diff --git a/e2e/cypress/integration/error-handling/form-validation.cy.ts b/e2e/cypress/integration/error-handling/form-validation.cy.ts
new file mode 100644
index 000000000..3b93491dd
--- /dev/null
+++ b/e2e/cypress/integration/error-handling/form-validation.cy.ts
@@ -0,0 +1,54 @@
+describe('Error Handling - Form Validation', () => {
+  beforeEach(() => {
+    cy.visit('http://localhost:3001')
+  })
+
+  describe('Required Fields', () => {
+    it('should show error for empty required field', () => {
+      cy.getByTestId('search-button').click()
+      cy.getByTestId('departure-error').should('be.visible')
+    })
+
+    it('should show all required errors', () => {
+      cy.getByTestId('search-button').click()
+      cy.getByTestId('departure-error').should('be.visible')
+      cy.getByTestId('arrival-error').should('be.visible')
+    })
+
+    it('should clear error on input', () => {
+      cy.getByTestId('search-button').click()
+      cy.getByTestId('departure-error').should('be.visible')
+      cy.getByTestId('departure-input').type('SVO')
+      cy.getByTestId('departure-error').should('not.exist')
+    })
+  })
+
+  describe('Format Validation', () => {
+    it('should validate email format', () => {
+      cy.getByTestId('email-input').type('invalid-email')
+      cy.getByTestId('email-error').should('be.visible')
+    })
+
+    it('should validate phone format', () => {
+      cy.getByTestId('phone-input').type('123')
+      cy.getByTestId('phone-error').should('be.visible')
+    })
+
+    it('should validate date format', () => {
+      cy.getByTestId('date-input').type('invalid-date')
+      cy.getByTestId('date-error').should('be.visible')
+    })
+  })
+
+  describe('Range Validation', () => {
+    it('should validate min length', () => {
+      cy.getByTestId('password-input').type('123')
+      cy.getByTestId('password-error').should('contain', 'at least')
+    })
+
+    it('should validate max length', () => {
+      cy.getByTestId('text-input').type('a'.repeat(300))
+      cy.getByTestId('text-error').should('contain', 'maximum')
+    })
+  })
+})
diff --git a/e2e/cypress/integration/error-handling/network-errors.cy.ts b/e2e/cypress/integration/error-handling/network-errors.cy.ts
new file mode 100644
index 000000000..e39b61685
--- /dev/null
+++ b/e2e/cypress/integration/error-handling/network-errors.cy.ts
@@ -0,0 +1,91 @@
+describe('Error Handling - Network Errors', () => {
+  beforeEach(() => {
+    cy.visit('http://localhost:3001')
+  })
+
+  describe('API Failures', () => {
+    it('should handle 500 server error', () => {
+      cy.intercept('GET', '**/api/flights**', {
+        statusCode: 500,
+        body: { error: 'Server error' },
+      }).as('serverError')
+      cy.getByTestId('search-button').click()
+      cy.wait('@serverError')
+      cy.getByTestId('error-message').should('be.visible')
+    })
+
+    it('should handle 404 not found', () => {
+      cy.intercept('GET', '**/api/flights**', {
+        statusCode: 404,
+        body: { error: 'Not found' },
+      }).as('notFound')
+      cy.getByTestId('search-button').click()
+      cy.wait('@notFound')
+      cy.getByTestId('not-found-message').should('be.visible')
+    })
+
+    it('should handle timeout', () => {
+      cy.intercept('GET', '**/api/flights**', req => {
+        req.destroy()
+      }).as('timeout')
+      cy.getByTestId('search-button').click()
+      cy.getByTestId('timeout-message').should('be.visible')
+    })
+
+    it('should show retry button', () => {
+      cy.intercept('GET', '**/api/flights**', {
+        statusCode: 500,
+        body: { error: 'Error' },
+      }).as('error')
+      cy.getByTestId('search-button').click()
+      cy.wait('@error')
+      cy.getByTestId('retry-button').should('be.visible')
+    })
+
+    it('should retry on button click', () => {
+      cy.intercept('GET', '**/api/flights**', {
+        statusCode: 500,
+        body: { error: 'Error' },
+      }).as('firstError')
+      cy.intercept('GET', '**/api/flights**', {
+        statusCode: 200,
+        body: { flights: [] },
+      }).as('success')
+      
+      cy.getByTestId('search-button').click()
+      cy.wait('@firstError')
+      cy.getByTestId('retry-button').click()
+      cy.wait('@success')
+      cy.getByTestId('error-message').should('not.exist')
+    })
+  })
+
+  describe('Offline Detection', () => {
+    it('should show offline message when offline', () => {
+      cy.window().then(win => {
+        win.dispatchEvent(new Event('offline'))
+      })
+      cy.getByTestId('offline-banner').should('be.visible')
+    })
+
+    it('should hide offline message when online', () => {
+      cy.window().then(win => {
+        win.dispatchEvent(new Event('offline'))
+        win.dispatchEvent(new Event('online'))
+      })
+      cy.getByTestId('offline-banner').should('not.exist')
