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Full CSS Styling Control.

Every block in CardBuilder exposes the complete spectrum of CSS properties — organized into 8 logical groups. Style the whole block, or drill into sub-components and style each part independently. No CSS knowledge required.

Styles panel showing property groups and style targets
8
Property groups
50+
CSS properties
6
CSS units supported
Sub-component targets
Block Style Targets
Entity State
Block State value Unit
Entity Attribute
Block Label Value
Icon
Block Icon Pre Template Post Template
Slider
Block Track Track Active Thumb Value
Button Toggle
Block Option Option Active Icon Label
Select Menu
Block Container Dropdown Selected Label
Style Targets

Style Every Part of a Block, Independently

Blocks with multiple visual components expose separate style targets — so you can give a different color to the state value and the unit, or style the active button differently from inactive ones.

How it works

Select any block, open the Styles panel. If the block has sub-components, a target selector appears at the top. Pick the target — the corresponding element is highlighted on the canvas with a dashed accent border. Your styles now apply only to that part.

Style target selector showing Block, State value, and Unit targets for an Entity State block
Property Groups

Every CSS Property, Organized

Properties are organized into 8 collapsible groups so you can find what you need instantly — without scrolling through an endless list.

Layout group

Layout

Display, overflow, z-index, and position coordinates for absolute blocks.

Show / Hide
Overflow X/Y
Z-Index
Position X / Y
Size group

Size

Explicit dimensions with min and max constraints, all with full unit selection.

Width / Height
Min Width / Height
Max Width / Height
Spacing group

Spacing

Margin and padding — set all sides at once or each side individually.

Margin (all / T R B L)
Padding (all / T R B L)
Typography group

Typography

Complete text control — font, size, weight, line height, transform, shadow, and more.

Color
Font Size / Weight / Family
Line Height
Text Align
Transform
Decoration
Letter Spacing
Text Shadow
Background group

Background

Solid colors, image URLs, CSS gradients, and full media manager integration.

Background Color
Background Image / Gradient
Size / Position / Repeat
Box Shadow
Blend Mode
Border group

Border

Border width, style, and color per side — plus corner radius for each corner independently.

Border Width (all / T R B L)
Border Style / Color
Border Radius (all / per corner)
Effects group

Effects

Opacity, drop shadow, CSS filters (blur, brightness, contrast, grayscale), backdrop filter, blend mode, and rotation.

Opacity
Box Shadow
Filter
Backdrop Filter
Mix Blend Mode
Rotate
Flex group

Flex

Full flex container and flex item control — direction, wrapping, alignment, gaps, grow, shrink, and order.

Direction / Wrap
Justify / Align / Gap
Flex Grow / Shrink / Basis
Align Self / Order
CSS Units

The Right Unit for Every Context

Every numeric property lets you choose the unit that makes the most sense — mix and match freely within a single card.

px Pixels

Fixed, absolute size. Precise and predictable — ideal for borders, shadows, and fixed-size elements.

% Percentage

Relative to the parent element. Perfect for fluid layouts that adapt to their container.

rem Root em

Relative to the root font size. Great for consistent typographic scaling across the card.

em Em

Relative to the current element's font size. Useful for spacing that scales with text.

vw Viewport Width

Percentage of the browser viewport width. Makes elements truly responsive to screen size.

vh Viewport Height

Percentage of the browser viewport height. Ideal for full-height sections.

Unit selector dropdown showing px, %, rem, em, vw, vh options
Typography & Effects

Pixel-Perfect Control Over Every Detail

From a subtle text shadow to a full CSS gradient background — every visual detail is adjustable without leaving the builder.

Showcase of styling capabilities: gradient background, typography, border radius, and effects

CSS Gradients

Enter any CSS gradient as a background image — linear, radial, conic. Or use a dynamic binding template to generate gradients from entity values.

linear-gradient(135deg, #667eea, #764ba2)

Backdrop Filter

Apply CSS backdrop-filter to create frosted glass effects — blur, brightness, and saturation on the area behind the block.

blur(12px) brightness(1.1)

Mix Blend Mode

Control how a block blends with the elements beneath it using CSS mix-blend-mode — multiply, screen, overlay, and more.

multiply

Box Shadow

Add drop shadows or inset shadows with full CSS syntax — offset, blur, spread, color, and multiple shadows on a single block.

0 4px 24px rgba(0,0,0,0.15)
Style binding editor showing a color binding based on entity state
Dynamic Style Binding

Styles That React to Entity State

Any style property can be connected to live Home Assistant entity data. Change background color based on temperature, opacity based on a switch state, or size based on a numeric sensor value.

Direct Map Threshold Condition Template
Explore Dynamic Style Binding →

Every Style. Every Block.

Install CardBuilder and start styling your cards with the full power of CSS — no code required.