diff --git a/assets/effects/flame.png b/assets/effects/flame.png
new file mode 100644
index 0000000..f33b5af
Binary files /dev/null and b/assets/effects/flame.png differ
diff --git a/assets/effects/flame.png.import b/assets/effects/flame.png.import
new file mode 100644
index 0000000..9ffbc70
--- /dev/null
+++ b/assets/effects/flame.png.import
@@ -0,0 +1,40 @@
+[remap]
+
+importer="texture"
+type="CompressedTexture2D"
+uid="uid://bvxhc5epqpwms"
+path="res://.godot/imported/flame.png-5c6c1591c52492c60f7d263f90723222.ctex"
+metadata={
+"vram_texture": false
+}
+
+[deps]
+
+source_file="res://assets/effects/flame.png"
+dest_files=["res://.godot/imported/flame.png-5c6c1591c52492c60f7d263f90723222.ctex"]
+
+[params]
+
+compress/mode=0
+compress/high_quality=false
+compress/lossy_quality=0.7
+compress/uastc_level=0
+compress/rdo_quality_loss=0.0
+compress/hdr_compression=1
+compress/normal_map=0
+compress/channel_pack=0
+mipmaps/generate=false
+mipmaps/limit=-1
+roughness/mode=0
+roughness/src_normal=""
+process/channel_remap/red=0
+process/channel_remap/green=1
+process/channel_remap/blue=2
+process/channel_remap/alpha=3
+process/fix_alpha_border=true
+process/premult_alpha=false
+process/normal_map_invert_y=false
+process/hdr_as_srgb=false
+process/hdr_clamp_exposure=false
+process/size_limit=0
+detect_3d/compress_to=1
diff --git a/docs/OFFICE-ATMOSPHERE.md b/docs/OFFICE-ATMOSPHERE.md
new file mode 100644
index 0000000..c44cb9b
--- /dev/null
+++ b/docs/OFFICE-ATMOSPHERE.md
@@ -0,0 +1,43 @@
+# Office horror atmosphere
+
+`scripts/office_atmosphere.gd` adds two desks, three chairs and a metal fire barrel.
+Props use low-poly primitives with simple static collisions on world layer 1.
+Positions avoid the four cardinal entry corridors and the central combat space.
+The zombies still use their existing direct pursuit, not a new pathfinding system;
+props can obstruct arbitrary paths when the player hides behind them.
+
+The central ceiling OmniLight was removed. Ambient energy is 0.12 with a cool blue
+color, preserving silhouette readability rather than total darkness. Two warm desk
+lamps use short-range unshadowed OmniLights. The barrel is the only persistent
+shadow-casting light (range10, energy1.9–2.8), with smooth bounded sine-based flicker.
+The existing muzzle flash is unchanged: four omni lights total.
+
+Fire uses 28 CPUParticles3D and small unshaded additive billboard quads. A generated
+64x96 alpha flame mask is in assets/effects/flame.png. No glow, volumetric fog, GI,
+GPU particles or Forward+-only effects are required. No fire damage was added.
+The flame mesh does not cast shadows. The barrel and furniture do.
+
+References consulted (Perplexity unavailable; official docs via Exa):
+- https://docs.godotengine.org/en/stable/tutorials/3d/lights_and_shadows.html
+- https://docs.godotengine.org/en/stable/classes/class_omnilight3d.html
+- https://docs.godotengine.org/en/stable/classes/class_cpuparticles3d.html
+
+Compatibility defaults to eight omni lights per mesh. Shadows are expensive and
+can change light brightness because Compatibility uses a different shadowed-light
+rendering path; visual checks were therefore done with gl_compatibility.
+
+Verification (installed Godot4.7.1):
+
+```sh
+"$G" --headless --path . --script res://tools/test_office_atmosphere.gd
+"$G" --display-driver x11 --rendering-method gl_compatibility --path . \
+  --script res://tools/test_office_atmosphere.gd -- --screenshot
+```
+
+Checks: prop counts/collisions, bounded flicker, CPU emitter, light count, absent
+ceiling light, low ambient, free cardinal ray corridors and desk collision.
