sanbuphy
d174ceea32
- Add new interactive components for frontend routing, browser rendering pipeline, and database transactions - Improve existing demos with better visuals, explanations, and examples - Update documentation structure and content for better clarity - Add new utility scripts and update package.json with new commands - Fix formatting and alignment in documentation tables
364 lines
8.3 KiB
Vue
364 lines
8.3 KiB
Vue
<template>
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<div class="macro-micro-task-demo">
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<div class="demo-header">
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<span class="icon">🔄</span>
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<span class="title">宏任务与微任务</span>
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<span class="subtitle">事件循环中的任务优先级</span>
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</div>
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<div class="intro-text">
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JavaScript 是单线程的，但可以通过<span class="highlight">任务队列</span>实现异步。就像餐厅只有一个厨师，但他可以同时处理多个订单：先做VIP订单（微任务），再做普通订单（宏任务）。
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</div>
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<div class="demo-content">
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<div class="event-loop-flow">
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<div class="flow-container">
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<div class="flow-section main-thread">
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<div class="section-title">主线程（执行栈）</div>
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<div class="execution-box">
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<div class="exec-item" :class="{ active: currentStep === 'script' }">
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<span class="exec-label">同步代码</span>
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</div>
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</div>
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</div>
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<div class="flow-section task-queues">
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<div class="section-title">任务队列</div>
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<div class="queues-container">
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<div class="queue-box micro">
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<div class="queue-title">微任务队列（优先级高）</div>
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<div class="queue-items">
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<div
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v-for="task in microTasks"
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:key="task.id"
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class="queue-item"
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:class="{ active: task.isActive, processing: task.isProcessing }"
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>
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{{ task.name }}
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</div>
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</div>
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</div>
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<div class="queue-box macro">
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<div class="queue-title">宏任务队列（优先级低）</div>
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<div class="queue-items">
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<div
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v-for="task in macroTasks"
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:key="task.id"
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class="queue-item"
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:class="{ active: task.isActive, processing: task.isProcessing }"
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>
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{{ task.name }}
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</div>
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</div>
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</div>
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</div>
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</div>
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</div>
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</div>
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<div class="code-example">
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<div class="example-title">代码示例</div>
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<pre class="code-block"><code>console.log('1')
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setTimeout(() => console.log('2'), 0) // 宏任务
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Promise.resolve().then(() => console.log('3')) // 微任务
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console.log('4')
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<span class="code-comment">// 输出顺序：1 → 4 → 3 → 2</span></code></pre>
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</div>
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<div class="control-panel">
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<button class="run-btn" @click="runDemo">
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{{ isRunning ? '🔄 运行中...' : '▶️ 运行演示' }}
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</button>
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</div>
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</div>
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<div class="info-box">
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<span class="icon">💡</span>
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<strong>核心要点：</strong>每次宏任务执行完后，会清空所有微任务，然后再执行下一个宏任务。这就是为什么 Promise.then() 比 setTimeout() 先执行。
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</div>
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</div>
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</template>
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<script setup>
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import { ref } from 'vue'
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const isRunning = ref(false)
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const currentStep = ref('script')
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const microTasks = ref([
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{ id: 1, name: 'Promise.then()', isActive: false, isProcessing: false },
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{ id: 2, name: 'queueMicrotask()', isActive: false, isProcessing: false }
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])
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const macroTasks = ref([
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{ id: 1, name: 'setTimeout()', isActive: false, isProcessing: false },
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{ id: 2, name: 'setInterval()', isActive: false, isProcessing: false },
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{ id: 3, name: 'I/O 操作', isActive: false, isProcessing: false }
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])
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async function runDemo() {
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if (isRunning.value) return
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isRunning.value = true
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// Reset
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microTasks.value.forEach(t => {
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t.isActive = false
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t.isProcessing = false
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})
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macroTasks.value.forEach(t => {
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t.isActive = false
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t.isProcessing = false
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})
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// Step 1: Sync code
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currentStep.value = 'script'
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await sleep(800)
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// Step 2: Process microtasks
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microTasks.value[0].isActive = true
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await sleep(500)
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microTasks.value[0].isActive = false
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microTasks.value[0].isProcessing = true
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await sleep(600)
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microTasks.value[0].isProcessing = false
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microTasks.value[1].isActive = true
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await sleep(500)
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microTasks.value[1].isActive = false
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microTasks.value[1].isProcessing = true
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await sleep(600)
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microTasks.value[1].isProcessing = false
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// Step 3: Process one macrotask
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macroTasks.value[0].isActive = true
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await sleep(500)
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macroTasks.value[0].isActive = false
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macroTasks.value[0].isProcessing = true
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await sleep(600)
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macroTasks.value[0].isProcessing = false
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currentStep.value = ''
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isRunning.value = false
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}
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function sleep(ms) {
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return new Promise(resolve => setTimeout(resolve, ms))
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}
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</script>
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<style scoped>
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.macro-micro-task-demo {
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border: 1px solid var(--vp-c-divider);
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border-radius: 8px;
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background: var(--vp-c-bg-soft);
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padding: 1rem;
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margin: 1rem 0;
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}
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.demo-header {
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display: flex;
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align-items: center;
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gap: 0.5rem;
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margin-bottom: 0.75rem;
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}
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.demo-header .icon { font-size: 1.25rem; }
