diff --git a/web/src/components/Layout.tsx b/web/src/components/Layout.tsx
index f0463b9..59798d2 100644
--- a/web/src/components/Layout.tsx
+++ b/web/src/components/Layout.tsx
@@ -211,9 +211,6 @@ export default function Layout() {
                     {active ? <span className="ml-auto h-1.5 w-1.5 rounded-full bg-[var(--bg-accent)]" /> : null}
                   </>
                 )}
-                {sidebarCollapsed && active ? (
-                  <span className="absolute right-1 top-1/2 h-1.5 w-1.5 -translate-y-1/2 rounded-full bg-[var(--bg-accent)]" />
-                ) : null}
               </button>
             )
           })}
diff --git a/web/src/components/ui/badge.tsx b/web/src/components/ui/badge.tsx
index df49d0e..9cf1aea 100644
--- a/web/src/components/ui/badge.tsx
+++ b/web/src/components/ui/badge.tsx
@@ -6,9 +6,11 @@ export type BadgeTone = 'default' | 'success' | 'warn' | 'danger' | 'info'
 export function Badge({
   children,
   tone = 'default',
+  size = 'md',
 }: {
   children: ReactNode
   tone?: BadgeTone
+  size?: 'sm' | 'md' | 'lg'
 }) {
   const tones: Record<BadgeTone, string> = {
     default: 'border-[var(--border)] bg-[var(--bg-tertiary)] text-[var(--text-secondary)]',
@@ -21,8 +23,13 @@ export function Badge({
     info:
       'border-[color-mix(in_srgb,var(--info)_25%,transparent)] bg-[color-mix(in_srgb,var(--info)_12%,transparent)] text-[var(--info)]',
   }
+  const badgeSizes = {
+    sm: 'px-1.5 py-px text-[10px]',
+    md: 'px-2 py-0.5 text-[11px]',
+    lg: 'px-2.5 py-1 text-[12px]',
+  }
   return (
-    <span className={cn('inline-flex items-center rounded-md border px-2 py-0.5 text-[11px] font-medium', tones[tone])}>
+    <span className={cn('inline-flex items-center rounded-md border font-medium', badgeSizes[size], tones[tone])}>
       {children}
     </span>
   )
diff --git a/web/src/components/ui/button.tsx b/web/src/components/ui/button.tsx
index ba9690e..51b41b6 100644
--- a/web/src/components/ui/button.tsx
+++ b/web/src/components/ui/button.tsx
@@ -2,7 +2,7 @@ import type { ButtonHTMLAttributes } from 'react'
 import { cn } from '@/lib/utils'
 
 export type ButtonVariant = 'default' | 'secondary' | 'ghost' | 'danger' | 'outline'
-export type ButtonSize = 'sm' | 'md' | 'icon'
+export type ButtonSize = 'sm' | 'md' | 'lg' | 'icon' | 'icon-sm' | 'icon-lg'
 
 export interface ButtonProps extends ButtonHTMLAttributes<HTMLButtonElement> {
   variant?: ButtonVariant
diff --git a/web/src/components/ui/index.ts b/web/src/components/ui/index.ts
index 4e48b5e..3eb21ed 100644
--- a/web/src/components/ui/index.ts
+++ b/web/src/components/ui/index.ts
@@ -10,6 +10,7 @@ export { Badge } from './badge'
 export type { BadgeTone } from './badge'
 export { Modal } from './modal'
 export { Table, Th, Td } from './table'
+export type { TableSize } from './table'
 export { Field } from './field'
 export { PageHeader } from './page-header'
 export { Empty } from './empty'
diff --git a/web/src/components/ui/input.tsx b/web/src/components/ui/input.tsx
index 831d5c5..69d1fcf 100644
--- a/web/src/components/ui/input.tsx
+++ b/web/src/components/ui/input.tsx
@@ -1,6 +1,12 @@
 import type { InputHTMLAttributes } from 'react'
 import { cn } from '@/lib/utils'
 
