diff --git a/release.sh b/release.sh
index adc8918..2785f29 100755
--- a/release.sh
+++ b/release.sh
@@ -4,17 +4,20 @@ set -e
 VERSION="$1"
 
 if [ -z "$VERSION" ]; then
-  echo "Usage: ./release.sh <semver>"
-  echo "Example: ./release.sh 1.4.0"
-  exit 1
+echo "Usage: ./release.sh <semver>"
+echo "Example: ./release.sh 1.4.0"
+exit 1
 fi
 
 # -----------------------------
+
 # SemVer validation
+
 # -----------------------------
-if ! [[ "$VERSION" =~ ^[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
-  echo "Version must be SemVer: X.Y.Z"
-  exit 1
+
+if ! [[ "$VERSION" =~ ^[0-9]+.[0-9]+.[0-9]+$ ]]; then
+echo "Version must be SemVer: X.Y.Z"
+exit 1
 fi
 
 TAG="v$VERSION"
@@ -22,125 +25,186 @@ TAG="v$VERSION"
 echo "=== Release $TAG ==="
 
 # -----------------------------
-# Branch check
+
+# portable sed
+
 # -----------------------------
+
+sedi() {
+if sed --version >/dev/null 2>&1; then
+sed -i "$@"
+else
+sed -i '' "$@"
+fi
+}
+
+# -----------------------------
+
+# Branch check
+
+# -----------------------------
+
 BRANCH=$(git rev-parse --abbrev-ref HEAD)
 if [ "$BRANCH" != "main" ]; then
-  echo "Not on main branch"
-  exit 1
+echo "Not on main branch"
+exit 1
 fi
 
 # -----------------------------
+
 # Working tree clean?
+
 # -----------------------------
+
 if ! git diff --quiet; then
-  echo "Working tree not clean — commit first"
-  exit 1
+echo "Working tree not clean — commit first"
+exit 1
 fi
 
 # -----------------------------
+
 # Sync with remote
+
 # -----------------------------
+
 git fetch origin
 
 LOCAL=$(git rev-parse main)
 REMOTE=$(git rev-parse origin/main)
 
 if [ "$LOCAL" != "$REMOTE" ]; then
-  echo "Local main not in sync with origin/main"
-  exit 1
+echo "Local main not in sync with origin/main"
+exit 1
 fi
 
 # -----------------------------
+
 # Tag already exists?
+
 # -----------------------------
+
 if git rev-parse "$TAG" >/dev/null 2>&1; then
-  echo "Tag already exists locally"
-  exit 1
+echo "Tag already exists locally"
+exit 1
 fi
 
-if git ls-remote --tags origin | grep -q "$TAG"; then
-  echo "Tag already exists on remote"
-  exit 1
+if git ls-remote --tags origin | grep -q "refs/tags/$TAG"; then
+echo "Tag already exists on remote"
+exit 1
 fi
 
 # -----------------------------
-# Update versions.env
+
+# versions.env update
+
 # -----------------------------
+
+if [ ! -f versions.env ]; then
+echo "versions.env not found"
+exit 1
+fi
+
 echo "Updating versions.env"
 
 if grep -q "^APP_VERSION=" versions.env; then
-  sed -i "s/^APP_VERSION=.*/APP_VERSION=${VERSION}/" versions.env
+sedi "s/^APP_VERSION=.*/APP_VERSION=${VERSION}/" versions.env
 else
-  echo "APP_VERSION=${VERSION}" >> versions.env
+echo "APP_VERSION=${VERSION}" >> versions.env
 fi
 
 # -----------------------------
-# Optional changelog entry
+
+# CHANGELOG generation
+
 # -----------------------------
+
 if [ -f CHANGELOG.md ]; then
-  echo "Updating CHANGELOG.md"
-  DATE=$(date +%Y-%m-%d)
-  sed -i "1i ## $VERSION - $DATE\n- release\n" CHANGELOG.md
-  git add CHANGELOG.md
-fi
+echo "Updating CHANGELOG.md"
 
-LAST_TAG=$(git describe --tags --abbrev=0 2>/dev/null || echo "")
+LAST_TAG=$(git describe --tags --abbrev=0 2>/dev/null || true)
 
 if [ -n "$LAST_TAG" ]; then
-  echo "Generating release notes from $LAST_TAG → HEAD"
-  git log $LAST_TAG..HEAD --pretty=format:"- %s" > RELEASE_NOTES.tmp
+git log $LAST_TAG..HEAD --pretty=format:"- %s" > RELEASE_NOTES.tmp
 else
-  git log --pretty=format:"- %s" > RELEASE_NOTES.tmp
+git log --pretty=format:"- %s" > RELEASE_NOTES.tmp
 fi
 
-echo -e "\n## $VERSION\n" | cat - RELEASE_NOTES.tmp >> CHANGELOG.md
+DATE=$(date +%Y-%m-%d)
+
+{
+echo "## $VERSION - $DATE"
+cat RELEASE_NOTES.tmp
+echo
+cat CHANGELOG.md
+} > CHANGELOG.new
+
+mv CHANGELOG.new CHANGELOG.md
 rm RELEASE_NOTES.tmp
 
+git add CHANGELOG.md
+fi
+
 # -----------------------------
+
 # Commit version bump
+
 # -----------------------------
+
 git add versions.env
 git commit -m "release: $VERSION"
 
 # -----------------------------
-# Push main → triggers edge build
-# -----------------------------
-git push origin main
 
+# Push main → edge build
+
+# -----------------------------
+
+git push origin main
 echo "Main pushed — edge build will run"
 
 # -----------------------------
+
 # Create annotated tag
+
 # -----------------------------
+
 git tag -a "$TAG" -m "Release $TAG"
 
 # -----------------------------
-# Push tag → triggers release build
-# -----------------------------
-git push origin "$TAG"
 
+# Push tag → release build
+
+# -----------------------------
+
+git push origin "$TAG"
 echo "Tag pushed — release build triggered"
 
 # -----------------------------
-# Optional: wait for CI success
+
+# Optional CI wait
+
 # -----------------------------
+
 if [ -n "$GITEA_TOKEN" ]; then
-  echo "Checking CI status..."
+echo "Checking CI status..."
 
-  REPO=$(git config --get remote.origin.url | sed 's#.*/##; s/.git$//')
-  OWNER=$(git config --get remote.origin.url | awk -F'[:/]' '{print $(NF-1)}')
+URL=$(git config --get remote.origin.url)
+REPO=$(basename "$URL" .git)
+OWNER=$(basename "$(dirname "$URL")")
 
-  for i in {1..30}; do
-    STATUS=$(curl -s \
-      -H "Authorization: token $GITEA_TOKEN" \
-      "https://git.pi-farm.de/api/v1/repos/$OWNER/$REPO/actions/runs?event=push" \
-      | jq -r '.workflow_runs[0].status')
+for i in {1..30}; do
+STATUS=$(curl -s 
+-H "Authorization: token $GITEA_TOKEN" 
+"[https://git.pi-farm.de/api/v1/repos/$OWNER/$REPO/actions/runs](https://git.pi-farm.de/api/v1/repos/$OWNER/$REPO/actions/runs)" 
+| jq -r '.workflow_runs[0].status // empty')
 
-    echo "CI status: $STATUS"
-    [ "$STATUS" = "success" ] && break
-    sleep 5
-  done
+```
+echo "CI status: $STATUS"
+[ "$STATUS" = "success" ] && break
+sleep 5
+```
+
+done
 fi
 
 echo "=== Release complete ==="