diff --git a/app/citizen-frontend/src/components/QRCode.vue b/app/citizen-frontend/src/components/QRCode.vue
new file mode 100644
index 0000000..db6a94f
--- /dev/null
+++ b/app/citizen-frontend/src/components/QRCode.vue
@@ -0,0 +1,55 @@
+<script setup lang="ts">
+import { computed } from 'vue'
+import { createQrCodeMatrix } from '@/utils/qrcode'
+
+const props = withDefaults(defineProps<{
+  value: string
+  size?: number
+}>(), {
+  size: 180,
+})
+
+const quietZone = 4
+
+const qrCode = computed(() => createQrCodeMatrix(props.value))
+const viewBoxSize = computed(() => qrCode.value.size + quietZone * 2)
+
+const darkModules = computed(() => {
+  return qrCode.value.modules.flatMap((row, y) => {
+    return row
+      .map((dark, x) => ({ dark, x: x + quietZone, y: y + quietZone }))
+      .filter(module => module.dark)
+  })
+})
+</script>
+
+<template>
+  <svg
+    aria-label="報到 QR Code"
+    class="qr-code"
+    :height="size"
+    role="img"
+    shape-rendering="crispEdges"
+    :viewBox="`0 0 ${viewBoxSize} ${viewBoxSize}`"
+    :width="size"
+    xmlns="http://www.w3.org/2000/svg"
+  >
+    <rect fill="#ffffff" height="100%" width="100%" />
+
+    <rect
+      v-for="module in darkModules"
+      :key="`${module.x}-${module.y}`"
+      fill="#000000"
+      height="1"
+      width="1"
+      :x="module.x"
+      :y="module.y"
+    />
+  </svg>
+</template>
+
+<style scoped>
+.qr-code {
+  display: block;
+}
+</style>
diff --git a/app/citizen-frontend/src/pages/appointment.vue b/app/citizen-frontend/src/pages/appointment.vue
index 4a3c889..a06ee5c 100644
--- a/app/citizen-frontend/src/pages/appointment.vue
+++ b/app/citizen-frontend/src/pages/appointment.vue
@@ -1,10 +1,13 @@
 <template>
   <Layout>
     <template #main>
-      <div class="mb-6 text-center">
-        <h1 class="text-h5 font-weight-black text-primary">公益普測與活動預約</h1>
-        <p class="text-caption text-grey">報名免費體能普測，取得個人運動處方</p>
-      </div>
+      <v-card class="mb-6" variant="flat">
+        <v-card-title class="text-primary">公益普測與活動預約</v-card-title>
+
+        <v-card-subtitle class="text-grey-darken-3">
+          報名免費體能普測，取得個人運動處方
+        </v-card-subtitle>
+      </v-card>
 
       <!-- 活動分類選擇 -->
       <v-tabs v-model="filterTab" class="mb-4 bg-white rounded-lg elevation-1" color="primary" grow>
@@ -169,156 +172,10 @@
 
             <p class="text-caption text-grey mb-4">請在現場合對處出示此條碼進行報到</p>
 
-            <!-- 模擬 QR Code SVG，更高級精緻 -->
             <div
               class="qrcode-wrapper mx-auto mb-4 elevation-3 rounded-lg pa-3 bg-white border d-flex justify-center align-center"
             >
-              <svg class="qrcode-svg" height="180" viewBox="0 0 100 100" width="180">
-                <!-- 四個角定位框 -->
-                <path d="M 0,0 H 25 V 8 H 8 V 25 H 0 Z" fill="#1D7063" />
-                <path d="M 75,0 H 100 V 25 H 92 V 8 H 75 Z" fill="#1D7063" />
-                <path d="M 0,75 V 100 H 25 V 92 H 8 V 75 Z" fill="#1D7063" />
-                <path d="M 92,75 V 92 H 75 V 100 H 100 V 75 Z" fill="#1D7063" />
-                <!-- 內嵌二維碼方塊 -->
-                <rect
-                  fill="#1D7063"
-                  height="20"
-                  width="20"
-                  x="12"
-                  y="12"
-                />
-
-                <rect
-                  fill="white"
-                  height="12"
-                  width="12"
-                  x="16"
-                  y="16"
-                />
-
-                <rect
-                  fill="#E66926"
-                  height="6"
-                  width="6"
-                  x="19"
-                  y="19"
-                />
-
-                <rect
