---
title: "Styling"
description: "Customize the appearance of the ThunderPhone voice widget with CSS"
---

The widget renders as a glassmorphic bar with built-in light and dark themes. Customization is available at three levels: props for common options, CSS custom properties for theming, and CSS class overrides for full control.

<Note>
  These styling options apply to the pre-built widget rendered by the `ThunderPhoneWidget` React component and the `ThunderPhone.mount()` CDN method. If you need a completely custom UI, use the [headless hook](/widget/headless-hook) instead.
</Note>

---

## Themes

The `theme` prop controls the widget's color scheme. It applies a `tp--light` or `tp--dark` class to the widget root:

```tsx
<ThunderPhoneWidget
  publishableKey="pk_live_your_publishable_key"
  theme="dark"
/>
```

| Theme | Class | Description |
|-------|-------|-------------|
| `'light'` | `tp--light` | Light background with dark text. Default. |
| `'dark'` | `tp--dark` | Dark background with light text. |

Both themes use the glassmorphic bar design with backdrop blur and subtle transparency.

---

## CSS Custom Properties

The widget exposes CSS custom properties (variables) that you can override to change colors without touching individual classes. They are defined by the theme class (`.tp--light` or `.tp--dark`) applied to the `.tp-widget` root:

| Property | Default (light) | Default (dark) | Description |
|----------|-----------------|-----------------|-------------|
| `--tp-accent` | `#000` | `#fff` | Accent color: start button, waveform bars, connecting dot, connected-status text. Set **inline** from the `primaryColor` prop. |
| `--tp-bg` | `rgba(255, 255, 255, 0.82)` | `rgba(15, 15, 15, 0.85)` | Bar background (translucent; blurred by `--tp-glass`). |
| `--tp-surface` | `rgba(0, 0, 0, 0.04)` | `rgba(255, 255, 255, 0.07)` | Mute-button background. |
| `--tp-surface-hover` | `rgba(0, 0, 0, 0.07)` | `rgba(255, 255, 255, 0.12)` | Mute-button hover background. |
| `--tp-border` | `rgba(0, 0, 0, 0.08)` | `rgba(255, 255, 255, 0.1)` | Bar and button borders. |
| `--tp-border-hover` | `rgba(0, 0, 0, 0.14)` | `rgba(255, 255, 255, 0.18)` | Border color on hover. |
| `--tp-text` | `rgba(0, 0, 0, 0.88)` | `rgba(255, 255, 255, 0.95)` | Primary text (title, agent name). |
| `--tp-text-2` | `rgba(0, 0, 0, 0.5)` | `rgba(255, 255, 255, 0.55)` | Secondary text (subtitle, status line, call timer). |
| `--tp-glass` | `blur(32px) saturate(180%)` | `blur(32px) saturate(180%)` | `backdrop-filter` that creates the glass effect on the bar. |
| `--tp-shadow` | three-layer shadow stack | three-layer shadow stack | The bar's `box-shadow` (ring + near + far layers). |
| `--tp-shadow-hover` | three-layer shadow stack | three-layer shadow stack | Declared for hover elevation; not currently applied by any rule. |
| `--tp-glow` | `inset 0 1px 0 0 rgba(255,255,255,0.5)` | `inset 0 1px 0 0 rgba(255,255,255,0.06)` | Inner top highlight layered onto the bar shadow. |
| `--tp-connected` | `#059669` | `#34d399` | Connected-state indicator color (status dot). |
| `--tp-error` | `#dc2626` | `#fb7185` | Error-state status text color. |
| `--tp-end-bg` | `rgba(239, 68, 68, 0.08)` | `rgba(251, 113, 133, 0.12)` | End-call button background. |
| `--tp-end-color` | `#ef4444` | `#fb7185` | End-call button icon color. |
| `--tp-end-border` | `rgba(239, 68, 68, 0.12)` | `rgba(251, 113, 133, 0.15)` | End-call button border. |
| `--tp-end-hover` | `rgba(239, 68, 68, 0.14)` | `rgba(251, 113, 133, 0.2)` | End-call button hover background. |
| `--tp-idle-opacity` | `0.4` | `0.3` | Declared for idle-state dimming; not currently applied by any rule. |

