Theme CSS Properties Reference

Complete reference of all CSS properties supported by CRT Terminal themes.

Selectors

Selector	Description
:terminal	Main terminal styling (typography, colors, background)
:terminal::selection	Text selection appearance
:terminal::highlight	Search match highlighting
:terminal::cursor	Cursor appearance
:terminal::backdrop	Background effects (grid, particles, CRT, etc.)
:terminal::palette	ANSI color palette (colors 0-255)
:terminal::tab-bar	Tab bar container
:tab	Individual tab styling
:tab.active	Active tab styling
:terminal::tab-close	Tab close button
:terminal::on-bell	Event override: bell triggered
:terminal::on-command-success	Event override: command exited with code 0
:terminal::on-command-fail	Event override: command exited with non-zero code
:terminal::on-focus	Event override: window gained focus
:terminal::on-blur	Event override: window lost focus
:terminal::ui-focus	Focus ring styling
:terminal::ui-hover	Hover state
:terminal::context-menu	Context menu styling
:terminal::search-bar	Search bar styling
:terminal::rename-bar	Window/tab rename bar

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:terminal Properties

Typography

Property	Type	Default	Description
font-family	string list	system default	Comma-separated font names
font-size	number	14	Font size in points
line-height	number	1.5	Line height multiplier
--font-bold	string	auto	Bold font family name
--font-italic	string	auto	Italic font family name
--font-bold-italic	string	auto	Bold italic font family name

Colors

Property	Type	Default	Description
color	color	#c8c8c8	Foreground text color
background	color/gradient	#1a1a1a	Background color or gradient
text-shadow	shadow	none	Text glow effect

Background Image

Property	Type	Default	Description
background-image	url	none	Path to background image
background-size	keyword/value	cover	cover, contain, auto, px, or %
background-position	keyword	center	center, top, bottom, left, right, or combinations
background-repeat	keyword	no-repeat	no-repeat, repeat, repeat-x, repeat-y
--background-opacity	number	1.0	Image opacity (0.0-1.0)

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:terminal::selection Properties

Property	Type	Default	Description
background	color	theme-based	Selection background color
color	color	theme-based	Selection text color

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:terminal::highlight Properties

Property	Type	Default	Description
background	color	yellow	Search match background
color	color	black	Search match text color
--current-background	color	orange	Current match background

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:terminal::cursor Properties

Property	Type	Default	Description
background	color	#ffffff	Cursor color
text-shadow	shadow	none	Cursor glow effect

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:terminal::palette Properties

ANSI colors using --color-N where N is 0-255.

Base 16 Colors (0-15)

Property	Color Name
--color-0	Black
--color-1	Red
--color-2	Green
--color-3	Yellow
--color-4	Blue
--color-5	Magenta
--color-6	Cyan
--color-7	White
--color-8	Bright Black
--color-9	Bright Red
--color-10	Bright Green
--color-11	Bright Yellow
--color-12	Bright Blue
--color-13	Bright Magenta
--color-14	Bright Cyan
--color-15	Bright White

Alternative Named Syntax

Can also use --ansi-{name} in :terminal:

:terminal {
    --ansi-red: #ff5555;
    --ansi-bright-red: #ff6e6e;
}

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:terminal::backdrop Properties

Grid Effect

Property	Type	Default	Description
--grid-enabled	bool	false	Enable grid effect
--grid-color	color	magenta	Grid line color
--grid-spacing	number	8.0	Space between grid lines
--grid-line-width	number	0.02	Grid line thickness
--grid-perspective	number	2.0	Perspective depth
--grid-horizon	number	0.35	Horizon line position (0-1)
--grid-animation-speed	number	0.5	Scroll animation speed
--grid-glow-radius	number	0.0	Glow blur radius
--grid-glow-intensity	number	0.0	Glow brightness
--grid-curved	bool	false	Enable curved grid lines
--grid-vanishing-spread	number	0.3	Vanishing point spread

Starfield Effect

Property	Type	Default	Description
--starfield-enabled	bool	false	Enable starfield
--starfield-color	color	white	Star color
--starfield-density	number	100	Number of stars
--starfield-layers	number	3	Parallax layers
--starfield-speed	number	0.3	Movement speed
--starfield-direction	keyword	down	up, down, left, right, static
--starfield-twinkle	bool	false	Enable twinkling
--starfield-twinkle-speed	number	2.0	Twinkle frequency
--starfield-min-size	number	1.0	Minimum star size
--starfield-max-size	number	3.0	Maximum star size
--starfield-glow-radius	number	0.0	Star glow radius
--starfield-glow-intensity	number	0.0	Star glow brightness

