diff --git a/packages/ui/README.md b/packages/ui/README.md
index 3fc5d111..ccddb48d 100644
--- a/packages/ui/README.md
+++ b/packages/ui/README.md
@@ -151,7 +151,7 @@ components/
 
 | 组件      | 描述   | 主要属性                                                |
 | --------- | ------ | ------------------------------------------------------- |
-| `Modal`   | 模态框 | `open`, `title`, `size`, `closeOnBackdrop`, `showClose` |
+| `Modal`   | 模态框 | `open`, `title`, `size`, `radius`, `bodyOverflow`, `showClose` |
 | `Drawer`  | 抽屉   | `open`, `position`, `title`, `size`                     |
 | `Confirm` | 确认框 | `open`, `title`, `message`, `variant`, `onconfirm`      |
 | `Popover` | 弹出层 | `open`, `position`, `trigger`, `offset`                 |
@@ -378,6 +378,8 @@ components/
 <ToastContainer />
 ```
 
+`Modal` 不传 `title` / `header` 时会保留右上角关闭按钮，但不额外渲染整条头部。需要调整圆角时可传 `radius="1.4rem"`，内部下拉等浮层需要越界显示时可传 `bodyOverflow="visible"`。
+
 ### 声明式 CRUD 页面（CrudPage）
 
 ```svelte
diff --git a/packages/ui/src/lib/components/compounds/Modal.svelte b/packages/ui/src/lib/components/compounds/Modal.svelte
index 2ddc5729..aa3d7637 100644
--- a/packages/ui/src/lib/components/compounds/Modal.svelte
+++ b/packages/ui/src/lib/components/compounds/Modal.svelte
@@ -11,6 +11,7 @@
     open = $bindable(false),
     title = '',
     size = 'md',
+    radius = '1rem',
     closeOnBackdrop = true,
     closeOnEscape = true,
     showClose = true,
@@ -29,8 +30,10 @@
   // 只有调用 `showModal()` 进入 top-layer 后，弹框才不会被父级布局和 overflow 裁剪。
   let modalElement: HTMLDialogElement | undefined = $state()
 
-  // 只要存在标题、自定义 header 或关闭按钮，就渲染顶部栏位，保证弹框结构稳定。
-  const hasHeader = $derived(Boolean(header || title || showClose))
+  // 标题区仅在显式提供标题或自定义 header 时出现；
+  // 仅需关闭按钮的场景改为右上角悬浮按钮，避免业务侧额外占一整行头部。
+  const hasHeader = $derived(Boolean(header || title))
+  const hasFloatingClose = $derived(showClose && !hasHeader)
   const sizeMap: Record<string, string> = {
     'xs': 'hai-modal__panel--xs',
     'sm': 'hai-modal__panel--sm',
@@ -55,12 +58,21 @@
       styles.push(`--hai-modal-height: ${height.trim()}`)
     }
 
+    if (typeof radius === 'string' && radius.trim().length > 0) {
+      styles.push(`--hai-modal-radius: ${radius.trim()}`)
+    }
+
+    if (bodyOverflow === 'visible') {
+      styles.push('--hai-modal-panel-overflow: visible')
+    }
+
     return styles.length > 0 ? styles.join('; ') : undefined
   })
 
   const modalBoxClass = $derived(
     cn(
       'hai-modal__panel flex min-h-0 flex-col',
+      'relative',
       'bg-base-100 p-0',
       sizeMap[size],
       className,
@@ -138,6 +150,25 @@
     onkeydown={handleViewportKeydown}
   >
     <div class={modalBoxClass} style={panelStyle}>
+      {#if hasFloatingClose}
+        <button
+          type='button'
+          class='hai-modal__close hai-modal__close--floating'
+          aria-label={uiM('common_close')}
+          onclick={handleClose}
+        >
+          <svg viewBox='0 0 24 24' class='hai-modal__close-icon' aria-hidden='true'>
+            <path
+              d='M6 6l12 12M18 6L6 18'
+              fill='none'
+              stroke='currentColor'
+              stroke-width='1.9'
+              stroke-linecap='round'
+            ></path>
+          </svg>
+        </button>
+      {/if}
+
       {#if hasHeader}
         <!-- 顶部栏单独固定，保证滚动时标题和关闭操作始终可见。 -->
         <div class='hai-modal__header flex flex-none items-start justify-between gap-4 px-6 py-5 sm:px-7'>
@@ -225,8 +256,8 @@
     height: var(--hai-modal-height, auto);
     max-height: calc(100vh - clamp(2rem, 5.2vw, 4rem));
     max-height: calc(100dvh - clamp(2rem, 5.2vw, 4rem));
-    border-radius: 1.4rem;
-    overflow: hidden;
+    border-radius: var(--hai-modal-radius, 1rem);
+    overflow: var(--hai-modal-panel-overflow, hidden);
     color: var(--color-base-content);
     outline: none;
     box-shadow:
@@ -247,7 +278,7 @@
     border-bottom-right-radius: inherit;
     border-bottom-left-radius: inherit;
     box-shadow: inset 0 1px 0 color-mix(in srgb, var(--color-base-content) 6%, transparent);
-    border-radius: 0 0 1.4rem 1.4rem;
+    border-radius: 0 0 var(--hai-modal-radius, 1rem) var(--hai-modal-radius, 1rem);
   }
 
