diff --git a/src/uix/eidos/components/button/button-spinner.svelte b/src/uix/eidos/components/button/button-spinner.svelte
index 5bda6dac6..19c1646eb 100644
--- a/src/uix/eidos/components/button/button-spinner.svelte
+++ b/src/uix/eidos/components/button/button-spinner.svelte
@@ -1,33 +1,22 @@
 <script lang="ts">
 	/**
-	 * Eidos `<Button.Spinner>` — visual wrapper over the soma spinner part.
+	 * Eidos `<Button.Spinner>` — visual wrapper over the soma spinner slot.
 	 *
-	 * Renders an inline SVG ring with a CSS rotate animation. The recipe
-	 * (`button.css`) controls the colour via `currentColor` and animates
-	 * via `@keyframes button-spinner-spin`.
+	 * Composes the canonical `<Spinner>` (variant `ring`) in presentational
+	 * mode (no `role=status` — the Button owns the loading a11y via `aria-busy`)
+	 * with `color="inherit"` so the ring follows the button's text colour.
 	 */
 	import * as Button from '$soma/components/button';
+	import { Spinner } from '../spinner';
 	import type { ButtonSpinnerWrapperProps } from './types';
 
-	let { children, ...rest }: ButtonSpinnerWrapperProps = $props();
+	let { children, size = 'md', ...rest }: ButtonSpinnerWrapperProps = $props();
 </script>
 
 <Button.Spinner {...rest}>
 	{#if children}
 		{@render children?.()}
 	{:else}
-		<!-- Default ring spinner. Stroked SVG with currentColor so it
-		     inherits the button's text colour. The recipe animates it. -->
-		<svg
-			class="eidos-button-spinner-ring"
-			viewBox="0 0 16 16"
-			fill="none"
-			stroke="currentColor"
-			stroke-width="2"
-			aria-hidden="true"
-		>
-			<circle cx="8" cy="8" r="6" opacity="0.25" />
-			<path d="M14 8a6 6 0 0 0-6-6" stroke-linecap="round" />
-		</svg>
+		<Spinner variant="ring" presentation color="inherit" {size} />
 	{/if}
 </Button.Spinner>
diff --git a/src/uix/eidos/components/button/button.css b/src/uix/eidos/components/button/button.css
index e8558315f..76355e81e 100644
--- a/src/uix/eidos/components/button/button.css
+++ b/src/uix/eidos/components/button/button.css
@@ -52,6 +52,13 @@
 	align-items: center;
 	justify-content: center;
 	gap: var(--_button-gap);
+	/* Defend the intrinsic box: a button is content-sized and NEVER stretched by a
+	   flex/grid parent. As a flex/grid item `inline-flex` blockifies to `flex`, and an
+	   `auto` main/cross size would stretch to fill the cell (filling H+W) — `fit-content`
+	   pins the button to its own size while the container's alignment still positions it.
+	   `[data-block]` opts INTO full width; `[data-icon-only]` overrides to a square. */
+	inline-size: fit-content;
+	block-size: fit-content;
 	min-block-size: var(--_button-height);
 	padding-inline: var(--_button-padding-inline);
 	border: var(--button-border-width) solid var(--_button-border);
@@ -81,12 +88,22 @@
 }
 
 [data-button]:active:not([data-disabled]):not([data-loading]) {
-	transform: translateY(1px);
+	/* Canonical press — the shared scale-down "squeeze" (`--press-*`), not a
+	   bespoke translateY. `transform: scale` composes with flex-centred content;
+	   absolutely-centred consumers (e.g. carousel triggers) centre via the
+	   `translate` property so the scale doesn't wipe their offset. */
+	transform: scale(var(--press-scale));
+	transition-duration: var(--press-duration);
 }
 
 [data-button]:focus-visible {
-	outline: var(--border-width-medium) solid var(--button-palette-border);
-	outline-offset: 2px;
+	/* Canonical focus ring — `outline` (survives forced-colors/HCM, unlike box-shadow)
+	   with the shared `--focus-ring-*` tokens. A single primary-tinted accent ring,
+	   not per-color: a consistent, high-contrast focus indicator (a11y), same as
+	   badge / card / carousel. If `--focus-ring-color` ever becomes intent-driven at
+	   the canon level, the Button inherits it for free. */
+	outline: var(--focus-ring-width) solid var(--focus-ring-color);
+	outline-offset: var(--focus-ring-offset);
 }
 