+    })
+  })
+
+  describe('Accessibility', () => {
+    it('should announce errors', () => {
+      cy.intercept('GET', '**/api/flights**', {
+        statusCode: 500,
+        body: { error: 'Error' },
+      }).as('error')
+      cy.getByTestId('search-button').click()
+      cy.wait('@error')
+      cy.getByTestId('error-message').should('have.attr', 'role', 'alert')
+    })
+  })
+})
diff --git a/e2e/cypress/integration/error-handling/performance.cy.ts b/e2e/cypress/integration/error-handling/performance.cy.ts
new file mode 100644
index 000000000..7d9273d86
--- /dev/null
+++ b/e2e/cypress/integration/error-handling/performance.cy.ts
@@ -0,0 +1,58 @@
+describe('Error Handling & Performance - Performance Tests', () => {
+  beforeEach(() => {
+    cy.visit('http://localhost:3001')
+  })
+
+  describe('Page Load Time', () => {
+    it('should load homepage quickly', () => {
+      cy.window().then(win => {
+        const perfData = win.performance.timing
+        const pageLoadTime = perfData.loadEventEnd - perfData.navigationStart
+        expect(pageLoadTime).to.be.lessThan(3000)
+      })
+    })
+
+    it('should display content before full load', () => {
+      cy.getByTestId('main-content').should('be.visible')
+    })
+
+    it('should lazy load images', () => {
+      cy.getByTestId('flight-item-image').should('have.attr', 'loading', 'lazy')
+    })
+  })
+
+  describe('Search Performance', () => {
+    it('should return search results quickly', () => {
+      cy.window().then(win => {
+        const start = win.performance.now()
+        cy.getByTestId('search-button').click()
+        cy.getByTestId('flight-item').should('have.length.greaterThan', 0)
+        cy.window().then(endWin => {
+          const end = endWin.performance.now()
+          expect(end - start).to.be.lessThan(2000)
+        })
+      })
+    })
+  })
+
+  describe('Memory Usage', () => {
+    it('should not leak memory on navigation', () => {
+      cy.visit('http://localhost:3001/flights')
+      cy.visit('http://localhost:3001/schedule')
+      cy.visit('http://localhost:3001/flights')
+      cy.window().then(win => {
+        expect(win.performance.memory).to.exist
+      })
+    })
+  })
+
+  describe('Rendering Performance', () => {
+    it('should render list without jank', () => {
+      cy.getByTestId('flight-list').should('be.visible')
+      cy.window().then(win => {
+        const fps = win.performance.getEntriesByName('flight-render')
+        expect(fps.length).to.be.greaterThan(0)
+      })
+    })
+  })
+})
diff --git a/e2e/cypress/integration/error-handling/session-timeout.cy.ts b/e2e/cypress/integration/error-handling/session-timeout.cy.ts
new file mode 100644
index 000000000..f748b7ce3
--- /dev/null
+++ b/e2e/cypress/integration/error-handling/session-timeout.cy.ts
@@ -0,0 +1,34 @@
+describe('Error Handling - Session Timeout', () => {
+  describe('Session Expiration', () => {
+    it('should show timeout warning before expiry', () => {
+      cy.visit('http://localhost:3001/booking')
+      cy.clock()
+      cy.tick(14 * 60 * 1000) // 14 minutes
+      cy.getByTestId('session-timeout-warning').should('be.visible')
+    })
+
+    it('should logout on timeout', () => {
+      cy.visit('http://localhost:3001/booking', { headers: { Authorization: 'Bearer token' } })
+      cy.clock()
+      cy.tick(16 * 60 * 1000) // 16 minutes
+      cy.url().should('include', '/login')
+    })
+
+    it('should allow extending session', () => {
+      cy.visit('http://localhost:3001/booking')
+      cy.clock()
+      cy.tick(14 * 60 * 1000)
+      cy.getByTestId('extend-session-button').click()
+      cy.getByTestId('session-timeout-warning').should('not.exist')
+    })
+  })
+
+  describe('Token Refresh', () => {
+    it('should refresh token automatically', () => {
+      cy.visit('http://localhost:3001/flights')
+      cy.window().then(win => {
+        expect(win.localStorage.getItem('auth_token')).to.exist
+      })
+    })
+  })
+})
diff --git a/e2e/cypress/integration/i18n/currency.cy.ts b/e2e/cypress/integration/i18n/currency.cy.ts
new file mode 100644
index 000000000..7e73a47a8
--- /dev/null
+++ b/e2e/cypress/integration/i18n/currency.cy.ts
@@ -0,0 +1,42 @@
+describe('i18n - Currency Formatting', () => {
+  beforeEach(() => {
+    cy.visit('http://localhost:3001/flights')
+  })
+
+  describe('Currency Display', () => {
+    it('should display prices with ruble symbol', () => {
+      cy.getByTestId('flight-price').should('contain', '₽')
+    })
+
+    it('should format large numbers', () => {
+      cy.getByTestId('flight-price').should('contain', '0')
+    })
+
+    it('should use correct decimal separator', () => {
+      cy.getByTestId('flight-price').then($el => {
+        const text = $el.text()
+        expect(text).to.match(/\d+[\s,]\d+/)
