diff --git a/frontend/cypress/e2e/kit-export.cy.js b/frontend/cypress/e2e/kit-export.cy.js
new file mode 100644
index 0000000..03eac9b
--- /dev/null
+++ b/frontend/cypress/e2e/kit-export.cy.js
@@ -0,0 +1,137 @@
+describe('Kit Export Feature', () => {
+  let adminToken
+  let authHeaders
+
+  before(() => {
+    cy.getAdminToken().then(token => {
+      adminToken = token
+      authHeaders = { Authorization: `Bearer ${token}` }
+    })
+  })
+
+  describe('API: recipes and oils available', () => {
+    it('loads oils list', () => {
+      cy.request({ url: '/api/oils', headers: authHeaders }).then(res => {
+        expect(res.status).to.eq(200)
+        expect(res.body).to.be.an('array')
+        expect(res.body.length).to.be.greaterThan(50)
+      })
+    })
+
+    it('loads recipes list', () => {
+      cy.request({ url: '/api/recipes', headers: authHeaders }).then(res => {
+        expect(res.status).to.eq(200)
+        expect(res.body).to.be.an('array')
+        expect(res.body.length).to.be.greaterThan(10)
+      })
+    })
+  })
+
+  describe('UI: Projects page access', () => {
+    it('shows login prompt when not logged in', () => {
+      cy.visit('/projects')
+      cy.contains('登录', { timeout: 10000 }).should('be.visible')
+    })
+
+    it('shows kit compare button when logged in as admin', () => {
+      cy.visit('/projects', {
+        onBeforeLoad(win) { win.localStorage.setItem('oil_auth_token', adminToken) }
+      })
+      cy.contains('套装方案对比', { timeout: 10000 }).should('be.visible')
+    })
+  })
+
+  describe('UI: Kit Export page', () => {
+    beforeEach(() => {
+      cy.visit('/kit-export', {
+        onBeforeLoad(win) { win.localStorage.setItem('oil_auth_token', adminToken) }
+      })
+    })
+
+    it('loads with 4 kit cards', () => {
+      cy.get('.kit-card', { timeout: 10000 }).should('have.length', 4)
+    })
+
+    it('shows kit names and prices', () => {
+      cy.contains('芳香调理套装').should('be.visible')
+      cy.contains('家庭医生套装').should('be.visible')
+      cy.contains('居家呵护套装').should('be.visible')
+      cy.contains('全精油套装').should('be.visible')
+      cy.contains('¥1575').should('be.visible')
+      cy.contains('¥2250').should('be.visible')
+      cy.contains('¥3988').should('be.visible')
+      cy.contains('¥17700').should('be.visible')
+    })
+
+    it('shows recipe count for each kit', () => {
+      cy.get('.kit-recipe-count').should('have.length', 4)
+      cy.get('.kit-recipe-count').each($el => {
+        expect($el.text()).to.match(/可做 \d+ 个配方/)
+      })
+    })
+
+    it('clicking a kit card shows its recipes', () => {
+      cy.get('.kit-card').eq(1).click()
+      cy.get('.kit-detail', { timeout: 5000 }).should('be.visible')
+      cy.get('.recipe-table').should('exist')
+    })
+
+    it('recipe table has cost and profit columns', () => {
+      cy.get('.kit-card').first().click()
+      cy.get('.recipe-table', { timeout: 5000 }).within(() => {
+        cy.contains('th', '套装成本').should('exist')
+        cy.contains('th', '原价成本').should('exist')
+        cy.contains('th', '售价').should('exist')
+        cy.contains('th', '利润率').should('exist')
+        cy.contains('th', '可做次数').should('exist')
+      })
+    })
+
+    it('shows cross comparison section', () => {
+      cy.get('.cross-section', { timeout: 10000 }).should('be.visible')
+      cy.get('.cross-table').should('exist')
+    })
+
+    it('cross comparison has single-buy column', () => {
+      cy.get('.cross-table', { timeout: 10000 }).within(() => {
+        cy.contains('th', '单买').should('exist')
+      })
+    })
+
