diff --git a/install.sh b/install.sh
index a372a96..74003fe 100755
--- a/install.sh
+++ b/install.sh
@@ -23,36 +23,146 @@ warn() { printf "${YELLOW}⚠${NC} %s\n" "$1"; }
 err()  { printf "${RED}✗${NC} %s\n" "$1"; }
 info() { printf "${CYAN}→${NC} %s\n" "$1"; }
 
-# ── Prerequisites ────────────────────────────────
-prereqs=("git" "docker")
-missing=()
-for cmd in "${prereqs[@]}"; do
-  if ! command -v "$cmd" &>/dev/null; then
-    missing+=("$cmd")
+# ── OS detection ──────────────────────────────────
+detect_os() {
+  if [ -f /etc/os-release ]; then
+    . /etc/os-release
+    echo "$ID"
+  elif command -v lsb_release &>/dev/null; then
+    lsb_release -si | tr '[:upper:]' '[:lower:]'
+  else
+    echo "unknown"
   fi
-done
+}
+
+OS=$(detect_os)
+ARCH=$(uname -m)
+
+# ── Git ──────────────────────────────────────────
+if ! command -v git &>/dev/null; then
+  info "Installing git..."
+  case "$OS" in
+    ubuntu|debian)          sudo apt update -qq && sudo apt install -y -qq git ;;
+    arch|endeavouros)       sudo pacman -S --noconfirm git ;;
+    fedora|centos|rhel|almalinux|rocky) sudo dnf install -y git ;;
+    *)                      err "Unsupported OS: $OS. Install git manually." && exit 1 ;;
+  esac
+  log "git installed"
+fi
+
+# ── Docker ───────────────────────────────────────
+NEED_DOCKER=false
+NEED_COMPOSE=false
+
+if ! command -v docker &>/dev/null; then
+  NEED_DOCKER=true
+fi
 
 if ! docker compose version &>/dev/null && ! docker-compose --version &>/dev/null; then
-  missing+=("docker compose plugin")
+  NEED_COMPOSE=true
 fi
 
-if [ ${#missing[@]} -gt 0 ]; then
-  err "Missing prerequisites: ${missing[*]}"
-  info "Install them and re-run:"
-  info "  Ubuntu/Debian: sudo apt update && sudo apt install -y git docker.io docker-compose-v2"
-  info "  Arch:           sudo pacman -S git docker docker-compose"
-  info "  Fedora:         sudo dnf install -y git docker docker-compose"
-  exit 1
+if $NEED_DOCKER; then
+  info "Installing Docker Engine..."
+  case "$OS" in
+    ubuntu|debian)
+      sudo apt update -qq
+      sudo apt install -y -qq ca-certificates curl
+      sudo install -m 0755 -d /etc/apt/keyrings
+      sudo curl -fsSL https://download.docker.com/linux/"$OS"/gpg -o /etc/apt/keyrings/docker.asc
+      sudo chmod a+r /etc/apt/keyrings/docker.asc
+      echo "deb [arch=$ARCH signed-by=/etc/apt/keyrings/docker.asc] https://download.docker.com/linux/$OS $(. /etc/os-release && echo "$VERSION_CODENAME") stable" \
+        | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
+      sudo apt update -qq
+      sudo apt install -y -qq docker-ce docker-ce-cli containerd.io
+      ;;
+    arch|endeavouros)
+      sudo pacman -S --noconfirm docker
+      ;;
+    fedora)
+      sudo dnf install -y dnf-plugins-core
+      sudo dnf config-manager --add-repo https://download.docker.com/linux/fedora/docker-ce.repo
+      sudo dnf install -y docker-ce docker-ce-cli containerd.io
+      ;;
+    centos|rhel|almalinux|rocky)
+      sudo dnf install -y dnf-plugins-core
+      sudo dnf config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
+      sudo dnf install -y docker-ce docker-ce-cli containerd.io
+      ;;
+    *)
+      err "Unsupported OS: $OS. Install Docker manually: https://docs.docker.com/engine/install/"
+      exit 1
+      ;;
+  esac
+  log "Docker Engine installed"
 fi
-log "Prerequisites satisfied"
 