-                  fill="#1D7063"
-                  height="20"
-                  width="20"
-                  x="68"
-                  y="12"
-                />
-
-                <rect
-                  fill="white"
-                  height="12"
-                  width="12"
-                  x="72"
-                  y="16"
-                />
-
-                <rect
-                  fill="#E66926"
-                  height="6"
-                  width="6"
-                  x="75"
-                  y="75"
-                />
-
-                <rect
-                  fill="#1D7063"
-                  height="20"
-                  width="20"
-                  x="12"
-                  y="68"
-                />
-
-                <rect
-                  fill="white"
-                  height="12"
-                  width="12"
-                  x="16"
-                  y="72"
-                />
-
-                <rect
-                  fill="#1D7063"
-                  height="6"
-                  width="6"
-                  x="19"
-                  y="75"
-                />
-
-                <!-- 中間隨機小方塊 -->
-                <rect
-                  fill="#1D7063"
-                  height="8"
-                  width="8"
-                  x="40"
-                  y="20"
-                />
-
-                <rect
-                  fill="#E66926"
-                  height="14"
-                  width="6"
-                  x="52"
-                  y="12"
-                />
-
-                <rect
-                  fill="#1D7063"
-                  height="6"
-                  width="16"
-                  x="42"
-                  y="36"
-                />
-
-                <rect
-                  fill="#47C2A6"
-                  height="10"
-                  width="28"
-                  x="36"
-                  y="48"
-                />
-
-                <rect
-                  fill="#1D7063"
-                  height="12"
-                  width="14"
-                  x="68"
-                  y="42"
-                />
-
-                <rect
-                  fill="#E66926"
-                  height="16"
-                  width="16"
-                  x="72"
-                  y="60"
-                />
-
-                <rect
-                  fill="#1D7063"
-                  height="12"
-                  width="18"
-                  x="44"
-                  y="68"
-                />
-
-                <rect
-                  fill="#47C2A6"
-                  height="6"
-                  width="24"
-                  x="40"
-                  y="82"
-                />
-              </svg>
-              <!-- 紅色掃描雷射線 -->
-              <div class="laser-line" />
+              <QRCode :size="220" :value="selectedCheckinPayload" />
             </div>
 
             <div class="text-caption text-grey-darken-2 font-weight-bold mb-4">
@@ -359,6 +216,7 @@
 <script setup lang="ts">
 import { computed, ref } from 'vue'
 import Layout from '@/components/layout/DefaultLayout.vue'
+import QRCode from '@/components/QRCode.vue'
 import { type Appointment, useAppStore } from '@/stores/app'
 
 const store = useAppStore()
@@ -374,6 +232,14 @@ const filteredAppointments = computed(() => {
   return store.appointments
 })
 
+const selectedCheckinPayload = computed(() => {
+  if (!selectedApt.value) {
+    return 'https://hp.local/c'
+  }
+
+  return `https://hp.local/c/${selectedApt.value.id}`
+})
+
 function getStatusColor (status: string) {
   switch (status) {
     case '未報名': {
@@ -422,36 +288,9 @@ function simulateOnSiteCheckin () {
 
 .qrcode-wrapper {
   position: relative;