+    it('cross comparison shows staircase pattern (available cells have green bg)', () => {
+      cy.get('.td-kit-available', { timeout: 10000 }).should('have.length.greaterThan', 0)
+      cy.get('.td-kit-na').should('have.length.greaterThan', 0)
+    })
+
+    it('kit cost is always <= original cost in recipe table', () => {
+      cy.get('.kit-card').first().click()
+      cy.get('.recipe-table tbody tr', { timeout: 5000 }).each($row => {
+        const cells = $row.find('td')
+        // td[1] = 可做次数, td[2] = 套装成本, td[3] = 原价成本
+        const kitCostText = cells.eq(2).text().replace(/[¥,\s]/g, '')
+        const origCostText = cells.eq(3).text().replace(/[¥,\s]/g, '')
+        const kitCost = parseFloat(kitCostText)
+        const origCost = parseFloat(origCostText)
+        if (!isNaN(kitCost) && !isNaN(origCost)) {
+          expect(kitCost).to.be.at.most(origCost + 0.01)
+        }
+      })
+    })
+
+    it('export buttons exist', () => {
+      cy.contains('button', '导出完整版').should('be.visible')
+      cy.contains('button', '导出简版').should('be.visible')
+    })
+
+    it('shows volume info next to recipe name', () => {
+      cy.get('.td-volume', { timeout: 10000 }).should('have.length.greaterThan', 0)
+    })
+  })
+
+  describe('UI: Kit Export access control', () => {
+    it('redirects to /projects when not logged in', () => {
+      cy.visit('/kit-export')
+      cy.url({ timeout: 10000 }).should('include', '/projects')
+    })
+  })
+})
diff --git a/frontend/src/__tests__/kitCost.test.js b/frontend/src/__tests__/kitCost.test.js
new file mode 100644
index 0000000..8d114a3
--- /dev/null
+++ b/frontend/src/__tests__/kitCost.test.js
@@ -0,0 +1,253 @@
+import { describe, it, expect } from 'vitest'
+import prodData from './fixtures/production-data.json'
+import { KITS } from '../config/kits'
+
+const oils = prodData.oils
+
+// ---------------------------------------------------------------------------
+// Replicate kit cost calculation logic from useKitCost.js (pure functions)
+// ---------------------------------------------------------------------------
+
+function resolveOilName(kitOilName) {
+  if (oils[kitOilName]) return kitOilName
+  const match = Object.keys(oils).find(n => n.endsWith(kitOilName) && n !== kitOilName)
+  return match || kitOilName
+}
+
+function calcKitPerDrop(kit) {
+  const resolved = kit.oils.map(resolveOilName)
+  const bc = kit.bottleCount || {}
+  let totalBottlePrice = 0
+  const oilBottlePrices = {}
+  for (const name of resolved) {
+    const meta = oils[name]
+    const count = bc[name] || 1
+    const bp = meta ? meta.bottlePrice * count : 0
+    oilBottlePrices[name] = bp
+    totalBottlePrice += bp
+  }
+  if (totalBottlePrice === 0) return {}
+
+  const totalValue = totalBottlePrice + (kit.accessoryValue || 0)
+  const discountRate = Math.min(kit.price / totalValue, 1)
+  const perDrop = {}
+  for (const name of resolved) {
+    const meta = oils[name]
+    const count = bc[name] || 1
+    const bp = oilBottlePrices[name]
+    const kitCostForOil = bp * discountRate
+    const totalDrops = meta ? meta.dropCount * count : 1
+    perDrop[name] = totalDrops > 0 ? kitCostForOil / totalDrops : 0
+  }
+  return perDrop
+}
+
+function canMakeRecipe(kit, recipe) {
+  const resolvedSet = new Set(kit.oils.map(resolveOilName))
+  return recipe.ingredients.every(ing => resolvedSet.has(ing.oil))
+}
+
+function calcRecipeCostWithKit(kitPerDrop, recipe) {
+  return recipe.ingredients.reduce((sum, ing) => {
+    return sum + (kitPerDrop[ing.oil] || 0) * ing.drops
+  }, 0)
+}
+
+function calcOriginalCost(recipe) {
+  return recipe.ingredients.reduce((sum, ing) => {