+Three screenshots `/tmp/zombie-office-{0,1,2}.png` inspected, including the barrel.
+All seven prior suites pass: health/sky, music, grenade, waves, death, damage, touch.
+Existing resource-in-use warnings at test shutdown remain. Actual smartphone
+performance has not been measured; this is a small light/particle budget, not an
+FPS guarantee. Keep testing arbitrary zombie routes around the new obstacles.
diff --git a/docs/WEB-DEPLOY.md b/docs/WEB-DEPLOY.md
index 936e6c2..ec8aceb 100644
--- a/docs/WEB-DEPLOY.md
+++ b/docs/WEB-DEPLOY.md
@@ -1,5 +1,13 @@
 # Web build and compressed deployment
 
+## Office atmosphere release: fd65770c62e811fe
+
+See `docs/OFFICE-ATMOSPHERE.md`: two desks, three chairs, two desk lamps and
+CPU-particle fire barrel; ceiling light removed, low cool ambient.
+PCK 3,946,516 bytes; gzip payload total 12,402,612 bytes. Previous releases retained.
+Root backup: `index-before-office.html`. Serial import workaround applied to staging.
+
+
 ## Health + starry sky release: 31564f79b9f5e299
 
 See `docs/HEALTH-SKY.md`: +1 HP/second while alive, capped at 100; Half-Life
diff --git a/scripts/main.gd b/scripts/main.gd
index 69a8bc4..8623ad5 100644
--- a/scripts/main.gd
+++ b/scripts/main.gd
@@ -39,16 +39,13 @@ func _ready() -> void:
 	# Solo sfondo: illuminazione e riflessi non dipendono dal cielo scuro.
 	env.reflected_light_source = Environment.REFLECTION_SOURCE_DISABLED
 	env.ambient_light_source = Environment.AMBIENT_SOURCE_COLOR
-	env.ambient_light_color = Color(0.65, 0.73, 0.85)
-	env.ambient_light_energy = 0.65
+	env.ambient_light_color = Color(0.28, 0.36, 0.48)
+	env.ambient_light_energy = 0.12
 	envnode.environment = env
 	add_child(envnode)
-	var light := OmniLight3D.new()
-	light.position = Vector3(0, 4.5, 0)
-	light.omni_range = 24
-	light.light_energy = 3
-	light.shadow_enabled = true
-	add_child(light)
+	var office := Node3D.new()
+	office.set_script(preload("res://scripts/office_atmosphere.gd"))
+	add_child(office)
 	var canvas := CanvasLayer.new()
 	add_child(canvas)
 	hud = Label.new()
diff --git a/scripts/office_atmosphere.gd b/scripts/office_atmosphere.gd
new file mode 100644
index 0000000..1cb1fe7
--- /dev/null
+++ b/scripts/office_atmosphere.gd
@@ -0,0 +1,166 @@
+extends Node3D
+## Sparse office props and bounded fire animation; Web/Compatibility safe.