-  width: 204px;
-  height: 204px;
+  width: 244px;
+  height: 244px;
   overflow: hidden;
 }
 
-.qrcode-svg {
-  display: block;
-}
-
-/* 掃描雷射線效果 */
-.laser-line {
-  position: absolute;
-  top: 0;
-  left: 0;
-  width: 100%;
-  height: 3px;
-  background-color: #ff3b30;
-  box-shadow: 0 0 8px #ff3b30;
-  animation: scan 2.5s infinite linear;
-}
-
-@keyframes scan {
-  0% {
-    top: 0%;
-  }
-  50% {
-    top: 100%;
-  }
-  100% {
-    top: 0%;
-  }
-}
 </style>
diff --git a/app/citizen-frontend/src/pages/index.vue b/app/citizen-frontend/src/pages/index.vue
index 023049e..e942ebb 100644
--- a/app/citizen-frontend/src/pages/index.vue
+++ b/app/citizen-frontend/src/pages/index.vue
@@ -180,23 +180,24 @@
 
       <template v-else>
         <div class="text-center mb-6">
-          <BrandAvatar class="elevation-3 mb-4" :icon-size="42" :size="72" />
-
-          <p class="text-body-medium text-grey-darken-1 mb-0">
-            不登入也可以先完成線上健康自評，<br />登入後可預約普測與查看量測紀錄。
-          </p>
+          <BrandAvatar class="elevation-2" :icon-size="42" :size="72" />
         </div>
 
-        <v-card class="rounded-xl elevation-2 mb-4" color="surface">
+        <v-card class="rounded-xl elevation-2 mb-12 py-4" color="surface">
           <v-card-text>
             <div class="d-flex align-center mb-4">
-              <v-avatar class="mr-3 text-white" color="accent" size="36">
+              <v-avatar class="mr-4 text-white" color="accent" size="36">
                 <v-icon icon="mdi-clipboard-text-outline" />
               </v-avatar>
 
               <div class="text-left">
-                <div class="text-title-medium font-weight-bold text-primary">先做線上健康自評</div>
-                <div class="text-title-small text-grey">約 3 分鐘完成，取得初步健康風險分級。</div>
+                <div class="text-title-medium font-weight-bold text-primary">
+                  無須登入，先做線上健康自評
+                </div>
+
+                <div class="text-title-small text-grey mt-2">
+                  約 3 分鐘完成，取得初步健康風險分級。
+                </div>
               </div>
             </div>
 
@@ -231,9 +232,7 @@
             <div>
               <div class="font-weight-bold text-grey-darken-4">登入後可使用完整功能</div>
 
-              <div class="text-title-small text-grey">
-                普測預約、現場報到、量測紀錄與運動處方需要登入狀態。
-              </div>
+              <div class="text-title-small text-grey">普測預約、現場報到、量測紀錄與運動處方。</div>
             </div>
           </v-card-text>
         </v-card>
diff --git a/app/citizen-frontend/src/stores/app.ts b/app/citizen-frontend/src/stores/app.ts
index ea447c6..f934818 100644
--- a/app/citizen-frontend/src/stores/app.ts
+++ b/app/citizen-frontend/src/stores/app.ts
@@ -71,51 +71,55 @@ function createDefaultSelfAssessment (): SelfAssessment {
 }
 
 function createDefaultAppointments (): Appointment[] {
+  const measurementItems = [
+    '血壓',
+    '體脂',
+    '握力',
+    '5次坐站',
+    '30秒椅子坐立',
+    '原地抬膝踏步',
+    '手臂屈舉',
+    '抓背測驗',
+    '坐姿體前彎',
+    '2.44米繞物',
+    '開眼單足立',
+  ]
+  const location = '信義區運動中心 3 樓多功能教室'
+  const organizer = '臺北市政府體育局'
+
   return [
     {
       id: 'apt-01',
-      title: '信義區銀髮活力公益普測',
-      date: '2026-06-20',
-      time: '09:00 - 11:30',
-      location: '信義區運動中心 3 樓多功能教室',
+      title: '銀髮活力公益普測 A 時段',
+      date: '2026-07-04',
+      time: '09:00 - 10:00',
+      location,
       status: '已報名',
       slots: 12,
-      organizer: '臺北市政府體育局',
-      items: ['血壓', '體脂', '握力', '30秒椅子坐立', '原地抬膝踏步', '抓背測驗', '開眼單足立'],
+      organizer,
+      items: measurementItems,
     },
     {
       id: 'apt-02',
-      title: '中山區樂齡健康普測與運動處方體驗站',
-      date: '2026-06-25',
-      time: '14:00 - 16:30',
-      location: '中山區民生社區活動中心 4 樓',