+      })
+    })
+
+    it('should add thousand separator', () => {
+      cy.getByTestId('large-price').then($el => {
+        const text = $el.text()
+        expect(text).to.match(/\d+\s\d+/)
+      })
+    })
+  })
+
+  describe('Price Formatting', () => {
+    it('should calculate total price correctly', () => {
+      cy.getByTestId('unit-price').then($unit => {
+        const unitPrice = parseFloat($unit.text())
+        cy.getByTestId('quantity').then($qty => {
+          const qty = parseInt($qty.text())
+          const expectedTotal = unitPrice * qty
+          cy.getByTestId('total-price').should('contain', expectedTotal.toString())
+        })
+      })
+    })
+  })
+})
diff --git a/e2e/cypress/integration/i18n/date-localization.cy.ts b/e2e/cypress/integration/i18n/date-localization.cy.ts
new file mode 100644
index 000000000..9e5c8c965
--- /dev/null
+++ b/e2e/cypress/integration/i18n/date-localization.cy.ts
@@ -0,0 +1,50 @@
+describe('i18n - Date & Time Localization', () => {
+  beforeEach(() => {
+    cy.visit('http://localhost:3001')
+  })
+
+  describe('Date Format', () => {
+    it('should format date in English', () => {
+      cy.getByTestId('language-selector').select('en')
+      cy.getByTestId('date-display').should('contain', 'May')
+    })
+
+    it('should format date in Russian', () => {
+      cy.getByTestId('language-selector').select('ru')
+      cy.getByTestId('date-display').should('contain', 'май')
+    })
+
+    it('should use correct date separator', () => {
+      cy.getByTestId('language-selector').select('en')
+      cy.getByTestId('date-value').then($el => {
+        const text = $el.text()
+        expect(text).to.match(/\d{1,2}\/\d{1,2}\/\d{4}/)
+      })
+    })
+  })
+
+  describe('Time Format', () => {
+    it('should format time correctly', () => {
+      cy.getByTestId('time-display').should('contain', ':')
+    })
+
+    it('should use 24-hour format', () => {
+      cy.getByTestId('language-selector').select('ru')
+      cy.getByTestId('time-value').should('match', /\d{2}:\d{2}/)
+    })
+  })
+
+  describe('Calendar Localization', () => {
+    it('should translate month names', () => {
+      cy.getByTestId('language-selector').select('ru')
+      cy.getByTestId('date-input').click()
+      cy.getByTestId('calendar-month').should('contain', 'май')
+    })
+
+    it('should translate day names', () => {
+      cy.getByTestId('language-selector').select('ru')
+      cy.getByTestId('date-input').click()
+      cy.getByTestId('calendar-day-header').should('contain', 'Пн')
+    })
+  })
+})
diff --git a/e2e/cypress/integration/i18n/language-switching.cy.ts b/e2e/cypress/integration/i18n/language-switching.cy.ts
new file mode 100644
index 000000000..265514965
--- /dev/null
+++ b/e2e/cypress/integration/i18n/language-switching.cy.ts
@@ -0,0 +1,51 @@
+describe('i18n - Language Switching', () => {
+  beforeEach(() => {
+    cy.visit('http://localhost:3001')
+  })
+
+  describe('Language Selection', () => {
+    it('should display language selector', () => {
+      cy.getByTestId('language-selector').should('be.visible')
+    })
+
+    it('should switch to English', () => {
+      cy.getByTestId('language-selector').select('en')
+      cy.getByTestId('page-title').should('contain', 'Flights')
+    })
+
+    it('should switch to Russian', () => {
+      cy.getByTestId('language-selector').select('ru')
+      cy.getByTestId('page-title').should('contain', 'Рейсы')
+    })
+
+    it('should persist language selection', () => {
+      cy.getByTestId('language-selector').select('ru')
+      cy.reload()
+      cy.getByTestId('language-selector').should('have.value', 'ru')
+    })
+  })
+
+  describe('Content Translation', () => {
+    it('should translate all labels', () => {
+      cy.getByTestId('language-selector').select('ru')
+      cy.getByTestId('search-button').should('contain', 'Поиск')
+    })
+
+    it('should translate form fields', () => {
+      cy.getByTestId('language-selector').select('ru')
+      cy.getByTestId('departure-input').should('have.attr', 'placeholder').and('contain', 'Из')
+    })
+
+    it('should translate error messages', () => {
+      cy.getByTestId('language-selector').select('ru')
+      cy.getByTestId('search-button').click()
+      cy.getByTestId('error-message').should('contain', 'обязательно')
+    })
+  })
+
+  describe('Accessibility', () => {
+    it('should have accessible language selector', () => {
+      cy.getByTestId('language-selector').should('have.attr', 'aria-label')
+    })
+  })
+})
diff --git a/e2e/cypress/integration/i18n/locale-persistence.cy.ts b/e2e/cypress/integration/i18n/locale-persistence.cy.ts
new file mode 100644
index 000000000..6724e99a6
--- /dev/null
+++ b/e2e/cypress/integration/i18n/locale-persistence.cy.ts
@@ -0,0 +1,50 @@
+describe('i18n - Locale Persistence', () => {
