diff --git a/.devcontainer/.env b/.devcontainer/.env
index d9abf75..5db7736 100644
--- a/.devcontainer/.env
+++ b/.devcontainer/.env
@@ -1,5 +1,36 @@
-PYTHON_BASE=3.13
-DEVCONTAINER_IMAGE_REV=0.1
-DEVCONTAINER_IMAGE_PULL_REPO=docker.masara.eu/python
-DEVCONTAINER_IMAGE_PUSH_REPO=repo.masara.eu/python
-
+# Python version used in devcontainer image tag (e.g. 3.13).
+PYTHON_BASE=3.13
+
+# Image revision for versioned tag: <repo>:<python>-<rev>-devcontainer.
+DEVCONTAINER_IMAGE_REV=0.1
+
+# Registry/repository used by docker-compose to pull the devcontainer image.
+DEVCONTAINER_IMAGE_PULL_REPO=docker.masara.eu/python
+
+# Registry/repository used by publish script to push the devcontainer image.
+DEVCONTAINER_IMAGE_PUSH_REPO=repo.masara.eu/python
+
+# Private PyPI index URL used by pip inside the container.
+PIP_INDEX_URL=https://dv.masara.eu/repository/pypi-group/simple
+
+# Allows running pip as root without interactive warning/failure.
+PIP_ROOT_USER_ACTION=ignore
+
+# Workspace mount path inside container.
+WORKSPACE_DIR=/workspace
+
+# Path to virtual environment created/used by post_create.sh.
+VENV_PATH=/workspace/.venv
+
+# Requirements file installed by post_create.sh (if file exists).
+REQUIREMENTS_FILE=/workspace/requirements.txt
+
+
+# User used by VS Code remote server inside container (e.g. root).
+DEVCONTAINER_RUN_USER=root
+
+# UID for app user created in project Dockerfile (non-devcontainer image build).
+APP_USER_ID=1000
+
+# Home directory for REMOTE_USER inside container.
+REMOTE_HOME=/root
diff --git a/.devcontainer/devcontainer.json b/.devcontainer/devcontainer.json
index 99b30e3..f2e7703 100644
--- a/.devcontainer/devcontainer.json
+++ b/.devcontainer/devcontainer.json
@@ -1,60 +1,49 @@
 {
-  "name": "Python Dev",
-  "dockerComposeFile": "docker-compose.yml",
-  "service": "dev",
-  "containerEnv": {
-    "PIP_INDEX_URL": "https://dv.masara.eu/repository/pypi-group/simple",
-    "PIP_ROOT_USER_ACTION": "ignore"
-  },
-  "remoteEnv": {
-    "DOCKER_BUILDKIT": "1",
-    "VIRTUAL_ENV": "/workspace/.venv",
-    "PATH": "/workspace/.venv/bin:${containerEnv:PATH}"
-  },
-  "workspaceFolder": "/workspace",
-  "remoteUser": "root",
-  "overrideCommand": true,
-  "customizations": {
-    "vscode": {
-      "extensions": [
-        "ms-python.python",
-        "ms-python.vscode-pylance",
-        "ms-python.autopep8",
-        "ms-toolsai.jupyter",
-        "ms-python.black-formatter",
-        "ms-python.isort",
-        "codezombiech.gitignore",
-        "davidanson.vscode-markdownlint",
-        "ms-azuretools.vscode-docker",
-        "docker.docker",
-        "openai.chatgpt",
-        "continue.continue"
-      ],
-      "settings": {
-        "python.formatting.provider": "black",
-        "python.analysis.extraPaths": [
-          "${workspaceFolder}/app"
-        ],
-        "editor.formatOnSave": true,
-        "python.terminal.activateEnvironment": true,
-        "python.defaultInterpreterPath": ".venv/bin/python",
-        "remote.restoreForwardedPorts": false,
-        "remote.autoForwardPortsSource": "output",
-        "debug.javascript.autoAttachFilter": "disabled"
-      }
+    "name": "Python Dev",
+    "dockerComposeFile": "docker-compose.yml",
+    "service": "dev",
+    "workspaceFolder": "/workspace",
+    "overrideCommand": true,
+    "customizations": {
+        "vscode": {