### Overriding Custom Properties

Set the accent color via the `primaryColor` prop:

```tsx
<ThunderPhoneWidget
  publishableKey="pk_live_your_publishable_key"
  primaryColor="#e11d48"
/>
```

<Warning>
  `--tp-accent` is set as an **inline style** from the `primaryColor` prop, so stylesheet overrides of `--tp-accent` have no effect. Change the accent with the prop. Every other custom property can be overridden in CSS.
</Warning>

Override the other custom properties with CSS. Use a two-class selector (`.tp-widget.tp--light` / `.tp-widget.tp--dark`) so your rule outweighs the theme class that defines the defaults, regardless of stylesheet order:

```css
.tp-widget.tp--light {
  --tp-bg: rgba(0, 0, 0, 0.9);
  --tp-text: rgba(255, 255, 255, 0.95);
  --tp-text-2: rgba(255, 255, 255, 0.55);
  --tp-border: rgba(255, 255, 255, 0.15);
}
```

---

## CSS Classes

All widget classes are prefixed with `tp-` to avoid conflicts with your existing styles.

| Class | Element | Description |
|-------|---------|-------------|
| `.tp-widget` | Root wrapper | Fixed-position container (`position: fixed`, corner set by the `position` prop, `z-index: 9999`). Carries the theme class and base font settings; no visual chrome of its own. |
| `.tp--light` / `.tp--dark` | Theme modifiers | Applied to `.tp-widget` alongside the theme; define all `--tp-*` custom properties. |
| `.tp-bar` | The bar | The glassmorphic pill itself: background, backdrop blur, border, `99px` radius, shadow. `300px` wide. |
| `.tp-meta` | Text block | Container for all text -- title and subtitle when idle, agent name and status during a call. |
| `.tp-name` | Primary label | Shows the `title` prop when idle, and the connected agent's name (falling back to `title`) during a call. |
| `.tp-sub` | Subtitle | The "Available now" line shown when idle. |
| `.tp-start` | Idle call button | The circular accent start button (42px). Uses `--tp-accent` as background. |
| `.tp-dot` | Connecting dot | Pulsing accent dot shown at the left of the bar while connecting. |
| `.tp-wave` / `.tp-wave--idle` | Waveform | The five-bar waveform. `--idle` adds the slow breathing animation; during a call the bars are audio-reactive. |
| `.tp-button` | In-call buttons | Base style for the in-call controls (42px, rounded 12px). |
| `.tp-button-group` | Button row | Wraps the mute and end buttons during a call. |
| `.tp-button--start` | Connect button variant | Accent-colored variant shown while a call is starting. |
| `.tp-button--mute` | Mute toggle | Mutes/unmutes the mic during a call. Uses `--tp-surface`. |
| `.tp-button--end` | End call button | Hangs up. Uses the `--tp-end-*` palette. |
| `.tp-button--loading` | Loading modifier | Dims the button while connecting. |
| `.tp-icon` / `.tp-spin` | Icons | Button icon sizing; `tp-spin` animates the connecting spinner. |
| `.tp-status` | In-call status block | Wraps the status line during connecting/connected/error states. |
| `.tp-status__text` | Status line | Connection state text (e.g., "Connecting...") or the call timer. Gets `.tp-status--connected` (accent color) or `.tp-status--error` (error color) per state. |
| `.tp-status__name` | Agent-name slot | Part of the status block, but not rendered in the current bar layout -- the agent name appears in `.tp-name` instead. |
| `.tp-status__dot` | Status dot | Pulsing connected-state dot style (uses `--tp-connected`). |