+      title: '銀髮活力公益普測 B 時段',
+      date: '2026-07-04',
+      time: '10:30 - 11:30',
+      location,
       status: '已報到',
       slots: 5,
-      organizer: '中山區健康服務中心',
-      items: [
-        '血壓',
-        '體脂',
-        '握力',
-        '5次坐站',
-        '30秒椅子坐立',
-        '原地抬膝踏步',
-        '手臂屈舉',
-        '抓背測驗',
-        '坐姿體前彎',
-        '2.44米繞物',
-        '開眼單足立',
-      ],
+      organizer,
+      items: measurementItems,
     },
     {
       id: 'apt-03',
-      title: '大安區樂齡體適能檢測活動',
-      date: '2026-07-02',
-      time: '09:00 - 12:00',
-      location: '大安運動中心 2 樓籃球場',
+      title: '銀髮活力公益普測 C 時段',
+      date: '2026-07-04',
+      time: '13:30 - 14:30',
+      location,
       status: '未報名',
       slots: 45,
-      organizer: '大安區公所',
-      items: ['血壓', '體脂', '握力', '5次坐站', '原地抬膝踏步', '坐姿體前彎', '開眼單足立'],
+      organizer,
+      items: measurementItems,
     },
   ]
 }
diff --git a/app/citizen-frontend/src/utils/qrcode.ts b/app/citizen-frontend/src/utils/qrcode.ts
new file mode 100644
index 0000000..d9c511d
--- /dev/null
+++ b/app/citizen-frontend/src/utils/qrcode.ts
@@ -0,0 +1,541 @@
+type Cell = boolean | null
+
+interface BlockGroup {
+  count: number
+  dataCodewords: number
+}
+
+interface VersionSpec {
+  version: number
+  size: number
+  dataCodewords: number
+  eccCodewords: number
+  blockGroups: BlockGroup[]
+  capacity: number
+  alignment: number[]
+}
+
+export interface QrCodeMatrix {
+  size: number
+  modules: boolean[][]
+}
+
+const VERSION_SPECS: VersionSpec[] = [
+  { version: 1, size: 21, dataCodewords: 16, eccCodewords: 10, blockGroups: [{ count: 1, dataCodewords: 16 }], capacity: 14, alignment: [] },
+  { version: 2, size: 25, dataCodewords: 28, eccCodewords: 16, blockGroups: [{ count: 1, dataCodewords: 28 }], capacity: 26, alignment: [6, 18] },
+  { version: 3, size: 29, dataCodewords: 44, eccCodewords: 26, blockGroups: [{ count: 1, dataCodewords: 44 }], capacity: 42, alignment: [6, 22] },
+  { version: 4, size: 33, dataCodewords: 64, eccCodewords: 18, blockGroups: [{ count: 2, dataCodewords: 32 }], capacity: 62, alignment: [6, 26] },
+  { version: 5, size: 37, dataCodewords: 86, eccCodewords: 24, blockGroups: [{ count: 2, dataCodewords: 43 }], capacity: 84, alignment: [6, 30] },
+  { version: 6, size: 41, dataCodewords: 108, eccCodewords: 16, blockGroups: [{ count: 4, dataCodewords: 27 }], capacity: 106, alignment: [6, 34] },
+  { version: 7, size: 45, dataCodewords: 124, eccCodewords: 18, blockGroups: [{ count: 4, dataCodewords: 31 }], capacity: 122, alignment: [6, 22, 38] },
+  { version: 8, size: 49, dataCodewords: 154, eccCodewords: 22, blockGroups: [{ count: 2, dataCodewords: 38 }, { count: 2, dataCodewords: 39 }], capacity: 152, alignment: [6, 24, 42] },
+  { version: 9, size: 53, dataCodewords: 182, eccCodewords: 22, blockGroups: [{ count: 3, dataCodewords: 36 }, { count: 2, dataCodewords: 37 }], capacity: 180, alignment: [6, 26, 46] },
+  { version: 10, size: 57, dataCodewords: 216, eccCodewords: 26, blockGroups: [{ count: 4, dataCodewords: 43 }, { count: 1, dataCodewords: 44 }], capacity: 213, alignment: [6, 28, 50] },
+]
+
+const FORMAT_XOR = 0x54_12
+const FORMAT_POLY = 0x5_37
+const VERSION_POLY = 0x1f_25
+
+const gfExp = Array.from({ length: 512 }, () => 0)
+const gfLog = Array.from({ length: 256 }, () => 0)
+let x = 1
+for (let i = 0; i < 255; i += 1) {
+  gfExp[i] = x
+  gfLog[x] = i
+  x <<= 1
+  if (x & 0x1_00) {
+    x ^= 0x1_1d
+  }
+}
+for (let i = 255; i < 512; i += 1) {
+  gfExp[i] = gfExp[i - 255]
+}
+
+export function createQrCodeMatrix (value: string): QrCodeMatrix {
+  const data = [...new TextEncoder().encode(value)]
+  const spec = VERSION_SPECS.find(item => data.length <= item.capacity)