 /* ── Size scale ────────────────────────────────────────────────────────── */
@@ -179,13 +196,14 @@
 }
 
 [data-button][data-variant='plain'] {
+	/* Pure-emphasis variant (text button): transparent chrome + underline on hover,
+	   but the SAME control box as every other variant — `variant` is the EMPHASIS
+	   axis only, never layout. Inline link-like actions belong to <Link>, not here. */
 	--_button-bg: transparent;
 	--_button-fg: var(--button-palette-text);
 	--_button-border: transparent;
 	--_button-hover-bg: transparent;
 	--_button-hover-border: transparent;
-	min-block-size: auto;
-	padding-inline: 0;
 }
 
 [data-button][data-variant='plain']:hover:not([data-disabled]):not([data-loading]) {
@@ -283,30 +301,16 @@
 /* ── Spinner ───────────────────────────────────────────────────────────── */
 
 [data-button-spinner] {
+	/* Presentational slot — the composed <Spinner> (variant ring, color=inherit)
+	   sizes + animates itself. The slot just centres it in the icon flow. */
 	display: inline-flex;
 	align-items: center;
 	justify-content: center;
-	inline-size: var(--_button-icon-size, 1em);
-	block-size: var(--_button-icon-size, 1em);
-	color: currentColor;
-}
-
-.eidos-button-spinner-ring {
-	inline-size: 100%;
-	block-size: 100%;
-	animation: button-spinner-spin var(--button-spinner-duration) linear infinite;
-}
-
-@keyframes button-spinner-spin {
-	from { transform: rotate(0deg); }
-	to { transform: rotate(360deg); }
 }
 
 @media (prefers-reduced-motion: reduce) {
-	[data-button],
-	.eidos-button-spinner-ring {
+	[data-button] {
 		transition: none;
-		animation: none;
 	}
 }
 
diff --git a/src/uix/eidos/components/button/button.svelte b/src/uix/eidos/components/button/button.svelte
index f656f081c..367824f13 100644
--- a/src/uix/eidos/components/button/button.svelte
+++ b/src/uix/eidos/components/button/button.svelte
@@ -13,16 +13,19 @@
 	import { ActiveEidos } from '$uix/eidos';
 	import * as Button from '$soma/components/button';
 	import ButtonSpinner from './button-spinner.svelte';
+	import { getButtonGroupEidosCtx } from '$uix/eidos/components/button-group/context';
 	import type { ButtonProps } from './types';
 
 	let {
-		variant = 'solid',
-		size = 'md',
+		variant,
+		size,
 		rounded,
 		shape,
 		block = false,
 		iconOnly = false,
 		loading = false,
+		color,
+		disabled,
 		icon,
 		endIcon,
 		spinner,
@@ -33,16 +36,27 @@
 	}: ButtonProps = $props();
 
 	const eidos = ActiveEidos.require();
-	const resolvedSize = $derived(eidos.resolve(size, 'md'));
+
+	// Optional <ButtonGroup> context supplies shared visual DEFAULTS. An
+	// explicit prop on this Button always wins; outside a group the getter is
+	// undefined and Button falls back to its own defaults (backward-compatible).
+	const group = getButtonGroupEidosCtx();
+
+	const resolvedVariant = $derived(variant ?? group?.variant ?? 'solid');
+	const resolvedSize = $derived(eidos.resolve(size ?? group?.size, 'md'));
 	const resolvedRounded = $derived(eidos.resolve(rounded));
+	const resolvedColor = $derived(color ?? group?.color);
+	const resolvedDisabled = $derived(disabled ?? group?.disabled);
 </script>
 