+  describe('Language Persistence', () => {
+    it('should persist language selection in localStorage', () => {
+      cy.visit('http://localhost:3001')
+      cy.getByTestId('language-selector').select('ru')
+      cy.window().then(win => {
+        expect(win.localStorage.getItem('lang')).to.equal('ru')
+      })
+    })
+
+    it('should restore language on page reload', () => {
+      cy.visit('http://localhost:3001')
+      cy.getByTestId('language-selector').select('ru')
+      cy.reload()
+      cy.getByTestId('language-selector').should('have.value', 'ru')
+      cy.getByTestId('page-title').should('contain', 'Рейсы')
+    })
+
+    it('should persist across different pages', () => {
+      cy.visit('http://localhost:3001')
+      cy.getByTestId('language-selector').select('ru')
+      cy.visit('http://localhost:3001/flights')
+      cy.getByTestId('language-selector').should('have.value', 'ru')
+    })
+
+    it('should set language from browser setting', () => {
+      cy.visit('http://localhost:3001')
+      cy.window().then(win => {
+        const navLang = win.navigator.language.split('-')[0]
+        expect(['en', 'ru']).to.include(navLang)
+      })
+    })
+  })
+
+  describe('Locale Preferences', () => {
+    it('should persist date format preference', () => {
+      cy.visit('http://localhost:3001')
+      cy.getByTestId('date-format-select').select('DD/MM/YYYY')
+      cy.reload()
+      cy.getByTestId('date-format-select').should('have.value', 'DD/MM/YYYY')
+    })
+
+    it('should persist timezone preference', () => {
+      cy.visit('http://localhost:3001')
+      cy.getByTestId('timezone-select').select('GMT+3')
+      cy.reload()
+      cy.getByTestId('timezone-select').should('have.value', 'GMT+3')
+    })
+  })
+})
diff --git a/e2e/cypress/integration/i18n/text-direction.cy.ts b/e2e/cypress/integration/i18n/text-direction.cy.ts
new file mode 100644
index 000000000..279479010
--- /dev/null
+++ b/e2e/cypress/integration/i18n/text-direction.cy.ts
@@ -0,0 +1,35 @@
+describe('i18n - Text Direction (RTL/LTR)', () => {
+  beforeEach(() => {
+    cy.visit('http://localhost:3001')
+  })
+
+  describe('Text Direction', () => {
+    it('should use LTR for English', () => {
+      cy.getByTestId('language-selector').select('en')
+      cy.get('html').should('have.attr', 'dir', 'ltr')
+    })
+
+    it('should mirror layout for RTL languages', () => {
+      cy.getByTestId('language-selector').select('ar')
+      cy.get('html').should('have.attr', 'dir', 'rtl')
+    })
+
+    it('should align text correctly', () => {
+      cy.getByTestId('language-selector').select('ar')
+      cy.getByTestId('main-content').should('have.css', 'text-align', 'right')
+    })
+  })
+
+  describe('Layout Mirroring', () => {
+    it('should mirror sidebar position', () => {
+      cy.viewport(1440, 900)
+      cy.getByTestId('language-selector').select('ar')
+      cy.getByTestId('sidebar').should('have.css', 'right', '0')
+    })
+
+    it('should mirror padding and margins', () => {
+      cy.getByTestId('language-selector').select('ar')
+      cy.getByTestId('main-content').should('have.css', 'margin-right')
+    })
+  })
+})
diff --git a/e2e/cypress/integration/navigation/404.cy.ts b/e2e/cypress/integration/navigation/404.cy.ts
new file mode 100644
index 000000000..c4f9ead84
--- /dev/null
+++ b/e2e/cypress/integration/navigation/404.cy.ts
@@ -0,0 +1,32 @@
+describe('Navigation - 404 Error Page', () => {
+  describe('404 Page Display', () => {
+    it('should show 404 for invalid route', () => {
+      cy.visit('http://localhost:3001/invalid-page', { failOnStatusCode: false })
+      cy.getByTestId('error-404-title').should('contain', '404')
+    })
+
+    it('should display error message', () => {
+      cy.visit('http://localhost:3001/invalid', { failOnStatusCode: false })
+      cy.getByTestId('error-message').should('be.visible')
+    })
+
+    it('should have back button', () => {
+      cy.visit('http://localhost:3001/invalid', { failOnStatusCode: false })
+      cy.getByTestId('back-button').click()
+      cy.url().should('not.include', 'invalid')
+    })
+
+    it('should have home link', () => {
+      cy.visit('http://localhost:3001/invalid', { failOnStatusCode: false })
+      cy.getByTestId('home-link').click()
+      cy.url().should('include', '/')
+    })
+  })
+
+  describe('Accessibility', () => {
+    it('should have proper heading', () => {
+      cy.visit('http://localhost:3001/invalid', { failOnStatusCode: false })
+      cy.getByTestId('error-heading').should('have.attr', 'role', 'heading')
+    })
+  })
+})
diff --git a/e2e/cypress/integration/navigation/back-forward.cy.ts b/e2e/cypress/integration/navigation/back-forward.cy.ts
new file mode 100644
index 000000000..95ca3e897
--- /dev/null
+++ b/e2e/cypress/integration/navigation/back-forward.cy.ts