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.demo-header .title { font-weight: bold; font-size: 1rem; }
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.demo-header .subtitle { color: var(--vp-c-text-2); font-size: 0.85rem; margin-left: 0.5rem; }
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.intro-text {
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font-size: 0.9rem;
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color: var(--vp-c-text-2);
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line-height: 1.6;
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margin-bottom: 1rem;
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padding: 0.75rem;
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background: var(--vp-c-bg);
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border-radius: 6px;
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}
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.intro-text .highlight {
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color: var(--vp-c-brand-1);
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font-weight: 500;
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}
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.demo-content {
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background: var(--vp-c-bg);
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border-radius: 6px;
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padding: 1rem;
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}
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.event-loop-flow {
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margin-bottom: 1rem;
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}
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.flow-container {
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display: flex;
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gap: 1rem;
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}
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.flow-section {
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flex: 1;
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}
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.section-title {
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font-size: 0.8rem;
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font-weight: 500;
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color: var(--vp-c-text-2);
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margin-bottom: 0.5rem;
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text-align: center;
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}
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.execution-box {
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background: var(--vp-c-bg-soft);
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border-radius: 6px;
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padding: 1rem;
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min-height: 80px;
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display: flex;
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align-items: center;
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justify-content: center;
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}
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.exec-item {
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padding: 0.5rem 1rem;
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background: var(--vp-c-bg-alt);
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border-radius: 4px;
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font-size: 0.85rem;
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color: var(--vp-c-text-2);
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transition: all 0.3s ease;
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}
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.exec-item.active {
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background: var(--vp-c-brand);
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color: white;
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transform: scale(1.05);
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}
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.queues-container {
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display: flex;
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flex-direction: column;
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gap: 0.75rem;
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}
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.queue-box {
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background: var(--vp-c-bg-soft);
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border-radius: 6px;
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padding: 0.75rem;
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}
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.queue-title {
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font-size: 0.75rem;
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color: var(--vp-c-text-2);
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margin-bottom: 0.5rem;
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font-weight: 500;
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}
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.queue-box.micro .queue-title {
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color: var(--vp-c-brand-1);
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}
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.queue-box.macro .queue-title {
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color: var(--vp-c-text-3);
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}
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.queue-items {
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display: flex;
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flex-direction: column;
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gap: 0.4rem;
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}
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.queue-item {
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padding: 0.4rem 0.6rem;
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background: var(--vp-c-bg);
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border: 1px solid var(--vp-c-divider);
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border-radius: 4px;
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font-size: 0.75rem;
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font-family: 'Courier New', monospace;
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color: var(--vp-c-text-2);
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transition: all 0.3s ease;
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}
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.queue-item.active {
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border-color: var(--vp-c-brand);
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background: var(--vp-c-brand-soft);
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color: var(--vp-c-brand-1);
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font-weight: 500;
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}
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.queue-item.processing {
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background: var(--vp-c-success);
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color: white;
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border-color: var(--vp-c-success);
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}
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.code-example {
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margin-bottom: 1rem;
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}
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.example-title {
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font-size: 0.8rem;
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font-weight: 500;
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color: var(--vp-c-text-2);
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margin-bottom: 0.5rem;
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}
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.code-block {
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background: var(--vp-c-bg-soft);
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border-radius: 6px;
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padding: 0.75rem;
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margin: 0;
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overflow-x: auto;
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}
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.code-block code {
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font-family: 'Courier New', monospace;
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font-size: 0.75rem;
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line-height: 1.6;
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color: var(--vp-c-text-1);
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}
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.code-comment {
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color: var(--vp-c-text-3);
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}
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.control-panel {
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display: flex;
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justify-content: center;
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}
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.run-btn {
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padding: 0.5rem 1.5rem;
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background: var(--vp-c-brand);
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color: white;
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border: none;
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border-radius: 6px;
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font-size: 0.9rem;
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cursor: pointer;
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transition: background 0.2s;
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}
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.run-btn:hover {
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background: var(--vp-c-brand-dark);
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}
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.run-btn:disabled {
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opacity: 0.6;
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cursor: not-allowed;
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}
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.info-box {
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background: var(--vp-c-bg-alt);
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padding: 0.75rem;
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border-radius: 6px;
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font-size: 0.85rem;
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color: var(--vp-c-text-2);
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margin-top: 0.75rem;
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}
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.info-box .icon { margin-right: 0.25rem; }
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</style>
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