 <Button.Provider
 	{...headlessProps}
+	color={resolvedColor}
+	disabled={resolvedDisabled}
 	{loading}
 	{loadingText}
 	{spinnerPlacement}
-	data-variant={variant}
+	data-variant={resolvedVariant}
 	data-size={resolvedSize}
 	data-rounded={resolvedRounded ?? undefined}
 	data-shape={shape}
@@ -54,7 +68,7 @@
 	{#snippet children(snippetProps)}
 		<!-- Start slot: spinner (when loading) wins over icon at start placement. -->
 		{#if loading && spinnerPlacement === 'start'}
-			{#if spinner}<ButtonSpinner>{@render spinner()}</ButtonSpinner>{:else}<ButtonSpinner />{/if}
+			{#if spinner}<ButtonSpinner size={resolvedSize}>{@render spinner()}</ButtonSpinner>{:else}<ButtonSpinner size={resolvedSize} />{/if}
 		{:else if icon}
 			<span class="eidos-button-icon" data-button-icon="start" aria-hidden="true">
 				{@render icon(snippetProps)}
@@ -79,7 +93,7 @@
 
 		<!-- End slot: spinner (when loading) wins over endIcon at end placement. -->
 		{#if loading && spinnerPlacement === 'end'}
-			{#if spinner}<ButtonSpinner>{@render spinner()}</ButtonSpinner>{:else}<ButtonSpinner />{/if}
+			{#if spinner}<ButtonSpinner size={resolvedSize}>{@render spinner()}</ButtonSpinner>{:else}<ButtonSpinner size={resolvedSize} />{/if}
 		{:else if endIcon}
 			<span class="eidos-button-icon" data-button-icon="end" aria-hidden="true">
 				{@render endIcon(snippetProps)}
diff --git a/src/uix/eidos/components/button/types.ts b/src/uix/eidos/components/button/types.ts
index 85c87df2b..6014f5c20 100644
--- a/src/uix/eidos/components/button/types.ts
+++ b/src/uix/eidos/components/button/types.ts
@@ -1,6 +1,7 @@
 import type { Snippet } from 'svelte';
 import type { ProviderProps, SpinnerProps } from '$soma/components/button';
 import type { ResponsiveProp, ShapeFamily, Size } from '$uix/eidos/lib/types';
+import type { SpinnerSize } from '../spinner/types';
 
 /**
  * Button visual variant. The 6-variant set ported from air covers the
@@ -76,4 +77,7 @@ export type ButtonProps = ProviderProps & {
 	spinner?: Snippet;
 };
 
-export type ButtonSpinnerWrapperProps = SpinnerProps;
+export type ButtonSpinnerWrapperProps = SpinnerProps & {
+	/** Sizes the embedded `<Spinner>` ring; forwarded from the Button's size. @default 'md' */
+	size?: SpinnerSize;
+};
diff --git a/src/uix/eidos/components/spinner/spinner.css b/src/uix/eidos/components/spinner/spinner.css
index 82da6e2c1..69c6c2c6e 100644
--- a/src/uix/eidos/components/spinner/spinner.css
+++ b/src/uix/eidos/components/spinner/spinner.css
@@ -74,6 +74,13 @@
 	--_spinner-track: color-mix(in srgb, var(--color-loss-track) 60%, transparent);
 }
 
+/* `inherit` — take the surrounding `currentColor` (for embedding in a control
+   that owns the colour, e.g. a solid Button whose text is the contrast colour). */
+[data-spinner][data-color='inherit'] {
+	--_spinner-color: currentColor;
+	--_spinner-track: color-mix(in srgb, currentColor 25%, transparent);
+}
+
 /* ── Ring variant ──────────────────────────────────────────────────── */
 
