diff --git a/src/App.tsx b/src/App.tsx
index 74b93be..624a7a8 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -19,6 +19,8 @@ import Settings from './components/settings';
 import LanguageSelector from './components/language-selector';
 import DisclaimerModal from './components/disclaimer-modal';
 import { Button } from './components/ui/button';
+import { TooltipProvider } from './components/ui/tooltip';
+import { IconButtonWithTooltip } from './components/ui/icon-button-with-tooltip';
 import { PROJECT_REPOSITORY_URL, APP_VERSION } from './constants/defaults';
 
 // Custom Hooks
@@ -100,19 +102,20 @@ const MedPlanAssistant = () => {
   } = useSimulation(appState);
 
   return (
-    <div className="min-h-screen bg-background p-4 sm:p-6 lg:p-8">
-      {/* Disclaimer Modal */}
-      <DisclaimerModal
-        isOpen={showDisclaimer}
-        onAccept={handleAcceptDisclaimer}
-        currentLanguage={currentLanguage}
-        onLanguageChange={changeLanguage}
-        t={t}
-      />
+    <TooltipProvider>
+      <div className="min-h-screen bg-background p-4 sm:p-6 lg:p-8">
+        {/* Disclaimer Modal */}
+        <DisclaimerModal
+          isOpen={showDisclaimer}
+          onAccept={handleAcceptDisclaimer}
+          currentLanguage={currentLanguage}
+          onLanguageChange={changeLanguage}
+          t={t}
+        />
 
-      <div className="max-w-7xl mx-auto">
-        <header className="mb-8">
-          <div className="flex justify-between items-start">
+        <div className="max-w-7xl mx-auto">
+          <header className="mb-8">
+            <div className="flex justify-between items-start">
             <div>
               <h1 className="text-3xl md:text-4xl font-bold tracking-tight">{t('appTitle')}</h1>
             </div>
@@ -147,15 +150,14 @@ const MedPlanAssistant = () => {
                   {t('both')}
                 </Button>
               </div>
-              <Button
+              <IconButtonWithTooltip
                 onClick={() => updateUiSetting('stickyChart', !uiSettings.stickyChart)}
+                icon={uiSettings.stickyChart ? <Pin size={16} /> : <PinOff size={16} />}
+                tooltip={uiSettings.stickyChart ? t('unpinChart') : t('pinChart')}
                 variant={uiSettings.stickyChart ? 'default' : 'outline'}
                 size="sm"
                 className="shrink-0"
-                title={uiSettings.stickyChart ? t('unpinChart') : t('pinChart')}
-              >
-                {uiSettings.stickyChart ? <Pin size={16} /> : <PinOff size={16} />}
-              </Button>
+              />
             </div>
 
             <SimulationChart
@@ -237,8 +239,9 @@ const MedPlanAssistant = () => {
             </div>
           </div>
         </footer>
+        </div>
       </div>
-    </div>
+    </TooltipProvider>
   );
 };
 
diff --git a/src/components/day-schedule.tsx b/src/components/day-schedule.tsx
index 5b94897..126cb81 100644
--- a/src/components/day-schedule.tsx
+++ b/src/components/day-schedule.tsx
@@ -14,7 +14,8 @@ import { Card, CardContent } from './ui/card';
 import { Badge } from './ui/badge';
 import { FormTimeInput } from './ui/form-time-input';
 import { FormNumericInput } from './ui/form-numeric-input';
-import { Tooltip, TooltipContent, TooltipProvider, TooltipTrigger } from './ui/tooltip';
+import { Tooltip, TooltipContent, TooltipTrigger } from './ui/tooltip';
+import { IconButtonWithTooltip } from './ui/icon-button-with-tooltip';
 import CollapsibleCardHeader from './ui/collapsible-card-header';
 import { Plus, Copy, Trash2, ArrowDownAZ, TrendingUp, TrendingDown } from 'lucide-react';
 import type { DayGroup } from '../constants/defaults';
@@ -116,25 +117,23 @@ const DaySchedule: React.FC<DayScheduleProps> = ({
             rightSection={
               <>
                 {canAddDay && (
-                  <Button
+                  <IconButtonWithTooltip
                     onClick={() => onAddDay(day.id)}
+                    icon={<Copy className="h-4 w-4" />}
+                    tooltip={t('cloneDay')}
                     size="sm"
                     variant="outline"
-                    title={t('cloneDay')}
-                  >
-                    <Copy className="h-4 w-4" />
-                  </Button>
+                  />
                 )}
                 {!day.isTemplate && (
-                  <Button
+                  <IconButtonWithTooltip
                     onClick={() => onRemoveDay(day.id)}
+                    icon={<Trash2 className="h-4 w-4" />}
