diff --git a/Makefile b/Makefile
index deb75f8..6ae9ab0 100644
--- a/Makefile
+++ b/Makefile
@@ -36,7 +36,7 @@ export TEST_PATTERN
 # ------------------------------------------------------------
 install:
 	@echo "Building and installing distro-native package-manager for this system..."
-	@bash scripts/installation/main.sh
+	@bash scripts/installation/init.sh
 
 # ------------------------------------------------------------
 # PKGMGR setup
diff --git a/scripts/installation/dependencies.sh b/scripts/installation/dependencies.sh
index 41187b7..f16f330 100755
--- a/scripts/installation/dependencies.sh
+++ b/scripts/installation/dependencies.sh
@@ -3,22 +3,19 @@ set -euo pipefail
 
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 
-# shellcheck source=/dev/null
-source "${SCRIPT_DIR}/lib.sh"
+# shellcheck disable=SC1091
+source "${SCRIPT_DIR}/os_resolver.sh"
 
-OS_ID="$(detect_os_id)"
+OS_ID="$(osr_get_os_id)"
 
 echo "[run-dependencies] Detected OS: ${OS_ID}"
 
-case "${OS_ID}" in
-  arch|debian|ubuntu|fedora|centos)
-    DEP_SCRIPT="${SCRIPT_DIR}/${OS_ID}/dependencies.sh"
-    ;;
-  *)
-    echo "[run-dependencies] Unsupported OS: ${OS_ID}"
-    exit 1
-    ;;
-esac
+if ! osr_is_supported "${OS_ID}"; then
+  echo "[run-dependencies] Unsupported OS: ${OS_ID}"
+  exit 1
+fi
+
+DEP_SCRIPT="$(osr_script_path_for "${SCRIPT_DIR}" "${OS_ID}" "dependencies")"
 
 if [[ ! -f "${DEP_SCRIPT}" ]]; then
   echo "[run-dependencies] Dependency script not found: ${DEP_SCRIPT}"
diff --git a/scripts/installation/main.sh b/scripts/installation/init.sh
similarity index 100%
rename from scripts/installation/main.sh
rename to scripts/installation/init.sh
diff --git a/scripts/installation/lib.sh b/scripts/installation/lib.sh
deleted file mode 100755
index 9838647..0000000
--- a/scripts/installation/lib.sh
+++ /dev/null
@@ -1,12 +0,0 @@
-#!/usr/bin/env bash
-set -euo pipefail
-
-detect_os_id() {
-  if [[ -f /etc/os-release ]]; then
-    # shellcheck disable=SC1091
-    . /etc/os-release
-    echo "${ID:-unknown}"
-  else
-    echo "unknown"
-  fi
-}
diff --git a/scripts/installation/os_resolver.sh b/scripts/installation/os_resolver.sh
new file mode 100644
index 0000000..8b1005d
--- /dev/null
+++ b/scripts/installation/os_resolver.sh
@@ -0,0 +1,82 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# -----------------------------------------------------------------------------
+# OsResolver (bash "class-style" module)
+# Centralizes OS detection + normalization + supported checks + script paths.
+# -----------------------------------------------------------------------------
+
+osr_detect_raw_id() {
+  if [[ -f /etc/os-release ]]; then
+    # shellcheck disable=SC1091
+    . /etc/os-release
+    echo "${ID:-unknown}"
+  else
+    echo "unknown"
+  fi
+}
+
+osr_detect_id_like() {
+  if [[ -f /etc/os-release ]]; then
+    # shellcheck disable=SC1091
+    . /etc/os-release
+    echo "${ID_LIKE:-}"
+  else
+    echo ""
+  fi
+}
+
+osr_normalize_id() {
+  local raw="${1:-unknown}"
+  local like="${2:-}"
+
+  # Explicit mapping first (your bugfix: manjaro -> arch everywhere)
+  case "${raw}" in
+    manjaro) echo "arch"; return 0 ;;
+  esac
+
+  # Keep direct IDs when they are already supported
+  case "${raw}" in
+    arch|debian|ubuntu|fedora|centos) echo "${raw}"; return 0 ;;
+  esac
+
+  # Fallback mapping via ID_LIKE for better portability
+  # Example: many Arch derivatives expose ID_LIKE="arch"
+  if [[ " ${like} " == *" arch "* ]]; then
+    echo "arch"; return 0
+  fi
+  if [[ " ${like} " == *" debian "* ]]; then
+    echo "debian"; return 0
+  fi
+  if [[ " ${like} " == *" fedora "* ]]; then
+    echo "fedora"; return 0
+  fi
+  if [[ " ${like} " == *" rhel "* || " ${like} " == *" centos "* ]]; then
+    echo "centos"; return 0
+  fi
+
+  echo "${raw}"
+}
+
+osr_get_os_id() {
+  local raw like
+  raw="$(osr_detect_raw_id)"
+  like="$(osr_detect_id_like)"
+  osr_normalize_id "${raw}" "${like}"
+}
+
+osr_is_supported() {
+  local id="${1:-unknown}"
+  case "${id}" in
+    arch|debian|ubuntu|fedora|centos) return 0 ;;
+    *) return 1 ;;
+  esac
+}
+
+osr_script_path_for() {
+  local script_dir="${1:?script_dir required}"
+  local os_id="${2:?os_id required}"
+  local kind="${3:?kind required}" # "dependencies" or "package"
+
+  echo "${script_dir}/${os_id}/${kind}.sh"
+}
diff --git a/scripts/installation/package.sh b/scripts/installation/package.sh
index b006046..8bf05c2 100755
--- a/scripts/installation/package.sh
+++ b/scripts/installation/package.sh
@@ -3,28 +3,19 @@ set -euo pipefail
 
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 
-# shellcheck source=/dev/null
-source "${SCRIPT_DIR}/lib.sh"
+# shellcheck disable=SC1091
+source "${SCRIPT_DIR}/os_resolver.sh"
 
-OS_ID="$(detect_os_id)"
-
-# Map Manjaro to Arch
-if [[ "${OS_ID}" == "manjaro" ]]; then
-  echo "[package] Mapping OS 'manjaro' → 'arch'"
-  OS_ID="arch"
-fi
+OS_ID="$(osr_get_os_id)"
 
 echo "[package] Detected OS: ${OS_ID}"
 
-case "${OS_ID}" in
-  arch|debian|ubuntu|fedora|centos)
-    PKG_SCRIPT="${SCRIPT_DIR}/${OS_ID}/package.sh"
-    ;;
-  *)
-    echo "[package] Unsupported OS: ${OS_ID}"
-    exit 1
-    ;;
-esac
+if ! osr_is_supported "${OS_ID}"; then
+  echo "[package] Unsupported OS: ${OS_ID}"
+  exit 1
+fi
+
+PKG_SCRIPT="$(osr_script_path_for "${SCRIPT_DIR}" "${OS_ID}" "package")"
 
 if [[ ! -f "${PKG_SCRIPT}" ]]; then
   echo "[package] Package script not found: ${PKG_SCRIPT}"