diff --git a/matinfio/cif/cif.ts b/matinfio/cif/cif.ts
index 5e10fea..49208f8 100644
--- a/matinfio/cif/cif.ts
+++ b/matinfio/cif/cif.ts
@@ -100,9 +100,13 @@ namespace $ {
 				continue
 
 			} else if( fingerprt.startsWith( '_cif_error' ) ) { // custom tag
-				const error_message = cur_line.substr( 12, cur_line.length - 13 )
+				const error_message = cur_line.substr( 11, cur_line.length - 11 )
 				return this.$mol_fail( new $mol_data_error( error_message ) )
 
+			} else if( fingerprt.startsWith( '_cif_warning' ) ) { // custom tag
+				cur_structure.warning = cur_line.substr( 13, cur_line.length - 13 )
+				continue
+
 			} else if( fingerprt.startsWith( '_pauling_file_entry' ) ) { // custom tag
 				cur_structure.mpds_data = true
 				continue
diff --git a/matinfio/matinfio.ts b/matinfio/matinfio.ts
index 413c48f..07e25f0 100644
--- a/matinfio/matinfio.ts
+++ b/matinfio/matinfio.ts
@@ -54,6 +54,8 @@ namespace $ {
 		cartesian: boolean,
 		mpds_demo: boolean,
 		mpds_data: boolean,
+
+		warning?: string,
 	}
 
 	export type $optimade_cifplayer_matinfio_player_obj = {
@@ -69,6 +71,8 @@ namespace $ {
 		info: string,
 		mpds_demo: boolean,
 		mpds_data: boolean,
+
+		warning?: string,
 	}
 
 	export class $optimade_cifplayer_matinfio extends $mol_object2 {
diff --git a/matinfio/player/player.ts b/matinfio/player/player.ts
index d1c3ce7..4bce1e5 100644
--- a/matinfio/player/player.ts
+++ b/matinfio/player/player.ts
@@ -35,7 +35,9 @@ namespace $ {
 			ng_name: parseInt( crystal.ng_name ),
 			info: crystal.info,
 			mpds_data: crystal.mpds_data,
-			mpds_demo: crystal.mpds_demo
+			mpds_demo: crystal.mpds_demo,
+
+			warning: crystal.warning,
 		}
 
 		const groups: { fpos: number[] | null, cpos: number[], atoms: $optimade_cifplayer_matinfio_internal_obj_atom[] }[] = []
diff --git a/player/player.view.css.ts b/player/player.view.css.ts
index 19c6bfa..44f1d6b 100644
--- a/player/player.view.css.ts
+++ b/player/player.view.css.ts
@@ -1,5 +1,19 @@
 namespace $.$$ {
 
+	const Message_card = {
+		position: 'absolute',
+		zIndex: 1,
+		top: '6rem',
+		width: '100%',
+		align: {
+			items: 'center'
+		},
+		background: {
+			color: 'transparent',
+		},
+		boxShadow: 'none',
+	} as const
+
 	$mol_style_define( $optimade_cifplayer_player, {
 
 		background: {
@@ -136,19 +150,24 @@ namespace $.$$ {
 			height: '2rem',
 		},
 
-		Message: {
-			position: 'absolute',
-			zIndex: 1,
-			top: '6rem',
-			left: 0,
-			right: 0,
+		Error_card: {
+			...Message_card,
+			
+			Content: {
+				background: {
+					color: $optimade_cifplayer_theme.error,
+				},
+			},
 		},
 
-		Message_card: {
-			background: {
-				color: $mol_theme.back,
+		Warning_card: {
+			...Message_card,
+
+			Content: {
+				background: {
+					color: $optimade_cifplayer_theme.warning,
+				},
 			},
-			margin: 'auto',
 		},
 
 		Three: {
diff --git a/player/player.web.view.tree b/player/player.web.view.tree
index 1fbeace..6a73334 100644
--- a/player/player.web.view.tree
+++ b/player/player.web.view.tree
@@ -118,11 +118,11 @@ $optimade_cifplayer_player $mol_view
 						\
 							\display none
 						S \elements
-		^ message_visible / <= Message $mol_view
-			sub /
-				<= Message_card $mol_card
-					theme \$mol_theme_special
-					title <= message \
+		^ message_visible /
+			<= Error_card $mol_card
+				title <= error \
+			<= Warning_card $mol_card
+				title <= warning \
 	colors_light *
 		a \#990000
 		b \#009900
diff --git a/player/player.web.view.ts b/player/player.web.view.ts
index 7d1f7f7..b5c7897 100644
--- a/player/player.web.view.ts
+++ b/player/player.web.view.ts
@@ -99,16 +99,27 @@ namespace $.$$ {
 
 		@ $mol_mem
 		message_visible() {
-			return this.message() ? super.message_visible() : []
+			if( this.error() ) return [ this.Error_card() ]
+			if( this.warning() ) return [ this.Warning_card() ]
+			return []
 		}
 
 		@ $mol_mem
-		message(): string {
+		warning(): string {
+			try {
+				return this.structure_3d_data()?.warning ?? ''
+			} catch( error ) {
+				return ''
+			}
+		}
+
+		@ $mol_mem
+		error(): string {
 			try {
 				this.structure_3d_data()
 				return ''
 
-			} catch ( error: any ) {
+			} catch( error: any ) {
 				return error.message || error
 			}
 		}
diff --git a/theme/theme.css b/theme/theme.css
new file mode 100644
index 0000000..03675f4
--- /dev/null
+++ b/theme/theme.css
@@ -0,0 +1,9 @@
+[mol_theme="$mol_theme_light"] {
+	--optimade_cifplayer_theme_error: hsl(0, 87%, 69%);
+	--optimade_cifplayer_theme_warning: hsl(290, 61%, 80%);
+}
+
+[mol_theme="$mol_theme_dark"] {
+	--optimade_cifplayer_theme_error: hsl(0, 59%, 26%);
+	--optimade_cifplayer_theme_warning: hsl(290, 53%, 28%);
+}
diff --git a/theme/theme.ts b/theme/theme.ts
new file mode 100644
index 0000000..33820e2
--- /dev/null
+++ b/theme/theme.ts
@@ -0,0 +1,11 @@
+namespace $ {
+	
+	export const $optimade_cifplayer_theme = $mol_style_prop( 
+		'optimade_cifplayer_theme',
+		[
+			'error',
+			'warning',
+		] as const
+	)
+
+}