+                    tooltip={t('removeDay')}
                     size="sm"
                     variant="outline"
                     className="border-destructive text-destructive hover:bg-destructive hover:text-destructive-foreground"
-                    title={t('removeDay')}
-                  >
-                    <Trash2 className="h-4 w-4" />
-                  </Button>
+                  />
                 )}
               </>
             }
@@ -143,58 +142,54 @@ const DaySchedule: React.FC<DayScheduleProps> = ({
               {t('day')} {dayIndex + 1}
             </Badge>
             {!day.isTemplate && doseCountDiff !== 0 ? (
-              <TooltipProvider>
-                <Tooltip>
-                  <TooltipTrigger asChild>
-                    <button
-                      type="button"
-                      className="inline-flex items-center cursor-help focus:outline-none focus:ring-2 focus:ring-ring focus:ring-offset-2 rounded-md"
+              <Tooltip>
+                <TooltipTrigger asChild>
+                  <button
+                    type="button"
+                    className="inline-flex items-center cursor-help focus:outline-none focus:ring-2 focus:ring-ring focus:ring-offset-2 rounded-md"
+                  >
+                    <Badge
+                      variant="outline"
+                      className={`text-xs ${doseCountDiff > 0 ? 'bg-blue-50' : 'bg-orange-50'}`}
                     >
-                      <Badge
-                        variant="outline"
-                        className={`text-xs ${doseCountDiff > 0 ? 'bg-blue-50' : 'bg-orange-50'}`}
-                      >
-                        {doseCountDiff > 0 ? <TrendingUp className="h-3 w-3 inline mr-1" /> : <TrendingDown className="h-3 w-3 inline mr-1" />}
-                        {day.doses.length} {day.doses.length === 1 ? t('dose') : t('doses')}
-                      </Badge>
-                    </button>
-                  </TooltipTrigger>
-                  <TooltipContent>
-                    <p className="text-xs">
-                      {doseCountDiff > 0 ? '+' : ''}{doseCountDiff} {Math.abs(doseCountDiff) === 1 ? t('dose') : t('doses')} {t('comparedToRegularPlan')}
-                    </p>
-                  </TooltipContent>
-                </Tooltip>
-              </TooltipProvider>
+                      {doseCountDiff > 0 ? <TrendingUp className="h-3 w-3 inline mr-1" /> : <TrendingDown className="h-3 w-3 inline mr-1" />}
+                      {day.doses.length} {day.doses.length === 1 ? t('dose') : t('doses')}
+                    </Badge>
+                  </button>
+                </TooltipTrigger>
+                <TooltipContent>
+                  <p className="text-xs">
+                    {doseCountDiff > 0 ? '+' : ''}{doseCountDiff} {Math.abs(doseCountDiff) === 1 ? t('dose') : t('doses')} {t('comparedToRegularPlan')}
+                  </p>
+                </TooltipContent>
+              </Tooltip>
             ) : (
               <Badge variant="outline" className="text-xs">
                 {day.doses.length} {day.doses.length === 1 ? t('dose') : t('doses')}
               </Badge>
             )}
             {!day.isTemplate && Math.abs(totalMgDiff) > 0.1 ? (
-              <TooltipProvider>
-                <Tooltip>
-                  <TooltipTrigger asChild>
-                    <button
-                      type="button"
-                      className="inline-flex items-center cursor-help focus:outline-none focus:ring-2 focus:ring-ring focus:ring-offset-2 rounded-md"
+              <Tooltip>
+                <TooltipTrigger asChild>
+                  <button
+                    type="button"
+                    className="inline-flex items-center cursor-help focus:outline-none focus:ring-2 focus:ring-ring focus:ring-offset-2 rounded-md"
+                  >
+                    <Badge
+                      variant="outline"
+                      className={`text-xs ${totalMgDiff > 0 ? 'bg-blue-50' : 'bg-orange-50'}`}
                     >
-                      <Badge
-                        variant="outline"
-                        className={`text-xs ${totalMgDiff > 0 ? 'bg-blue-50' : 'bg-orange-50'}`}
-                      >
-                        {totalMgDiff > 0 ? <TrendingUp className="h-3 w-3 inline mr-1" /> : <TrendingDown className="h-3 w-3 inline mr-1" />}
-                        {day.doses.reduce((sum, dose) => sum + (parseFloat(dose.ldx) || 0), 0).toFixed(1)} mg
-                      </Badge>
