Add visual smoothing for snake game and systemd deployment

CSS animations for smoother 60fps feel despite 7Hz game ticks:
- 130ms transitions on cell background/box-shadow
- Head pop-in animation on direction changes
- Food pulse animation
- Smooth death state fade with grayscale

Per-snake colored glow on head cells.

Make server port configurable via PORT env var (default 8080).

Add deploy/ with systemd service and scripts:
- setup.sh: create games user, /opt/c4, install unit
- deploy.sh: build and install binary, restart service
- package.sh: cross-compile, tarball, base64 split for transfer
- reassemble.sh: decode and extract on target server

assets/css/input.css

@@ -75,13 +75,30 @@
 .snake-cell {
   background: #16213e;
   border: 1px solid rgba(255,255,255,0.03);
-  transition: background 0.05s;
+  transition: background 130ms ease-in-out, box-shadow 130ms ease-out;
+}
+.snake-cell.snake-head {
+  border-radius: 4px;
+  animation: head-pop 130ms ease-out;
+}
+@keyframes head-pop {
+  0% { transform: scale(0.6); }
+  50% { transform: scale(1.08); }
+  100% { transform: scale(1); }
 }
 .snake-cell.snake-food {
   background: #ff6b6b;
   border-radius: 50%;
   box-shadow: 0 0 6px rgba(255,107,107,0.6);
+  animation: food-pulse 1.2s ease-in-out infinite alternate;
+}
+@keyframes food-pulse {
+  from { box-shadow: 0 0 6px rgba(255,107,107,0.4); transform: scale(0.85); }
+  to { box-shadow: 0 0 12px rgba(255,107,107,0.9); transform: scale(1); }
+}
+.snake-cell.snake-dead {
+  opacity: 0.35;
+  filter: grayscale(0.5);
+  transition: opacity 400ms ease-out, background 130ms ease-in-out;
 }
-.snake-cell.snake-head { border-radius: 4px; }
-.snake-cell.snake-dead { opacity: 0.35; }
 .snake-wrapper:focus { outline: none; }

deploy/c4.service

@@ -0,0 +1,24 @@
+[Unit]
+Description=C4 Game Lobby
+After=network.target
+
+[Service]
+Type=simple
+User=games
+Group=games
+WorkingDirectory=/opt/c4
+ExecStart=/opt/c4/c4
+Restart=on-failure
+RestartSec=5
+
+Environment=PORT=8080
+
+# Hardening
+NoNewPrivileges=true
+ProtectSystem=strict
+ProtectHome=true
+ReadWritePaths=/opt/c4
+PrivateTmp=true
+
+[Install]
+WantedBy=multi-user.target

deploy/deploy.sh

@@ -0,0 +1,31 @@
+#!/usr/bin/env bash
+# Deploy the c4 binary to /opt/c4, then restart the service.
+# Works from the repo (builds first) or from an extracted tarball (pre-built binary).
+set -euo pipefail
+
+ROOT_DIR="$(cd "$(dirname "$0")/.." && pwd)"
+INSTALL_DIR="/opt/c4"
+BINARY="$ROOT_DIR/c4"
+
+# If Go is available and we have source, build fresh
+if [[ -f "$ROOT_DIR/go.mod" ]] && command -v go &>/dev/null; then
+  echo "Building CSS..."
+  (cd "$ROOT_DIR" && go tool gotailwind -i assets/css/input.css -o assets/css/output.css --minify)
+
+  echo "Building binary..."
+  (cd "$ROOT_DIR" && CGO_ENABLED=0 go build -o c4 .)
+fi
+
+if [[ ! -f "$BINARY" ]]; then
+  echo "ERROR: Binary not found at $BINARY" >&2
+  exit 1
+fi
+
+echo "Installing to $INSTALL_DIR..."
+install -o games -g games -m 755 "$BINARY" "$INSTALL_DIR/c4"
+
+echo "Restarting service..."
+systemctl restart c4.service
+
+echo "Done. Status:"
+systemctl status c4.service --no-pager