@@ -0,0 +1,74 @@
+import { uiHelpers } from '../../support/helpers/ui-helpers'
+
+describe('Navigation - Browser Back/Forward', () => {
+  beforeEach(() => {
+    cy.visit('http://localhost:3001')
+  })
+
+  describe('Back Button', () => {
+    it('should go back in history', () => {
+      cy.visit('http://localhost:3001/flights')
+      cy.visit('http://localhost:3001/schedule')
+      cy.go('back')
+      cy.url().should('include', '/flights')
+    })
+
+    it('should disable back at start', () => {
+      cy.visit('http://localhost:3001')
+      cy.window().then(win => {
+        expect(win.history.length).to.equal(1)
+      })
+    })
+
+    it('should work multiple times', () => {
+      cy.visit('http://localhost:3001/flights')
+      cy.visit('http://localhost:3001/schedule')
+      cy.visit('http://localhost:3001/booking')
+      cy.go('back')
+      cy.go('back')
+      cy.url().should('include', '/flights')
+    })
+  })
+
+  describe('Forward Button', () => {
+    it('should go forward in history', () => {
+      cy.visit('http://localhost:3001/flights')
+      cy.visit('http://localhost:3001/schedule')
+      cy.go('back')
+      cy.go('forward')
+      cy.url().should('include', '/schedule')
+    })
+
+    it('should disable forward at end', () => {
+      cy.visit('http://localhost:3001/flights')
+      cy.go('forward')
+      cy.url().should('include', '/flights')
+    })
+  })
+
+  describe('History State', () => {
+    it('should preserve state on back', () => {
+      cy.visit('http://localhost:3001/flights')
+      cy.getByTestId('search-input').type('SVO')
+      cy.visit('http://localhost:3001/schedule')
+      cy.go('back')
+      cy.getByTestId('search-input').should('have.value', 'SVO')
+    })
+
+    it('should maintain scroll position', () => {
+      cy.visit('http://localhost:3001/flights')
+      cy.scrollTo('bottom')
+      cy.visit('http://localhost:3001/schedule')
+      cy.go('back')
+      cy.window().its('scrollY').should('be.greaterThan', 0)
+    })
+  })
+
+  describe('Accessibility', () => {
+    it('should announce navigation changes', () => {
+      cy.visit('http://localhost:3001/flights')
+      cy.go('back')
+      cy.getByTestId('page-title').should('have.attr', 'role', 'status')
+    })
+  })
+})
diff --git a/e2e/cypress/integration/navigation/breadcrumb.cy.ts b/e2e/cypress/integration/navigation/breadcrumb.cy.ts
new file mode 100644
index 000000000..256692d8a
--- /dev/null
+++ b/e2e/cypress/integration/navigation/breadcrumb.cy.ts
@@ -0,0 +1,31 @@
+describe('Navigation - Breadcrumb', () => {
+  describe('Breadcrumb Display', () => {
+    it('should display breadcrumbs', () => {
+      cy.visit('http://localhost:3001/flights/details')
+      cy.getByTestId('breadcrumb').should('be.visible')
+    })
+
+    it('should show correct path', () => {
+      cy.visit('http://localhost:3001/flights/SU123/details')
+      cy.getByTestId('breadcrumb-item').should('have.length.greaterThan', 1)
+    })
+
+    it('should navigate using breadcrumb', () => {
+      cy.visit('http://localhost:3001/flights/SU123/details')
+      cy.getByTestId('breadcrumb-link').first().click()
+      cy.url().should('not.include', 'details')
+    })
+  })
+
+  describe('Accessibility', () => {
+    it('should have navigation role', () => {
+      cy.visit('http://localhost:3001/flights/SU123/details')
+      cy.getByTestId('breadcrumb').should('have.attr', 'role', 'navigation')
+    })
+
+    it('should mark current page', () => {
+      cy.visit('http://localhost:3001/flights/SU123/details')
+      cy.getByTestId('breadcrumb-current').should('have.attr', 'aria-current')
+    })
+  })
+})
diff --git a/e2e/cypress/integration/navigation/links.cy.ts b/e2e/cypress/integration/navigation/links.cy.ts
new file mode 100644
index 000000000..f2d2d6912
--- /dev/null
+++ b/e2e/cypress/integration/navigation/links.cy.ts
@@ -0,0 +1,57 @@
+describe('Navigation - Link Navigation', () => {
+  beforeEach(() => {
+    cy.visit('http://localhost:3001')
+  })
+
+  describe('Internal Links', () => {
+    it('should navigate with internal link', () => {
+      cy.getByTestId('flights-link').click()
+      cy.url().should('include', '/flights')
+    })
+
+    it('should not reload page', () => {
+      let reloaded = false
+      cy.window().then(win => {
+        win.onbeforeunload = () => { reloaded = true }
+      })
+      cy.getByTestId('flights-link').click()
+      cy.window().then(win => {
+        expect(reloaded).to.be.false
+      })
+    })
+  })
+
+  describe('External Links', () => {
+    it('should have target blank', () => {
+      cy.getByTestId('external-link').should('have.attr', 'target', '_blank')
+    })
+
+    it('should have rel attribute', () => {
+      cy.getByTestId('external-link').should('have.attr', 'rel')
+    })
+  })
+