 [data-spinner][data-variant='ring'] [data-spinner-track] {
diff --git a/src/uix/eidos/components/spinner/spinner.svelte b/src/uix/eidos/components/spinner/spinner.svelte
index d0e7ac67c..108b8ba57 100644
--- a/src/uix/eidos/components/spinner/spinner.svelte
+++ b/src/uix/eidos/components/spinner/spinner.svelte
@@ -19,6 +19,7 @@
 		variant = 'ring',
 		size = 'md',
 		color = 'primary',
+		presentation = false,
 		'aria-label': ariaLabel,
 		children,
 		...rest
@@ -35,9 +36,10 @@
 	data-variant={variant}
 	data-size={resolvedSize}
 	data-color={color}
-	role="status"
-	aria-live="polite"
-	aria-label={resolvedLabel}
+	role={presentation ? undefined : 'status'}
+	aria-live={presentation ? undefined : 'polite'}
+	aria-label={presentation ? undefined : resolvedLabel}
+	aria-hidden={presentation ? 'true' : undefined}
 	{...rest}
 >
 	{#if variant === 'dots'}
diff --git a/src/uix/eidos/components/spinner/types.ts b/src/uix/eidos/components/spinner/types.ts
index 5b55af4f2..f655f91d0 100644
--- a/src/uix/eidos/components/spinner/types.ts
+++ b/src/uix/eidos/components/spinner/types.ts
@@ -3,7 +3,7 @@ import type { ColorRole, ResponsiveProp, Size } from '$uix/eidos/lib/types';
 import type { BoxProps } from '../box/types';
 
 export type SpinnerSize = Extract<Size, 'xs' | 'sm' | 'md' | 'lg' | 'xl'>;
-export type SpinnerColor = ColorRole;
+export type SpinnerColor = ColorRole | 'inherit';
 export type SpinnerVariant = 'ring' | 'dots' | 'bars';
 
 /**
@@ -19,8 +19,18 @@ export type SpinnerProps = Omit<BoxProps, 'display'> & {
 	variant?: SpinnerVariant;
 	/** Spinner size. @default 'md' */
 	size?: ResponsiveProp<SpinnerSize>;
-	/** Accent palette. @default 'primary' */
+	/**
+	 * Accent palette, or `'inherit'` to take the surrounding `currentColor`
+	 * (for embedding inside a control that owns the colour, e.g. Button).
+	 * @default 'primary'
+	 */
 	color?: SpinnerColor;
+	/**
+	 * Presentational mode — drops `role="status"` / `aria-live` / `aria-label`
+	 * and marks the spinner `aria-hidden`. Use when an ancestor already owns the
+	 * loading a11y (e.g. a Button with `aria-busy`). @default false
+	 */
+	presentation?: boolean;
 	/** Override the SR text. Defaults to a translated `'Loading'`. */
 	'aria-label'?: string;
 	/** Optional visible label rendered next to the spinner. */
diff --git a/src/uix/eidos/generated/base.css b/src/uix/eidos/generated/base.css
index 72a729965..82a87c10e 100644
--- a/src/uix/eidos/generated/base.css
+++ b/src/uix/eidos/generated/base.css
@@ -178,6 +178,8 @@
 	--focus-ring-inner-width: 0px;
 	--focus-ring: inset 0 0 0 var(--focus-ring-inner-width) var(--focus-ring-color), 0 0 0 var(--focus-ring-offset) var(--color-surface-default), 0 0 0 calc(var(--focus-ring-offset) + var(--focus-ring-width)) var(--focus-ring-color);
 	--focus-ring-error: inset 0 0 0 var(--focus-ring-inner-width) var(--focus-ring-color-error), 0 0 0 var(--focus-ring-offset) var(--color-surface-default), 0 0 0 calc(var(--focus-ring-offset) + var(--focus-ring-width)) var(--focus-ring-color-error);
+	--press-scale: 0.985;
+	--press-duration: 80ms;
 	--field-segment-active-bg: color-mix(in srgb, var(--color-primary-border) 40%, transparent);
 	--field-segment-active-text: var(--color-primary-text);
 	--field-segment-hover-bg: color-mix(in srgb, var(--color-content-primary) 6%, transparent);
@@ -878,8 +880,8 @@
 	--card-emerge-distance: 8px;
 	--card-hover-lift: -2px;
 	--card-hover-shadow: var(--depth-overlay-shadow), var(--depth-overlay-halo);
-	--card-press-scale: 0.985;
-	--card-press-duration: 80ms;
+	--card-press-scale: var(--press-scale);
+	--card-press-duration: var(--press-duration);
 	--card-selected-ring-width: var(--border-width-medium);
 	--card-disabled-opacity: var(--opacity-disabled);
 	--card-color-custom: currentColor;
@@ -1625,7 +1627,6 @@
 	--button-shadow: none;
 	--button-transition-duration: var(--duration-fast);
 	--button-transition-ease: var(--ease-default);
-	--button-spinner-duration: 720ms;
 	--button-disabled-opacity: var(--opacity-disabled);
 	--button-primary-track: var(--color-primary-track);
 	--button-primary-element: var(--color-primary-element);
@@ -1760,6 +1761,7 @@
 	--chronos-lane-height-sm: var(--space-5);
 	--chronos-lane-height-md: var(--space-6);
 	--chronos-lane-height-lg: var(--space-7);
+	--chronos-timegrid-block-size: min(70vh, 40rem);
 	--chronos-focus-shadow: inset 0 0 0 var(--focus-ring-inner-width) var(--focus-ring-color), 0 0 0 var(--focus-ring-offset) var(--color-surface-default), 0 0 0 calc(var(--focus-ring-offset) + var(--focus-ring-width)) var(--focus-ring-color);
 	--chronos-disabled-opacity: var(--opacity-disabled);
 	--pagination-gap-xs: var(--space-0-5);
diff --git a/src/uix/eidos/lib/config-types.ts b/src/uix/eidos/lib/config-types.ts
index 735ac1a63..728e5a2df 100644
--- a/src/uix/eidos/lib/config-types.ts
+++ b/src/uix/eidos/lib/config-types.ts
@@ -247,6 +247,13 @@ export interface FocusRingPrimitiveSet {
 	readonly innerWidth: string;
 }
 
