diff --git a/server.cjs b/server.cjs
index 0195fac..f4d3744 100644
--- a/server.cjs
+++ b/server.cjs
@@ -259,6 +259,7 @@ function ensureAnalyticsDb() {
       os text not null default 'Unknown',
       device text not null default 'Desktop',
       screen text not null default '',
+      theme text not null default 'light',
       language text not null default '',
       timezone text not null default '',
       country text not null default '',
@@ -284,6 +285,7 @@ function ensureAnalyticsDb() {
       os text not null default 'Unknown',
       device text not null default 'Desktop',
       screen text not null default '',
+      theme text not null default 'light',
       language text not null default '',
       timezone text not null default '',
       country text not null default '',
@@ -314,6 +316,8 @@ function ensureAnalyticsDb() {
     `alter table active_viewers add column latitude real`,
     `alter table viewer_events add column longitude real`,
     `alter table active_viewers add column longitude real`,
+    `alter table viewer_events add column theme text not null default 'light'`,
+    `alter table active_viewers add column theme text not null default 'light'`,
   ]) {
     try {
       analyticsDb.exec(statement)
@@ -578,6 +582,10 @@ function numberHeader(req, name, min, max) {
   return value
 }
 
+function sanitizeTheme(value) {
+  return value === 'dark' ? 'dark' : 'light'
+}
+
 const CITY_COORDINATE_OVERRIDES = new Map([
   ['GB|ENGLAND|MILTON KEYNES', { latitude: 52.0406, longitude: -0.7594 }],
 ])
@@ -969,6 +977,7 @@ function recordViewerEvent(req, payload) {
     os: sanitizeText(payload.os || (shareUserAgent ? serverClient.os : 'Not shared'), 80),
     device: sanitizeText(payload.device || (shareUserAgent ? serverClient.device : 'Not shared'), 80),
     screen: sanitizeText(payload.screen, 40),
+    theme: sanitizeTheme(payload.theme),
     language: sanitizeText(payload.language, 40),
     timezone: sanitizeText(payload.timezone, 80),
     country: location.country,
@@ -989,22 +998,22 @@ function recordViewerEvent(req, payload) {
     db.prepare(`
       insert into viewer_events
         (occurred_at, visitor_id, session_id, ip_hash, event_type, page_path, page_title,
-         referrer, user_agent, browser, os, device, screen, language, timezone,
+         referrer, user_agent, browser, os, device, screen, theme, language, timezone,
          country, region, city, latitude, longitude, consent, metadata)
       values
         (@occurred_at, @visitor_id, @session_id, @ip_hash, @event_type, @page_path, @page_title,
-         @referrer, @user_agent, @browser, @os, @device, @screen, @language, @timezone,
+         @referrer, @user_agent, @browser, @os, @device, @screen, @theme, @language, @timezone,
          @country, @region, @city, @latitude, @longitude, @consent, @metadata)
     `).run({ ...event, occurred_at: now })
 
     db.prepare(`
       insert into active_viewers
         (session_id, visitor_id, ip_hash, first_seen_at, last_seen_at, page_path, page_title,
-         referrer, user_agent, browser, os, device, screen, language, timezone,
+         referrer, user_agent, browser, os, device, screen, theme, language, timezone,
          country, region, city, latitude, longitude)
       values
         (@session_id, @visitor_id, @ip_hash, @now, @now, @page_path, @page_title,
-         @referrer, @user_agent, @browser, @os, @device, @screen, @language, @timezone,
+         @referrer, @user_agent, @browser, @os, @device, @screen, @theme, @language, @timezone,
          @country, @region, @city, @latitude, @longitude)
       on conflict(session_id) do update set
         last_seen_at = excluded.last_seen_at,
@@ -1016,6 +1025,7 @@ function recordViewerEvent(req, payload) {
         os = excluded.os,
         device = excluded.device,
         screen = excluded.screen,
+        theme = excluded.theme,
         language = excluded.language,
         timezone = excluded.timezone,
         country = excluded.country,
@@ -1077,6 +1087,7 @@ function viewerDashboard() {
       max(os) as os,
       max(device) as device,
       max(screen) as screen,
+      max(theme) as theme,
       max(language) as language,
       max(timezone) as timezone,
       max(country) as country,
@@ -1102,6 +1113,7 @@ function viewerDashboard() {
     os: row.os,
     device: row.device,
     screen: row.screen,
+    theme: sanitizeTheme(row.theme),
     language: row.language,
     timezone: row.timezone,
     country: row.country,
@@ -1121,12 +1133,14 @@ function viewerDashboard() {
       visitors: new Set(),
       clients: new Map(),
       countries: new Set(),
+      themes: new Map(),
       last_seen_at: viewer.last_seen_at,
     }
 
     existing.viewers += viewer.sessions || 1
     existing.visitors.add(viewer.visitor)
     if (viewer.country) existing.countries.add(viewer.country)
+    existing.themes.set(viewer.theme, (existing.themes.get(viewer.theme) || 0) + (viewer.sessions || 1))
     const clientKey = `${viewer.browser} on ${viewer.os}`
     existing.clients.set(clientKey, (existing.clients.get(clientKey) || 0) + 1)
     if (new Date(viewer.last_seen_at).getTime() > new Date(existing.last_seen_at).getTime()) {
@@ -1142,6 +1156,9 @@ function viewerDashboard() {
       viewers: page.viewers,
       visitors: page.visitors.size,
       countries: Array.from(page.countries).sort(),
+      themes: Array.from(page.themes.entries())
+        .sort((a, b) => b[1] - a[1] || a[0].localeCompare(b[0]))
+        .map(([theme, count]) => ({ theme, count })),
       clients: Array.from(page.clients.entries())
         .sort((a, b) => b[1] - a[1] || a[0].localeCompare(b[0]))
         .slice(0, 4)
@@ -1188,6 +1205,22 @@ function viewerDashboard() {
      limit 12
   `).all(thirtyDaysSince)
 