+  describe('Link States', () => {
+    it('should show visited state', () => {
+      cy.getByTestId('flights-link').click()
+      cy.go('back')
+      cy.getByTestId('flights-link').should('have.class', 'visited')
+    })
+
+    it('should show hover state', () => {
+      cy.getByTestId('flights-link').trigger('mouseenter')
+      cy.getByTestId('flights-link').should('have.class', 'hover')
+    })
+  })
+
+  describe('Accessibility', () => {
+    it('should have descriptive link text', () => {
+      cy.getByTestId('flights-link').should('contain', 'Flights')
+    })
+
+    it('should be keyboard accessible', () => {
+      cy.getByTestId('flights-link').focus().type('{enter}')
+      cy.url().should('include', '/flights')
+    })
+  })
+})
diff --git a/e2e/cypress/integration/navigation/routes.cy.ts b/e2e/cypress/integration/navigation/routes.cy.ts
new file mode 100644
index 000000000..36f471b1a
--- /dev/null
+++ b/e2e/cypress/integration/navigation/routes.cy.ts
@@ -0,0 +1,165 @@
+import { uiHelpers } from '../../support/helpers/ui-helpers'
+
+describe('Navigation - Routes & Links', () => {
+  beforeEach(() => {
+    cy.visit('http://localhost:3001')
+  })
+
+  describe('Navigation Links', () => {
+    it('should navigate to home page', () => {
+      cy.getByTestId('nav-home-link').click()
+      cy.url().should('include', '/')
+    })
+
+    it('should navigate to flights page', () => {
+      cy.getByTestId('nav-flights-link').click()
+      cy.url().should('include', '/flights')
+    })
+
+    it('should navigate to schedule page', () => {
+      cy.getByTestId('nav-schedule-link').click()
+      cy.url().should('include', '/schedule')
+    })
+
+    it('should navigate to booking page', () => {
+      cy.getByTestId('nav-booking-link').click()
+      cy.url().should('include', '/booking')
+    })
+
+    it('should navigate to account page', () => {
+      cy.getByTestId('nav-account-link').click()
+      cy.url().should('include', '/account')
+    })
+
+    it('should highlight active route', () => {
+      cy.getByTestId('nav-flights-link').click()
+      cy.getByTestId('nav-flights-link').should('have.class', 'active')
+    })
+  })
+
+  describe('Navigation Menu', () => {
+    it('should display navigation menu', () => {
+      cy.getByTestId('navigation-menu').should('be.visible')
+    })
+
+    it('should display all menu items', () => {
+      cy.getByTestId('menu-item').should('have.length.greaterThan', 3)
+    })
+
+    it('should show dropdown menu', () => {
+      cy.getByTestId('more-menu-button').click()
+      cy.getByTestId('dropdown-menu').should('be.visible')
+    })
+
+    it('should navigate from dropdown', () => {
+      cy.getByTestId('more-menu-button').click()
+      cy.getByTestId('dropdown-item').first().click()
+      cy.url().should('not.equal', 'http://localhost:3001/')
+    })
+  })
+
+  describe('Route Parameters', () => {
+    it('should pass route parameters', () => {
+      cy.visit('http://localhost:3001/flights/SU123')
+      cy.url().should('include', '/flights/SU123')
+    })
+
+    it('should load page with parameters', () => {
+      cy.visit('http://localhost:3001/booking/123')
+      cy.getByTestId('booking-id').should('contain', '123')
+    })
+
+    it('should handle query parameters', () => {
+      cy.visit('http://localhost:3001/flights?from=SVO&to=LED')
+      cy.url().should('include', 'from=SVO')
+      cy.url().should('include', 'to=LED')
+    })
+  })
+
+  describe('Breadcrumb Navigation', () => {
+    it('should display breadcrumbs', () => {
+      cy.visit('http://localhost:3001/flights/SU123/details')
+      cy.getByTestId('breadcrumb-list').should('be.visible')
+    })
+
+    it('should show current page in breadcrumb', () => {
+      cy.visit('http://localhost:3001/flights/SU123/details')
+      cy.getByTestId('breadcrumb-current').should('contain', 'Details')
+    })
+
+    it('should navigate using breadcrumb', () => {
+      cy.visit('http://localhost:3001/flights/SU123/details')
+      cy.getByTestId('breadcrumb-link').first().click()
+      cy.url().should('include', '/flights')
+    })
+  })
+
+  describe('Programmatic Navigation', () => {
+    it('should navigate with router', () => {
+      cy.window().then(win => {
+        win.router?.push('/flights')
+      })
+      cy.url().should('include', '/flights')
+    })
+
+    it('should go back', () => {
+      cy.visit('http://localhost:3001/flights')
+      cy.visit('http://localhost:3001/schedule')
+      cy.go('back')
+      cy.url().should('include', '/flights')
+    })
+
+    it('should go forward', () => {
+      cy.visit('http://localhost:3001/flights')
+      cy.visit('http://localhost:3001/schedule')
+      cy.go('back')
+      cy.go('forward')
+      cy.url().should('include', '/schedule')
+    })
+  })
+
+  describe('Link Opening', () => {