-                    </button>
-                  </TooltipTrigger>
-                  <TooltipContent>
-                    <p className="text-xs">
-                      {totalMgDiff > 0 ? '+' : ''}{totalMgDiff.toFixed(1)} mg {t('comparedToRegularPlan')}
-                    </p>
-                  </TooltipContent>
-                </Tooltip>
-              </TooltipProvider>
+                      {totalMgDiff > 0 ? <TrendingUp className="h-3 w-3 inline mr-1" /> : <TrendingDown className="h-3 w-3 inline mr-1" />}
+                      {day.doses.reduce((sum, dose) => sum + (parseFloat(dose.ldx) || 0), 0).toFixed(1)} mg
+                    </Badge>
+                  </button>
+                </TooltipTrigger>
+                <TooltipContent>
+                  <p className="text-xs">
+                    {totalMgDiff > 0 ? '+' : ''}{totalMgDiff.toFixed(1)} mg {t('comparedToRegularPlan')}
+                  </p>
+                </TooltipContent>
+              </Tooltip>
             ) : (
               <Badge variant="outline" className="text-xs">
                 {day.doses.reduce((sum, dose) => sum + (parseFloat(dose.ldx) || 0), 0).toFixed(1)} mg
@@ -207,31 +202,29 @@ const DaySchedule: React.FC<DayScheduleProps> = ({
             <div className="grid grid-cols-[120px_1fr_auto] gap-3 text-sm font-medium text-muted-foreground">
               <div className="flex items-center gap-2">
                 <span>{t('time')}</span>
-                <TooltipProvider>
-                  <Tooltip>
-                    <TooltipTrigger asChild>
-                      <Button
-                        type="button"
-                        size="sm"
-                        variant="ghost"
-                        className={
-                          isDaySorted(day)
-                            ? "h-6 w-6 p-0 text-muted-foreground hover:text-muted-foreground cursor-default"
-                            : "h-6 w-6 p-0 text-primary hover:text-primary hover:bg-primary/10"
-                        }
-                        onClick={() => !isDaySorted(day) && onSortDoses(day.id)}
-                        disabled={isDaySorted(day)}
-                      >
-                        <ArrowDownAZ className="h-4 w-4" />
-                      </Button>
-                    </TooltipTrigger>
-                    <TooltipContent>
-                      <p className="text-xs">
-                        {isDaySorted(day) ? t('sortByTimeSorted') : t('sortByTimeNeeded')}
-                      </p>
-                    </TooltipContent>
-                  </Tooltip>
-                </TooltipProvider>
+                <Tooltip>
+                  <TooltipTrigger asChild>
+                    <Button
+                      type="button"
+                      size="sm"
+                      variant="ghost"
+                      className={
+                        isDaySorted(day)
+                          ? "h-6 w-6 p-0 text-muted-foreground hover:text-muted-foreground cursor-default"
+                          : "h-6 w-6 p-0 text-primary hover:text-primary hover:bg-primary/10"
+                      }
+                      onClick={() => !isDaySorted(day) && onSortDoses(day.id)}
+                      disabled={isDaySorted(day)}
+                    >
+                      <ArrowDownAZ className="h-4 w-4" />
+                    </Button>
+                  </TooltipTrigger>
+                  <TooltipContent>
+                    <p className="text-xs">
+                      {isDaySorted(day) ? t('sortByTimeSorted') : t('sortByTimeNeeded')}
+                    </p>
+                  </TooltipContent>
+                </Tooltip>
               </div>
               <div>{t('ldx')} (mg)</div>
               <div></div>
@@ -267,16 +260,15 @@ const DaySchedule: React.FC<DayScheduleProps> = ({
                     errorMessage={t('errorNumberRequired')}
                     warningMessage={t('warningZeroDose')}
                   />
-                  <Button
+                  <IconButtonWithTooltip
                     onClick={() => onRemoveDose(day.id, dose.id)}
+                    icon={<Trash2 className="h-4 w-4" />}
+                    tooltip={t('removeDose')}
                     size="sm"
                     variant="ghost"
                     disabled={day.isTemplate && day.doses.length === 1}
                     className="h-9 w-9 p-0"
-                    title={t('removeDose')}
-                  >
-                    <Trash2 className="h-4 w-4" />
