diff --git a/bin/unzip b/bin/unzip
new file mode 100755
index 0000000..581ff8e
Binary files /dev/null and b/bin/unzip differ
diff --git a/models/problem.js b/models/problem.js
index 1e6a32f..bafd72b 100644
--- a/models/problem.js
+++ b/models/problem.js
@@ -340,7 +340,8 @@ class Problem extends Model {
       await fs.remove(dir);
       await fs.ensureDir(dir);
 
-      await p7zip.extract(path, dir);
+      let execFileAsync = Promise.promisify(require('child_process').execFile);
+      await execFileAsync(__dirname + '/../bin/unzip', ['-j', '-o', '-d', dir, path]);
       await fs.move(path, this.getTestdataArchivePath(), { overwrite: true });
     });
   }
diff --git a/static/style.css b/static/style.css
index 8ddf9ba..c3ed601 100644
--- a/static/style.css
+++ b/static/style.css
@@ -35,6 +35,42 @@ body
     sans-serif;
 }
 
+.ui.header,
+.ui.button,
+.ui.input input,
+.ui.menu,
+.ui.form input:not([type]),
+.ui.form input[type=date],
+.ui.form input[type=datetime-local],
+.ui.form input[type=email],
+.ui.form input[type=file],
+.ui.form input[type=number],
+.ui.form input[type=password],
+.ui.form input[type=search],
+.ui.form input[type=tel],
+.ui.form input[type=text],
+.ui.form input[type=time],
+.ui.form input[type=url],
+h1,
+h2,
+h3,
+h4,
+h5,
+body
+ {
+  font-family: 
+    -apple-system, 
+    'PingFang SC',/* Apple */ 
+    'Source Han Sans SC', 
+    'Noto Sans CJK SC', /* Google */
+    'Microsoft Yahei', 
+    'Lantinghei SC', 
+    'Hiragino Sans GB', 
+    'Microsoft Sans Serif', /* M$ */
+    'WenQuanYi Micro Hei', /* *nix */
+    sans-serif;
+}
+
 .font-content {
   font-family: 'Open Sans', 'Source Han Sans SC', 'Noto Sans CJK SC', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft Yahei', sans-serif;
 }