+  const themes = db.prepare(`
+    select theme, count(*) as events, count(distinct visitor_id) as visitors
+      from viewer_events
+     where occurred_at >= ?
+     group by theme
+     order by events desc
+  `).all(daySince).map((row) => ({ ...row, theme: sanitizeTheme(row.theme) }))
+
+  const themes30d = db.prepare(`
+    select theme, count(*) as events, count(distinct visitor_id) as visitors
+      from viewer_events
+     where occurred_at >= ?
+     group by theme
+     order by events desc
+  `).all(thirtyDaysSince).map((row) => ({ ...row, theme: sanitizeTheme(row.theme) }))
+
   const activity24h = db.prepare(`
     select
       substr(occurred_at, 1, 13) || ':00:00.000Z' as date,
@@ -1447,6 +1480,8 @@ function viewerDashboard() {
     top_pages_30d: topPages30d,
     clients,
     clients_30d: clients30d,
+    themes,
+    themes_30d: themes30d,
     activity_24h: activity24hWithLabels,
     activity_30d: activityWithLocations,
     countries_24h: countries24h,
diff --git a/src/App.jsx b/src/App.jsx
index 9043fb6..157530d 100644
--- a/src/App.jsx
+++ b/src/App.jsx
@@ -37,6 +37,8 @@ const analyticsPreferencesKey = 'tssbot.analyticsPreferences'
 const analyticsPreferencesCookie = 'tssbot_analytics_preferences'
 const analyticsVisitorKey = 'tssbot.analyticsVisitor'
 const analyticsConsentVersion = 3
+const themePreferenceKey = 'tssbot.theme'
+const themePreferenceCookie = 'tssbot_theme'
 const liveRefreshMs = 15000
 
 const turnstileSiteKey = import.meta.env.VITE_TURNSTILE_SITE_KEY || ''
@@ -193,6 +195,34 @@ function writeCookie(name, value) {
   }
 }
 
+function normalizeThemePreference(value) {
+  return value === 'dark' ? 'dark' : 'light'
+}
+
+function storedThemePreference() {
+  const cookieValue = readCookie(themePreferenceCookie)
+  if (cookieValue) return normalizeThemePreference(cookieValue)
+
+  try {
+    return normalizeThemePreference(window.localStorage.getItem(themePreferenceKey))
+  } catch {
+    return 'light'
+  }
+}
+
+function persistThemePreference(theme) {
+  const normalized = normalizeThemePreference(theme)
+  writeCookie(themePreferenceCookie, normalized)
+
+  try {
+    window.localStorage.setItem(themePreferenceKey, normalized)
+  } catch {
+    // Cookies still remember the theme when local storage is blocked.
+  }
+
+  return normalized
+}
+
 function storedAnalyticsPreferences() {
   const cookieValue = readCookie(analyticsPreferencesCookie)
   if (cookieValue) {
@@ -374,6 +404,98 @@ function Stat({ label, value }) {
   )
 }
 