-export function Input({ className, ...props }: InputHTMLAttributes<HTMLInputElement>) {
-  return <input {...props} className={cn('ui-control h-9 px-3', className)} />
+const heights: Record<string, string> = {
+  sm: 'h-[var(--ui-height-sm)] text-[length:var(--ui-font-sm)] px-[var(--ui-px-sm)]',
+  md: 'h-[var(--ui-height-md)] text-[length:var(--ui-font-md)] px-[var(--ui-px-md)]',
+  lg: 'h-[var(--ui-height-lg)] text-[length:var(--ui-font-lg)] px-[var(--ui-px-lg)]',
+}
+
+export function Input({ className, size = 'md', ...props }: InputHTMLAttributes<HTMLInputElement> & { size?: 'sm' | 'md' | 'lg' }) {
+  return <input {...props} className={cn('ui-control', heights[size], className)} />
 }
diff --git a/web/src/components/ui/select.tsx b/web/src/components/ui/select.tsx
index d19fee2..c77e8bf 100644
--- a/web/src/components/ui/select.tsx
+++ b/web/src/components/ui/select.tsx
@@ -144,7 +144,7 @@ export function Select({
         disabled={disabled}
         aria-haspopup="listbox"
         aria-expanded={open}
-        className={cn('ui-control ui-select-trigger h-9 px-3 text-left', open && 'ui-control-open')}
+        className={cn('ui-control ui-select-trigger h-[var(--ui-height-md)] px-[var(--ui-px-md)] text-left text-[length:var(--ui-font-md)]', open && 'ui-control-open')}
         onClick={() => {
           if (disabled) return
           setOpen((v) => !v)
diff --git a/web/src/components/ui/switch.tsx b/web/src/components/ui/switch.tsx
index 5e26887..3fd45ee 100644
--- a/web/src/components/ui/switch.tsx
+++ b/web/src/components/ui/switch.tsx
@@ -1,16 +1,25 @@
 import { cn } from '@/lib/utils'
 
+const sizes = {
+  sm: { track: 'h-4 w-7', thumb: 'h-2.5 w-2.5', on: 'translate-x-[14px]', off: 'translate-x-[2px]' },
+  md: { track: 'h-5 w-9', thumb: 'h-3.5 w-3.5', on: 'translate-x-[18px]', off: 'translate-x-[3px]' },
+  lg: { track: 'h-6 w-11', thumb: 'h-4 w-4', on: 'translate-x-[22px]', off: 'translate-x-[3px]' },
+}
+
 export function Switch({
   checked,
   onCheckedChange,
   disabled,
   className,
+  size = 'md',
 }: {
   checked: boolean
   onCheckedChange: (v: boolean) => void
   disabled?: boolean
   className?: string
+  size?: 'sm' | 'md' | 'lg'
 }) {
+  const s = sizes[size]
   return (
     <button
       type="button"
@@ -18,7 +27,8 @@ export function Switch({
       aria-checked={checked}
       disabled={disabled}
       className={cn(
-        'relative inline-flex h-5 w-9 shrink-0 items-center rounded-full border transition',
+        'relative inline-flex shrink-0 items-center rounded-full border transition',
+        s.track,
         checked ? 'border-transparent bg-[var(--bg-accent)]' : 'border-[var(--border)] bg-[var(--bg-tertiary)]',
         disabled && 'opacity-55 cursor-not-allowed',
         className,
@@ -27,8 +37,9 @@ export function Switch({
     >
       <span
         className={cn(
-          'inline-block h-3.5 w-3.5 rounded-full bg-white shadow transition-transform',
-          checked ? 'translate-x-[18px]' : 'translate-x-[3px]',
+          'inline-block rounded-full bg-white shadow transition-transform',
+          s.thumb,
+          checked ? s.on : s.off,
         )}
       />
     </button>
diff --git a/web/src/components/ui/table.tsx b/web/src/components/ui/table.tsx
index cea8314..52981bb 100644
--- a/web/src/components/ui/table.tsx
+++ b/web/src/components/ui/table.tsx
@@ -1,6 +1,20 @@
 import type { ReactNode } from 'react'
 import { cn } from '@/lib/utils'
 