+const FIRE_MIN := 1.9
+const FIRE_MAX := 2.8
+var fire_light: OmniLight3D
+var _time := 0.0
+
+func _ready() -> void:
+	name = "OfficeAtmosphere"
+	_desk(Vector3(-5, 0, -4))
+	_desk(Vector3(5, 0, 4))
+	_chair(Vector3(-5, 0, -2.6), 0)
+	_chair(Vector3(5, 0, 5.4), PI)
+	_chair(Vector3(6.8, 0, -4), -0.35)
+	_barrel(Vector3(-4, 0, 4))
+
+func _material(color: Color, metallic: float = 0.0) -> StandardMaterial3D:
+	var mat := StandardMaterial3D.new()
+	mat.albedo_color = color
+	mat.roughness = 0.85
+	mat.metallic = metallic
+	return mat
+
+func _box(parent: Node3D, pos: Vector3, size: Vector3, mat: Material) -> MeshInstance3D:
+	var mesh := BoxMesh.new()
+	mesh.size = size
+	mesh.material = mat
+	var node := MeshInstance3D.new()
+	node.mesh = mesh
+	node.position = pos
+	parent.add_child(node)
+	return node
+
+func _body(pos: Vector3, label: String) -> StaticBody3D:
+	var body := StaticBody3D.new()
+	body.name = label
+	body.position = pos
+	body.collision_layer = 1
+	body.collision_mask = 0
+	body.add_to_group("office_props")
+	add_child(body, true)
+	return body
+
+func _collision(body: StaticBody3D, center: Vector3, size: Vector3) -> void:
+	var shape := BoxShape3D.new()
+	shape.size = size
+	var collider := CollisionShape3D.new()
+	collider.shape = shape
+	collider.position = center
+	body.add_child(collider)
+
+func _desk(pos: Vector3) -> void:
+	var desk := _body(pos, "OfficeDesk")
+	var wood := _material(Color(0.19, 0.12, 0.07))
+	var metal := _material(Color(0.12, 0.15, 0.14), 0.5)
+	_box(desk, Vector3(0, 0.84, 0), Vector3(2.5, 0.12, 1.15), wood)
+	for x in [-1.05, 1.05]:
+		for z in [-0.43, 0.43]:
+			_box(desk, Vector3(x, 0.4, z), Vector3(0.08, 0.8, 0.08), metal)
+	_box(desk, Vector3(-0.82, 0.53, 0), Vector3(0.48, 0.5, 0.94), metal)
+	for y in [0.4, 0.62]:
+		_box(desk, Vector3(-0.82, y, 0.49), Vector3(0.23, 0.025, 0.035), wood)
+	_box(desk, Vector3(0.3, 0.91, 0.05), Vector3(0.48, 0.015, 0.35), _material(Color(0.45, 0.43, 0.32)))
+	_collision(desk, Vector3(0, 0.45, 0), Vector3(2.5, 0.9, 1.15))
+	_lamp(desk, Vector3(0.84, 0.91, -0.23))
+
+func _chair(pos: Vector3, yaw: float) -> void:
+	var chair := _body(pos, "OfficeChair")
+	chair.rotation.y = yaw
+	var metal := _material(Color(0.12, 0.12, 0.13), 0.6)
+	var fabric := _material(Color(0.1, 0.14, 0.12))
+	_box(chair, Vector3(0, 0.48, 0), Vector3(0.58, 0.12, 0.56), fabric)
+	_box(chair, Vector3(0, 0.84, 0.25), Vector3(0.58, 0.64, 0.09), fabric)
+	for x in [-0.23, 0.23]:
+		for z in [-0.22, 0.22]:
+			_box(chair, Vector3(x, 0.21, z), Vector3(0.045, 0.42, 0.045), metal)
+	_collision(chair, Vector3(0, 0.53, 0), Vector3(0.6, 1.06, 0.6))
+
+func _cylinder(parent: Node3D, pos: Vector3, radius: float, height: float, mat: Material) -> void:
+	var mesh := CylinderMesh.new()
+	mesh.top_radius = radius
+	mesh.bottom_radius = radius
+	mesh.height = height
+	mesh.radial_segments = 24
+	mesh.material = mat
+	var node := MeshInstance3D.new()
+	node.mesh = mesh
+	node.position = pos
+	parent.add_child(node)