+function ThemeToggle({ theme, onThemeChange }) {
+  const isDark = theme === 'dark'
+
+  return (
+    <button
+      aria-label={isDark ? 'Switch to light mode' : 'Switch to dark mode'}
+      aria-pressed={isDark}
+      className="grid h-9 w-9 shrink-0 place-items-center rounded-full border border-border bg-surface text-sm font-semibold text-text-soft transition hover:border-ring hover:text-text"
+      onClick={() => onThemeChange(isDark ? 'light' : 'dark')}
+      title={isDark ? 'Light mode' : 'Dark mode'}
+      type="button"
+    >
+      <span aria-hidden="true">{isDark ? '☾' : '☼'}</span>
+    </button>
+  )
+}
+
+function defaultThemeTogglePosition() {
+  const inset = window.innerWidth >= 640 ? 32 : 20
+  return {
+    x: window.innerWidth - inset - 36,
+    y: inset,
+  }
+}
+
+function themeToggleDockPosition(navPill) {
+  if (!navPill) return defaultThemeTogglePosition()
+
+  const width = navPill.offsetWidth
+  const height = navPill.offsetHeight
+  const left = (window.innerWidth - width) / 2
+  const top = 16
+
+  return {
+    x: Math.round(left + width - 48),
+    y: Math.round(top + (height - 36) / 2),
+  }
+}
+
+function ThemeToggleMover({ position, theme, onThemeChange }) {
+  const previousPositionRef = useRef(position)
+  const [motion, setMotion] = useState(() => ({
+    from: position,
+    to: position,
+    mid: position,
+    key: 0,
+    animate: false,
+  }))
+
+  useEffect(() => {
+    const from = previousPositionRef.current
+    const to = position
+    if (from.x === to.x && from.y === to.y) return
+
+    const distance = Math.hypot(to.x - from.x, to.y - from.y)
+    const lift = Math.min(96, Math.max(24, distance * 0.16))
+    const mid = {
+      x: Math.round((from.x + to.x) / 2),
+      y: Math.round(Math.min(from.y, to.y) - lift),
+    }
+
+    previousPositionRef.current = to
+    setMotion((current) => ({
+      from,
+      to,
+      mid,
+      key: current.key + 1,
+      animate: true,
+    }))
+  }, [position])
+
+  return (
+    <div
+      className={`theme-toggle-mover fixed left-0 top-0 z-[60] ${
+        motion.animate ? 'theme-toggle-mover-arc' : ''
+      }`}
+      key={motion.key}
+      style={{
+        '--from-x': `${motion.from.x}px`,
+        '--from-y': `${motion.from.y}px`,
+        '--mid-x': `${motion.mid.x}px`,
+        '--mid-y': `${motion.mid.y}px`,
+        '--to-x': `${motion.to.x}px`,
+        '--to-y': `${motion.to.y}px`,
+        transform: `translate3d(${motion.to.x}px, ${motion.to.y}px, 0)`,
+      }}
+    >
+      <ThemeToggle theme={theme} onThemeChange={onThemeChange} />
+    </div>
+  )
+}
+
 function TurnstileWidget({ siteKey, theme = 'auto', size = 'normal', action, onVerify, onExpire, onError, resetSignal = 0 }) {
   const containerRef = useRef(null)
   const widgetIdRef = useRef(null)
@@ -545,7 +667,9 @@ function AppContent() {
   const [uptime, setUptime] = useState({ status: 'idle', checks: [], history: [], updatedAt: null })
   const [viewers, setViewers] = useState({ status: 'idle', data: null, error: null, updatedAt: null })
   const [analyticsPreferences, setAnalyticsPreferences] = useState(() => storedAnalyticsPreferences())
+  const [theme, setTheme] = useState(() => storedThemePreference())
   const [showFloatingNav, setShowFloatingNav] = useState(() => window.scrollY > 40)
+  const [themeTogglePosition, setThemeTogglePosition] = useState(() => defaultThemeTogglePosition())
   const [teamQuery, setTeamQuery] = useState('')
   const [searchHint, setSearchHint] = useState({ status: 'idle', name: '' })
   const [teamSearchResults, setTeamSearchResults] = useState([])
@@ -561,11 +685,29 @@ function AppContent() {
   )
   const matches = live.data?.matches || []
   const liveRef = useRef(live)
+  const navPillRef = useRef(null)
+  const themeRef = useRef(theme)
+  const themeTransitionTimerRef = useRef(null)
 
   useEffect(() => {
     liveRef.current = live
   }, [live])
 
+  useEffect(() => {
+    themeRef.current = theme
+    document.documentElement.dataset.theme = theme
+    document.documentElement.style.colorScheme = theme
+    document.querySelector('meta[name="theme-color"]')?.setAttribute(
+      'content',
+      theme === 'dark' ? '#101211' : '#e82517',
+    )
+  }, [theme])
+
+  useEffect(() => () => {
+    window.clearTimeout(themeTransitionTimerRef.current)
+    document.documentElement.classList.remove('theme-transition')
+  }, [])
+
   function navigate(path, { replace = false } = {}) {
     if (replace) {
       window.history.replaceState({}, '', path)
@@ -647,6 +789,7 @@ function AppContent() {
           locale: localeDetails,
           referrer: referrerDetails,
           diagnostics: diagnosticsDetails,
+          theme: themeRef.current,
         },
       }
 
@@ -695,6 +838,7 @@ function AppContent() {
         screen: displayDetails ? `${window.screen.width}x${window.screen.height}` : '',
         language: localeDetails ? navigator.language : '',
         timezone: localeDetails ? Intl.DateTimeFormat().resolvedOptions().timeZone : '',
+        theme: themeRef.current,
         metadata,
       }
 
@@ -1150,6 +1294,16 @@ function AppContent() {
     setAnalyticsPreferences(nextPreferences)
   }
 
+  function chooseTheme(nextTheme) {
+    if (nextTheme === themeRef.current) return
+    window.clearTimeout(themeTransitionTimerRef.current)
+    document.documentElement.classList.add('theme-transition')
+    themeTransitionTimerRef.current = window.setTimeout(() => {
+      document.documentElement.classList.remove('theme-transition')
+    }, 460)
+    setTheme(persistThemePreference(nextTheme))
+  }
+
   const activeNavPath =
     route.page === 'team'
       ? '/teams'
@@ -1160,6 +1314,28 @@ function AppContent() {
         : window.location.pathname
   const shouldShowFloatingNav = route.page !== 'home' || showFloatingNav
 
