diff --git a/app/components/malio/select/SelectCheckbox.test.ts b/app/components/malio/select/SelectCheckbox.test.ts
index 8b87322..d3dd975 100644
--- a/app/components/malio/select/SelectCheckbox.test.ts
+++ b/app/components/malio/select/SelectCheckbox.test.ts
@@ -26,6 +26,7 @@ type SelectCheckboxProps = {
   displaySelectAll?: boolean
   selectAllLabel?: string
   disabled?: boolean
+  groupClass?: string
 }
 
 const SelectCheckboxForTest = SelectCheckbox as DefineComponent<SelectCheckboxProps>
@@ -175,4 +176,21 @@ describe('MalioSelectCheckbox', () => {
     const checkboxes = wrapper.findAll('input[type="checkbox"]')
     expect((checkboxes[0].element as HTMLInputElement).checked).toBe(false)
   })
+
+  it('applies minWidth via twMerge so it overrides w-full (parity with MalioSelect)', () => {
+    const wrapper = mount(SelectCheckboxForTest, {
+      props: {modelValue: [], options: [], minWidth: 'w-80'},
+    })
+    const root = wrapper.find('button').element.parentElement
+    expect(root?.className).toContain('w-80')
+    expect(root?.className).not.toContain('w-full')
+  })
+
+  it('applies groupClass via twMerge', () => {
+    const wrapper = mount(SelectCheckboxForTest, {
+      props: {modelValue: [], options: [], groupClass: 'mt-4'},
+    })
+    const root = wrapper.find('button').element.parentElement
+    expect(root?.className).toContain('mt-4')
+  })
 })
diff --git a/app/components/malio/select/SelectCheckbox.vue b/app/components/malio/select/SelectCheckbox.vue
index 401c79c..e987c63 100644
--- a/app/components/malio/select/SelectCheckbox.vue
+++ b/app/components/malio/select/SelectCheckbox.vue
@@ -2,8 +2,7 @@
   <div>
     <div
       ref="root"
-      class="relative w-full"
-      :class="[minWidth, maxWidth]"
+      :class="mergedGroupClass"
     >
     <button
       :id="buttonId"
@@ -26,7 +25,7 @@
                 ? openDirection === 'down'
                   ? 'rounded-b-none !border-2 !border-m-primary !border-b-0'
                   : 'rounded-t-none !border-2 !border-m-primary !border-t-0'
-            : isOptionSelected
+                : isOptionSelected
                   ? 'border-black'
                   : 'border-m-muted',
           disabled ? 'cursor-not-allowed border-m-muted text-black/60' : 'cursor-pointer',
@@ -45,7 +44,7 @@
         v-if="label"
         class="floating-label pointer-events-none absolute left-3 inline-block origin-left transition-transform duration-150 font-medium"
         :class="[
-          shouldFloatLabel ? 'top-2 z-30' : 'top-1/2 -translate-y-1/2',
+          isOpen ? 'top-2  z-30' : 'top-2',
           hasError
             ? 'text-m-danger'
             : hasSuccess
@@ -206,6 +205,7 @@
 <script setup lang="ts">
 import {computed, onBeforeUnmount, onMounted, ref, useId, nextTick} from 'vue'
 import {Icon as IconifyIcon} from '@iconify/vue'
+import {twMerge} from 'tailwind-merge'
 import Checkbox from '../checkbox/Checkbox.vue'
 
 defineOptions({name: 'MalioSelectCheckbox', inheritAttrs: false})
@@ -232,6 +232,7 @@ const props = withDefaults(defineProps<{
   displaySelectAll?: boolean
   selectAllLabel?: string
   disabled?: boolean
+  groupClass?: string
 }>(), {
   options: () => [],
   emptyOptionLabel: '',
@@ -249,6 +250,7 @@ const props = withDefaults(defineProps<{
   displaySelectAll: false,
   selectAllLabel: 'Tout sélectionner',
   disabled: false,
+  groupClass: '',
 })
 
 const emit = defineEmits<{
@@ -264,6 +266,9 @@ const listboxId = `custom-select-listbox-${uid}`
 const listRef = ref<HTMLElement | null>(null)
 const listHeight = ref(0)
 const normalizedOptions = computed<Option[]>(() => props.options)
+const mergedGroupClass = computed(() =>
+  twMerge('relative w-full', props.minWidth, props.maxWidth, props.groupClass),
+)
 const hasError = computed(() => !!props.error)
 const hasSuccess = computed(() => !!props.success && !hasError.value)
 const isOptionSelected = computed(() =>
@@ -281,6 +286,10 @@ const shouldFloatLabel = computed(() =>
 const selectionSummary = computed(() =>
   `${props.modelValue.length}/${normalizedOptions.value.length}`
 )
+const allSelected = computed(() =>
+  normalizedOptions.value.length > 0
+  && normalizedOptions.value.every(opt => props.modelValue.includes(opt.value)),
+)
 const describedBy = computed(() =>
   (hasError.value || hasSuccess.value || !!props.hint) ? `${buttonId}-describedby` : undefined,
 )
@@ -320,18 +329,22 @@ function open() {
 }
 
 const labelTransformStyle = computed(() => {
+  // label non flottant
   if (!shouldFloatLabel.value) {
-    return undefined
+    return {}
   }
 
+  // fermé ou ouverture vers le bas : comportement classique
   if (!isOpen.value || openDirection.value === 'down') {
     return {
       transform: 'translateY(-1.15rem) scale(0.9)',
     }
   }
 
+  // ouverture vers le haut : on remonte en fonction de la hauteur de la liste
   const extraOffset = 8 // marge visuelle au-dessus de la liste en px
-  const total = 4 + listHeight.value + extraOffset
+  const total = 4 +listHeight.value + extraOffset
+  // 18 ≈ 1.15rem pour garder la même base que votre flottant actuel
 
   return {
     transform: `translateY(-${total}px) scale(0.9)`,
@@ -351,19 +364,6 @@ function toggle() {
   open()
 }
 
-const allSelected = computed(() =>
-  normalizedOptions.value.length > 0
-  && normalizedOptions.value.every(opt => props.modelValue.includes(opt.value)),
-)
-
-function toggleAll() {
-  if (allSelected.value) {
-    emit('update:modelValue', [])
-  } else {
-    emit('update:modelValue', normalizedOptions.value.map(opt => opt.value))
-  }
-}
-
 function isChecked(value: string | number) {
   return props.modelValue.includes(value)
 }
@@ -373,10 +373,17 @@ function toggleOption(value: string | number) {
     emit('update:modelValue', props.modelValue.filter(item => item !== value))
     return
   }
-
   emit('update:modelValue', [...props.modelValue, value])
 }
 
+function toggleAll() {
+  if (allSelected.value) {
+    emit('update:modelValue', [])
+  } else {
+    emit('update:modelValue', normalizedOptions.value.map(opt => opt.value))
+  }
+}
+
 function onClickOutside(e: MouseEvent) {
   if (!root.value) return
   if (!root.value.contains(e.target as Node)) close()