diff --git a/src/design-system/primitives/Collapsible/Collapsible.module.css b/src/design-system/primitives/Collapsible/Collapsible.module.css
new file mode 100644
index 0000000..35fa720
--- /dev/null
+++ b/src/design-system/primitives/Collapsible/Collapsible.module.css
@@ -0,0 +1,59 @@
+.root {
+  border: 1px solid var(--border);
+  border-radius: var(--radius-sm);
+  overflow: hidden;
+}
+
+.trigger {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  width: 100%;
+  padding: 10px 14px;
+  background: var(--bg-raised);
+  border: none;
+  cursor: pointer;
+  text-align: left;
+  font-family: var(--font-body);
+  font-size: 13px;
+  color: var(--text-primary);
+  transition: background 0.15s;
+}
+
+.trigger:hover {
+  background: var(--bg-hover);
+}
+
+.title {
+  font-weight: 500;
+}
+
+.chevron {
+  color: var(--text-muted);
+  font-size: 14px;
+  transition: transform 0.2s;
+  transform: rotate(-90deg);
+}
+
+.chevronOpen {
+  transform: rotate(0deg);
+}
+
+.content {
+  max-height: 0;
+  overflow: hidden;
+  transition: max-height 0.25s ease;
+}
+
+.content[hidden] {
+  display: block;
+  max-height: 0;
+}
+
+.contentOpen {
+  max-height: 2000px;
+}
+
+.inner {
+  padding: 12px 14px;
+}
diff --git a/src/design-system/primitives/Collapsible/Collapsible.test.tsx b/src/design-system/primitives/Collapsible/Collapsible.test.tsx
new file mode 100644
index 0000000..75a6e56
--- /dev/null
+++ b/src/design-system/primitives/Collapsible/Collapsible.test.tsx
@@ -0,0 +1,36 @@
+import { describe, it, expect, vi } from 'vitest'
+import { render, screen } from '@testing-library/react'
+import userEvent from '@testing-library/user-event'
+import { Collapsible } from './Collapsible'
+
+describe('Collapsible', () => {
+  it('renders title', () => {
+    render(<Collapsible title="Details">Content</Collapsible>)
+    expect(screen.getByText('Details')).toBeInTheDocument()
+  })
+
+  it('hides content by default', () => {
+    render(<Collapsible title="Details">Hidden content</Collapsible>)
+    expect(screen.queryByText('Hidden content')).not.toBeVisible()
+  })
+
+  it('shows content when defaultOpen', () => {
+    render(<Collapsible title="Details" defaultOpen>Visible content</Collapsible>)
+    expect(screen.getByText('Visible content')).toBeVisible()
+  })
+
+  it('toggles content on click', async () => {
+    const user = userEvent.setup()
+    render(<Collapsible title="Details">Content</Collapsible>)
+    await user.click(screen.getByText('Details'))
+    expect(screen.getByText('Content')).toBeVisible()
+  })
+
+  it('calls onToggle when toggled', async () => {
+    const onToggle = vi.fn()
+    const user = userEvent.setup()
+    render(<Collapsible title="Details" onToggle={onToggle}>Content</Collapsible>)
+    await user.click(screen.getByText('Details'))
+    expect(onToggle).toHaveBeenCalled()
+  })
+})
diff --git a/src/design-system/primitives/Collapsible/Collapsible.tsx b/src/design-system/primitives/Collapsible/Collapsible.tsx
new file mode 100644
index 0000000..52b2881
--- /dev/null
+++ b/src/design-system/primitives/Collapsible/Collapsible.tsx
@@ -0,0 +1,53 @@
+import { useState, useRef, useEffect } from 'react'
+import styles from './Collapsible.module.css'
+import type { ReactNode } from 'react'
+
+interface CollapsibleProps {
+  title: ReactNode
+  children: ReactNode
+  defaultOpen?: boolean
+  open?: boolean
+  onToggle?: (open: boolean) => void
+  className?: string
+}
+
+export function Collapsible({
+  title,
+  children,
+  defaultOpen = false,
+  open: controlledOpen,
+  onToggle,
+  className,
+}: CollapsibleProps) {
+  const isControlled = controlledOpen !== undefined
+  const [internalOpen, setInternalOpen] = useState(defaultOpen)
+  const open = isControlled ? controlledOpen : internalOpen
+  const contentRef = useRef<HTMLDivElement>(null)
+
+  function handleToggle() {
+    const next = !open
+    if (!isControlled) setInternalOpen(next)
+    onToggle?.(next)
+  }
+
+  return (
+    <div className={`${styles.root} ${className ?? ''}`}>
+      <button
+        type="button"
+        className={styles.trigger}
+        onClick={handleToggle}
+        aria-expanded={open}
+      >
+        <span className={styles.title}>{title}</span>
+        <span className={`${styles.chevron} ${open ? styles.chevronOpen : ''}`}>▾</span>
+      </button>
+      <div
+        ref={contentRef}
+        className={`${styles.content} ${open ? styles.contentOpen : ''}`}
+        hidden={!open}
+      >
+        <div className={styles.inner}>{children}</div>
+      </div>
+    </div>
+  )
+}
diff --git a/src/design-system/primitives/Tooltip/Tooltip.module.css b/src/design-system/primitives/Tooltip/Tooltip.module.css
new file mode 100644
index 0000000..ed4f4fd
--- /dev/null
+++ b/src/design-system/primitives/Tooltip/Tooltip.module.css
@@ -0,0 +1,50 @@
+.wrapper {
+  position: relative;
+  display: inline-flex;
+  align-items: center;
+}
+
+.tip {
+  position: absolute;
+  z-index: 100;
+  padding: 5px 9px;
+  background: var(--text-primary);
+  color: var(--bg-surface);
+  font-size: 11px;
+  font-family: var(--font-body);
+  border-radius: var(--radius-sm);
+  white-space: nowrap;
+  pointer-events: none;
+  opacity: 0;
+  transition: opacity 0.15s;
+  box-shadow: var(--shadow-md);
+}
+
+.wrapper:hover .tip {
+  opacity: 1;
+}
+
+/* Positions */
+.top {
+  bottom: calc(100% + 6px);
+  left: 50%;
+  transform: translateX(-50%);
+}
+
+.bottom {
+  top: calc(100% + 6px);
+  left: 50%;
+  transform: translateX(-50%);
+}
+
+.left {
+  right: calc(100% + 6px);
+  top: 50%;
+  transform: translateY(-50%);
+}
+
+.right {
+  left: calc(100% + 6px);
+  top: 50%;
+  transform: translateY(-50%);
+}
diff --git a/src/design-system/primitives/Tooltip/Tooltip.tsx b/src/design-system/primitives/Tooltip/Tooltip.tsx
new file mode 100644
index 0000000..4c7ba90
--- /dev/null
+++ b/src/design-system/primitives/Tooltip/Tooltip.tsx
@@ -0,0 +1,27 @@
+import styles from './Tooltip.module.css'
+import type { ReactNode } from 'react'
+
+type TooltipPosition = 'top' | 'bottom' | 'left' | 'right'
+
+interface TooltipProps {
+  content: ReactNode
+  position?: TooltipPosition
+  children: ReactNode
+  className?: string
+}
+
+export function Tooltip({
+  content,
+  position = 'top',
+  children,
+  className,
+}: TooltipProps) {
+  return (
+    <span className={`${styles.wrapper} ${className ?? ''}`}>
+      {children}
+      <span className={`${styles.tip} ${styles[position]}`} role="tooltip">
+        {content}
+      </span>
+    </span>
+  )
+}