+  useEffect(() => {
+    let frame = 0
+
+    function updateThemeTogglePosition() {
+      window.cancelAnimationFrame(frame)
+      frame = window.requestAnimationFrame(() => {
+        setThemeTogglePosition(
+          shouldShowFloatingNav
+            ? themeToggleDockPosition(navPillRef.current)
+            : defaultThemeTogglePosition(),
+        )
+      })
+    }
+
+    updateThemeTogglePosition()
+    window.addEventListener('resize', updateThemeTogglePosition)
+    return () => {
+      window.cancelAnimationFrame(frame)
+      window.removeEventListener('resize', updateThemeTogglePosition)
+    }
+  }, [route.page, shouldShowFloatingNav])
+
   return (
     <main className="min-h-screen bg-bg text-text">
       <header
@@ -1168,7 +1344,10 @@ function AppContent() {
           : 'pointer-events-none -translate-y-8 opacity-0'
           }`}
       >
-        <div className="flex max-w-[calc(100vw-2rem)] items-center gap-2 rounded-full border border-border bg-fury-white/92 px-2 py-2 shadow-[0_12px_36px_rgba(0,0,0,0.16)] backdrop-blur sm:px-3">
+        <div
+          className="flex max-w-[calc(100vw-2rem)] items-center gap-2 rounded-full border border-border bg-fury-white/92 py-2 pl-2 pr-13 shadow-[0_12px_36px_rgba(0,0,0,0.16)] backdrop-blur sm:pl-3"
+          ref={navPillRef}
+        >
           <button
             className="hidden shrink-0 rounded-full px-3 py-2 text-sm font-bold tracking-tight transition hover:bg-surface hover:text-fury-cyan sm:block"
             onClick={() => navigate('/')}
@@ -1181,7 +1360,7 @@ function AppContent() {
             {navItems.map((item) => (
               <button
                 className={`shrink-0 rounded-full px-3 py-2 text-sm font-semibold transition ${activeNavPath === item.path
-                  ? 'bg-text text-bg'
+                  ? 'bg-text text-bg apricot-button-text'
                   : 'text-text-soft hover:bg-surface hover:text-text'
                   }`}
                 key={item.path}
@@ -1194,6 +1373,11 @@ function AppContent() {
           </nav>
         </div>
       </header>
+      <ThemeToggleMover
+        position={themeTogglePosition}
+        theme={theme}
+        onThemeChange={chooseTheme}
+      />
 
       <section className="mx-auto w-full max-w-7xl px-5 sm:px-8">
         {route.page === 'home' ? (
@@ -1514,9 +1698,9 @@ function PrivacyPage() {
 
       <div className="mt-8 grid gap-6 text-sm leading-6 text-text-soft">
         <PrivacySection title="What we collect">
-          Necessary cookies store your cookie and analytics choices. If you opt in to
+          Necessary cookies store your cookie, theme, and analytics choices. If you opt in to
           viewer analytics, we collect page views, live viewing status, a pseudonymous
-          visitor ID, and a session ID. Optional settings control whether browser/device,
+          visitor ID, a session ID, and the active light/dark theme. Optional settings control whether browser/device,
           screen, language/timezone, referrer, and technical diagnostics are included.
           Technical diagnostics can include HTTP version, request protocol details,
           content negotiation headers, browser privacy signals, network quality, touch
@@ -1524,7 +1708,7 @@ function PrivacyPage() {
         </PrivacySection>
 
         <PrivacySection title="Why we collect it">
-          Necessary cookies are used to remember your privacy choices. Optional viewer
+          Necessary cookies are used to remember your privacy and theme choices. Optional viewer
           analytics are used only to power the public viewers page, understand basic site
           activity, and keep abuse low.
         </PrivacySection>
@@ -1601,7 +1785,7 @@ function Landing({
             <div className="mt-8 w-full max-w-xl">
               <div className="grid gap-4 sm:grid-cols-3">
                 <button
-                  className="min-h-15 rounded-lg bg-text px-5 py-4 text-base font-semibold text-bg transition hover:bg-fury-cyan"
+                  className="apricot-button-text min-h-15 rounded-lg bg-text px-5 py-4 text-base font-semibold text-bg transition hover:bg-fury-cyan"
                   onClick={() => navigate('/teams')}
                   type="button"
                 >
@@ -1809,7 +1993,7 @@ function LandingTrustSection({ navigate }) {
 
         <div className="flex flex-wrap gap-3 lg:justify-end">
           <a
-            className="rounded-lg bg-text px-5 py-3 text-sm font-semibold text-bg transition hover:bg-fury-cyan"
+            className="apricot-button-text rounded-lg bg-text px-5 py-3 text-sm font-semibold text-bg transition hover:bg-fury-cyan"
             href="https://sre.pawjob.us/"
           >
             Visit SREBOT
@@ -1894,10 +2078,16 @@ function RecentGamesSection({ live, matches, navigate }) {
   )
 }
 
-let cachedPixelMountainsCanvas = null
+const cachedPixelMountainsCanvases = new Map()
 
-function renderPixelMountainsCanvas() {
-  if (cachedPixelMountainsCanvas) return cachedPixelMountainsCanvas
+function renderPixelMountainsCanvas(theme = 'light') {
+  const isDark = theme === 'dark'
+  const palette =
+    isDark
+      ? ['#332614', '#4c341b', '#68431f', '#8a5824']
+      : ['#fcfbcf', '#fff2e6', '#fee5cd', '#fdca9b']
+  const cached = cachedPixelMountainsCanvases.get(theme)
+  if (cached) return cached
 
   const canvas = document.createElement('canvas')
   const ctx = canvas.getContext('2d')
@@ -1952,7 +2142,7 @@ function renderPixelMountainsCanvas() {
           [width * 0.86, height * 0.56],
           [width, height * 0.64],
         ],
-        '#fcfbcf',
+        palette[0],
         1.1,
       )
 