+  if (!spec) {
+    throw new Error('QR Code 內容過長，請將 payload 控制在 213 bytes 以內')
+  }
+
+  const dataCodewords = createDataCodewords(data, spec)
+  const codewords = createFinalCodewords(dataCodewords, spec)
+  const dataBits = codewords.flatMap(codeword => byteToBits(codeword))
+  const base = createBaseMatrix(spec)
+
+  let bestModules = base.modules
+  let bestScore = Number.POSITIVE_INFINITY
+
+  for (let mask = 0; mask < 8; mask += 1) {
+    const modules = cloneMatrix(base.modules)
+    placeDataBits(modules, base.reserved, dataBits, mask)
+    drawFormatBits(modules, spec.size, mask)
+
+    if (spec.version >= 7) {
+      drawVersionBits(modules, spec)
+    }
+
+    const score = getPenaltyScore(modules)
+    if (score < bestScore) {
+      bestScore = score
+      bestModules = modules
+    }
+  }
+
+  return {
+    size: spec.size,
+    modules: bestModules.map(row => row.map(Boolean)),
+  }
+}
+
+export function createQrCodeSvg (value: string, options: { scale?: number, quietZone?: number } = {}) {
+  const { size, modules } = createQrCodeMatrix(value)
+  const quietZone = options.quietZone ?? 4
+  const scale = options.scale ?? 6
+  const viewSize = size + quietZone * 2
+  const rects: string[] = []
+
+  for (const [y, row] of modules.entries()) {
+    for (const [x, dark] of row.entries()) {
+      if (dark) {
+        rects.push(`<rect x="${x + quietZone}" y="${y + quietZone}" width="1" height="1"/>`)
+      }
+    }
+  }
+
+  return [
+    `<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 ${viewSize} ${viewSize}" width="${viewSize * scale}" height="${viewSize * scale}" shape-rendering="crispEdges">`,
+    '<rect width="100%" height="100%" fill="#fff"/>',
+    '<g fill="#000">',
+    ...rects,
+    '</g>',
+    '</svg>',
+  ].join('')
+}
+
+function createDataCodewords (data: number[], spec: VersionSpec) {
+  const bits: number[] = []
+  appendBits(bits, 0b0100, 4)
+  appendBits(bits, data.length, spec.version < 10 ? 8 : 16)
+  for (const byte of data) {
+    appendBits(bits, byte, 8)
+  }
+
+  const capacityBits = spec.dataCodewords * 8
+  appendBits(bits, 0, Math.min(4, capacityBits - bits.length))
+
+  while (bits.length % 8 !== 0) {
+    bits.push(0)
+  }
+
+  const codewords: number[] = []
+  for (let i = 0; i < bits.length; i += 8) {
+    codewords.push(bitsToByte(bits.slice(i, i + 8)))
+  }
+
+  for (let pad = 0xec; codewords.length < spec.dataCodewords; pad ^= 0xec ^ 0x11) {
+    codewords.push(pad)
+  }
+
+  return codewords
+}
+
+function createFinalCodewords (dataCodewords: number[], spec: VersionSpec) {
+  const blocks: { data: number[], ecc: number[] }[] = []
+  let offset = 0
+
+  for (const group of spec.blockGroups) {
+    for (let i = 0; i < group.count; i += 1) {
+      const data = dataCodewords.slice(offset, offset + group.dataCodewords)
+      offset += group.dataCodewords
+      blocks.push({ data, ecc: createErrorCorrectionCodewords(data, spec.eccCodewords) })
+    }
+  }
+
+  const result: number[] = []
+  const maxDataLength = Math.max(...blocks.map(block => block.data.length))
+
+  for (let i = 0; i < maxDataLength; i += 1) {
+    for (const block of blocks) {
+      if (i < block.data.length) {
+        result.push(block.data[i])
+      }
+    }
+  }
+
+  for (let i = 0; i < spec.eccCodewords; i += 1) {
+    for (const block of blocks) {
+      result.push(block.ecc[i])
+    }
+  }
+
+  return result
+}
+
+function createErrorCorrectionCodewords (data: number[], degree: number) {
+  const generator = createGeneratorPolynomial(degree)
+  const result = Array.from({ length: degree }, () => 0)
+
+  for (const byte of data) {
+    const factor = byte ^ result.shift()!