Rain Effect

Property	Type	Default	Description
--rain-enabled	bool	false	Enable rain
--rain-color	color	blue	Raindrop color
--rain-density	number	150	Number of drops
--rain-speed	number	1.0	Fall speed
--rain-angle	number	0.0	Rain angle (degrees)
--rain-length	number	20.0	Raindrop length
--rain-thickness	number	1.5	Raindrop width
--rain-glow-radius	number	0.0	Drop glow radius
--rain-glow-intensity	number	0.0	Drop glow brightness

Particle Effect

Property	Type	Default	Description
--particles-enabled	bool	false	Enable particles
--particles-color	color	white	Particle color
--particles-count	number	50	Number of particles
--particles-shape	keyword	dot	dot, circle, star, heart, sparkle
--particles-behavior	keyword	float	float, drift, rise, fall
--particles-size	number	4.0	Particle size
--particles-speed	number	0.5	Movement speed
--particles-glow-radius	number	0.0	Glow radius
--particles-glow-intensity	number	0.0	Glow brightness

Matrix Effect

Property	Type	Default	Description
--matrix-enabled	bool	false	Enable matrix rain
--matrix-color	color	green	Character color
--matrix-density	number	1.0	Column density
--matrix-speed	number	8.0	Fall speed
--matrix-font-size	number	14.0	Character size
--matrix-charset	string	A-Z0-9	Characters to display

Shape Effect

Property	Type	Default	Description
--shape-enabled	bool	false	Enable shape
--shape-type	keyword	circle	circle, rect, ellipse, triangle, star, heart, polygon
--shape-size	number	100.0	Shape size
--shape-fill	color	none	Fill color
--shape-stroke	color	none	Stroke color
--shape-stroke-width	number	2.0	Stroke thickness
--shape-glow-radius	number	0.0	Glow radius
--shape-glow-color	color	stroke	Glow color
--shape-rotation	keyword	none	none, spin, wobble
--shape-rotation-speed	number	1.0	Rotation speed
--shape-motion	keyword	bounce	none, bounce, scroll, float, orbit
--shape-motion-speed	number	1.0	Motion speed
--shape-polygon-sides	number	6	Sides for polygon type

Sprite Animation

Property	Type	Default	Description
--sprite-enabled	bool	false	Enable sprite
--sprite-path	string	none	Path to sprite sheet
--sprite-frame-width	number	64	Frame width in pixels
--sprite-frame-height	number	64	Frame height in pixels
--sprite-columns	number	1	Columns in sprite sheet
--sprite-rows	number	1	Rows in sprite sheet
--sprite-frame-count	number	auto	Total frames
--sprite-fps	number	12.0	Animation speed
--sprite-scale	number	1.0	Display scale
--sprite-opacity	number	1.0	Sprite opacity
--sprite-position	keyword	center	Position on screen
--sprite-motion	keyword	none	none, bounce, scroll, float, orbit
--sprite-motion-speed	number	1.0	Motion speed

CRT Post-Processing

Property	Type	Default	Description
--crt-enabled	bool	false	Enable CRT effect
--crt-scanline-intensity	number	0.15	Scanline darkness (0.0-1.0)
--crt-scanline-frequency	number	2.0	Scanline density
--crt-curvature	number	0.02	Screen curvature (0.0-0.1)
--crt-vignette	number	0.3	Edge darkening (0.0-1.0)
--crt-chromatic-aberration	number	0.0	RGB color separation
--crt-bloom	number	0.0	Bright area glow
--crt-flicker	number	0.0	Brightness variation

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Tab Bar Properties

:terminal::tab-bar

Property	Type	Default	Description
background	color	theme-based	Bar background
border-color	color	theme-based	Bottom border
height	number	36	Bar height in pixels
padding	number	4	Internal padding

:tab

Property	Type	Default	Description
background	color	theme-based	Tab background
color	color	theme-based	Tab text color
border-radius	number	4	Corner radius
min-width	number	80	Minimum tab width
max-width	number	200	Maximum tab width
text-shadow	shadow	none	Text glow

:tab.active

Property	Type	Default	Description
background	color	theme-based	Active tab background
color	color	theme-based	Active tab text
accent-color	color	theme-based	Accent indicator
text-shadow	shadow	none	Text glow

:terminal::tab-close

Property	Type	Default	Description
color	color	theme-based	Close button color
--hover-background	color	red	Hover background
--hover-color	color	white	Hover text color

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Event Selectors (Reactive Theming)

Event selectors allow temporary theme overrides that trigger on terminal events. These enable reactive animations like changing sprites on command failure, flashing on bell, etc.