@@ -1968,7 +2158,7 @@ function renderPixelMountainsCanvas() {
           [width * 0.78, height * 0.48],
           [width, height * 0.5],
         ],
-        '#fff2e6',
+        palette[1],
         1.6,
       )
 
@@ -1984,7 +2174,7 @@ function renderPixelMountainsCanvas() {
           [width * 0.84, height * 0.7],
           [width, height * 0.68],
         ],
-        '#fee5cd',
+        palette[2],
         2.1,
       )
 
@@ -1999,31 +2189,90 @@ function renderPixelMountainsCanvas() {
           [width * 0.86, height * 0.95],
           [width, height * 0.93],
         ],
-        '#fdca9b',
+        palette[3],
         1.4,
       )
   }
 
   draw()
-  cachedPixelMountainsCanvas = canvas
+  cachedPixelMountainsCanvases.set(theme, canvas)
   return canvas
 }
 
 function PixelMountains() {
-  const canvasRef = useRef(null)
+  const [activeTheme, setActiveTheme] = useState(() =>
+    document.documentElement.dataset.theme === 'dark' ? 'dark' : 'light',
+  )
+  const [previousTheme, setPreviousTheme] = useState(null)
+  const [skyTransition, setSkyTransition] = useState('')
+  const activeCanvasRef = useRef(null)
+  const previousCanvasRef = useRef(null)
+  const fadeTimerRef = useRef(null)
+  const skyTimerRef = useRef(null)
 
-  useEffect(() => {
-    const canvas = canvasRef.current
-    const source = renderPixelMountainsCanvas()
+  function drawCanvas(canvas, theme) {
+    if (!canvas || !theme) return
+    const source = renderPixelMountainsCanvas(theme)
     const ctx = canvas.getContext('2d')
 
     canvas.width = source.width
     canvas.height = source.height
     ctx.imageSmoothingEnabled = false
     ctx.drawImage(source, 0, 0)
+  }
+
+  useEffect(() => {
+    drawCanvas(activeCanvasRef.current, activeTheme)
+  }, [activeTheme])
+
+  useEffect(() => {
+    drawCanvas(previousCanvasRef.current, previousTheme)
+  }, [previousTheme])
+
+  useEffect(() => {
+    function syncTheme() {
+      const theme = document.documentElement.dataset.theme === 'dark' ? 'dark' : 'light'
+      setActiveTheme((current) => {
+        if (theme === current) return current
+        window.clearTimeout(fadeTimerRef.current)
+        window.clearTimeout(skyTimerRef.current)
+        setPreviousTheme(current)
+        setSkyTransition(`${current}-to-${theme}`)
+        fadeTimerRef.current = window.setTimeout(() => setPreviousTheme(null), 440)
+        skyTimerRef.current = window.setTimeout(() => setSkyTransition(''), 900)
+        return theme
+      })
+    }
+
+    syncTheme()
+    const observer = new MutationObserver(syncTheme)
+    observer.observe(document.documentElement, { attributes: true, attributeFilter: ['data-theme'] })
+    return () => {
+      observer.disconnect()
+      window.clearTimeout(fadeTimerRef.current)
+      window.clearTimeout(skyTimerRef.current)
+    }
   }, [])
 
-  return <canvas ref={canvasRef} className="pixel-mountains" aria-hidden="true" />
+  return (
+    <div className="pixel-mountains" aria-hidden="true">
+      <div className={`pixel-sky pixel-sky-${skyTransition || activeTheme}`}>
+        <span className="pixel-sun" />
+        <span className="pixel-moon">
+          <span className="pixel-star pixel-star-a" />
+          <span className="pixel-star pixel-star-b" />
+          <span className="pixel-star pixel-star-c" />
+        </span>
+      </div>
+      {previousTheme ? (
+        <canvas
+          className="pixel-mountains-previous"
+          ref={previousCanvasRef}
+        />
+      ) : null}
+      <canvas className="pixel-mountains-active" ref={activeCanvasRef} />
+    </div>
+  )
 }
 