-                  </Button>
+                  />
                 </div>
               );
             })}
diff --git a/src/components/settings.tsx b/src/components/settings.tsx
index f8f9aec..198be09 100644
--- a/src/components/settings.tsx
+++ b/src/components/settings.tsx
@@ -15,7 +15,7 @@ import { Label } from './ui/label';
 import { Switch } from './ui/switch';
 import { Separator } from './ui/separator';
 import { Button } from './ui/button';
-import { Tooltip, TooltipContent, TooltipProvider, TooltipTrigger } from './ui/tooltip';
+import { Tooltip, TooltipContent, TooltipTrigger } from './ui/tooltip';
 import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from './ui/select';
 import { FormNumericInput } from './ui/form-numeric-input';
 import CollapsibleCardHeader from './ui/collapsible-card-header';
@@ -269,7 +269,6 @@ const Settings = ({
                 <Label htmlFor="showTemplateDay" className="font-medium">
                   {t('showTemplateDayInChart')}
                 </Label>
-                <TooltipProvider>
                   <Tooltip open={openTooltipId === 'showTemplateDay'} onOpenChange={(open) => setOpenTooltipId(open ? 'showTemplateDay' : null)}>
                     <TooltipTrigger asChild>
                       <button
@@ -286,7 +285,6 @@ const Settings = ({
                       <p className="text-xs max-w-xs">{tWithDefaults(t, 'showTemplateDayTooltip', defaultsForT)}</p>
                     </TooltipContent>
                   </Tooltip>
-                </TooltipProvider>
               </div>
             </div>
 
@@ -300,7 +298,6 @@ const Settings = ({
                 <Label htmlFor="showDayReferenceLines" className="font-medium">
                   {t('showDayReferenceLines')}
                 </Label>
-                <TooltipProvider>
                   <Tooltip open={openTooltipId === 'showDayReferenceLines'} onOpenChange={(open) => setOpenTooltipId(open ? 'showDayReferenceLines' : null)}>
                     <TooltipTrigger asChild>
                       <button
@@ -317,7 +314,6 @@ const Settings = ({
                       <p className="text-xs max-w-xs">{tWithDefaults(t, 'showDayReferenceLinesTooltip', defaultsForT)}</p>
                     </TooltipContent>
                   </Tooltip>
-                </TooltipProvider>
               </div>
             </div>
 
@@ -331,7 +327,6 @@ const Settings = ({
                 <Label htmlFor="showTherapeuticRange" className="font-medium">
                   {t('showTherapeuticRangeLines')}
                 </Label>
-                <TooltipProvider>
                   <Tooltip open={openTooltipId === 'showTherapeuticRangeLines'} onOpenChange={(open) => setOpenTooltipId(open ? 'showTherapeuticRangeLines' : null)}>
                     <TooltipTrigger asChild>
                       <button
@@ -348,7 +343,6 @@ const Settings = ({
                       <p className="text-xs max-w-xs">{tWithDefaults(t, 'showTherapeuticRangeLinesTooltip', defaultsForT)}</p>
                     </TooltipContent>
                   </Tooltip>
-                </TooltipProvider>
               </div>
               {showTherapeuticRange && (
                 <div className="ml-8 space-y-2">
@@ -356,7 +350,6 @@ const Settings = ({
                     <Label className="font-medium">
                       {t('therapeuticRange')}
                     </Label>
-                    <TooltipProvider>
                       <Tooltip open={openTooltipId === 'therapeuticRange'} onOpenChange={(open) => setOpenTooltipId(open ? 'therapeuticRange' : null)}>
                     <TooltipTrigger asChild>
                       <button
@@ -373,7 +366,6 @@ const Settings = ({
                           <p className="text-xs max-w-xs">{tWithDefaults(t, 'therapeuticRangeTooltip', defaultsForT)}</p>
                         </TooltipContent>
                       </Tooltip>
-                    </TooltipProvider>
                   </div>
                   <div className="flex flex-wrap items-center gap-2">
                     <FormNumericInput
@@ -406,7 +398,6 @@ const Settings = ({
             <div className="space-y-2">
               <div className="flex items-center gap-2">
                 <Label className="font-medium">{t('displayedDays')}</Label>
-                <TooltipProvider>
                   <Tooltip open={openTooltipId === 'displayedDays'} onOpenChange={(open) => setOpenTooltipId(open ? 'displayedDays' : null)}>
                     <TooltipTrigger asChild>
                       <button
