diff --git a/packages/stage-ui/src/components/misc/container-error.story.vue b/packages/stage-ui/src/components/misc/container-error.story.vue
new file mode 100644
index 000000000..521aa21c8
--- /dev/null
+++ b/packages/stage-ui/src/components/misc/container-error.story.vue
@@ -0,0 +1,58 @@
+<script setup lang="ts">
+import { ContainerError } from '@proj-airi/ui'
+import { ref } from 'vue'
+
+const actionLog = ref('No action yet')
+
+const sampleError = new Error('Request failed with status code 500')
+
+function noteCopy(content: string) {
+  actionLog.value = `Copied ${content.length} characters`
+}
+
+function noteFeedback() {
+  actionLog.value = 'Feedback action clicked'
+}
+</script>
+
+<template>
+  <Story
+    title="Error Message Panel"
+    group="misc"
+    :layout="{ type: 'grid', width: '100%' }"
+  >
+    <template #controls>
+      <ThemeColorsHueControl />
+    </template>
+
+    <Variant
+      id="message-only"
+      title="Message Only"
+    >
+      <div class="max-w-3xl">
+        <ContainerError message="Unable to load project settings. Please try again." />
+      </div>
+    </Variant>
+
+    <Variant
+      id="with-stack"
+      title="With Stack Trace"
+    >
+      <div class="max-w-3xl">
+        <ContainerError :error="sampleError" height-preset="lg" />
+      </div>
+    </Variant>
+
+    <Variant
+      id="actions"
+      title="Action Callbacks"
+    >
+      <div class="max-w-3xl flex flex-col gap-3">
+        <ContainerError :error="sampleError" @copy="noteCopy" @feedback="noteFeedback" />
+        <div class="text-sm text-neutral-600 dark:text-neutral-300">
+          {{ actionLog }}
+        </div>
+      </div>
+    </Variant>
+  </Story>
+</template>
diff --git a/packages/ui/package.json b/packages/ui/package.json
index 41af94b65..eed775264 100644
--- a/packages/ui/package.json
+++ b/packages/ui/package.json
@@ -26,6 +26,7 @@
     "typecheck": "vue-tsc --noEmit"
   },
   "dependencies": {
+    "@moeru/std": "catalog:",
     "@vueuse/core": "^14.2.1",
     "floating-vue": "^5.2.2",
     "reka-ui": "^2.9.2",
diff --git a/packages/ui/src/components/misc/button.vue b/packages/ui/src/components/misc/button.vue
index 80ed26203..2497cc29e 100644
--- a/packages/ui/src/components/misc/button.vue
+++ b/packages/ui/src/components/misc/button.vue
@@ -19,6 +19,7 @@ interface ButtonProps {
   loading?: boolean // Loading state
   variant?: ButtonVariant // Button style variant
   size?: ButtonSize // Button size variant
+  shape?: 'rounded' | 'pill' | 'square' // Button shape
   theme?: ButtonTheme // Button theme
   block?: boolean // Full width button
 }
@@ -127,9 +128,21 @@ const variantClasses: Record<ButtonVariant, Record<ButtonTheme, {
 
 // Extract size styles for better organization
 const sizeClasses: Record<ButtonSize, string> = {
-  sm: 'px-3 py-1.5 text-xs',
-  md: 'px-4 py-2 text-sm',
-  lg: 'px-6 py-3 text-base',
+  sm: props.shape === 'pill'
+    ? 'px-3 py-1.5 text-xs'
+    : props.shape === 'square'
+      ? 'p-2 text-xs'
+      : 'px-4 py-2 text-sm',
+  md: props.shape === 'pill'
+    ? 'px-4 py-2 text-sm'
+    : props.shape === 'square'
+      ? 'p-3 text-sm'
+      : 'px-5 py-3 text-base',
+  lg: props.shape === 'pill'
+    ? 'px-6 py-3 text-base'
+    : props.shape === 'square'
+      ? 'p-4 text-base'
+      : 'px-6 py-3 text-base',
 }
 
 // Base classes that are always applied
diff --git a/packages/ui/src/components/misc/container-error.vue b/packages/ui/src/components/misc/container-error.vue
new file mode 100644
index 000000000..1f6427d88
--- /dev/null
+++ b/packages/ui/src/components/misc/container-error.vue
@@ -0,0 +1,219 @@
+<script setup lang="ts">
+import { errorCauseFrom, errorMessageFrom, errorNameFrom, errorStackFrom } from '@moeru/std'
+import { ScrollAreaCorner, ScrollAreaRoot, ScrollAreaScrollbar, ScrollAreaThumb, ScrollAreaViewport } from 'reka-ui'