+    result.push(0)
+
+    for (const [index, coefficient] of generator.entries()) {
+      result[index] ^= gfMultiply(coefficient, factor)
+    }
+  }
+
+  return result
+}
+
+function createGeneratorPolynomial (degree: number) {
+  let result = [1]
+
+  for (let i = 0; i < degree; i += 1) {
+    const next = Array.from({ length: result.length + 1 }, () => 0)
+    for (const [index, coefficient] of result.entries()) {
+      next[index] ^= gfMultiply(coefficient, 1)
+      next[index + 1] ^= gfMultiply(coefficient, gfExp[i])
+    }
+    result = next
+  }
+
+  return result.slice(1)
+}
+
+function createBaseMatrix (spec: VersionSpec) {
+  const modules = Array.from({ length: spec.size }, (): Cell[] => {
+    return Array.from({ length: spec.size }, (): Cell => null)
+  })
+  const reserved = Array.from({ length: spec.size }, (): boolean[] => {
+    return Array.from({ length: spec.size }, () => false)
+  })
+
+  drawFinderPattern(modules, reserved, 3, 3)
+  drawFinderPattern(modules, reserved, spec.size - 4, 3)
+  drawFinderPattern(modules, reserved, 3, spec.size - 4)
+  drawTimingPatterns(modules, reserved)
+  drawAlignmentPatterns(modules, reserved, spec.alignment)
+  drawDarkModule(modules, reserved, spec.size)
+  reserveFormatAreas(reserved, spec.size)
+
+  if (spec.version >= 7) {
+    reserveVersionAreas(reserved, spec.size)
+  }
+
+  return { modules, reserved }
+}
+
+function drawFinderPattern (modules: Cell[][], reserved: boolean[][], centerX: number, centerY: number) {
+  for (let y = -4; y <= 4; y += 1) {
+    for (let x = -4; x <= 4; x += 1) {
+      const xx = centerX + x
+      const yy = centerY + y
+      if (!isInBounds(modules.length, xx, yy)) {
+        continue
+      }
+
+      const distance = Math.max(Math.abs(x), Math.abs(y))
+      modules[yy][xx] = distance !== 2 && distance !== 4
+      reserved[yy][xx] = true
+    }
+  }
+}
+
+function drawTimingPatterns (modules: Cell[][], reserved: boolean[][]) {
+  for (let i = 8; i < modules.length - 8; i += 1) {
+    const dark = i % 2 === 0
+    modules[6][i] = dark
+    modules[i][6] = dark
+    reserved[6][i] = true
+    reserved[i][6] = true
+  }
+}
+
+function drawAlignmentPatterns (modules: Cell[][], reserved: boolean[][], positions: number[]) {
+  for (const y of positions) {
+    for (const x of positions) {
+      if (reserved[y][x]) {
+        continue
+      }
+
+      for (let dy = -2; dy <= 2; dy += 1) {
+        for (let dx = -2; dx <= 2; dx += 1) {
+          const distance = Math.max(Math.abs(dx), Math.abs(dy))
+          modules[y + dy][x + dx] = distance !== 1
+          reserved[y + dy][x + dx] = true
+        }
+      }
+    }
+  }
+}
+
+function drawDarkModule (modules: Cell[][], reserved: boolean[][], size: number) {
+  modules[size - 8][8] = true
+  reserved[size - 8][8] = true
+}
+
+function reserveFormatAreas (reserved: boolean[][], size: number) {
+  for (let i = 0; i <= 5; i += 1) {
+    reserved[8][i] = true
+    reserved[i][8] = true
+  }
+
+  reserved[8][7] = true
+  reserved[8][8] = true
+  reserved[7][8] = true
+