+export interface PressPrimitiveSet {
+	/** Scale-down factor applied on `:active` (unitless, e.g. `0.985`). */
+	readonly scale: string;
+	/** Transition duration of the press squeeze (the press IN). */
+	readonly duration: string;
+}
+
 export const SHADOW_PHYSICAL_KEYS = ['1', '2', '3', '4', '5', '6'] as const;
 export const SHADOW_SEMANTIC_KEYS = ['none', 'subtle', 'raised', 'overlay'] as const;
 // Inner-shadow (recessed/well) tier — soft, mode-aware, drawn `inset`. Distinct
@@ -816,6 +823,7 @@ export interface PrimitiveSet {
 	readonly gradients?: Record<string, string>;
 	readonly border?: BorderPrimitiveSet;
 	readonly focusRing?: FocusRingPrimitiveSet;
+	readonly press?: PressPrimitiveSet;
 	readonly layout?: LayoutPrimitiveSet;
 	readonly density?: DensityPrimitiveSet;
 	readonly typography?: TypographyPrimitiveSet;
diff --git a/src/uix/eidos/lib/contract.ts b/src/uix/eidos/lib/contract.ts
index 86b287ea3..ce0d322df 100644
--- a/src/uix/eidos/lib/contract.ts
+++ b/src/uix/eidos/lib/contract.ts
@@ -92,6 +92,11 @@ function appendStaticContractTokens(tokens: EidosCssContractToken[], options: Ei
 		pushToken(tokens, 'static', 'focus-ring', 'focus-ring-error', 'primitives.focusRing.error')
 	}
 
+	if (primitives.press) {
+		pushToken(tokens, 'static', 'press', 'press-scale', 'primitives.press.scale')
+		pushToken(tokens, 'static', 'press', 'press-duration', 'primitives.press.duration')
+	}
+
 	if (primitives.layout) {
 		appendLayoutContractTokens(tokens, primitives.layout)
 	}
diff --git a/src/uix/eidos/lib/primitives/static.ts b/src/uix/eidos/lib/primitives/static.ts
index 1761f101b..6a38c56c2 100644
--- a/src/uix/eidos/lib/primitives/static.ts
+++ b/src/uix/eidos/lib/primitives/static.ts
@@ -111,6 +111,18 @@ export const STATIC_FOCUS_RING = {
 	innerWidth: '0px'
 } as const
 