+import { computed, shallowRef } from 'vue'
+
+import Button from './button.vue'
+
+type HeightPreset = 'sm' | 'md' | 'lg' | 'xl' | 'auto'
+
+interface ContainerErrorProps {
+  error?: unknown
+  message?: string
+  stack?: string
+  includeStack?: boolean
+  showCopyButton?: boolean
+  showFeedbackButton?: boolean
+  copyButtonLabel?: string
+  copiedButtonLabel?: string
+  feedbackButtonLabel?: string
+  heightPreset?: HeightPreset
+}
+
+const props = withDefaults(defineProps<ContainerErrorProps>(), {
+  includeStack: true,
+  showCopyButton: true,
+  showFeedbackButton: true,
+  copyButtonLabel: 'Copy',
+  copiedButtonLabel: 'Copied',
+  feedbackButtonLabel: 'Feedback',
+  heightPreset: 'md',
+})
+
+const emit = defineEmits<{
+  (e: 'copy', content: string): void
+  (e: 'feedback'): void
+}>()
+
+const copied = shallowRef(false)
+
+const heightPresetClasses: Record<HeightPreset, string[]> = {
+  sm: ['h-32'],
+  md: ['h-36'],
+  lg: ['h-42'],
+  xl: ['h-48'],
+  auto: [],
+}
+
+function indentLines(content: string, indent = 2): string {
+  const spaces = ' '.repeat(indent)
+  return content
+    .split('\n')
+    .map(line => `${spaces}${line}`)
+    .join('\n')
+}
+
+const resolvedErrorName = computed(() => {
+  return (errorNameFrom(props.error) ?? '').trim()
+})
+
+const resolvedMessage = computed(() => {
+  const fromProp = props.message?.trim()
+  if (fromProp)
+    return fromProp
+
+  const normalizedMessage = errorMessageFrom(props.error)
+  if (normalizedMessage)
+    return normalizedMessage.trim()
+
+  return props.error == null ? '' : String(props.error).trim()
+})
+
+const resolvedStack = computed(() => {
+  const fromProp = props.stack?.trim()
+  if (fromProp) {
+    const index = fromProp.indexOf(resolvedMessage.value)
+    if (index >= 0)
+      return fromProp.slice(index + resolvedMessage.value.length).trim()
+  }
+
+  if (!props.includeStack)
+    return ''
+
+  const resolved = (errorStackFrom(props.error) ?? '').trim()
+  const index = resolved.indexOf(resolvedMessage.value)
+  if (index >= 0)
+    return resolved.slice(index + resolvedMessage.value.length).trim()
+
+  return resolved
+})
+
+const resolvedCause = computed(() => {
+  if (props.error == null)
+    return ''
+
+  const cause = errorCauseFrom(props.error)
+  if (cause == null)
+    return ''
+
+  if (cause instanceof Error) {
+    const name = errorNameFrom(cause) ?? cause.name ?? 'Error'
+    const message = (errorMessageFrom(cause) ?? cause.message ?? '').trim()
+    const stack = (errorStackFrom(cause) ?? cause.stack ?? '').trim()
+
+    const header = message ? `${name}: ${message}` : name
+    if (!stack)
+      return header
+
+    return `${header}\n${indentLines(stack, 2)}`
+  }
+
+  return String(cause).trim()
+})
+
+const panelContent = computed(() => {
+  const sections: string[] = []
+
+  if (resolvedErrorName.value || resolvedMessage.value) {
+    const header = resolvedErrorName.value
+      ? (resolvedMessage.value ? `${resolvedErrorName.value}: ${resolvedMessage.value}` : resolvedErrorName.value)
+      : resolvedMessage.value
+    if (header)
+      sections.push(header)
+  }
+
+  if (resolvedStack.value)
+    sections.push(`Stack:\n${resolvedStack.value}`)
+
+  if (resolvedCause.value)
+    sections.push(`Cause:\n${resolvedCause.value}`)
+
+  return sections.join('\n\n')
+})
+
+async function copyContent() {
+  if (!panelContent.value)
+    return
+
+  emit('copy', panelContent.value)
+
+  try {
+    const clipboard = globalThis.navigator?.clipboard
+    if (!clipboard)
+      return
+
+    await clipboard.writeText(panelContent.value)
+    copied.value = true
+    globalThis.setTimeout(() => {
+      copied.value = false
+    }, 1200)
+  }
+  catch {
+    // Ignore clipboard failures and still keep emitted copy payload.