+  for (let i = 0; i < 8; i += 1) {
+    reserved[8][size - 1 - i] = true
+  }
+
+  for (let i = 8; i < 15; i += 1) {
+    reserved[size - 15 + i][8] = true
+  }
+}
+
+function reserveVersionAreas (reserved: boolean[][], size: number) {
+  for (let i = 0; i < 6; i += 1) {
+    for (let j = 0; j < 3; j += 1) {
+      reserved[size - 11 + j][i] = true
+      reserved[i][size - 11 + j] = true
+    }
+  }
+}
+
+function placeDataBits (modules: Cell[][], reserved: boolean[][], bits: number[], mask: number) {
+  const size = modules.length
+  let bitIndex = 0
+  let direction = -1
+  let y = size - 1
+
+  for (let right = size - 1; right >= 1; right -= 2) {
+    if (right === 6) {
+      right -= 1
+    }
+
+    while (y >= 0 && y < size) {
+      for (let column = 0; column < 2; column += 1) {
+        const x = right - column
+        if (!reserved[y][x]) {
+          const bit = bitIndex < bits.length ? bits[bitIndex] === 1 : false
+          modules[y][x] = bit !== getMaskBit(mask, x, y)
+          bitIndex += 1
+        }
+      }
+      y += direction
+    }
+
+    y -= direction
+    direction = -direction
+  }
+}
+
+function drawFormatBits (modules: Cell[][], size: number, mask: number) {
+  const bits = getFormatBits(mask)
+
+  for (let i = 0; i <= 5; i += 1) {
+    setModule(modules, 8, i, getBit(bits, i))
+  }
+  setModule(modules, 8, 7, getBit(bits, 6))
+  setModule(modules, 8, 8, getBit(bits, 7))
+  setModule(modules, 7, 8, getBit(bits, 8))
+  for (let i = 9; i < 15; i += 1) {
+    setModule(modules, 14 - i, 8, getBit(bits, i))
+  }
+
+  for (let i = 0; i < 8; i += 1) {
+    setModule(modules, size - 1 - i, 8, getBit(bits, i))
+  }
+  for (let i = 8; i < 15; i += 1) {
+    setModule(modules, 8, size - 15 + i, getBit(bits, i))
+  }
+}
+
+function drawVersionBits (modules: Cell[][], spec: VersionSpec) {
+  const bits = getVersionBits(spec.version)
+  const size = spec.size
+
+  for (let i = 0; i < 18; i += 1) {
+    const bit = getBit(bits, i)
+    const x = i % 3
+    const y = Math.floor(i / 3)
+    setModule(modules, size - 11 + x, y, bit)
+    setModule(modules, y, size - 11 + x, bit)
+  }
+}
+
+function getFormatBits (mask: number) {
+  let data = mask
+  let bits = data << 10
+
+  for (let i = 4; i >= 0; i -= 1) {
+    if (((bits >>> (i + 10)) & 1) === 1) {
+      bits ^= FORMAT_POLY << i
+    }
+  }
+
+  data = (data << 10) | (bits & 0x03_ff)
+  return data ^ FORMAT_XOR
+}
+
+function getVersionBits (version: number) {
+  let bits = version << 12
+
+  for (let i = 5; i >= 0; i -= 1) {
+    if (((bits >>> (i + 12)) & 1) === 1) {
+      bits ^= VERSION_POLY << i
+    }
+  }
+
+  return (version << 12) | (bits & 0x0f_ff)
+}
+
+function getPenaltyScore (modules: Cell[][]) {
+  const size = modules.length
+  let score = 0
+
+  for (let y = 0; y < size; y += 1) {
+    score += getRunPenalty(modules[y].map(Boolean))
+  }
+
+  for (let x = 0; x < size; x += 1) {
+    score += getRunPenalty(modules.map(row => Boolean(row[x])))
+  }
+
+  for (let y = 0; y < size - 1; y += 1) {
+    for (let x = 0; x < size - 1; x += 1) {