+export type TableSize = 'sm' | 'md' | 'lg'
+
+const thSizes: Record<TableSize, string> = {
+  sm: 'px-2 py-[var(--ui-table-py-sm)] text-[10px]',
+  md: 'px-3 py-[var(--ui-table-py-md)] text-[11px]',
+  lg: 'px-4 py-[var(--ui-table-py-lg)] text-[12px]',
+}
+
+const tdSizes: Record<TableSize, string> = {
+  sm: 'px-2 py-[var(--ui-table-py-sm)] text-[length:var(--ui-font-sm)]',
+  md: 'px-3 py-[var(--ui-table-py-md)] text-[length:var(--ui-font-md)]',
+  lg: 'px-4 py-[var(--ui-table-py-lg)] text-[length:var(--ui-font-lg)]',
+}
+
 export function Table({ children }: { children: ReactNode }) {
   return (
     <div className="overflow-x-auto">
@@ -9,11 +23,12 @@ export function Table({ children }: { children: ReactNode }) {
   )
 }
 
-export function Th({ children, className }: { children?: ReactNode; className?: string }) {
+export function Th({ children, className, size = 'md' }: { children?: ReactNode; className?: string; size?: TableSize }) {
   return (
     <th
       className={cn(
-        'border-b border-[var(--border)] bg-[var(--bg-secondary)] px-3 py-2.5 text-[11px] font-medium uppercase tracking-wide text-[var(--text-muted)]',
+        'border-b border-[var(--border)] bg-[var(--bg-secondary)] font-medium uppercase tracking-wide text-[var(--text-muted)]',
+        thSizes[size],
         className,
       )}
     >
@@ -22,9 +37,9 @@ export function Th({ children, className }: { children?: ReactNode; className?:
   )
 }
 
-export function Td({ children, className }: { children?: ReactNode; className?: string }) {
+export function Td({ children, className, size = 'md' }: { children?: ReactNode; className?: string; size?: TableSize }) {
   return (
-    <td className={cn('border-b border-[var(--border)] px-3 py-2.5 align-middle text-[var(--text-primary)]', className)}>
+    <td className={cn('border-b border-[var(--border)] align-middle text-[var(--text-primary)]', tdSizes[size], className)}>
       {children}
     </td>
   )
diff --git a/web/src/components/ui/tabs.tsx b/web/src/components/ui/tabs.tsx
index 9243429..a6011a3 100644
--- a/web/src/components/ui/tabs.tsx
+++ b/web/src/components/ui/tabs.tsx
@@ -5,12 +5,19 @@ export function Tabs({
   onValueChange,
   items,
   className,
+  size = 'md',
 }: {
   value: string
   onValueChange: (v: string) => void
   items: { value: string; label: string }[]
   className?: string
+  size?: 'sm' | 'md' | 'lg'
 }) {
+  const tabSizes = {
+    sm: 'px-2.5 py-1 text-[12px]',
+    md: 'px-3.5 py-1.5 text-[13px]',
+    lg: 'px-4 py-2 text-[14px]',
+  }
   return (
     <div
       className={cn(
@@ -29,7 +36,8 @@ export function Tabs({
             role="tab"
             aria-selected={active}
             className={cn(
-              'relative shrink-0 rounded-md px-3.5 py-1.5 text-[13px] font-medium whitespace-nowrap transition-colors',
+              'relative shrink-0 rounded-md font-medium whitespace-nowrap transition-colors',
+              tabSizes[size],
               'focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-[var(--focus-ring)]',
               active
                 ? 'bg-[var(--bg-secondary)] text-[var(--text-primary)] shadow-[var(--shadow-sm)] ring-1 ring-[var(--border)]'
diff --git a/web/src/components/ui/textarea.tsx b/web/src/components/ui/textarea.tsx
index 9664928..31ceb03 100644
--- a/web/src/components/ui/textarea.tsx
+++ b/web/src/components/ui/textarea.tsx
@@ -1,6 +1,12 @@
 import type { TextareaHTMLAttributes } from 'react'
 import { cn } from '@/lib/utils'
 
-export function Textarea({ className, ...props }: TextareaHTMLAttributes<HTMLTextAreaElement>) {
-  return <textarea {...props} className={cn('ui-control min-h-24 resize-y px-3 py-2', className)} />
+const sizes: Record<string, string> = {
+  sm: 'text-[length:var(--ui-font-sm)] px-[var(--ui-px-sm)] py-1.5 min-h-16',
+  md: 'text-[length:var(--ui-font-md)] px-[var(--ui-px-md)] py-2 min-h-24',
+  lg: 'text-[length:var(--ui-font-lg)] px-[var(--ui-px-lg)] py-2.5 min-h-32',
+}
+
+export function Textarea({ className, size = 'md', ...props }: TextareaHTMLAttributes<HTMLTextAreaElement> & { size?: 'sm' | 'md' | 'lg' }) {
+  return <textarea {...props} className={cn('ui-control resize-y', sizes[size], className)} />
 }
diff --git a/web/src/index.css b/web/src/index.css
index 37a99e4..ea7397d 100644
--- a/web/src/index.css
+++ b/web/src/index.css
@@ -78,6 +78,44 @@
   --info: #2563eb;
 }
 