+            "extensions": [
+                "ms-python.python",
+                "ms-python.vscode-pylance",
+                "ms-python.autopep8",
+                "ms-toolsai.jupyter",
+                "ms-python.black-formatter",
+                "ms-python.isort",
+                "codezombiech.gitignore",
+                "davidanson.vscode-markdownlint",
+                "ms-azuretools.vscode-docker",
+                "docker.docker",
+                "openai.chatgpt",
+                "continue.continue"
+            ],
+            "settings": {
+                "python.formatting.provider": "black",
+                "python.analysis.extraPaths": [
+                    "${workspaceFolder}/app"
+                ],
+                "python.analysis.typeCheckingMode": "basic",
+                "python.analysis.diagnosticMode": "workspace",
+                "editor.formatOnSave": true,
+                "python.terminal.activateEnvironment": true,
+                "python.defaultInterpreterPath": "${env:VENV_PATH}/bin/python",
+                "remote.restoreForwardedPorts": false,
+                "remote.autoForwardPortsSource": "output",
+                "debug.javascript.autoAttachFilter": "disabled"
+            }
+        }
+    },
+    "mounts": [
+        "type=bind,source=/var/run/docker.sock,target=/var/run/docker.sock"
+    ],
+    "postCreateCommand": "bash .devcontainer/post_create.sh",
+    "forwardPorts": [],
+    "portsAttributes": {
+        "*": {
+            "onAutoForward": "ignore"
+        }
     }
-  },
-  "mounts": [
-    "type=bind,source=/var/run/docker.sock,target=/var/run/docker.sock",
-    "type=volume,source=docextractor-codex,target=/root/.codex",
-    "type=bind,source=${localEnv:USERPROFILE}/.codex/auth.json,target=/root/.codex/auth.json,readonly",
-    "type=bind,source=${localEnv:USERPROFILE}/.pypirc,target=/root/.pypirc,readonly"
-  ],
-  "postCreateCommand": "bash .devcontainer/post_create.sh",
-  "forwardPorts": [],
-  "portsAttributes": {
-    "*": {
-      "onAutoForward": "ignore"
-    }
-  }
-}
+}
\ No newline at end of file
diff --git a/.devcontainer/docker-compose.yml b/.devcontainer/docker-compose.yml
index 50e46ec..faa2052 100644
--- a/.devcontainer/docker-compose.yml
+++ b/.devcontainer/docker-compose.yml
@@ -1,11 +1,22 @@
-services:
+services:
   dev:
     image: ${DEVCONTAINER_IMAGE_PULL_REPO}:${PYTHON_BASE}-${DEVCONTAINER_IMAGE_REV}-devcontainer
     pull_policy: always
     init: true
+    user: ${DEVCONTAINER_RUN_USER:-root}
     command: sleep infinity
     tty: true
     volumes:
       - ..:/workspace:cached
+      - docextractor-codex:${REMOTE_HOME:-/root}/.codex
+      - ${USERPROFILE}/.codex/auth.json:${REMOTE_HOME:-/root}/.codex/auth.json:ro
+      - ${USERPROFILE}/.pypirc:${REMOTE_HOME:-/root}/.pypirc:ro
     environment:
-      PYTHON_BASE: ${PYTHON_BASE}
+      PIP_INDEX_URL: ${PIP_INDEX_URL}
+      PIP_ROOT_USER_ACTION: ${PIP_ROOT_USER_ACTION}
+      WORKSPACE_DIR: ${WORKSPACE_DIR}
+      VENV_PATH: ${VENV_PATH}
+      REQUIREMENTS_FILE: ${REQUIREMENTS_FILE}
+
+volumes:
+  docextractor-codex:
\ No newline at end of file
diff --git a/.devcontainer/post_create.sh b/.devcontainer/post_create.sh
index ffa6d69..781c66d 100644
--- a/.devcontainer/post_create.sh
+++ b/.devcontainer/post_create.sh
@@ -1,7 +1,18 @@
 #!/usr/bin/env bash
-set -e
+set -euo pipefail
 
