diff --git a/web/App.vue b/web/App.vue
index 1c1e490..ff867c4 100644
--- a/web/App.vue
+++ b/web/App.vue
@@ -244,7 +244,8 @@ const current = computed(() => NAV.find((n) => n.key === active.value))
 }
 
 .nav-item {
-  width: 100%;
+  /* 写死而不是 100%：百分比到像素之间没法插值，宽度动画会直接跳变 */
+  width: 159px;
   display: flex;
   align-items: center;
   gap: var(--s-3);
@@ -256,6 +257,18 @@ const current = computed(() => NAV.find((n) => n.key === active.value))
   cursor: pointer;
   text-align: left;
   white-space: nowrap;
+  overflow: hidden;
+  /* width 跟侧栏同节奏，颜色沿用全局的 0.15s；transition 不叠加，这里要写全 */
+  transition:
+    width 0.3s ease,
+    color 0.15s ease,
+    background-color 0.15s ease,
+    border-color 0.15s ease;
+}
+
+/* 收拢后按钮缩成正方形贴着图标，高亮块不再被裁切：8 + 18 + 8 加两侧边框 = 36 */
+.is-compact .nav-item {
+  width: 36px;
 }
 
 .nav-item:hover {
diff --git a/web/views/InboundDetail.vue b/web/views/InboundDetail.vue
index c43a0b8..2fd42a1 100644
--- a/web/views/InboundDetail.vue
+++ b/web/views/InboundDetail.vue
@@ -160,6 +160,39 @@ function lockHeight() {
   el.style.overflow = 'hidden'
 }
 
+/**
+ * v-if 内容的展开收起动画：高度在 0 和实际值之间过渡，结束后清掉内联样式。
+ * 给配置表单和链式代理段用。auto 高度不可插值，只能量出来做。
+ */
+function foldEnter(element: Element, done: () => void) {
+  const el = element as HTMLElement
+  el.style.height = '0'
+  el.style.overflow = 'hidden'
+  void el.offsetHeight
+  el.style.transition = 'height 0.15s ease'
+  el.style.height = `${String(el.scrollHeight)}px`
+  el.addEventListener(
+    'transitionend',
+    () => {
+      el.style.transition = ''
+      el.style.height = ''
+      el.style.overflow = ''
+      done()
+    },
+    { once: true },
+  )
+}
+
+function foldLeave(element: Element, done: () => void) {
+  const el = element as HTMLElement
+  el.style.height = `${String(el.offsetHeight)}px`
+  el.style.overflow = 'hidden'
+  void el.offsetHeight
+  el.style.transition = 'height 0.15s ease'
+  el.style.height = '0'
+  el.addEventListener('transitionend', done, { once: true })
+}
+
 function settleHeight() {
   const el = rootEl.value
   if (!el || !el.style.height) return
@@ -507,6 +540,7 @@ const complete = computed(
       </section>
 
       <!-- 跟着表单里的开关走：拨开立刻出现，拨掉（哪怕还没保存）立刻消失 -->
+      <Transition name="fold" @enter="foldEnter" @leave="foldLeave">
       <section v-if="form.chain" class="block">
         <h3>
           链式代理
@@ -546,6 +580,7 @@ const complete = computed(
           />
         </div>
       </section>
+      </Transition>
 
       <!-- 共用的组只能换选中，改不了它的成员来源：那是别人的组 -->
       <section v-if="panel.shared && !locked" class="block">
@@ -560,6 +595,7 @@ const complete = computed(
           <IconRight :class="['chev', open && 'is-open']" />
         </button>
 
+        <Transition name="fold" @enter="foldEnter" @leave="foldLeave">
         <div v-if="open" class="form">
           <h4>代理</h4>
 
@@ -631,6 +667,7 @@ const complete = computed(
             </button>
           </div>
         </div>
+        </Transition>
       </section>
     </template>
     </div>
@@ -899,12 +936,13 @@ h3 {
   transform: rotate(90deg);
 }
 
-/* 表单不套盒子，靠小标题和一条分割线分段（设计基调第 2 条：不要卡片套卡片） */
+/* 表单不套盒子，靠小标题和一条分割线分段（设计基调第 2 条：不要卡片套卡片）。
+   上方留白用 padding 而不是 margin：margin 在高度折叠动画之外，会瞬跳 */
 .form {
   display: flex;
   flex-direction: column;
   gap: var(--s-3);
-  margin-top: var(--s-4);
+  padding-top: var(--s-4);
 }
 
 .form h4 {
diff --git a/web/views/RouterPage.vue b/web/views/RouterPage.vue
index d63c436..8c7268f 100644
--- a/web/views/RouterPage.vue
+++ b/web/views/RouterPage.vue
@@ -28,7 +28,6 @@ import type { ListenerFields } from '../api'
 import type { GroupView } from '../runtime'
 import { optimisticSelect, providerLines, reloadRuntime, runtime } from '../runtime'
 import { useDelayTest } from '../delay-test'
-import { density } from '../prefs'
 import ConfirmDialog from '../components/ConfirmDialog.vue'
 import InboundList from '../components/InboundList.vue'
 import InboundDetail from './InboundDetail.vue'
@@ -258,9 +257,10 @@ async function removeConfirmed() {
         </div>
       </div>
 
+      <!-- 侧栏收拢是侧栏自己的事，页面内容不跟着变形 -->
       <button class="add" type="button" :disabled="saving" @click="openAdd">
         <IconAdd />
-        <span v-if="density === 'full'">新增</span>
+        <span>新增</span>
       </button>
     </header>