+    it('should open link in same tab', () => {
+      cy.getByTestId('nav-flights-link').click()
+      cy.url().should('include', '/flights')
+    })
+
+    it('should open external link', () => {
+      cy.getByTestId('external-link').should('have.attr', 'target', '_blank')
+    })
+
+    it('should not have blank target on internal links', () => {
+      cy.getByTestId('nav-flights-link').should('not.have.attr', 'target', '_blank')
+    })
+  })
+
+  describe('Error Routes', () => {
+    it('should show 404 page', () => {
+      cy.visit('http://localhost:3001/nonexistent', { failOnStatusCode: false })
+      cy.getByTestId('error-404-page').should('be.visible')
+    })
+
+    it('should have back button on error page', () => {
+      cy.visit('http://localhost:3001/nonexistent', { failOnStatusCode: false })
+      cy.getByTestId('error-back-button').click()
+      cy.url().should('not.include', '/nonexistent')
+    })
+  })
+
+  describe('Accessibility', () => {
+    it('should have accessible navigation', () => {
+      cy.getByTestId('navigation-menu').should('have.attr', 'role', 'navigation')
+    })
+
+    it('should announce active route', () => {
+      cy.getByTestId('nav-flights-link').click()
+      cy.getByTestId('nav-flights-link').should('have.attr', 'aria-current', 'page')
+    })
+
+    it('should support keyboard navigation', () => {
+      cy.getByTestId('nav-home-link').focus()
+      cy.getByTestId('nav-home-link').type('{tab}')
+      cy.getByTestId('nav-flights-link').should('have.focus')
+    })
+  })
+})
diff --git a/e2e/cypress/integration/responsive/desktop.cy.ts b/e2e/cypress/integration/responsive/desktop.cy.ts
new file mode 100644
index 000000000..c94f2f50a
--- /dev/null
+++ b/e2e/cypress/integration/responsive/desktop.cy.ts
@@ -0,0 +1,55 @@
+describe('Responsive - Desktop Layout (1440px)', () => {
+  beforeEach(() => {
+    cy.viewport(1440, 900)
+    cy.visit('http://localhost:3001')
+  })
+
+  describe('Layout', () => {
+    it('should display full layout', () => {
+      cy.getByTestId('header').should('be.visible')
+      cy.getByTestId('sidebar').should('be.visible')
+      cy.getByTestId('main-content').should('be.visible')
+    })
+
+    it('should display sidebar', () => {
+      cy.getByTestId('sidebar').should('not.have.css', 'display', 'none')
+    })
+
+    it('should display all navigation items', () => {
+      cy.getByTestId('nav-item').should('have.length.greaterThan', 3)
+    })
+
+    it('should display content without horizontal scroll', () => {
+      cy.window().then(win => {
+        expect(win.innerWidth).to.be.greaterThan(win.document.body.scrollWidth)
+      })
+    })
+
+    it('should have proper spacing', () => {
+      cy.getByTestId('main-content').should('have.css', 'margin-left')
+    })
+  })
+
+  describe('Components', () => {
+    it('should display buttons inline', () => {
+      cy.getByTestId('button-group').within(() => {
+        cy.getByTestId('button').each($btn => {
+          expect($btn).to.have.css('display')
+        })
+      })
+    })
+
+    it('should show multi-column layout', () => {
+      cy.getByTestId('grid-container').should('have.css', 'grid-template-columns')
+    })
+  })
+
+  describe('Accessibility', () => {
+    it('should be fully accessible', () => {
+      cy.getByTestId('header').should('have.attr', 'role')
+      cy.getByTestId('nav-item').each($item => {
+        cy.wrap($item).should('be.visible')
+      })
+    })
+  })
+})
diff --git a/e2e/cypress/integration/responsive/mobile.cy.ts b/e2e/cypress/integration/responsive/mobile.cy.ts
new file mode 100644
index 000000000..134e02da4
--- /dev/null
+++ b/e2e/cypress/integration/responsive/mobile.cy.ts
@@ -0,0 +1,49 @@
+describe('Responsive - Mobile Layout (375px)', () => {
+  beforeEach(() => {
+    cy.viewport(375, 667)
+    cy.visit('http://localhost:3001')
+  })
+
+  describe('Layout', () => {
+    it('should display mobile layout', () => {
+      cy.getByTestId('header').should('be.visible')
+      cy.getByTestId('main-content').should('be.visible')
+    })
+
+    it('should stack layout vertically', () => {
+      cy.getByTestId('page-layout').should('have.css', 'flex-direction', 'column')
+    })
+
+    it('should have full-width content', () => {
+      cy.getByTestId('main-content').should('have.css', 'width', '100%')
+    })
+
+    it('should not have horizontal scroll', () => {
+      cy.window().then(win => {
+        expect(win.document.body.scrollWidth).to.equal(win.innerWidth)
+      })
+    })
+  })
+
+  describe('Navigation', () => {
+    it('should show hamburger menu', () => {
+      cy.getByTestId('hamburger-menu').should('be.visible')
+    })
+
+    it('should hide sidebar by default', () => {
+      cy.getByTestId('sidebar').should('not.be.visible')
+    })
+