+/* ---- 尺寸系统：默认 md ---- */
+:root {
+  --ui-height-sm: 1.75rem;   /* 28px */
+  --ui-height-md: 2.25rem;   /* 36px */
+  --ui-height-lg: 2.75rem;   /* 44px */
+  --ui-font-sm: 12px;
+  --ui-font-md: 14px;
+  --ui-font-lg: 15px;
+  --ui-px-sm: 0.5rem;
+  --ui-px-md: 0.75rem;
+  --ui-px-lg: 1rem;
+  --ui-gap-sm: 0.25rem;
+  --ui-gap-md: 0.375rem;
+  --ui-gap-lg: 0.5rem;
+  --ui-table-py-sm: 0.375rem;
+  --ui-table-py-md: 0.625rem;
+  --ui-table-py-lg: 0.75rem;
+}
+
+/* 紧凑模式 */
+[data-density='compact'] {
+  --ui-height-sm: 1.5rem;    /* 24px */
+  --ui-height-md: 1.875rem;  /* 30px */
+  --ui-height-lg: 2.25rem;   /* 36px */
+  --ui-font-sm: 11px;
+  --ui-font-md: 13px;
+  --ui-font-lg: 14px;
+  --ui-px-sm: 0.375rem;
+  --ui-px-md: 0.5rem;
+  --ui-px-lg: 0.75rem;
+  --ui-gap-sm: 0.125rem;
+  --ui-gap-md: 0.25rem;
+  --ui-gap-lg: 0.375rem;
+  --ui-table-py-sm: 0.25rem;
+  --ui-table-py-md: 0.375rem;
+  --ui-table-py-lg: 0.5rem;
+}
+
 *,
 *::before,
 *::after {
@@ -234,10 +272,10 @@ pre,
   display: inline-flex;
   align-items: center;
   justify-content: center;
-  gap: 0.375rem;
+  gap: var(--ui-gap-md);
   border: 1px solid transparent;
   border-radius: var(--radius-md);
-  font-size: 14px;
+  font-size: var(--ui-font-md);
   font-weight: 500;
   line-height: 1.2;
   transition:
@@ -310,19 +348,38 @@ pre,
 }
 
 .ui-btn-sm {
-  height: 2rem;
-  padding: 0 0.625rem;
-  font-size: 12px;
+  height: var(--ui-height-sm);
+  padding: 0 var(--ui-px-sm);
+  font-size: var(--ui-font-sm);
 }
 
 .ui-btn-md {
-  height: 2.25rem;
-  padding: 0 0.75rem;
+  height: var(--ui-height-md);
+  padding: 0 var(--ui-px-md);
+  font-size: var(--ui-font-md);
+}
+
+.ui-btn-lg {
+  height: var(--ui-height-lg);
+  padding: 0 var(--ui-px-lg);
+  font-size: var(--ui-font-lg);
 }
 
 .ui-btn-icon {
-  height: 2.25rem;
-  width: 2.25rem;
+  height: var(--ui-height-md);
+  width: var(--ui-height-md);
+  padding: 0;
+}
+
+.ui-btn-icon-sm {
+  height: var(--ui-height-sm);
+  width: var(--ui-height-sm);
+  padding: 0;
+}
+
+.ui-btn-icon-lg {
+  height: var(--ui-height-lg);
+  width: var(--ui-height-lg);
   padding: 0;
 }
 
@@ -357,9 +414,9 @@ pre,
   background: transparent;
   color: var(--text-primary);
   cursor: pointer;
-  font-size: 13px;
+  font-size: var(--ui-font-sm);
   line-height: 1.35;
-  min-height: 2rem;
+  min-height: var(--ui-height-sm);
   padding: 0.5rem 0.75rem;
   text-align: left;
 }