-# Check docker is running
+if $NEED_COMPOSE && ! command -v docker &>/dev/null; then
+  # fresh install — compose plugin is already included in docker-ce package
+  NEED_COMPOSE=false
+fi
+
+if $NEED_COMPOSE; then
+  info "Installing Docker Compose plugin..."
+  case "$OS" in
+    ubuntu|debian)
+      sudo apt install -y -qq docker-compose-v2 2>/dev/null || {
+        sudo apt install -y -qq docker-compose-plugin 2>/dev/null || {
+          warn "Compose plugin not in apt. Installing via CLI plugin..."
+          CLI_PLUGINS="/usr/lib/docker/cli-plugins"
+          sudo mkdir -p "$CLI_PLUGINS"
+          sudo curl -fsSL "https://github.com/docker/compose/releases/latest/download/docker-compose-$(uname -s)-$(uname -m)" -o "$CLI_PLUGINS/docker-compose"
+          sudo chmod +x "$CLI_PLUGINS/docker-compose"
+        }
+      }
+      ;;
+    arch|endeavouros)
+      sudo pacman -S --noconfirm docker-compose
+      ;;
+    fedora|centos|rhel|almalinux|rocky)
+      sudo dnf install -y docker-compose-v2 2>/dev/null || {
+        CLI_PLUGINS="/usr/lib/docker/cli-plugins"
+        sudo mkdir -p "$CLI_PLUGINS"
+        sudo curl -fsSL "https://github.com/docker/compose/releases/latest/download/docker-compose-$(uname -s)-$(uname -m)" -o "$CLI_PLUGINS/docker-compose"
+        sudo chmod +x "$CLI_PLUGINS/docker-compose"
+      }
+      ;;
+  esac
+  log "Docker Compose plugin installed"
+fi
+
+log "Docker prerequisites satisfied"
+
+# ── Start Docker daemon ─────────────────────────
 if ! docker info &>/dev/null; then
-  err "Docker daemon is not running. Start it with: sudo systemctl start docker"
-  exit 1
+  info "Starting Docker daemon..."
+  if command -v systemctl &>/dev/null; then
+    sudo systemctl enable --now docker
+  elif command -v service &>/dev/null; then
+    sudo service docker start
+  else
+    sudo dockerd &>/dev/null &
+    sleep 3
+  fi
 fi
 log "Docker daemon is running"
 
+# ── Add user to docker group ────────────────────
+if ! groups "$USER" | grep -q docker; then
+  info "Adding $USER to the docker group..."
+  sudo usermod -aG docker "$USER"
+  # Spawn subshell with the new group so rest of script can use docker without sudo
+  sg docker -c "true" 2>/dev/null || true
+  warn "You may need to re-login for group changes to take effect in new shells"
+fi
+
+# Use sudo for docker commands if the current shell can't run docker directly
+if docker info &>/dev/null 2>&1; then
+  DOCKER_CMD="docker"
+else
+  DOCKER_CMD="sg docker -c docker"
+fi
+
 # ── Clone / Pull ─────────────────────────────────
 if [ -d "$INSTALL_DIR" ]; then
   info "Directory $INSTALL_DIR already exists — pulling latest"
@@ -86,22 +196,22 @@ log "Data directory ready"
 
 # ── Build & Start ────────────────────────────────
 info "Building Docker image (this may take a few minutes)..."
-docker compose build web
+$DOCKER_CMD compose build web
 log "Build complete"
 
 info "Starting containers..."
-docker compose up -d
+$DOCKER_CMD compose up -d
 log "Containers are running"
 
 # ── Wait for health ──────────────────────────────
 info "Waiting for web service to be healthy..."
 for i in $(seq 1 30); do
-  if docker compose exec -T web wget --no-verbose --tries=1 --spider http://127.0.0.1:3000/api/health &>/dev/null; then
+  if $DOCKER_CMD compose exec -T web wget --no-verbose --tries=1 --spider http://127.0.0.1:3000/api/health &>/dev/null; then
     log "Web service is healthy"
     break
   fi
   if [ "$i" -eq 30 ]; then
-    warn "Timed out waiting for health check — check logs with: docker compose logs web"
+    warn "Timed out waiting for health check — check logs with: $DOCKER_CMD compose logs web"
   fi
   sleep 2
 done
@@ -110,17 +220,19 @@ done
 IP=$(curl -fsSL http://checkip.amazonaws.com 2>/dev/null || curl -fsSL https://api.ipify.org 2>/dev/null || echo "localhost")
 
 # ── Summary ──────────────────────────────────────
+BOX_W=60
+hr() { printf "║  %-*s  ║\n" "$((BOX_W-6))" "$1"; }
 printf "\n"
-printf "╔══════════════════════════════════════════════╗\n"
-printf "║         ${GREEN}worst-scan-web installed!${NC}         ║\n"
-printf "╠══════════════════════════════════════════════╣\n"
-printf "║  Web:      http://%s:3000              ║\n" "$IP"
-printf "║  Config:   %s/.env                  ║\n" "$INSTALL_DIR"
-printf "║  Logs:     docker compose logs -f            ║\n"
-printf "║  Restart:  docker compose restart            ║\n"
-printf "║  Stop:     docker compose down               ║\n"
-printf "║  Update:   bash %s/install.sh         ║\n" "$INSTALL_DIR"
-printf "╚══════════════════════════════════════════════╝\n"
+printf "╔══════════════════════════════════════════════════════════════╗\n"
+printf "║             ${GREEN}worst-scan-web installed!${NC}                    ║\n"
+printf "╠══════════════════════════════════════════════════════════════╣\n"
+hr "Web:      http://$IP:3000"
+hr "Config:   $INSTALL_DIR/.env"
+hr "Logs:     cd $INSTALL_DIR && docker compose logs -f"
+hr "Restart:  cd $INSTALL_DIR && docker compose restart"
+hr "Stop:     cd $INSTALL_DIR && docker compose down"
+hr "Update:   bash install.sh"
+printf "╚══════════════════════════════════════════════════════════════╝\n"
 printf "\n"
 info "Next steps:"
 printf "  1. Open http://%s:3000/setup in your browser\n" "$IP"