+    it('should show slide-out menu', () => {
+      cy.getByTestId('hamburger-menu').click()
+      cy.getByTestId('mobile-menu').should('be.visible')
+    })
+  })
+
+  describe('Touch Targets', () => {
+    it('should have proper touch target size', () => {
+      cy.getByTestId('button').should('have.css', 'min-height').and('not.equal', '0px')
+      cy.getByTestId('button').should('have.css', 'min-width').and('not.equal', '0px')
+    })
+  })
+})
diff --git a/e2e/cypress/integration/responsive/tablet.cy.ts b/e2e/cypress/integration/responsive/tablet.cy.ts
new file mode 100644
index 000000000..51ece06ba
--- /dev/null
+++ b/e2e/cypress/integration/responsive/tablet.cy.ts
@@ -0,0 +1,38 @@
+describe('Responsive - Tablet Layout (768px)', () => {
+  beforeEach(() => {
+    cy.viewport(768, 1024)
+    cy.visit('http://localhost:3001')
+  })
+
+  describe('Layout', () => {
+    it('should display tablet layout', () => {
+      cy.getByTestId('header').should('be.visible')
+      cy.getByTestId('main-content').should('be.visible')
+    })
+
+    it('should hide or collapse sidebar', () => {
+      cy.getByTestId('sidebar').should('not.be.visible')
+    })
+
+    it('should show hamburger menu', () => {
+      cy.getByTestId('hamburger-menu').should('be.visible')
+    })
+
+    it('should not have horizontal scroll', () => {
+      cy.window().then(win => {
+        expect(win.document.body.scrollWidth).to.be.lessThanOrEqual(win.innerWidth)
+      })
+    })
+  })
+
+  describe('Navigation', () => {
+    it('should open menu on hamburger click', () => {
+      cy.getByTestId('hamburger-menu').click()
+      cy.getByTestId('mobile-menu').should('be.visible')
+    })
+
+    it('should have touch-friendly spacing', () => {
+      cy.getByTestId('button').should('have.css', 'min-height', '48px')
+    })
+  })
+})
diff --git a/e2e/cypress/integration/responsive/touch-interactions.cy.ts b/e2e/cypress/integration/responsive/touch-interactions.cy.ts
new file mode 100644
index 000000000..5ef60254b
--- /dev/null
+++ b/e2e/cypress/integration/responsive/touch-interactions.cy.ts
@@ -0,0 +1,39 @@
+describe('Responsive - Touch Interactions', () => {
+  beforeEach(() => {
+    cy.viewport('iphone-x')
+    cy.visit('http://localhost:3001')
+  })
+
+  describe('Touch Targets', () => {
+    it('should have proper touch target size', () => {
+      cy.getByTestId('button').should('have.css', 'min-height', '48px')
+      cy.getByTestId('button').should('have.css', 'min-width', '48px')
+    })
+
+    it('should have adequate spacing between targets', () => {
+      cy.getByTestId('button').each(($btn, i) => {
+        if (i > 0) {
+          cy.wrap($btn).should('have.css', 'margin')
+        }
+      })
+    })
+  })
+
+  describe('Swipe Gestures', () => {
+    it('should handle swipe right', () => {
+      cy.getByTestId('carousel').swipe('right')
+      cy.getByTestId('carousel-item').first().should('not.be.visible')
+    })
+
+    it('should handle swipe left', () => {
+      cy.getByTestId('carousel').swipe('left')
+      cy.getByTestId('carousel-item').last().should('be.visible')
+    })
+  })
+
+  describe('Pinch Zoom', () => {
+    it('should allow pinch zoom on images', () => {
+      cy.getByTestId('zoomable-image').should('be.visible')
+    })
+  })
+})
diff --git a/e2e/cypress/integration/responsive/viewport-resize.cy.ts b/e2e/cypress/integration/responsive/viewport-resize.cy.ts
new file mode 100644
index 000000000..d0582bbb3
--- /dev/null
+++ b/e2e/cypress/integration/responsive/viewport-resize.cy.ts
@@ -0,0 +1,40 @@
+describe('Responsive - Viewport Resize', () => {
+  beforeEach(() => {
+    cy.visit('http://localhost:3001')
+  })
+
+  describe('Dynamic Resize', () => {
+    it('should adapt to viewport resize', () => {
+      cy.viewport(1440, 900)
+      cy.getByTestId('main-content').should('be.visible')
+      cy.viewport('iphone-x')
+      cy.getByTestId('hamburger-menu').should('be.visible')
+    })
+
+    it('should update layout on resize', () => {
+      cy.viewport(1440, 900)
+      cy.getByTestId('sidebar').should('be.visible')
+      cy.viewport(375, 667)
+      cy.getByTestId('sidebar').should('not.be.visible')
+    })
+
+    it('should maintain functionality after resize', () => {
+      cy.viewport(1440, 900)
+      cy.getByTestId('search-input').type('test')
+      cy.viewport('iphone-x')
+      cy.getByTestId('search-input').should('have.value', 'test')
+    })
+  })
+
+  describe('Orientation Change', () => {
+    it('should handle portrait orientation', () => {
+      cy.viewport('iphone-x', { orientation: 'portrait' })
+      cy.getByTestId('main-content').should('be.visible')
+    })
+
+    it('should handle landscape orientation', () => {
+      cy.viewport('iphone-x', { orientation: 'landscape' })
+      cy.getByTestId('main-content').should('be.visible')
+    })
+  })
+})