+}
+
+.app-header h1 {
+  margin: 0;
+  font-size: 28px;
+  letter-spacing: -0.5px;
+}
+
+.subtitle {
+  margin: 6px 0 22px;
+  color: var(--muted);
+  font-size: 14px;
+}
+
+.todo-form {
+  display: flex;
+  gap: 10px;
+}
+
+.todo-input {
+  flex: 1;
+  padding: 12px 14px;
+  border: 1px solid var(--border);
+  border-radius: 10px;
+  font-size: 15px;
+  outline: none;
+  transition: border-color 0.2s, box-shadow 0.2s;
+}
+
+.todo-input:focus {
+  border-color: var(--primary);
+  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
+}
+
+.add-btn {
+  padding: 12px 18px;
+  border: none;
+  border-radius: 10px;
+  background: var(--primary);
+  color: #fff;
+  font-size: 15px;
+  font-weight: 600;
+  cursor: pointer;
+  transition: background 0.2s;
+}
+
+.add-btn:hover {
+  background: var(--primary-hover);
+}
+
+.todo-stats {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  margin: 18px 0 10px;
+  color: var(--muted);
+  font-size: 13px;
+}
+
+.clear-btn {
+  background: transparent;
+  border: none;
+  color: var(--muted);
+  cursor: pointer;
+  font-size: 13px;
+}
+
+.clear-btn:hover {
+  color: var(--danger);
+}
+
+.todo-list {
+  list-style: none;
+  margin: 0;
+  padding: 0;
+  display: flex;
+  flex-direction: column;
+  gap: 8px;
+}
+
+.todo-item {
+  display: flex;
+  align-items: center;
+  gap: 12px;
+  padding: 12px 14px;
+  border: 1px solid var(--border);
+  border-radius: 10px;
+  background: #fff;
+  transition: background 0.2s, transform 0.1s;
+}
+
+.todo-item:hover {
+  background: #fafafa;
+}
+
+.todo-item input[type="checkbox"] {
+  width: 18px;
+  height: 18px;
+  accent-color: var(--primary);
+  cursor: pointer;
+  flex-shrink: 0;
+}
+
+.todo-text {
+  flex: 1;
+  font-size: 15px;
+  word-break: break-word;
+}
+
+.todo-item.completed .todo-text {
+  text-decoration: line-through;
+  color: var(--done);
+}
+
+.delete-btn {
+  border: none;
+  background: transparent;
+  color: var(--muted);
+  font-size: 18px;
+  line-height: 1;
+  cursor: pointer;
+  padding: 4px 8px;
+  border-radius: 6px;
+  transition: background 0.2s, color 0.2s;
+}
+
+.delete-btn:hover {
+  background: #fee2e2;
+  color: var(--danger);
+}
+
+.empty-state {
+  margin: 24px 0 0;
+  text-align: center;
+  color: var(--muted);
+  font-size: 14px;
+}
+
+.empty-state.hidden {
+  display: none;
+}