deploy/package.sh

@@ -0,0 +1,87 @@
+#!/usr/bin/env bash
+# Build the c4 binary, bundle it with deploy files into a tarball,
+# base64-encode it, and split into 25MB chunks for transfer.
+set -euo pipefail
+
+REPO_DIR="$(cd "$(dirname "$0")/.." && pwd)"
+cd "$REPO_DIR"
+
+TIMESTAMP=$(date +%Y%m%d-%H%M%S)
+TARBALL="c4-deploy-${TIMESTAMP}.tar.gz"
+BASE64_FILE="c4-deploy-${TIMESTAMP}_b64.txt"
+
+#==============================================================================
+# Clean previous artifacts
+#==============================================================================
+echo "--- Cleaning old artifacts ---"
+rm -f ./c4 c4-deploy-*.tar.gz c4-deploy-*_b64*.txt
+
+#==============================================================================
+# Build
+#==============================================================================
+echo "--- Building CSS ---"
+go tool gotailwind -i assets/css/input.css -o assets/css/output.css --minify
+
+echo "--- Building binary (linux/amd64) ---"
+CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -o c4 .
+
+#==============================================================================
+# Verify required files
+#==============================================================================
+echo "--- Verifying files ---"
+REQUIRED_FILES=(
+  c4
+  deploy/setup.sh
+  deploy/deploy.sh
+  deploy/reassemble.sh
+  deploy/c4.service
+)
+for f in "${REQUIRED_FILES[@]}"; do
+  if [[ ! -f "$f" ]]; then
+    echo "ERROR: Missing required file: $f" >&2
+    exit 1
+  fi
+  echo "  OK $f"
+done
+
+#==============================================================================
+# Create tarball
+#==============================================================================
+echo "--- Creating tarball ---"
+tar -czf "/tmp/${TARBALL}" --transform 's,^,c4/,' \
+  c4 \
+  deploy/setup.sh \
+  deploy/deploy.sh \
+  deploy/reassemble.sh \
+  deploy/c4.service
+
+mv "/tmp/${TARBALL}" .
+echo "  -> ${TARBALL} ($(du -h "${TARBALL}" | cut -f1))"
+
+#==============================================================================
+# Base64 encode and split
+#==============================================================================
+echo "--- Base64 encoding ---"
+base64 "${TARBALL}" > "${BASE64_FILE}"
+echo "  -> ${BASE64_FILE} ($(du -h "${BASE64_FILE}" | cut -f1))"
+
+echo "--- Splitting into 25MB chunks ---"
+split -b 25M -d --additional-suffix=.txt "${BASE64_FILE}" "c4-deploy-${TIMESTAMP}_b64_part"
+rm -f "${BASE64_FILE}"
+
+CHUNKS=(c4-deploy-${TIMESTAMP}_b64_part*.txt)
+echo "  -> ${#CHUNKS[@]} chunk(s):"
+for chunk in "${CHUNKS[@]}"; do
+  echo "     $chunk ($(du -h "$chunk" | cut -f1))"
+done
+
+#==============================================================================
+# Done
+#==============================================================================
+echo ""
+echo "=== Package Complete ==="
+echo ""
+echo "Transfer the chunk files to the target server, then run:"
+echo "  ./reassemble.sh"
+echo "  cd ~/c4 && sudo ./deploy/setup.sh   # first time only"
+echo "  cd ~/c4 && sudo ./deploy/deploy.sh"

deploy/reassemble.sh

@@ -0,0 +1,96 @@
+#!/usr/bin/env bash
+# Reassembles base64 chunks and extracts the c4 deployment tarball.
+# Expects chunk files in the current directory.
+set -euo pipefail
+
+cd "$HOME"
+
+echo "=== C4 Deployment Reassembler ==="
+echo "Working directory: $HOME"
+echo ""
+
+#==============================================================================
+# Find and validate chunk files
+#==============================================================================
+echo "--- Finding chunk files ---"
+
+CHUNKS=($(ls -1 c4-deploy-*_b64_part*.txt 2>/dev/null | sort))
+
+if [[ ${#CHUNKS[@]} -eq 0 ]]; then
+  echo "ERROR: No chunk files found matching c4-deploy-*_b64_part*.txt"
+  exit 1
+fi
+
+echo "Found ${#CHUNKS[@]} chunks:"
+for chunk in "${CHUNKS[@]}"; do
+  echo "  - $chunk ($(du -h "$chunk" | cut -f1))"
+done
+
+#==============================================================================
+# Reassemble and decode
+#==============================================================================
+echo ""
+echo "--- Reassembling chunks ---"
+
+TIMESTAMP=$(echo "${CHUNKS[0]}" | sed -E 's/c4-deploy-([0-9]+-[0-9]+)_b64_part.*/\1/')
+TARBALL="c4-deploy-${TIMESTAMP}.tar.gz"
+COMBINED="combined_b64.txt"
+
+echo "Concatenating chunks..."
+cat "${CHUNKS[@]}" > "$COMBINED"
+echo "  -> Created $COMBINED ($(du -h "$COMBINED" | cut -f1))"
+
+echo "Decoding base64..."
+base64 -d "$COMBINED" > "$TARBALL"
+echo "  -> Created $TARBALL ($(du -h "$TARBALL" | cut -f1))"
+
+echo "Verifying tarball..."
+if tar -tzf "$TARBALL" > /dev/null 2>&1; then
+  echo "  -> Tarball is valid"
+else
+  echo "ERROR: Tarball verification failed"
+  exit 1
+fi
+
+#==============================================================================
+# Archive existing source
+#==============================================================================
+echo ""
+echo "--- Archiving existing source ---"
+
+if [[ -d c4 ]]; then
+  rm -rf c4.bak
+  mv c4 c4.bak
+  echo "  -> Moved c4 -> c4.bak"
+else
+  echo "  -> No existing c4 directory"
+fi
+
+#==============================================================================
+# Extract
+#==============================================================================
+echo ""
+echo "--- Extracting tarball ---"
+
+tar -xzf "$TARBALL"
+echo "  -> Extracted to ~/c4"
+
+#==============================================================================
+# Cleanup
+#==============================================================================
+echo ""
+echo "--- Cleaning up ---"
+
+rm -f "$COMBINED" "$TARBALL" "${CHUNKS[@]}"
+echo "  -> Removed chunks, combined base64, and tarball"
+
+#==============================================================================
+# Next steps
+#==============================================================================
+echo ""
+echo "=== Reassembly Complete ==="
+echo ""
+echo "Next steps:"
+echo "  cd ~/c4"
+echo "  sudo ./deploy/setup.sh   # first time only"
+echo "  sudo ./deploy/deploy.sh"