 function TeamsPage({ leaderboard, navigate, teams }) {
@@ -2456,9 +2705,9 @@ function MiniLineChart({
           <span>0</span>
         </div>
         <svg className="ml-8 h-28 w-[calc(100%-2rem)] overflow-visible" viewBox={`0 0 ${width} ${height}`} role="img" aria-label={`${label} line chart`}>
-        <path d={`M ${padding} ${height - padding} H ${width - padding}`} fill="none" stroke="#fee5cd" strokeWidth="1" />
-        <path d={`M ${padding} ${padding} H ${width - padding}`} fill="none" stroke="#fee5cd" strokeDasharray="4 5" strokeWidth="1" />
-        <path d={`M ${padding} ${height / 2} H ${width - padding}`} fill="none" stroke="#fee5cd" strokeDasharray="4 5" strokeWidth="1" />
+        <path d={`M ${padding} ${height - padding} H ${width - padding}`} fill="none" stroke="var(--color-border)" strokeWidth="1" />
+        <path d={`M ${padding} ${padding} H ${width - padding}`} fill="none" stroke="var(--color-border)" strokeDasharray="4 5" strokeWidth="1" />
+        <path d={`M ${padding} ${height / 2} H ${width - padding}`} fill="none" stroke="var(--color-border)" strokeDasharray="4 5" strokeWidth="1" />
         <path d={pathData} fill="none" stroke={stroke} strokeLinecap="round" strokeLinejoin="round" strokeWidth="3" />
         {points.map((point) => (
           <circle
@@ -2577,7 +2826,7 @@ function AnalyticsPeriodSection({
           label="Clients"
           metric="clients"
           pointFormat={pointFormat}
-          stroke="#000000"
+          stroke="var(--color-text)"
         />
         <MiniLineChart
           accent="text-fury-cyan"
@@ -2612,6 +2861,7 @@ function ViewersPage({ viewers }) {
       activity: activity24h,
       topPages: data.top_pages || [],
       clients: data.clients || [],
+      themes: data.themes || [],
       countries: data.countries_24h || [],
       locations: data.locations_24h || [],
       totals: {
@@ -2630,6 +2880,7 @@ function ViewersPage({ viewers }) {
       activity: activity30d,
       topPages: data.top_pages_30d || data.top_pages || [],
       clients: data.clients_30d || [],
+      themes: data.themes_30d || data.themes || [],
       countries: data.countries || [],
       locations: data.locations || [],
       totals: {
@@ -2660,7 +2911,7 @@ function ViewersPage({ viewers }) {
               {Object.entries(periods).map(([key, period]) => (
                 <button
                   className={`rounded px-3 py-1.5 transition ${
-                    analyticsWindow === key ? 'bg-fury-red text-fury-cyan shadow-sm' : 'text-text-soft hover:text-text'
+                    analyticsWindow === key ? 'bg-text text-bg apricot-button-text shadow-sm' : 'text-text-soft hover:text-text'
                   }`}
                   key={key}
                   onClick={() => setAnalyticsWindow(key)}
@@ -2726,6 +2977,11 @@ function ViewersPage({ viewers }) {
                     {country}
                   </span>
                 ))}
+                {(page.themes || []).map((theme) => (
+                  <span className="rounded-md bg-surface px-2 py-1" key={theme.theme}>
+                    {theme.theme} theme ({formatNumber(theme.count)})
+                  </span>
+                ))}
               </div>
             </div>
             <div className="grid grid-cols-2 gap-2 text-right sm:grid-cols-1">
@@ -2763,7 +3019,7 @@ function ViewersPage({ viewers }) {
                 {viewer.browser} on {viewer.os}
               </p>
               <p className="truncate text-xs text-text-soft">
-                {viewer.device} · {viewer.screen || 'unknown screen'} · {viewer.country || viewer.timezone || 'unknown location'}
+                {viewer.device} · {viewer.screen || 'unknown screen'} · {viewer.theme || 'light'} theme · {viewer.country || viewer.timezone || 'unknown location'}
               </p>
             </div>
             <p className="text-text-soft">{viewer.language || 'unknown language'}</p>
@@ -2820,6 +3076,34 @@ function ViewersPage({ viewers }) {
         </div>
       </div>
 
+      <div className="rounded-lg border border-border bg-fury-white shadow-sm">
+        <div className="border-b border-surface px-5 py-4">
+          <h2 className="text-lg font-semibold">Themes</h2>
+          <p className="mt-1 text-sm text-text-soft">Light and dark mode usage over {periodData.title.toLowerCase()}</p>
+        </div>
+        <div className="grid gap-3 p-5 sm:grid-cols-2">
+          {periodData.themes.map((theme) => {
+            const totalEvents = periodData.themes.reduce((sum, item) => sum + Number(item.events || 0), 0) || 1
+            const percent = Math.round((Number(theme.events || 0) / totalEvents) * 100)
+            return (
+              <div className="rounded-md border border-border bg-surface p-4" key={theme.theme}>
+                <div className="flex items-center justify-between gap-3">
+                  <p className="text-sm font-semibold capitalize">{theme.theme} mode</p>
+                  <p className="text-sm font-semibold text-fury-cyan">{percent}%</p>
+                </div>
+                <div className="mt-3 h-2 overflow-hidden rounded-full bg-bg">
+                  <div className="h-full rounded-full bg-fury-cyan" style={{ width: `${percent}%` }} />
+                </div>
+                <p className="mt-3 text-xs text-text-soft">
+                  {formatNumber(theme.visitors || 0)} visitors · {formatNumber(theme.events || 0)} events
+                </p>
+              </div>
+            )
+          })}
+          {!periodData.themes.length ? <p className="text-sm text-text-soft">No theme data recorded yet</p> : null}
+        </div>
+      </div>
+
       <div className="grid gap-6 xl:grid-cols-[0.9fr_1.1fr]">
         <div className="rounded-lg border border-border bg-fury-white shadow-sm">
           <div className="border-b border-surface px-5 py-4">
diff --git a/src/styles.css b/src/styles.css
index 0dd55b1..83ae0f8 100644
--- a/src/styles.css
+++ b/src/styles.css
@@ -82,6 +82,33 @@
     --color-danger: #e82517;
   }
 
