style: improve project order signature input

src/pages/ProjectOrderComplete.tsx

@@ -284,7 +284,7 @@ function ProjectOrderCompletePage() {
               <label className="aftersales-upload-trigger">
                 <UploadOutlined />
                 <span>{uploadingImages ? '上传中...' : '上传现场图片'}</span>
-                <small>最多 6 张，上传前自动压缩</small>
+                <small>最多 18 张，上传前自动压缩</small>
                 <input
                   type="file"
                   accept="image/*"
@@ -310,19 +310,35 @@ function ProjectOrderCompletePage() {
 
             <div className="aftersales-signature-section">
               <p className="aftersales-signature-section-title">工程师签名</p>
-              <div className="aftersales-signature-card">
+              <div className="aftersales-signature-item">
+                <div className="aftersales-signature-header">
+                  <p className="aftersales-signature-tip">工程师签名</p>
+                  {engineerSignature && (
+                    <Button size="small" type="link" onClick={() => setEngineerSignature('')}>
+                      清除
+                    </Button>
+                  )}
+                </div>
                 {engineerSignature ? (
-                  <img
-                    src={engineerSignature}
-                    alt="工程师签名"
+                  <button
+                    type="button"
                     className="aftersales-signature-preview"
-                  />
+                    onClick={() => setSignatureOpen(true)}
+                  >
+                    <img src={engineerSignature} alt="工程师签名" />
+                    <span className="aftersales-signature-preview-hint">点击可重新签名</span>
+                  </button>
                 ) : (
-                  <span className="aftersales-signature-empty">未签名</span>
+                  <button
+                    type="button"
+                    className="aftersales-signature-trigger"
+                    onClick={() => setSignatureOpen(true)}
+                  >
+                    <EditOutlined />
+                    <span>工程师签名</span>
+                    <small>将进入签名页</small>
+                  </button>
                 )}
-                <Button icon={<EditOutlined />} onClick={() => setSignatureOpen(true)}>
-                  {engineerSignature ? '重签' : '签名'}
-                </Button>
               </div>
             </div>