polish global drag state with minimal futuristic feedback

apps/jingrow/frontend/src/views/tools/RemoveBackground.vue

@@ -1,5 +1,16 @@
 <template>
-  <div class="remove-background-page">
+  <div
+    class="remove-background-page"
+    @dragenter.prevent="handleDragEnter"
+    @dragover.prevent="handleDragOver"
+    @dragleave="handleDragLeave"
+    @drop.prevent="handleDrop"
+  >
+    <div v-if="isDragging" class="global-drag-overlay">
+      <div class="overlay-content">
+        <p>{{ t('Drop image anywhere to remove background') }}</p>
+      </div>
+    </div>
     <!-- 文件输入框，始终存在 -->
     <input
       ref="fileInputRef"
@@ -39,9 +50,6 @@
             v-if="!uploadedImage"
             class="upload-area"
             :class="{ 'dragging': isDragging }"
-            @drop.prevent="handleDrop"
-            @dragover.prevent="handleDragOver"
-            @dragleave="handleDragLeave"
             @click="triggerFileInput"
           >
             <div class="upload-content">
@@ -191,6 +199,7 @@ const currentHistoryIndex = ref<number>(-1) // -1 表示当前正在处理的图
 
 // 状态
 const isDragging = ref(false)
+const dragCounter = ref(0)
 const processing = ref(false)
 const splitPosition = ref(0) // 分割线位置（百分比），0表示最左边，默认只显示结果图
 const comparisonContainerRef = ref<HTMLElement | null>(null)
@@ -214,16 +223,38 @@ const handleFileSelect = (event: Event) => {
   }
 }
 
+// 判断拖拽是否包含文件
+const hasFiles = (event: DragEvent) => {
+  const types = event.dataTransfer?.types
+  if (!types) return false
+  return Array.from(types).includes('Files')
+}
+
 // 处理拖拽
-const handleDragOver = () => {
+const handleDragEnter = (event: DragEvent) => {
+  if (!hasFiles(event)) return
+  dragCounter.value += 1
   isDragging.value = true
 }
 
-const handleDragLeave = () => {
-  isDragging.value = false
+const handleDragOver = (event: DragEvent) => {
+  if (!hasFiles(event)) return
+  event.dataTransfer!.dropEffect = 'copy'
+  isDragging.value = true
+}
+
+const handleDragLeave = (event: DragEvent) => {
+  if (!hasFiles(event)) return
+  dragCounter.value = Math.max(0, dragCounter.value - 1)
+  if (dragCounter.value === 0) {
+    isDragging.value = false
+  }
 }
 
 const handleDrop = (event: DragEvent) => {
+  if (!hasFiles(event)) return
+  event.preventDefault()
+  dragCounter.value = 0
   isDragging.value = false
   const file = event.dataTransfer?.files[0]
   if (file && file.type.startsWith('image/')) {
@@ -497,6 +528,112 @@ const handleDownload = () => {
   min-height: 100vh;
   display: flex;
   flex-direction: column;
+  position: relative;
+}
+
+.global-drag-overlay {
+  position: fixed;
+  inset: 0;
+  background: radial-gradient(circle at center, rgba(248, 250, 252, 0.92), rgba(248, 250, 252, 0.82));
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  z-index: 1000;
+  pointer-events: none;
+  animation: fade-in 0.15s ease;
+
+  &::before {
+    content: '';
+    position: absolute;
+    width: 55vmax;
+    height: 55vmax;
+    border-radius: 35%;
+    border: 1px solid rgba(148, 163, 184, 0.25);
+    animation: rotate 12s linear infinite;
+    pointer-events: none;
+  }
+}
+
+.overlay-content {
+  position: relative;
+  display: inline-flex;
+  align-items: center;
+  gap: 8px;
+  padding: 18px 30px;
+  color: #0f172a;
+  font-size: 18px;
+  font-weight: 600;
+  text-align: center;
+  letter-spacing: 0.04em;
+  text-transform: uppercase;
+
+  &::before {
+    content: '';
+    position: absolute;
+    inset: -10px;
+    border-radius: 999px;
+    border: 1px solid rgba(79, 70, 229, 0.35);
+    opacity: 0.7;
+    animation: pulse-line 1.8s ease-out infinite;
+  }
+
+  &::after {
+    content: '';
+    position: absolute;
+    inset: -28px 16px;
+    border-radius: 999px;
+    background: linear-gradient(90deg, rgba(59, 130, 246, 0), rgba(59, 130, 246, 0.24), rgba(59, 130, 246, 0));
+    filter: blur(10px);
+    opacity: 0.65;
+    animation: shimmer 2.4s linear infinite;
+  }
+}
+
+@keyframes fade-in {
+  from {
+    opacity: 0;
+    transform: scale(0.98);
+  }
+
+  to {
+    opacity: 1;
+    transform: scale(1);
+  }
+}
+
+@keyframes rotate {
+  to {
+    transform: rotate(360deg);
+  }
+}
+
+@keyframes pulse-line {
+  0% {
+    transform: scale(0.9);
+    opacity: 0;
+  }
+
+  50% {
+    transform: scale(1);
+    opacity: 0.5;
+  }
+
+  100% {
+    transform: scale(1.05);
+    opacity: 0;
+  }
+}
+
+@keyframes shimmer {
+  0% {
+    opacity: 0.2;
+  }
+  50% {
+    opacity: 0.7;
+  }
+  100% {
+    opacity: 0.2;
+  }
 }
 
 .remove-background-page > .page-content {