-VENV_PATH="/workspace/.venv"
+WORKSPACE_DIR="${WORKSPACE_DIR:-/workspace}"
+VENV_PATH="${VENV_PATH:-$WORKSPACE_DIR/.venv}"
+REQUIREMENTS_FILE="${REQUIREMENTS_FILE:-$WORKSPACE_DIR/requirements.txt}"
+# Resolve current user's home robustly (works for root and non-root users).
+USER_HOME="${HOME:-}"
+if [ -z "$USER_HOME" ] && command -v getent >/dev/null 2>&1; then
+    USER_HOME="$(getent passwd "$(id -un)" | cut -d: -f6)"
+fi
+if [ -z "$USER_HOME" ]; then
+    USER_HOME="/root"
+fi
+BASHRC_PATH="${BASHRC_PATH:-$USER_HOME/.bashrc}"
 
 # Ak venv neexistuje, vytvor ho a priprav pip
 if [ ! -d "$VENV_PATH" ]; then
@@ -19,17 +30,17 @@ echo "Aktualizujem pip a základné nástroje..."
 python -m pip install --upgrade pip setuptools wheel
 
 # Inštalácia závislostí, ak existuje requirements.txt
-if [ -f "/workspace/requirements.txt" ]; then
+if [ -f "$REQUIREMENTS_FILE" ]; then
     echo "Inštalujem závislosti z requirements.txt..."
-    python -m pip install -r /workspace/requirements.txt
+    python -m pip install -r "$REQUIREMENTS_FILE"
 else
     echo "requirements.txt nenájdený – preskakujem inštaláciu závislostí."
 fi
 
 # Ak sa terminál otvorí skôr, než Python extension stihne auto-aktiváciu,
 # zabezpečíme aktiváciu aj cez shell init.
-BASHRC="/root/.bashrc"
-ACTIVATE_LINE='[ -f /workspace/.venv/bin/activate ] && source /workspace/.venv/bin/activate'
-if ! grep -Fq "$ACTIVATE_LINE" "$BASHRC"; then
-    echo "$ACTIVATE_LINE" >> "$BASHRC"
+ACTIVATE_LINE="[ -f \"$VENV_PATH/bin/activate\" ] && source \"$VENV_PATH/bin/activate\""
+touch "$BASHRC_PATH"
+if ! grep -Fq "$ACTIVATE_LINE" "$BASHRC_PATH"; then
+    echo "$ACTIVATE_LINE" >> "$BASHRC_PATH"
 fi
diff --git a/Dockerfile b/Dockerfile
index 344e20d..d66b3a9 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,14 +1,20 @@
 # syntax=docker/dockerfile:1.6
 
-ARG PYTHON_BASE=3.13
-FROM python:${PYTHON_BASE}-slim
+ARG PYTHON_BASE=3.13
+ARG PIP_INDEX_URL=https://dv.masara.eu/repository/pypi-group/simple
+ARG APP_USER_ID=1000
+FROM python:${PYTHON_BASE}-slim
+
+# Re-declare build args for use in this build stage.
+ARG PIP_INDEX_URL
+ARG APP_USER_ID
 
-ENV PYTHONDONTWRITEBYTECODE=1 \
-    PYTHONUNBUFFERED=1 \
-    PIP_NO_CACHE_DIR=1 \
-    PIP_DISABLE_PIP_VERSION_CHECK=1 \
-    PIP_INDEX_URL=https://dv.masara.eu/repository/pypi-group/simple \
-    PIP_NO_INPUT=1
+ENV PYTHONDONTWRITEBYTECODE=1 \
+    PYTHONUNBUFFERED=1 \
+    PIP_NO_CACHE_DIR=1 \
+    PIP_DISABLE_PIP_VERSION_CHECK=1 \
+    PIP_INDEX_URL=${PIP_INDEX_URL} \
+    PIP_NO_INPUT=1
 
 WORKDIR /app
 
@@ -21,9 +27,8 @@ RUN --mount=type=cache,target=/root/.cache/pip \
 COPY app/ /app/
 