+      const dark = modules[y][x]
+      if (modules[y][x + 1] === dark && modules[y + 1][x] === dark && modules[y + 1][x + 1] === dark) {
+        score += 3
+      }
+    }
+  }
+
+  score += getFinderLikePenalty(modules)
+
+  const darkCount = modules.flat().filter(Boolean).length
+  const percent = (darkCount * 100) / (size * size)
+  score += Math.floor(Math.abs(percent - 50) / 5) * 10
+
+  return score
+}
+
+function getRunPenalty (line: boolean[]) {
+  let score = 0
+  let runColor = line[0]
+  let runLength = 1
+
+  for (let i = 1; i < line.length; i += 1) {
+    if (line[i] === runColor) {
+      runLength += 1
+    } else {
+      if (runLength >= 5) {
+        score += runLength - 2
+      }
+      runColor = line[i]
+      runLength = 1
+    }
+  }
+
+  return runLength >= 5 ? score + runLength - 2 : score
+}
+
+function getFinderLikePenalty (modules: Cell[][]) {
+  const pattern = '10111010000'
+  const reversePattern = '00001011101'
+  const size = modules.length
+  let score = 0
+
+  const scan = (line: boolean[]) => {
+    const text = line.map(bit => (bit ? '1' : '0')).join('')
+    for (let i = 0; i <= text.length - pattern.length; i += 1) {
+      const chunk = text.slice(i, i + pattern.length)
+      if (chunk === pattern || chunk === reversePattern) {
+        score += 40
+      }
+    }
+  }
+
+  for (const row of modules) {
+    scan(row.map(Boolean))
+  }
+  for (let x = 0; x < size; x += 1) {
+    scan(modules.map(row => Boolean(row[x])))
+  }
+
+  return score
+}
+
+function getMaskBit (mask: number, x: number, y: number) {
+  switch (mask) {
+    case 0: {
+      return (x + y) % 2 === 0
+    }
+    case 1: {
+      return y % 2 === 0
+    }
+    case 2: {
+      return x % 3 === 0
+    }
+    case 3: {
+      return (x + y) % 3 === 0
+    }
+    case 4: {
+      return (Math.floor(y / 2) + Math.floor(x / 3)) % 2 === 0
+    }
+    case 5: {
+      return ((x * y) % 2) + ((x * y) % 3) === 0
+    }
+    case 6: {
+      return (((x * y) % 2) + ((x * y) % 3)) % 2 === 0
+    }
+    case 7: {
+      return (((x + y) % 2) + ((x * y) % 3)) % 2 === 0
+    }
+    default: {
+      return false
+    }
+  }
+}
+
+function appendBits (target: number[], value: number, length: number) {
+  for (let i = length - 1; i >= 0; i -= 1) {
+    target.push((value >>> i) & 1)
+  }
+}
+
+function byteToBits (value: number) {
+  const bits: number[] = []
+  appendBits(bits, value, 8)
+  return bits
+}
+
+function bitsToByte (bits: number[]) {
+  return bits.reduce((value, bit) => (value << 1) | bit, 0)
+}
+
+function gfMultiply (a: number, b: number) {
+  if (a === 0 || b === 0) {
+    return 0
+  }
+
+  return gfExp[gfLog[a] + gfLog[b]]
+}
+
+function getBit (value: number, index: number) {
+  return ((value >>> index) & 1) === 1
+}
+
+function cloneMatrix (modules: Cell[][]) {
+  return modules.map(row => [...row])
+}
+
+function setModule (modules: Cell[][], x: number, y: number, value: boolean) {
+  modules[y][x] = value
+}
+
+function isInBounds (size: number, x: number, y: number) {
+  return x >= 0 && y >= 0 && x < size && y < size
+}