+
+func _lamp(parent: Node3D, pos: Vector3) -> void:
+	var lamp := Node3D.new()
+	lamp.name = "DeskLamp"
+	lamp.position = pos
+	parent.add_child(lamp)
+	var metal := _material(Color(0.13, 0.19, 0.15), 0.5)
+	_cylinder(lamp, Vector3(0, 0.035, 0), 0.16, 0.07, metal)
+	_box(lamp, Vector3(0, 0.24, 0), Vector3(0.04, 0.4, 0.04), metal)
+	_box(lamp, Vector3(0, 0.44, 0), Vector3(0.4, 0.12, 0.24), metal)
+	var bulb := _material(Color(0.8, 0.63, 0.3))
+	bulb.shading_mode = BaseMaterial3D.SHADING_MODE_UNSHADED
+	_box(lamp, Vector3(0, 0.375, 0), Vector3(0.32, 0.012, 0.18), bulb)
+	var light := OmniLight3D.new()
+	light.name = "DeskLampLight"
+	light.position = Vector3(0, 0.31, 0)
+	light.light_color = Color(1.0, 0.7, 0.35)
+	light.light_energy = 1.2
+	light.omni_range = 5.5
+	light.shadow_enabled = false
+	lamp.add_child(light)
+
+func _barrel(pos: Vector3) -> void:
+	var barrel := _body(pos, "FireBarrel")
+	var metal := _material(Color(0.15, 0.1, 0.075), 0.65)
+	_cylinder(barrel, Vector3(0, 0.5, 0), 0.43, 1.0, metal)
+	for y in [0.12, 0.78, 1.01]:
+		_cylinder(barrel, Vector3(0, y, 0), 0.46, 0.055, metal)
+	_cylinder(barrel, Vector3(0, 1.045, 0), 0.39, 0.015, _material(Color(0.025, 0.012, 0.005)))
+	_collision(barrel, Vector3(0, 0.52, 0), Vector3(0.92, 1.04, 0.92))
+	var fire := CPUParticles3D.new()
+	fire.name = "BarrelFlames"
+	fire.position = Vector3(0, 1.08, 0)
+	fire.amount = 28
+	fire.lifetime = 0.85
+	fire.preprocess = 1.0
+	fire.emission_shape = CPUParticles3D.EMISSION_SHAPE_SPHERE
+	fire.emission_sphere_radius = 0.23
+	fire.direction = Vector3.UP
+	fire.spread = 12
+	fire.gravity = Vector3(0, 0.6, 0)
+	fire.initial_velocity_min = 0.5
+	fire.initial_velocity_max = 1.15
+	fire.scale_amount_min = 0.5
+	fire.scale_amount_max = 1.0
+	var gradient := Gradient.new()
+	gradient.set_color(0, Color(1, 0.65, 0.12, 0.8))
+	gradient.set_color(1, Color(0.6, 0.04, 0.005, 0))
+	fire.color_ramp = gradient
+	var quad := QuadMesh.new()
+	quad.size = Vector2(0.48, 0.8)
+	var flame := StandardMaterial3D.new()
+	flame.shading_mode = BaseMaterial3D.SHADING_MODE_UNSHADED
+	flame.transparency = BaseMaterial3D.TRANSPARENCY_ALPHA
+	flame.blend_mode = BaseMaterial3D.BLEND_MODE_ADD
+	flame.billboard_mode = BaseMaterial3D.BILLBOARD_PARTICLES
+	flame.albedo_texture = load("res://assets/effects/flame.png")
+	flame.vertex_color_use_as_albedo = true
+	flame.cull_mode = BaseMaterial3D.CULL_DISABLED
+	quad.material = flame
+	fire.mesh = quad
+	fire.cast_shadow = GeometryInstance3D.SHADOW_CASTING_SETTING_OFF
+	barrel.add_child(fire)
+	fire_light = OmniLight3D.new()
+	fire_light.name = "BarrelFireLight"
+	fire_light.position = Vector3(0, 1.5, 0)
+	fire_light.light_color = Color(1, 0.36, 0.07)
+	fire_light.light_energy = (FIRE_MIN + FIRE_MAX) * 0.5
+	fire_light.omni_range = 10
+	fire_light.shadow_enabled = true
+	barrel.add_child(fire_light)
+
+func _process(dt: float) -> void:
+	_time += dt
+	# Smooth, deterministic, bounded flicker: no per-frame random flashes.