@@ -423,7 +414,6 @@ const Settings = ({
                       <p className="text-xs max-w-xs">{tWithDefaults(t, 'displayedDaysTooltip', defaultsForT)}</p>
                     </TooltipContent>
                   </Tooltip>
-                </TooltipProvider>
               </div>
               <FormNumericInput
                 value={displayedDays}
@@ -440,7 +430,6 @@ const Settings = ({
             <div className="space-y-2">
               <div className="flex items-center gap-2">
                 <Label className="font-medium">{t('yAxisRange')}</Label>
-                <TooltipProvider>
                   <Tooltip open={openTooltipId === 'yAxisRange'} onOpenChange={(open) => setOpenTooltipId(open ? 'yAxisRange' : null)}>
                     <TooltipTrigger asChild>
                       <button
@@ -457,7 +446,6 @@ const Settings = ({
                       <p className="text-xs max-w-xs">{tWithDefaults(t, 'yAxisRangeTooltip', defaultsForT)}</p>
                     </TooltipContent>
                   </Tooltip>
-                </TooltipProvider>
               </div>
               <div className="flex flex-wrap items-center gap-2">
                 <FormNumericInput
@@ -487,7 +475,6 @@ const Settings = ({
 
             <div className="space-y-2">
               <Label className="font-medium">{t('xAxisTimeFormat')}</Label>
-              <TooltipProvider>
                 <Select
                   value={showDayTimeOnXAxis}
                   onValueChange={value => onUpdateUiSetting('showDayTimeOnXAxis', value)}
@@ -528,7 +515,6 @@ const Settings = ({
                     </Tooltip>
                   </SelectContent>
                 </Select>
-              </TooltipProvider>
             </div>
           </CardContent>
         )}
@@ -546,7 +532,6 @@ const Settings = ({
             <div className="space-y-2">
               <div className="flex items-center gap-2">
                 <Label className="font-medium">{t('simulationDuration')}</Label>
-                <TooltipProvider>
                   <Tooltip open={openTooltipId === 'simulationDuration'} onOpenChange={(open) => setOpenTooltipId(open ? 'simulationDuration' : null)}>
                     <TooltipTrigger asChild>
                       <button
@@ -563,7 +548,6 @@ const Settings = ({
                       <p className="text-xs max-w-xs">{tWithDefaults(t, 'simulationDurationTooltip', defaultsForT)}</p>
                     </TooltipContent>
                   </Tooltip>
-                </TooltipProvider>
               </div>
               <FormNumericInput
                 value={simulationDays}
@@ -598,7 +582,6 @@ const Settings = ({
                 <Label htmlFor="steadyStateDaysEnabled" className="font-medium">
                   {t('steadyStateDays')}
                 </Label>
-                <TooltipProvider>
                   <Tooltip open={openTooltipId === 'steadyStateDays'} onOpenChange={(open) => setOpenTooltipId(open ? 'steadyStateDays' : null)}>
                     <TooltipTrigger asChild>
                       <button
@@ -615,7 +598,6 @@ const Settings = ({
                       <p className="text-xs max-w-xs">{tWithDefaults(t, 'steadyStateDaysTooltip', defaultsForT)}</p>
                     </TooltipContent>
                   </Tooltip>
-                </TooltipProvider>
               </div>
               {steadyStateDaysEnabled && (
                 <div className="ml-8 space-y-2">
@@ -648,7 +630,6 @@ const Settings = ({
             <div className="space-y-2">
               <div className="flex items-center gap-2">
                 <Label className="font-medium">{t('halfLife')}</Label>
-                <TooltipProvider>
                   <Tooltip open={openTooltipId === 'halfLife'} onOpenChange={(open) => setOpenTooltipId(open ? 'halfLife' : null)}>
                     <TooltipTrigger asChild>
                       <button
@@ -665,7 +646,6 @@ const Settings = ({
                       <p className="text-xs max-w-xs">{renderTooltipWithLinks(tWithDefaults(t, 'halfLifeTooltip', defaultsForT))}</p>
                     </TooltipContent>
                   </Tooltip>
-                </TooltipProvider>
               </div>
               <FormNumericInput
                 value={pkParams.damph.halfLife}
@@ -688,7 +668,6 @@ const Settings = ({
             <div className="space-y-2">
               <div className="flex items-center gap-2">
                 <Label className="font-medium">{t('conversionHalfLife')}</Label>
-                <TooltipProvider>
