diff --git a/package-lock.json b/package-lock.json
index 84e81b1..6396f2f 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "wegwichtel-next",
-  "version": "0.12.9",
+  "version": "0.12.10",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "wegwichtel-next",
-      "version": "0.12.9",
+      "version": "0.12.10",
       "hasInstallScript": true,
       "dependencies": {
         "@file-type/av": "0.2.0",
diff --git a/package.json b/package.json
index fa5266e..7eebc74 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "wegwichtel-next",
-  "version": "0.12.9",
+  "version": "0.12.10",
   "private": true,
   "description": "GPS-gestützte Lern- und Wanderwege mit GPX, POIs, Bildern und Audioansagen.",
   "type": "module",
diff --git a/public/css/app.css b/public/css/app.css
index 1f5bc8f..f869a0c 100644
--- a/public/css/app.css
+++ b/public/css/app.css
@@ -406,21 +406,26 @@ button,
 }
 
 #slideshow > fieldset {
-  display: grid;
-  margin: 0;
-  grid-template-columns: var(--icon-button-size) minmax(0, 1fr) var(--icon-button-size);
-  align-items: stretch;
+  display: flex;
+  flex-flow: row nowrap;
+  align-items: center;
   gap: .5rem;
   width: 100%;
+  min-width: 0;
   box-sizing: border-box;
+  margin: 0;
   padding: .65rem;
 }
 
-#slideshow > fieldset .ui-button {
+#slideshow > fieldset > button.ui-button {
   display: grid;
+  flex: 0 0 var(--icon-button-size);
+  align-self: center;
   place-items: center;
-  min-width: 0;
-  min-height: 100%;
+  width: var(--icon-button-size);
+  height: var(--icon-button-size);
+  min-width: var(--icon-button-size);
+  min-height: var(--icon-button-size);
   margin: 0;
   padding: .45rem;
 }
@@ -433,6 +438,8 @@ button,
 
 #slideshow > fieldset > div {
   display: flex;
+  flex: 1 1 0;
+  align-self: stretch;
   min-width: 0;
   min-height: var(--icon-button-size);
   padding: .25rem .4rem;
diff --git a/src/services/routes-service.js b/src/services/routes-service.js
index 21586ac..04d9a9a 100644
--- a/src/services/routes-service.js
+++ b/src/services/routes-service.js
@@ -21,11 +21,21 @@ const UPDATE_METRICS_SQL = `UPDATE routes SET
   start_lat=?, start_lon=?, center_lat=?, center_lon=?, min_lat=?, min_lon=?, max_lat=?, max_lon=?,
   distance_m=?, elevation_gain_m=?, point_count=?, updated_at=CURRENT_TIMESTAMP WHERE id=?`;
 
+function trimEdgeHyphens(value) {
+  let start = 0;
+  let end = value.length;
+
+  while (start < end && value[start] === '-') start += 1;
+  while (end > start && value[end - 1] === '-') end -= 1;
+
+  return value.slice(start, end);
+}
+
 function slugify(value) {
   const normalized = String(value).toLowerCase().normalize('NFKD');
   const withoutMarks = normalized.replaceAll(/[\u0300-\u036f]/g, '');
   const separated = withoutMarks.replaceAll(/[^a-z0-9]+/g, '-');
-  const trimmed = separated.replaceAll(/(?:^-+|-+$)/g, '');
+  const trimmed = trimEdgeHyphens(separated);
   return trimmed.slice(0, 80) || `route-${Date.now()}`;
 }
 
diff --git a/test/mobile-navigation-ui.test.js b/test/mobile-navigation-ui.test.js
index 1807092..bbf82ec 100644
--- a/test/mobile-navigation-ui.test.js
+++ b/test/mobile-navigation-ui.test.js
@@ -182,7 +182,11 @@ test('POI page uses icon-based back and slideshow controls in a single responsiv
   assert.match(html, /id="slide-prev"[\s\S]*images\/icons\/chevron-left\.svg/);
   assert.match(html, /id="slide-next"[\s\S]*images\/icons\/chevron-right\.svg/);
   assert.match(html, /<fieldset>[\s\S]*<legend>Bildnavigation<\/legend>/);
-  assert.match(css, /#slideshow > fieldset[\s\S]*grid-template-columns:\s*var\(--icon-button-size\) minmax\(0, 1fr\) var\(--icon-button-size\)/);
+  assert.match(css, /#slideshow > fieldset[\s\S]*display:\s*flex/);
+  assert.match(css, /#slideshow > fieldset[\s\S]*flex-flow:\s*row nowrap/);
+  assert.match(css, /#slideshow > fieldset[\s\S]*align-items:\s*center/);
+  assert.match(css, /#slideshow > fieldset > button\.ui-button[\s\S]*flex:\s*0 0 var\(--icon-button-size\)/);
+  assert.match(css, /#slideshow > fieldset > div[\s\S]*flex:\s*1 1 0/);
   assert.match(css, /#slideshow > fieldset > div[\s\S]*justify-content:\s*center/);
   assert.match(css, /#slide-caption[\s\S]*overflow-wrap:\s*anywhere/);
   assert.doesNotMatch(loader, /controlgroup/);