+	var wave := 0.5 + 0.3 * sin(_time * 7.1) + 0.2 * sin(_time * 11.7 + 1.2)
+	fire_light.light_energy = lerpf(FIRE_MIN, FIRE_MAX, wave)
diff --git a/scripts/office_atmosphere.gd.uid b/scripts/office_atmosphere.gd.uid
new file mode 100644
index 0000000..606a51f
--- /dev/null
+++ b/scripts/office_atmosphere.gd.uid
@@ -0,0 +1 @@
+uid://cx02g4bsbwanh
diff --git a/tools/test_health_sky.gd.uid b/tools/test_health_sky.gd.uid
new file mode 100644
index 0000000..656844f
--- /dev/null
+++ b/tools/test_health_sky.gd.uid
@@ -0,0 +1 @@
+uid://dvv3ey14k862x
diff --git a/tools/test_office_atmosphere.gd b/tools/test_office_atmosphere.gd
new file mode 100644
index 0000000..f78ea8e
--- /dev/null
+++ b/tools/test_office_atmosphere.gd
@@ -0,0 +1,61 @@
+extends SceneTree
+
+func _initialize() -> void:
+	call_deferred("run_test")
+
+func run_test() -> void:
+	var world = load("res://scenes/main.tscn").instantiate()
+	root.add_child(world)
+	var office = world.get_node("OfficeAtmosphere")
+	assert(get_nodes_in_group("office_props").size() == 6)
+	var desks := 0
+	var chairs := 0
+	for prop in get_nodes_in_group("office_props"):
+		if prop.name.begins_with("OfficeDesk"):
+			desks += 1
+		if prop.name.begins_with("OfficeChair"):
+			chairs += 1
+		assert(prop.collision_layer == 1)
+	assert(desks == 2 and chairs == 3)
+	print("PASS: due scrivanie, tre sedie, bidone con collisioni")
+	var flames = office.get_node("FireBarrel/BarrelFlames")
+	assert(flames is CPUParticles3D and flames.amount == 28 and flames.emitting)
+	assert(office.fire_light.shadow_enabled)
+	for i in 100:
+		office._process(0.016)
+		assert(office.fire_light.light_energy >= office.FIRE_MIN and office.fire_light.light_energy <= office.FIRE_MAX)
+	print("PASS: fiamme CPU leggere e flicker continuo entro limiti")
+	var lights: Array[Node] = world.find_children("*", "OmniLight3D", true, false)
+	assert(lights.size() == 4) # due lampade, bidone, muzzle flash
+	assert(world.find_children("DeskLampLight", "OmniLight3D", true, false).size() == 2)
+	for node in world.get_children():
+		assert(not node is OmniLight3D) # nessuna plafoniera
+		if node is WorldEnvironment:
+			assert(node.environment.ambient_light_energy <= 0.15)
+	print("PASS: plafoniera rimossa, ambient basso e quattro luci totali")
+	await physics_frame
+	await physics_frame
+	var space = world.get_world_3d().direct_space_state
+	# Cardinal routes from windows to center remain free at zombie torso height.
+	for edge in [Vector3(0, 0.8, -8), Vector3(0, 0.8, 8), Vector3(-8, 0.8, 0), Vector3(8, 0.8, 0)]:
+		var q := PhysicsRayQueryParameters3D.create(edge, Vector3(0, 0.8, 0), 1)
+		q.exclude = [world.player.get_rid()]
+		assert(space.intersect_ray(q).is_empty())
+	var q := PhysicsRayQueryParameters3D.create(Vector3(-5, 0.5, -2), Vector3(-5, 0.5, -4), 1)
+	assert(not space.intersect_ray(q).is_empty())
+	print("PASS: corridoi cardinali liberi, scrivanie bloccano fisicamente")
+	if "--screenshot" in OS.get_cmdline_user_args():
+		world.player.set_physics_process(false)
+		world.player.position = Vector3(0, 0.1, 0)
+		world.player.camera.rotation.x = -0.08
+		for i in 3:
+			if i == 2:
+				world.player.look_at(Vector3(-4, 0.1, 4))
+			else:
+				world.player.rotation.y = -PI * 0.25 if i == 0 else PI * 0.25 + PI
+			await create_timer(0.4).timeout
+			await RenderingServer.frame_post_draw
+			root.get_texture().get_image().save_png("/tmp/zombie-office-%d.png" % i)
+	world.queue_free()
+	await process_frame
+	quit()
diff --git a/tools/test_office_atmosphere.gd.uid b/tools/test_office_atmosphere.gd.uid
new file mode 100644
index 0000000..5a0db61
--- /dev/null
+++ b/tools/test_office_atmosphere.gd.uid
@@ -0,0 +1 @@
+uid://dbyackx6d67ns