deploy/setup.sh

@@ -0,0 +1,29 @@
+#!/usr/bin/env bash
+# One-time setup: create the games user, install directory, and systemd unit.
+# Run as root (or with sudo).
+set -euo pipefail
+
+if [[ $EUID -ne 0 ]]; then
+  echo "Run as root: sudo $0" >&2
+  exit 1
+fi
+
+# Create system user if it doesn't exist
+if ! id -u games &>/dev/null; then
+  useradd --system --shell /usr/sbin/nologin --home-dir /opt/c4 --create-home games
+  echo "Created system user: games"
+else
+  echo "User 'games' already exists"
+fi
+
+# Ensure install directory exists with correct ownership
+install -d -o games -g games -m 755 /opt/c4
+install -d -o games -g games -m 755 /opt/c4/data
+
+# Install systemd unit
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+cp "$SCRIPT_DIR/c4.service" /etc/systemd/system/c4.service
+systemctl daemon-reload
+systemctl enable c4.service
+
+echo "Setup complete. Run deploy.sh to build and start the service."

main.go

@@ -6,6 +6,7 @@ import (
 	_ "embed"
 	"log"
 	"net/http"
+	"os"
 
 	"github.com/google/uuid"
 
@@ -20,9 +21,11 @@ import (
 	"github.com/ryanhamamura/via/vianats"
 )
 
-var store = game.NewGameStore()
+var (
-var snakeStore = snake.NewSnakeStore()
+	store      = game.NewGameStore()
-var queries *gen.Queries
+	snakeStore = snake.NewSnakeStore()
+	queries    *gen.Queries
+)
 
 //go:embed assets/css/output.css
 var daisyUICSS []byte
@@ -35,6 +38,13 @@ func DaisyUIPlugin(v *via.V) {
 	v.AppendToHead(h.Link(h.Rel("stylesheet"), h.Href("/_plugins/daisyui/style.css")))
 }
 
+func port() string {
+	if p := os.Getenv("PORT"); p != "" {
+		return p
+	}
+	return "7331"
+}
+
 func main() {
 	if err := db.Init("c4.db"); err != nil {
 		log.Fatal(err)
@@ -60,7 +70,7 @@ func main() {
 	v.Config(via.Options{
 		LogLevel:       via.LogLevelDebug,
 		DocumentTitle:  "Game Lobby",
-		ServerAddress:  ":7331",
+		ServerAddress:  ":" + port(),
 		SessionManager: sessionManager,
 		PubSub:         ns,
 		Plugins:        []via.Plugin{DaisyUIPlugin},

ui/snakeboard.go

@@ -64,8 +64,9 @@ func SnakeBoard(sg *snake.SnakeGame) h.H {
 			case ci.snakeIdx >= 0:
 				s := state.Snakes[ci.snakeIdx]
 				colorIdx := ci.snakeIdx
+				bg := ""
 				if colorIdx < len(snake.SnakeColors) {
-					bg := snake.SnakeColors[colorIdx]
+					bg = snake.SnakeColors[colorIdx]
 					style += fmt.Sprintf("background:%s;", bg)
 				}
 				if !s.Alive {
@@ -73,6 +74,9 @@ func SnakeBoard(sg *snake.SnakeGame) h.H {
 				}
 				if ci.isHead {
 					class += " snake-head"
+					if bg != "" {
+						style += fmt.Sprintf("box-shadow:0 0 8px %s;", bg)
+					}
 				}
 			}