+export const STATIC_PRESS = {
+	/* Press feedback — a subtle scale-down "squeeze" on `:active`. ONE shared
+	   tactile signature for every interactive surface (button, card, …), the
+	   sibling of the focus ring: a single recognisable press across the system.
+	   `scale` is unitless; `duration` is snappier than `--duration-fast` for an
+	   immediate, physical response (the press IN; release rides the base
+	   transition). Centred consumers must compose it via the `translate`
+	   property, not `transform`, so the scale doesn't wipe their offset. */
+	scale: '0.985',
+	duration: '80ms'
+} as const
+
 export const STATIC_LAYOUT = {
 	containerWidth: {
 		sm: '448px',
@@ -417,6 +429,7 @@ export const STATIC_PRIMITIVES: Pick<
 	| 'gradients'
 	| 'border'
 	| 'focusRing'
+	| 'press'
 	| 'layout'
 	| 'density'
 	| 'typography'
@@ -436,6 +449,7 @@ export const STATIC_PRIMITIVES: Pick<
 	gradients: STATIC_GRADIENTS,
 	border: STATIC_BORDER,
 	focusRing: STATIC_FOCUS_RING,
+	press: STATIC_PRESS,
 	layout: STATIC_LAYOUT,
 	density: STATIC_DENSITY,
 	typography: STATIC_TYPOGRAPHY,
diff --git a/src/uix/eidos/lib/recipes/base.ts b/src/uix/eidos/lib/recipes/base.ts
index 79c0619b9..76527ef60 100644
--- a/src/uix/eidos/lib/recipes/base.ts
+++ b/src/uix/eidos/lib/recipes/base.ts
@@ -523,8 +523,8 @@ export const THEME_BASE_RECIPE_TOKENS = {
 		'emerge-distance': '8px',
 		'hover-lift': '-2px',
 		'hover-shadow': 'var(--depth-overlay-shadow), var(--depth-overlay-halo)',
-		'press-scale': '0.985',
-		'press-duration': '80ms',
+		'press-scale': 'var(--press-scale)',
+		'press-duration': 'var(--press-duration)',
 		'selected-ring-width': 'var(--border-width-medium)',
 		'disabled-opacity': 'var(--opacity-disabled)',
 		// ── Custom color (set inline by consumer via style) ───────────────
@@ -1502,7 +1502,6 @@ export const THEME_BASE_RECIPE_TOKENS = {
 		shadow: 'none',
 		'transition-duration': 'var(--duration-fast)',
 		'transition-ease': 'var(--ease-default)',
-		'spinner-duration': '720ms',
 		'disabled-opacity': 'var(--opacity-disabled)',
 		// Per-color palettes — 7 slots per color, uniform across all 8: track /
 		// element / border / solid / solid-hover / text / contrast. soft + surface
@@ -1739,6 +1738,8 @@ export const THEME_BASE_RECIPE_TOKENS = {
 		'lane-height-sm': 'var(--space-5)',
 		'lane-height-md': 'var(--space-6)',
 		'lane-height-lg': 'var(--space-7)',
+		// Week/Day time-grid viewport height (scrolls internally).
+		'timegrid-block-size': 'min(70vh, 40rem)',
 		'focus-shadow':
 			'inset 0 0 0 var(--focus-ring-inner-width) var(--focus-ring-color), 0 0 0 var(--focus-ring-offset) var(--color-surface-default), 0 0 0 calc(var(--focus-ring-offset) + var(--focus-ring-width)) var(--focus-ring-color)',
 		'disabled-opacity': 'var(--opacity-disabled)'
diff --git a/src/uix/eidos/lib/render-css.ts b/src/uix/eidos/lib/render-css.ts
index ae87b7a62..712f5b622 100644
--- a/src/uix/eidos/lib/render-css.ts
+++ b/src/uix/eidos/lib/render-css.ts
@@ -198,6 +198,11 @@ export function renderStaticCss(options: EidosConfig): string {
 		)
 	}
 
+	if (primitives.press) {
+		declarations.push(cssVar('press-scale', primitives.press.scale))
+		declarations.push(cssVar('press-duration', primitives.press.duration))
+	}
+
 	// Active-segment highlight — single foundation source for the date/time/
 	// color field active segment. `-bg` is the full background colour (bake in
 	// whatever transparency you want, e.g. via `color-mix`) and `-text` is the