                   <Tooltip open={openTooltipId === 'conversionHalfLife'} onOpenChange={(open) => setOpenTooltipId(open ? 'conversionHalfLife' : null)}>
                     <TooltipTrigger asChild>
                       <button
@@ -705,7 +684,6 @@ const Settings = ({
                       <p className="text-xs max-w-xs">{tWithDefaults(t, 'conversionHalfLifeTooltip', defaultsForT)}</p>
                     </TooltipContent>
                   </Tooltip>
-                </TooltipProvider>
               </div>
               <FormNumericInput
                 value={pkParams.ldx.halfLife}
@@ -724,7 +702,6 @@ const Settings = ({
             <div className="space-y-2">
               <div className="flex items-center gap-2">
                 <Label className="font-medium">{t('absorptionHalfLife')}</Label>
-                <TooltipProvider>
                   <Tooltip open={openTooltipId === 'absorptionHalfLife'} onOpenChange={(open) => setOpenTooltipId(open ? 'absorptionHalfLife' : null)}>
                     <TooltipTrigger asChild>
                       <button
@@ -741,7 +718,6 @@ const Settings = ({
                       <p className="text-xs max-w-xs">{tWithDefaults(t, 'absorptionHalfLifeTooltip', defaultsForT)}</p>
                     </TooltipContent>
                   </Tooltip>
-                </TooltipProvider>
               </div>
               <FormNumericInput
                 value={pkParams.ldx.absorptionHalfLife}
@@ -784,7 +760,6 @@ const Settings = ({
                 <Label htmlFor="weightBasedVdEnabled" className="font-medium">
                   {t('weightBasedVdScaling')}
                 </Label>
-                <TooltipProvider>
                   <Tooltip open={openTooltipId === 'weightBasedVd'} onOpenChange={(open) => setOpenTooltipId(open ? 'weightBasedVd' : null)}>
                     <TooltipTrigger asChild>
                       <button
@@ -801,13 +776,11 @@ const Settings = ({
                       <p className="text-xs max-w-xs">{tWithDefaults(t, 'weightBasedVdTooltip', defaultsForT)}</p>
                     </TooltipContent>
                   </Tooltip>
-                </TooltipProvider>
               </div>
               {pkParams.advanced.weightBasedVd.enabled && (
                 <div className="ml-8 space-y-2">
                   <div className="flex items-center gap-2">
                     <Label className="text-sm font-medium">{t('bodyWeight')}</Label>
-                    <TooltipProvider>
                       <Tooltip open={openTooltipId === 'bodyWeight'} onOpenChange={(open) => setOpenTooltipId(open ? 'bodyWeight' : null)}>
                     <TooltipTrigger asChild>
                       <button
@@ -824,7 +797,6 @@ const Settings = ({
                           <p className="text-xs max-w-xs">{renderTooltipWithLinks(tWithDefaults(t, 'bodyWeightTooltip', defaultsForT))}</p>
                         </TooltipContent>
                       </Tooltip>
-                    </TooltipProvider>
                   </div>
                   <FormNumericInput
                     value={pkParams.advanced.weightBasedVd.bodyWeight}
@@ -852,7 +824,6 @@ const Settings = ({
                 <Label htmlFor="foodEffectEnabled" className="font-medium">
                   {t('foodEffectEnabled')}
                 </Label>
-                <TooltipProvider>
                   <Tooltip open={openTooltipId === 'foodEffect'} onOpenChange={(open) => setOpenTooltipId(open ? 'foodEffect' : null)}>
                     <TooltipTrigger asChild>
                       <button
@@ -869,13 +840,11 @@ const Settings = ({
                       <p className="text-xs max-w-xs">{tWithDefaults(t, 'foodEffectTooltip', defaultsForT)}</p>
                     </TooltipContent>
                   </Tooltip>
-                </TooltipProvider>
               </div>
               {pkParams.advanced.foodEffect.enabled && (
                 <div className="ml-8 space-y-2">
                   <div className="flex items-center gap-2">
                     <Label className="text-sm font-medium">{t('tmaxDelay')}</Label>
-                    <TooltipProvider>
                       <Tooltip open={openTooltipId === 'tmaxDelay'} onOpenChange={(open) => setOpenTooltipId(open ? 'tmaxDelay' : null)}>
                     <TooltipTrigger asChild>
                       <button
@@ -892,7 +861,6 @@ const Settings = ({
                           <p className="text-xs max-w-xs">{renderTooltipWithLinks(tWithDefaults(t, 'tmaxDelayTooltip', defaultsForT))}</p>