   .hai-modal__close {
@@ -284,6 +315,13 @@
     height: 1rem;
   }
 
+  .hai-modal__close--floating {
+    position: absolute;
+    top: 1rem;
+    right: 1rem;
+    z-index: 1;
+  }
+
   .hai-modal__panel--xs {
     --hai-modal-width: min(100%, 24rem);
   }
@@ -342,7 +380,7 @@
       max-width: 100%;
       max-height: calc(100vh - 1.7rem);
       max-height: calc(100dvh - 1.7rem);
-      border-radius: 1rem;
+      border-radius: min(var(--hai-modal-radius, 1rem), 1rem);
     }
   }
 </style>
diff --git a/packages/ui/src/lib/components/scenes/app/ThemeColorPicker.svelte b/packages/ui/src/lib/components/scenes/app/ThemeColorPicker.svelte
index 75aae18b..33c14a31 100644
--- a/packages/ui/src/lib/components/scenes/app/ThemeColorPicker.svelte
+++ b/packages/ui/src/lib/components/scenes/app/ThemeColorPicker.svelte
@@ -163,3 +163,44 @@
     />
   </div>
 </div>
+
+<style>
+  button {
+    border-color: var(--soft-border, color-mix(in oklab, var(--color-base-content) 12%, transparent));
+    background: var(--soft-surface, var(--color-base-100));
+    color: var(--soft-text-body, var(--color-base-content));
+    box-shadow: none;
+    font-weight: 500;
+  }
+
+  button:hover:not(:disabled) {
+    border-color: color-mix(in oklab, var(--color-primary) 28%, var(--soft-border, transparent) 72%);
+    background: color-mix(
+      in oklab,
+      var(--soft-surface, var(--color-base-100)) 88%,
+      var(--color-base-200) 12%
+    );
+  }
+
+  button[aria-pressed='true'] {
+    border-color: color-mix(in oklab, var(--color-primary) 42%, var(--soft-border, transparent) 58%);
+    background: color-mix(
+      in oklab,
+      var(--color-primary) 10%,
+      var(--soft-surface, var(--color-base-100)) 90%
+    );
+    color: var(--color-primary);
+  }
+
+  button:focus,
+  button:focus-visible {
+    outline: none;
+    border-color: color-mix(in oklab, var(--color-primary) 48%, var(--soft-border, transparent) 52%);
+    box-shadow: 0 0 0 4px color-mix(in oklab, var(--color-primary) 12%, transparent 88%);
+  }
+
+  button > span:first-child {
+    border-color: color-mix(in oklab, var(--color-base-content) 10%, transparent 90%);
+    box-shadow: none;
+  }
+</style>
diff --git a/packages/ui/src/lib/types.ts b/packages/ui/src/lib/types.ts
index 9eefa568..28e7f2a2 100644
--- a/packages/ui/src/lib/types.ts
+++ b/packages/ui/src/lib/types.ts
@@ -432,6 +432,8 @@ export interface ModalProps {
   title?: string
   /** 尺寸 */
   size?: Size | 'full'
+  /** 面板圆角（任意合法 CSS border-radius 值，默认 1rem） */
+  radius?: string
   /** 是否可通过点击遮罩关闭 */
   closeOnBackdrop?: boolean
   /** 是否可通过 ESC 键关闭 */
diff --git a/packages/ui/tests/types.test.ts b/packages/ui/tests/types.test.ts
index 3f0b2c67..a8166ca5 100644
--- a/packages/ui/tests/types.test.ts
+++ b/packages/ui/tests/types.test.ts
@@ -217,6 +217,7 @@ describe('组合组件 Props', () => {
     expectTypeOf<ModalProps>().toHaveProperty('open')
     expectTypeOf<ModalProps>().toHaveProperty('title')
     expectTypeOf<ModalProps>().toHaveProperty('size')
+    expectTypeOf<ModalProps>().toHaveProperty('radius')
     expectTypeOf<ModalProps>().toHaveProperty('closeOnBackdrop')
     expectTypeOf<ModalProps>().toHaveProperty('width')
     expectTypeOf<ModalProps>().toHaveProperty('height')