+  }
+}
+</script>
+
+<template>
+  <div
+    :class="[
+      'relative w-full rounded-xl border-2 border-red-200/70 bg-red-50/60 backdrop-blur-md p-1',
+      'dark:border-red-900/50 dark:bg-red-950/25',
+    ]"
+  >
+    <div :class="['absolute right-4 -translate-x-full top-2 z-10']">
+      <Button
+        v-if="showCopyButton"
+        size="sm"
+        variant="secondary"
+        shape="square"
+        icon="i-solar:copy-line-duotone"
+        :title="copied ? copiedButtonLabel : copyButtonLabel"
+        :aria-label="copied ? copiedButtonLabel : copyButtonLabel"
+        @click="copyContent"
+      />
+    </div>
+
+    <div :class="['absolute right-2 top-2 z-10']">
+      <Button
+        v-if="showFeedbackButton"
+        size="sm"
+        variant="secondary"
+        shape="square"
+        icon="i-solar:square-share-line-line-duotone"
+        :title="feedbackButtonLabel"
+        :aria-label="feedbackButtonLabel"
+        @click="emit('feedback')"
+      />
+    </div>
+
+    <ScrollAreaRoot
+      type="auto"
+      :class="[
+        'relative w-full overflow-hidden rounded-xl',
+        'bg-neutral-50/80 dark:bg-neutral-950/80',
+        ...heightPresetClasses[heightPreset],
+      ]"
+    >
+      <ScrollAreaViewport :class="['h-full w-full']">
+        <div :class="['flex flex-col gap-2 p-3 text-xs']">
+          <div v-if="resolvedErrorName || resolvedMessage" :class="['font-mono font-semibold text-red-700 leading-relaxed dark:text-red-300']">
+            {{ resolvedErrorName || 'Error' }}
+            <span v-if="resolvedMessage">
+              : {{ resolvedMessage }}
+            </span>
+          </div>
+          <pre v-if="resolvedStack" :class="['whitespace-pre-wrap break-words text-neutral-700 leading-relaxed dark:text-neutral-200']">    {{ resolvedStack }}</pre>
+          <pre v-if="resolvedCause" :class="['whitespace-pre-wrap break-words text-neutral-700 leading-relaxed dark:text-neutral-200']">{{ `Cause:\n${resolvedCause}` }}</pre>
+          <div v-if="!panelContent" :class="['text-neutral-600 dark:text-neutral-300']">
+            No error details available.
+          </div>
+        </div>
+      </ScrollAreaViewport>
+      <ScrollAreaScrollbar orientation="vertical" :class="['w-2 p-0.5']">
+        <ScrollAreaThumb :class="['rounded-full bg-neutral-300/80 dark:bg-neutral-700/80']" />
+      </ScrollAreaScrollbar>
+      <ScrollAreaCorner />
+    </ScrollAreaRoot>
+  </div>
+</template>
diff --git a/packages/ui/src/components/misc/index.ts b/packages/ui/src/components/misc/index.ts
index ef17b89e9..62b549c37 100644
--- a/packages/ui/src/components/misc/index.ts
+++ b/packages/ui/src/components/misc/index.ts
@@ -1,4 +1,5 @@
 export { default as Button } from './button.vue'
 export { default as Callout } from './callout.vue'
+export { default as ContainerError } from './container-error.vue'
 export { default as DoubleCheckButton } from './double-check-button.vue'
 export { default as Progress } from './progress.vue'
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 5668bf9b6..dd74adccf 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -3481,6 +3481,9 @@ importers:
 
   packages/ui:
     dependencies:
+      '@moeru/std':
+        specifier: 'catalog:'
+        version: 0.1.0-beta.17
       '@vueuse/core':
         specifier: ^14.2.1
         version: 14.2.1(vue@3.5.30(typescript@5.9.3))