 # Vytvorenie ne-root usera
-ARG APP_USER_ID=1000
-RUN useradd -u ${APP_USER_ID} -m appuser && \
-    chown -R appuser:appuser /app
+RUN useradd -u ${APP_USER_ID} -m appuser && \
+    chown -R appuser:appuser /app
 
 USER appuser
 
diff --git a/README.md b/README.md
index 618beaa..34035ed 100644
--- a/README.md
+++ b/README.md
@@ -6,19 +6,34 @@ Template pre Python projekt s Dev Container workflow, kde sa devcontainer image
 
 - devcontainer konfiguraciu (`.devcontainer/devcontainer.json`)
 - compose definiciu pre devcontainer (`.devcontainer/docker-compose.yml`)
-- centralne nastavenie verzie Pythonu a image tagov (`.devcontainer/.env`)
+- centralne nastavenie premennych (`.devcontainer/.env`)
 - skript na build/push devcontainer image (`scripts/publish-devcontainer-image.ps1`)
 - VS Code tasky na build/push (`.vscode/tasks.json`)
-- vzorovy `Dockerfile` pre aplikaciu (`Dockerfile`)
+- hlavny `Dockerfile` pre aplikacny image (`Dockerfile`)
 
-## Centralne nastavenie verzie a repo
+## Konfiguracia cez `.devcontainer/.env`
 
-Vsetko sa riadi cez `.devcontainer/.env`:
+`.devcontainer/.env` je centralne miesto pre devcontainer premenne.
+Pouziva ho:
 
-- `PYTHON_BASE` - verzia Pythonu pre devcontainer image
-- `DEVCONTAINER_IMAGE_PULL_REPO` - odkial sa image taha pri otvoreni devcontainera (napr. `docker.masara.eu/python`)
-- `DEVCONTAINER_IMAGE_PUSH_REPO` - kam sa image pushuje pri publikovani (napr. `repo.masara.eu/python`)
-- `DEVCONTAINER_IMAGE_REV` - revizia image (napr. `0.1`)
+- `.devcontainer/docker-compose.yml` (image tag, user, volume cesty, container environment)
+- `scripts/publish-devcontainer-image.ps1` (tagovanie a push devcontainer image)
+- `Dockerfile` aplikacie (volitelne cez `--build-arg`)
+
+Aktualne premenne:
+
+- `PYTHON_BASE` - verzia Pythonu pre devcontainer image tag
+- `DEVCONTAINER_IMAGE_REV` - revizia devcontainer image
+- `DEVCONTAINER_IMAGE_PULL_REPO` - registry/repo odkial sa image taha pri otvoreni devcontainera
+- `DEVCONTAINER_IMAGE_PUSH_REPO` - registry/repo kam sa image publikuje
+- `PIP_INDEX_URL` - pip index URL v kontajneri
+- `PIP_ROOT_USER_ACTION` - pip spravanie pri root userovi
+- `WORKSPACE_DIR` - workspace cesta v kontajneri
+- `VENV_PATH` - cesta k virtualnemu prostrediu
+- `REQUIREMENTS_FILE` - cesta k requirements suboru pre `post_create.sh`
+- `DEVCONTAINER_RUN_USER` - Linux user, pod ktorym bezi devcontainer service
+- `APP_USER_ID` - UID usera `appuser` v hlavnom `Dockerfile`
+- `REMOTE_HOME` - home adresar pouzity pre `.codex` a `.pypirc` mounty
 
 ## Build a publish devcontainer image
 
@@ -29,8 +44,8 @@ Predpoklady:
 
 ### Cez VS Code task
 
-1. Spusti task `devcontainer: build and push image`.
-2. Task zavola skript `scripts/publish-devcontainer-image.ps1 -Push`.
+1. Spusti task `devcontainer: build image`.
+2. Alebo spusti `devcontainer: build and push image` pre build + push.
 