+    const meta = oils[ing.oil]
+    if (!meta || !meta.dropCount) return sum
+    return sum + (meta.bottlePrice / meta.dropCount) * ing.drops
+  }, 0)
+}
+
+// ---------------------------------------------------------------------------
+// Kit Configuration
+// ---------------------------------------------------------------------------
+describe('Kit Configuration', () => {
+  it('has 4 kits defined', () => {
+    expect(KITS).toHaveLength(4)
+  })
+
+  it('each kit has required fields', () => {
+    for (const kit of KITS) {
+      expect(kit).toHaveProperty('id')
+      expect(kit).toHaveProperty('name')
+      expect(kit).toHaveProperty('price')
+      expect(kit).toHaveProperty('oils')
+      expect(kit.price).toBeGreaterThan(0)
+      expect(kit.oils.length).toBeGreaterThan(0)
+    }
+  })
+
+  it('all kits include coconut oil', () => {
+    for (const kit of KITS) {
+      expect(kit.oils).toContain('椰子油')
+    }
+  })
+
+  it('kit ids are unique', () => {
+    const ids = KITS.map(k => k.id)
+    expect(new Set(ids).size).toBe(ids.length)
+  })
+
+  it('芳香调理 has 9 oils at ¥1575', () => {
+    const kit = KITS.find(k => k.id === 'aroma')
+    expect(kit.price).toBe(1575)
+    expect(kit.oils).toHaveLength(9)
+  })
+
+  it('家庭医生 has 11 oils at ¥2250', () => {
+    const kit = KITS.find(k => k.id === 'family')
+    expect(kit.price).toBe(2250)
+    expect(kit.oils).toHaveLength(11)
+  })
+
+  it('居家呵护 has 22 oils at ¥3988', () => {
+    const kit = KITS.find(k => k.id === 'home3988')
+    expect(kit.price).toBe(3988)
+    expect(kit.oils).toHaveLength(22)
+  })
+
+  it('全精油 has 80 oils at ¥17700 with bottleCount for coconut oil', () => {
+    const kit = KITS.find(k => k.id === 'full')
+    expect(kit.price).toBe(17700)
+    expect(kit.oils.length).toBe(80)
+    expect(kit.bottleCount).toBeDefined()
+    expect(kit.bottleCount['椰子油']).toBeCloseTo(2.57, 2)
+  })
+})
+
+// ---------------------------------------------------------------------------
+// Oil Name Resolution
+// ---------------------------------------------------------------------------
+describe('Oil Name Resolution', () => {
+  it('resolves exact match', () => {
+    expect(resolveOilName('薰衣草')).toBe('薰衣草')
+    expect(resolveOilName('乳香')).toBe('乳香')
+  })
+
+  it('resolves 牛至 to 西班牙牛至 via endsWith', () => {
+    expect(resolveOilName('牛至')).toBe('西班牙牛至')
+  })
+
+  it('does NOT resolve 牛至 to 牛至呵护', () => {
+    expect(resolveOilName('牛至')).not.toBe('牛至呵护')
+  })
+
+  it('returns original name for unknown oil', () => {
+    expect(resolveOilName('不存在的油')).toBe('不存在的油')
+  })
+})
+
+// ---------------------------------------------------------------------------
+// Kit Cost Calculation
+// ---------------------------------------------------------------------------
+describe('Kit Cost Calculation', () => {
+  it('discount rate is always <= 1 (kit never more expensive than buying individually)', () => {
+    for (const kit of KITS) {
+      const perDrop = calcKitPerDrop(kit)
+      for (const [name, ppd] of Object.entries(perDrop)) {
+        const meta = oils[name]
+        if (!meta || !meta.dropCount) continue
+        const originalPpd = meta.bottlePrice / meta.dropCount
+        expect(ppd).toBeLessThanOrEqual(originalPpd + 0.001) // tiny float tolerance
+      }
+    }
+  })
+
+  it('家庭医生 discount is ~32-33%', () => {
+    const kit = KITS.find(k => k.id === 'family')
+    const bc = kit.bottleCount || {}
+    let totalBp = 0
+    for (const name of kit.oils) {
+      const resolved = resolveOilName(name)
+      const meta = oils[resolved]