Available Event Selectors

Selector	Trigger	Description
:terminal::on-bell	Bell character (\a)	Alert/notification sound
:terminal::on-command-success	Exit code 0	Command completed successfully
:terminal::on-command-fail	Exit code != 0	Command failed
:terminal::on-focus	Window focused	Terminal gained focus
:terminal::on-blur	Window blurred	Terminal lost focus

Event Properties

Property	Type	Default	Description
--duration	duration	500ms	How long the override lasts

Overridable Properties

Within event selectors, you can override:

• Theme colors: color, background, text-shadow
• Cursor: cursor-color
• Sprite patches: All --sprite-* properties
• Effect patches: All --starfield-*, --particles-*, --grid-*, --rain-*, --matrix-*, --shape-* properties

Note on sprite paths: All --sprite-path values (both base and event overrides) are resolved relative to the theme directory. If your base sprite is sprites/idle.png, use sprites/alert.png for event overrides to load from the same subdirectory.

Duration Behavior

• Non-zero duration: Override applies for specified time, then reverts
• Zero duration (--duration: 0ms): Persists until cleared by another event (used for ::on-blur)

Example: Reactive Sprite Theme

:terminal::backdrop {
    /* Default sprite */
    --sprite-enabled: true;
    --sprite-path: "character_idle.png";
    --sprite-frame-width: 64;
    --sprite-frame-height: 64;
    --sprite-columns: 4;
    --sprite-fps: 8;
}

/* Show happy sprite on success */
:terminal::on-command-success {
    --duration: 1500ms;
    --sprite-path: "character_happy.png";
    --sprite-opacity: 0.8;
    text-shadow: 0 0 20px rgba(0, 255, 0, 0.6);
}

/* Show sad sprite on failure */
:terminal::on-command-fail {
    --duration: 3000ms;
    --sprite-path: "character_sad.png";
    --sprite-opacity: 0.6;
    text-shadow: 0 0 20px rgba(255, 0, 0, 0.6);
}

/* Alert animation on bell */
:terminal::on-bell {
    --duration: 800ms;
    --sprite-path: "character_alert.png";
    --sprite-fps: 12;
}

/* Dim when unfocused */
:terminal::on-blur {
    --duration: 0ms;  /* Persist until focused */
    --sprite-opacity: 0.3;
    color: rgba(200, 200, 200, 0.7);
}

Shell Integration Requirements

Command success/failure detection requires OSC 133 semantic prompt support in your shell. See How to Set Up Reactive Themes for setup instructions.

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UI Selectors

:terminal::ui-focus Properties

Focus ring styling applied when the terminal window has keyboard focus.

Property	Type	Description
--ring-color	color	Focus ring color
--ring-thickness	number, px	Ring thickness
--glow-color	color	Focus glow color
--glow-size	number, px	Glow blur size

:terminal::ui-hover Properties

Hover state applied when the cursor is over interactive UI elements.

Property	Type	Description
background	color	Hover background color

:terminal::context-menu Properties

Context menu styling (right-click menu).

Property	Type	Description
background	color	Menu background
border-color	color	Menu border
color	color	Menu text color

:terminal::search-bar Properties

Search bar styling (shown when using Cmd+F).

Property	Type	Description
background	color	Search bar background
color	color	Search text color
--placeholder-color	color	Placeholder text color
--no-match-color	color	Color when no matches found

:terminal::rename-bar Properties

Window/tab rename bar styling.

Property	Type	Description
background	color	Rename bar background
color	color	Input text color
--label-color	color	Label text color

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Color Formats

Supported color formats:

• Hex: #rgb, #rgba, #rrggbb, #rrggbbaa
• RGB: rgb(255, 128, 0)
• RGBA: rgba(255, 128, 0, 0.5)
• Named: red, blue, transparent, etc.

Gradient Format

background: linear-gradient(to bottom, #color1, #color2);