                         </TooltipContent>
                       </Tooltip>
-                    </TooltipProvider>
                   </div>
                   <FormNumericInput
                     value={pkParams.advanced.foodEffect.tmaxDelay}
@@ -920,7 +888,6 @@ const Settings = ({
                 <Label htmlFor="urinePHEnabled" className="font-medium">
                   {t('urinePHTendency')}
                 </Label>
-                <TooltipProvider>
                   <Tooltip open={openTooltipId === 'urinePH'} onOpenChange={(open) => setOpenTooltipId(open ? 'urinePH' : null)}>
                     <TooltipTrigger asChild>
                       <button
@@ -937,13 +904,11 @@ const Settings = ({
                       <p className="text-xs max-w-xs">{tWithDefaults(t, 'urinePHTooltip', defaultsForT)}</p>
                     </TooltipContent>
                   </Tooltip>
-                </TooltipProvider>
               </div>
               {pkParams.advanced.urinePh.enabled && (
                 <div className="ml-8 space-y-2">
                   <div className="flex items-center gap-2">
                     <Label className="text-sm font-medium">{t('urinePHValue')}</Label>
-                    <TooltipProvider>
                       <Tooltip open={openTooltipId === 'urinePHValue'} onOpenChange={(open) => setOpenTooltipId(open ? 'urinePHValue' : null)}>
                     <TooltipTrigger asChild>
                       <button
@@ -960,7 +925,6 @@ const Settings = ({
                           <p className="text-xs max-w-xs">{tWithDefaults(t, 'urinePHValueTooltip', defaultsForT)}</p>
                         </TooltipContent>
                       </Tooltip>
-                    </TooltipProvider>
                   </div>
                   <FormNumericInput
                     value={pkParams.advanced.urinePh.phTendency}
@@ -981,7 +945,6 @@ const Settings = ({
             <div className="space-y-2">
               <div className="flex items-center gap-2">
                 <Label className="font-medium">{t('oralBioavailability')}</Label>
-                <TooltipProvider>
                   <Tooltip open={openTooltipId === 'oralBioavailability'} onOpenChange={(open) => setOpenTooltipId(open ? 'oralBioavailability' : null)}>
                     <TooltipTrigger asChild>
                       <button
@@ -998,7 +961,6 @@ const Settings = ({
                       <p className="text-xs max-w-xs">{renderTooltipWithLinks(tWithDefaults(t, 'oralBioavailabilityTooltip', defaultsForT))}</p>
                     </TooltipContent>
                   </Tooltip>
-                </TooltipProvider>
               </div>
               <FormNumericInput
                 value={pkParams.advanced.fOral}
diff --git a/src/components/simulation-chart.tsx b/src/components/simulation-chart.tsx
index 07fdff0..f4c4017 100644
--- a/src/components/simulation-chart.tsx
+++ b/src/components/simulation-chart.tsx
@@ -25,7 +25,6 @@ import {
   Tooltip as UiTooltip,
   TooltipTrigger as UiTooltipTrigger,
   TooltipContent as UiTooltipContent,
-  TooltipProvider as UiTooltipProvider,
 } from './ui/tooltip';
 
 // Chart color scheme
@@ -310,41 +309,39 @@ const chartDomain = React.useMemo(() => {
     ? scrollableWidth
     : Math.ceil((scrollableWidth / dispDays) * simDays);
 
+  // Render legend with tooltips for full names (custom legend renderer)
   const renderLegend = React.useCallback((props: any) => {
     const { payload } = props;
     if (!payload) return null;
 
     return (
-      <UiTooltipProvider>
-        <ul className="flex flex-wrap gap-2 text-xs leading-tight">
-          {payload.map((item: any) => {
-            const labelInfo = seriesLabels[item.dataKey] || { display: item.value, full: item.value };
-            const opacity = item.payload?.opacity ?? 1;
+      <ul className="flex flex-wrap gap-2 text-xs leading-tight">
+        {payload.map((item: any) => {
+          const labelInfo = seriesLabels[item.dataKey] || { display: item.value, full: item.value };
+          const opacity = item.payload?.opacity ?? 1;
 
-            return (
-              <li key={item.dataKey} className="flex items-center gap-1 max-w-[140px]">
-                <span
-                  className="inline-block w-3 h-3 rounded-sm"
-                  style={{ backgroundColor: item.color, opacity }}
-                />
-                <UiTooltip>
-                  <UiTooltipTrigger asChild>
-                    <span
-                      className="px-1 py-0.5 rounded-sm bg-white text-black shadow-sm border border-muted truncate inline-block max-w-[100px]"