---

## Examples

### Custom Accent via Props

The simplest way to brand the widget:

```tsx
<ThunderPhoneWidget
  publishableKey="pk_live_your_publishable_key"
  theme="light"
  primaryColor="#059669"
  title="Talk to support"
/>
```

### Custom Colors via CSS

Override the custom properties for full color control. Remember that the accent comes from the `primaryColor` prop, not CSS:

```tsx
<ThunderPhoneWidget
  publishableKey="pk_live_your_publishable_key"
  primaryColor="#059669"
/>
```

```css
/* Emerald theme for everything else */
.tp-widget.tp--light {
  --tp-bg: rgba(236, 253, 245, 0.85);
  --tp-text: rgba(6, 78, 59, 0.95);
  --tp-text-2: rgba(4, 120, 87, 0.8);
  --tp-border: rgba(5, 150, 105, 0.2);
}
```

### Custom Size

Make the widget larger or smaller by adjusting the bar, button, and text dimensions:

```css
/* Wider bar */
.tp-bar {
  width: 340px;
}

/* Larger buttons (42px by default) */
.tp-start,
.tp-button {
  width: 56px;
  height: 56px;
}

/* Larger text */
.tp-name {
  font-size: 16px;
}

.tp-sub,
.tp-status__text {
  font-size: 14px;
}
```

### Hide the Text Labels

All of the widget's text lives in `.tp-meta`. Hide it entirely to keep just the waveform and buttons:

```css
.tp-meta {
  display: none;
}
```

Or hide individual pieces:

```css
/* Hide only the idle "Available now" subtitle */
.tp-sub {
  display: none;
}

/* Hide only the in-call status line (connection state / timer) */
.tp-status {
  display: none;
}
```

<Note>
  The idle label lives in `.tp-name`/`.tp-sub`, not `.tp-status` -- hiding `.tp-status` alone still shows the title when the widget is idle.
</Note>

### Theme-Specific Overrides

Target a specific theme with the theme class:

```css
/* Only affect dark theme */
.tp--dark .tp-start {
  box-shadow: 0 0 20px rgba(255, 255, 255, 0.25);
}

/* Only affect light theme */
.tp-widget.tp--light {
  --tp-bg: rgba(255, 255, 255, 0.95);
}
```

---

## Scoping with className

When using the React component, pass a `className` prop to scope your overrides to a specific widget instance:

```tsx
<ThunderPhoneWidget
  publishableKey="pk_live_your_publishable_key"
  theme="dark"
  className="support-widget"
/>
```

Then target that class in your CSS:

```css
.support-widget.tp--dark {
  --tp-bg: rgba(30, 30, 46, 0.9);
}

.support-widget .tp-name {
  font-weight: 700;
}
```

This lets you have multiple widget instances on the same page with different styles. Give each instance its own accent through its `primaryColor` prop (CSS cannot override `--tp-accent` -- it is set inline).

---

## Fully Custom UI

If CSS overrides are not enough, the [headless hook](/widget/headless-hook) gives you full control. You provide all the HTML and styling while `useThunderPhone` handles the voice session. The hook also provides `audioLevelRef` for building audio-reactive visualizations like waveforms.

```tsx
import { useThunderPhone } from '@thunderphone/widget'

function MyWidget() {
  const phone = useThunderPhone({
    publishableKey: 'pk_live_your_publishable_key',
  })

  return (
    <div className="my-totally-custom-widget">
      {/* Your own buttons, animations, layouts -- anything */}
      <button onClick={phone.state === 'connected' ? phone.disconnect : phone.connect}>
        {phone.state === 'connected' ? 'Hang up' : 'Call us'}
      </button>
      {phone.audio}
    </div>
  )
}
```

<Tip>
  The headless hook is the right choice when you need audio-reactive animations, custom layouts, or integration into an existing component library. CSS overrides and custom properties are better for quick theming adjustments.
</Tip>