+      totalBp += meta ? meta.bottlePrice * (bc[resolved] || 1) : 0
+    }
+    const totalValue = totalBp + (kit.accessoryValue || 0)
+    const discount = 1 - kit.price / totalValue
+    expect(discount).toBeGreaterThan(0.30)
+    expect(discount).toBeLessThan(0.40)
+  })
+
+  it('kit cost for a recipe is less than original cost', () => {
+    const kit = KITS.find(k => k.id === 'family')
+    const perDrop = calcKitPerDrop(kit)
+    // 灰指甲: 西班牙牛至 + 椰子油
+    const recipe = prodData.recipes.find(r => r.name === '灰指甲')
+    if (recipe && canMakeRecipe(kit, recipe)) {
+      const kitCost = calcRecipeCostWithKit(perDrop, recipe)
+      const origCost = calcOriginalCost(recipe)
+      expect(kitCost).toBeLessThan(origCost)
+      expect(kitCost).toBeGreaterThan(0)
+    }
+  })
+
+  it('全精油 bottleCount 2.57 makes coconut oil cheaper per drop than without multiplier', () => {
+    const fullKit = KITS.find(k => k.id === 'full')
+    const perDrop = calcKitPerDrop(fullKit)
+    // With 2.57 bottles, per-drop cost should be roughly 1/2.57 of single-bottle kit cost
+    // at the same discount rate. Just verify it's significantly less than original per-drop.
+    const origPpd = oils['椰子油'].bottlePrice / oils['椰子油'].dropCount
+    expect(perDrop['椰子油']).toBeLessThan(origPpd)
+    expect(perDrop['椰子油']).toBeGreaterThan(0)
+  })
+
+  it('accessoryValue reduces effective oil cost', () => {
+    const kit = KITS.find(k => k.id === 'family')
+    // Without accessory: rate = price / totalBp
+    // With accessory: rate = price / (totalBp + accessoryValue) < previous rate
+    expect(kit.accessoryValue).toBeGreaterThan(0)
+
+    const bc = kit.bottleCount || {}
+    let totalBp = 0
+    for (const name of kit.oils) {
+      const resolved = resolveOilName(name)
+      const meta = oils[resolved]
+      totalBp += meta ? meta.bottlePrice * (bc[resolved] || 1) : 0
+    }
+    const rateWithAcc = kit.price / (totalBp + kit.accessoryValue)
+    const rateWithoutAcc = kit.price / totalBp
+    expect(rateWithAcc).toBeLessThan(rateWithoutAcc)
+  })
+})
+
+// ---------------------------------------------------------------------------
+// Recipe Matching
+// ---------------------------------------------------------------------------
+describe('Recipe Matching', () => {
+  it('larger kits can make at least as many recipes as smaller ones', () => {
+    const counts = KITS.map(kit => {
+      const matched = prodData.recipes.filter(r => canMakeRecipe(kit, r))
+      return { id: kit.id, count: matched.length, oilCount: kit.oils.length }
+    }).sort((a, b) => a.oilCount - b.oilCount)
+
+    for (let i = 1; i < counts.length; i++) {
+      expect(counts[i].count).toBeGreaterThanOrEqual(counts[i - 1].count)
+    }
+  })
+
+  it('全精油 can make the most recipes', () => {
+    const fullKit = KITS.find(k => k.id === 'full')
+    const fullCount = prodData.recipes.filter(r => canMakeRecipe(fullKit, r)).length
+
+    for (const kit of KITS) {
+      if (kit.id === 'full') continue
+      const count = prodData.recipes.filter(r => canMakeRecipe(kit, r)).length
+      expect(fullCount).toBeGreaterThanOrEqual(count)
+    }
+  })
+
+  it('灰指甲 (牛至+椰子油) can be made by 家庭医生', () => {
+    const kit = KITS.find(k => k.id === 'family')
+    const recipe = prodData.recipes.find(r => r.name === '灰指甲')
+    expect(canMakeRecipe(kit, recipe)).toBe(true)
+  })
+
+  it('recipe requiring 永久花 cannot be made by 芳香调理', () => {
+    const kit = KITS.find(k => k.id === 'aroma')
+    const recipe = prodData.recipes.find(r => r.name === '小v脸') // has 永久花
+    expect(canMakeRecipe(kit, recipe)).toBe(false)
+  })
+})