-                      title={labelInfo.full}
-                    >
-                      {labelInfo.display}
-                    </span>
-                  </UiTooltipTrigger>
-                  <UiTooltipContent className="bg-white text-black shadow-md border max-w-xs">
-                    <span className="font-medium">{labelInfo.full}</span>
-                  </UiTooltipContent>
-                </UiTooltip>
-              </li>
-            );
-          })}
-        </ul>
-      </UiTooltipProvider>
+          return (
+            <li key={item.dataKey} className="flex items-center gap-1 max-w-[140px]">
+              <span
+                className="inline-block w-3 h-3 rounded-sm"
+                style={{ backgroundColor: item.color, opacity }}
+              />
+              <UiTooltip>
+                <UiTooltipTrigger asChild>
+                  <span
+                    className="px-1 py-0.5 rounded-sm bg-white text-black shadow-sm border border-muted truncate inline-block max-w-[100px]"
+                  >
+                    {labelInfo.display}
+                  </span>
+                </UiTooltipTrigger>
+                <UiTooltipContent className="bg-white text-black shadow-md border max-w-xs">
+                  <span className="font-medium">{labelInfo.full}</span>
+                </UiTooltipContent>
+              </UiTooltip>
+            </li>
+          );
+        })}
+      </ul>
     );
   }, [seriesLabels]);
 
diff --git a/src/components/ui/form-numeric-input.tsx b/src/components/ui/form-numeric-input.tsx
index fd25fd8..714e27b 100644
--- a/src/components/ui/form-numeric-input.tsx
+++ b/src/components/ui/form-numeric-input.tsx
@@ -11,6 +11,7 @@
 import * as React from "react"
 import { Minus, Plus, X } from "lucide-react"
 import { Button } from "./button"
+import { IconButtonWithTooltip } from "./icon-button-with-tooltip"
 import { Input } from "./input"
 import { cn } from "../../lib/utils"
 import { useTranslation } from "react-i18next"
@@ -199,8 +200,10 @@ const FormNumericInput = React.forwardRef<HTMLInputElement, NumericInputProps>(
             <Plus className="h-4 w-4" />
           </Button>
           {clearButton && allowEmpty && (
-            <Button
+            <IconButtonWithTooltip
               type="button"
+              icon={<X className="h-4 w-4" />}
+              tooltip={t('buttonClear')}
               variant="outline"
               size="icon"
               className={cn(
@@ -210,10 +213,7 @@ const FormNumericInput = React.forwardRef<HTMLInputElement, NumericInputProps>(
               )}
               onClick={() => onChange('')}
               tabIndex={-1}
-              title={ t('buttonClear') }
-            >
-              <X className="h-4 w-4" />
-            </Button>
+            />
           )}
         </div>
         {unit && <span className="text-sm text-muted-foreground whitespace-nowrap">{unit}</span>}
diff --git a/src/components/ui/icon-button-with-tooltip.tsx b/src/components/ui/icon-button-with-tooltip.tsx
new file mode 100644
index 0000000..8551a1e
--- /dev/null
+++ b/src/components/ui/icon-button-with-tooltip.tsx
@@ -0,0 +1,49 @@
+/**
+ * IconButtonWithTooltip
+ *
+ * A reusable button component that combines an icon button with a tooltip.
+ * Provides consistent tooltip behavior across the app for icon-only action buttons.
+ *
+ * @author Andreas Weyer
+ * @license MIT
+ */
+
+import React from 'react';
+import { Button, ButtonProps } from './button';
+import { Tooltip, TooltipContent, TooltipTrigger } from './tooltip';
+
+interface IconButtonWithTooltipProps extends Omit<ButtonProps, 'children'> {
+  /** The icon element to display in the button */
+  icon: React.ReactNode;
+  /** The tooltip text to show on hover */
+  tooltip: string;
+  /** Optional side for tooltip positioning */
+  tooltipSide?: 'top' | 'right' | 'bottom' | 'left';
+}
+
+export const IconButtonWithTooltip: React.FC<IconButtonWithTooltipProps> = ({
+  icon,
+  tooltip,
+  tooltipSide = 'top',
+  disabled,
+  ...buttonProps
+}) => {
+  return (
+    <Tooltip>
+      <TooltipTrigger asChild>
+        <Button
+          disabled={disabled}
+          aria-label={tooltip}
+          {...buttonProps}
+        >
+          {icon}
+        </Button>
+      </TooltipTrigger>
+      {!disabled && (
+        <TooltipContent side={tooltipSide}>
+          <p className="text-xs">{tooltip}</p>
+        </TooltipContent>
+      )}
+    </Tooltip>
+  );
+};