+:root[data-theme="dark"] {
+  --color-bg: #130d08;
+  --color-surface: #24170d;
+  --color-surface-alt: #34210f;
+  --color-fury-white: #18100a;
+  --color-fury-ice: #24170d;
+  --color-fury-blue: #34210f;
+  --color-fury-glow: #a86224;
+  --color-fury-cyan: #ff6a5f;
+  --color-fury-aqua: #ff8d84;
+  --color-fury-violet: #ffac4d;
+  --color-text: #fdb068;
+  --color-text-soft: #fff2e6;
+  --color-text-muted: #fee5cd;
+  --color-border: #68401f;
+  --color-ring: #ff8d84;
+  --color-shadow: rgba(255, 106, 95, 0.18);
+  --color-success: #58f0f5;
+  --color-warning: #f4ee3e;
+  --color-danger: #ff6a5f;
+  color-scheme: dark;
+}
+
+:root[data-theme="light"] {
+  color-scheme: light;
+}
+
 @font-face {
   font-display: swap;
   font-family: "SF Pro Text Local";
@@ -164,6 +191,7 @@ body {
   margin: 0;
   min-width: 320px;
   min-height: 100vh;
+  background: var(--color-bg);
   font-family:
     "SF Pro Rounded Local", "SF Pro Rounded", "SF Pro Text Local",
     "SF Pro Text", -apple-system, BlinkMacSystemFont, "Segoe UI", Inter,
@@ -179,6 +207,15 @@ h3 {
 }
 
 .pixel-mountains {
+  position: absolute;
+  inset: 0;
+  width: 100%;
+  height: 100%;
+  pointer-events: none;
+  z-index: 0;
+}
+
+.pixel-mountains canvas {
   position: absolute;
   inset: 0;
   width: 100%;
@@ -186,16 +223,205 @@ h3 {
   image-rendering: pixelated;
   object-fit: cover;
   object-position: center bottom;
-  pointer-events: none;
+  transition: opacity 420ms ease;
+}
+
+.pixel-mountains-previous {
+  animation: pixelMountainsFadeOut 420ms ease forwards;
+  z-index: 1;
+}
+
+.pixel-mountains-active {
   z-index: 0;
 }
 
+.pixel-sky {
+  position: absolute;
+  inset: 0;
+  pointer-events: none;
+  z-index: 2;
+}
+
+.pixel-sun,
+.pixel-moon {
+  position: absolute;
+  display: block;
+  image-rendering: pixelated;
+  transform: translate(-50%, -50%);
+  will-change: left, opacity, top, transform;
+}
+
+.pixel-sun {
+  left: 78%;
+  top: 18%;
+  width: 88px;
+  height: 88px;
+  background: #fdb068;
+  clip-path: polygon(
+    36% 0,
+    64% 0,
+    64% 12%,
+    84% 12%,
+    84% 36%,
+    100% 36%,
+    100% 64%,
+    84% 64%,
+    84% 84%,
+    64% 84%,
+    64% 100%,
+    36% 100%,
+    36% 84%,
+    12% 84%,
+    12% 64%,
+    0 64%,
+    0 36%,
+    12% 36%,
+    12% 12%,
+    36% 12%
+  );
+  box-shadow:
+    0 -36px 0 -28px #fdb068,
+    0 36px 0 -28px #fdb068,
+    -36px 0 0 -28px #fdb068,
+    36px 0 0 -28px #fdb068,
+    28px 28px 0 -30px #fdb068,
+    -28px 28px 0 -30px #fdb068,
+    28px -28px 0 -30px #fdb068,
+    -28px -28px 0 -30px #fdb068;
+}
+
+.pixel-sun::after {
+  position: absolute;
+  left: 18px;
+  top: 18px;
+  width: 24px;
+  height: 24px;
+  background: #fff2e6;
+  clip-path: polygon(25% 0, 75% 0, 75% 25%, 100% 25%, 100% 75%, 75% 75%, 75% 100%, 25% 100%, 25% 75%, 0 75%, 0 25%, 25% 25%);
+  content: "";
+}
+
+.pixel-moon {
+  left: 78%;
+  top: 18%;
+  width: 80px;
+  height: 80px;
+  background: #fff2e6;
+  clip-path: polygon(
+    35% 0,
+    72% 0,
+    72% 12%,
+    88% 12%,
+    88% 28%,
+    100% 28%,
+    100% 72%,
+    88% 72%,
+    88% 88%,
+    72% 88%,
+    72% 100%,
+    35% 100%,
+    35% 88%,
+    18% 88%,
+    18% 72%,
+    0 72%,
+    0 28%,
+    18% 28%,
+    18% 12%,
+    35% 12%
+  );
+}
+
+.pixel-moon::after {
+  position: absolute;
+  left: 30px;
+  top: -8px;
+  width: 74px;
+  height: 74px;
+  background: var(--color-bg);
+  clip-path: polygon(
+    35% 0,
+    72% 0,
+    72% 12%,
+    88% 12%,
+    88% 28%,
+    100% 28%,
+    100% 72%,
+    88% 72%,
+    88% 88%,
+    72% 88%,
+    72% 100%,
+    35% 100%,
+    35% 88%,
+    18% 88%,
+    18% 72%,
+    0 72%,
+    0 28%,
+    18% 28%,
+    18% 12%,
+    35% 12%
+  );
+  content: "";
+}
+
+.pixel-star {
+  position: absolute;
+  display: block;
+  width: 6px;
+  height: 6px;
+  background: #fee5cd;
+}
+
+.pixel-star-a {
+  right: -68px;
+  top: -32px;
+}
+
+.pixel-star-b {
+  left: -92px;
+  top: 22px;
+}
+
+.pixel-star-c {
+  right: -116px;
+  top: 54px;
+}
+
+.pixel-sky-light .pixel-sun,
+.pixel-sky-dark .pixel-moon {
+  opacity: 1;
+}
+
+.pixel-sky-light .pixel-moon,
+.pixel-sky-dark .pixel-sun {
+  opacity: 0;
+}
+
+.pixel-sky-light-to-dark .pixel-sun {
+  animation: sunSetWest 980ms cubic-bezier(0.55, 0.085, 0.68, 0.53) forwards;
+}
+
+.pixel-sky-light-to-dark .pixel-moon {
+  animation: moonRiseEast 980ms cubic-bezier(0.25, 0.46, 0.45, 0.94) forwards;
+}
+
+.pixel-sky-dark-to-light .pixel-moon {
+  animation: moonSetWest 980ms cubic-bezier(0.55, 0.085, 0.68, 0.53) forwards;
+}
+
+.pixel-sky-dark-to-light .pixel-sun {
+  animation: sunRiseEast 980ms cubic-bezier(0.25, 0.46, 0.45, 0.94) forwards;
+}
+
+:root[data-theme="dark"] .pixel-mountains {
+  opacity: 1;
+}
+
 .tree {
   width: min(100%, 500px);
   height: auto;
   display: block;
-  background: #fefde7;
-  border: 3px solid #fdca9b;
+  background: var(--color-fury-white);
+  border: 3px solid var(--color-border);
   border-radius: 16px;
   padding: 12px;
   box-shadow:
@@ -203,6 +429,30 @@ h3 {
     0 1px 3px rgba(50, 25, 1, 0.08);
 }
 