 ### Cez terminal
 
@@ -44,27 +59,62 @@ powershell -ExecutionPolicy Bypass -File scripts/publish-devcontainer-image.ps1
 
 Poznamka:
 
-- Ak `docker push` zlyha (napr. neautorizovany pristup), skript spravi fallback `docker login <registry>` a push zopakuje este raz.
+- Ak `docker push` zlyha (napr. neautorizovany pristup), skript skusi `docker login <registry>` a push zopakuje este raz.
 
-## Pouzitie pri vytvoreni/otvoreni projektu
+## Pouzitie vo VS Code
 
-1. Naklonuj alebo vytvor projekt z tejto sablony.
-2. Nastav hodnoty v `.devcontainer/.env` (hlavne `PYTHON_BASE`, pull/push repo, revision).
-3. Ak menis base image (napr. Python verziu), publikuj novu verziu devcontainer image do push registry.
-4. Otvor projekt vo VS Code a pouzi `Reopen in Container`.
+1. Nastav hodnoty v `.devcontainer/.env`.
+2. Ak si menil `PYTHON_BASE` alebo image repo/rev, najprv publikuj novu devcontainer image.
+3. Otvor projekt vo VS Code a pouzi `Reopen in Container`.
 
-Devcontainer sa spusti z image definovaneho v `.devcontainer/docker-compose.yml`:
+Pri starte kontajnera:
 
 - image sa taha z `DEVCONTAINER_IMAGE_PULL_REPO`
-- workspace je pripojeny bind mountom do `/workspace`
-- `postCreateCommand` vytvori `.venv` a nainstaluje zavislosti z `requirements.txt`
+- workspace sa mountuje do `/workspace`
+- `postCreateCommand` (`.devcontainer/post_create.sh`) vytvori `.venv` a nainstaluje zavislosti z `REQUIREMENTS_FILE`
+- Python vo VS Code pouziva `${env:VENV_PATH}/bin/python`
 
-## Bezne scenare
+## VS Code extensions a settings
 
-- Chcem iba zmenit Python verziu:
-  1. Zmen `PYTHON_BASE` v `.devcontainer/.env`.
-  2. Spusti `devcontainer: build and push image`.
-  3. Vo VS Code daj `Rebuild/Reopen in Container`.
+Devcontainer automaticky instaluje tieto VS Code extensions:
 
-- Chcem zmenit iba aplikacny kod:
-  - Nerebuildi sa devcontainer image, staci reopen/restart kontajnera podla potreby.
+- `ms-python.python`
+- `ms-python.vscode-pylance`
+- `ms-python.autopep8`
+- `ms-toolsai.jupyter`
+- `ms-python.black-formatter`
+- `ms-python.isort`
+- `codezombiech.gitignore`
+- `davidanson.vscode-markdownlint`
+- `ms-azuretools.vscode-docker`
+- `docker.docker`
+- `openai.chatgpt`
+- `continue.continue`
+
+Pouzite VS Code settings v devcontainery:
+
+- `python.formatting.provider: black`
+- `python.analysis.extraPaths: ["${workspaceFolder}/app"]`
+- `python.analysis.typeCheckingMode: "basic"`
+- `python.analysis.diagnosticMode: "workspace"`
+- `editor.formatOnSave: true`
+- `python.terminal.activateEnvironment: true`
+- `python.defaultInterpreterPath: "${env:VENV_PATH}/bin/python"`
+- `remote.restoreForwardedPorts: false`
+- `remote.autoForwardPortsSource: "output"`
+- `debug.javascript.autoAttachFilter: "disabled"`
+
+## Aplikacny Dockerfile
+
+Hlavny `Dockerfile` podporuje build argumenty `PYTHON_BASE`, `PIP_INDEX_URL` a `APP_USER_ID`.
+
+Priklad buildu s hodnotami z `.devcontainer/.env`:
+
+```bash
+set -a; source .devcontainer/.env; set +a
+docker build \
+  --build-arg PYTHON_BASE="$PYTHON_BASE" \
+  --build-arg PIP_INDEX_URL="$PIP_INDEX_URL" \
+  --build-arg APP_USER_ID="$APP_USER_ID" \
+  -t myapp:local .
+```