+:root[data-theme="dark"] .apricot-button-text {
+  color: #fff2e6;
+}
+
+:root[data-theme="dark"] .tree {
+  filter: brightness(0.78) sepia(0.18) saturate(0.92);
+  box-shadow:
+    0 4px 24px rgba(255, 106, 95, 0.14),
+    0 1px 3px rgba(0, 0, 0, 0.35);
+}
+
+.theme-toggle-mover-arc {
+  animation: themeToggleArc 560ms cubic-bezier(0.22, 1, 0.36, 1) forwards;
+}
+
+:root.theme-transition,
+:root.theme-transition *,
+:root.theme-transition *::before,
+:root.theme-transition *::after {
+  transition-duration: 420ms;
+  transition-property: background-color, border-color, box-shadow, color, fill, opacity, stroke, text-decoration-color;
+  transition-timing-function: ease;
+}
+
 .falling-leaves {
   position: absolute;
   inset: 0;
@@ -227,3 +477,107 @@ h3 {
     opacity: 0;
   }
 }
+
+@keyframes pixelMountainsFadeOut {
+  from {
+    opacity: 1;
+  }
+
+  to {
+    opacity: 0;
+  }
+}
+
+@keyframes themeToggleArc {
+  0% {
+    transform: translate3d(var(--from-x), var(--from-y), 0);
+  }
+
+  50% {
+    transform: translate3d(var(--mid-x), var(--mid-y), 0);
+  }
+
+  100% {
+    transform: translate3d(var(--to-x), var(--to-y), 0);
+  }
+}
+
+@keyframes sunSetWest {
+  0% {
+    left: 78%;
+    opacity: 1;
+    top: 18%;
+  }
+
+  42% {
+    left: 48%;
+    opacity: 0.85;
+    top: 9%;
+  }
+
+  100% {
+    left: 12%;
+    opacity: 0;
+    top: 68%;
+  }
+}
+
+@keyframes moonRiseEast {
+  0% {
+    left: 93%;
+    opacity: 0;
+    top: 68%;
+  }
+
+  55% {
+    left: 86%;
+    opacity: 0.86;
+    top: 8%;
+  }
+
+  100% {
+    left: 78%;
+    opacity: 1;
+    top: 18%;
+  }
+}
+
+@keyframes moonSetWest {
+  0% {
+    left: 78%;
+    opacity: 1;
+    top: 18%;
+  }
+
+  42% {
+    left: 48%;
+    opacity: 0.85;
+    top: 9%;
+  }
+
+  100% {
+    left: 12%;
+    opacity: 0;
+    top: 68%;
+  }
+}
+
+@keyframes sunRiseEast {
+  0% {
+    left: 93%;
+    opacity: 0;
+    top: 68%;
+  }
+
+  55% {
+    left: 86%;
+    opacity: 0.86;
+    top: 8%;
+  }
+
+  100% {
+    left: 78%;
+    opacity: 1;
+    top: 18%;
+  }
+}