MagicNumberPadding [counter-example] v1.0.0

A header layout that uses off-grid pixel values and a calc() expression with a bare numeric constant. The values were nudged into place visually with no underlying system.

Label

Off-Grid 13px and calc() With Unnamed Constants

Meta

• License: Apache-2.0
• License Provenance: package-authorship-claim

Bad Code

.site-header {
height: 73px;
padding: 13px 21px;
z-index: 999;
}

.site-content {
min-height: calc(100vh - 73px);
margin-top: 7px;
}

.modal {
z-index: 9999;
top: 47px;
}

Why Bad

• 73/13/21/7/47 are not on any 4px or 8px grid — they are pure visual nudges
• calc(100vh - 73px) duplicates the magic 73px — change header height and the layout breaks silently
• z-index values (999, 9999) have no scale; the next dev will write 99999 to win
• No way for the next reader to tell which numbers were intentional vs leftover from debugging
• Pixel-perfect look is fragile — a 14px font bump pushes everything out of alignment again

Good Code

:root {
--header-height: 64px;
--space-sm: 8px;
--space-md: 16px;
--space-lg: 24px;
--z-dropdown: 10;
--z-modal: 40;
}

.site-header {
height: var(--header-height);
padding: var(--space-md) var(--space-lg);
z-index: var(--z-dropdown);
}

.site-content {
min-height: calc(100vh - var(--header-height));
margin-top: var(--space-sm);
}

.modal {
z-index: var(--z-modal);
top: var(--header-height);
}

Why Good

• All values land on an 8px grid — header-height: 64px (8 * 8) is intentional, not accidental
• Single source of truth: change --header-height once, content min-height + modal offset both update
• Z-index scale prevents the 999 → 9999 → 99999 escalation war
• Token names communicate intent: --z-modal is self-documenting, 9999 is not
• Future adjustments happen at the token layer, not scattered through component CSS

Anti Pattern

@community/anti-pattern-magic-numbers

MagicNumberPadding [counter-example] v1.0.0

A header layout that uses off-grid pixel values and a calc() expression with a bare numeric constant. The values were nudged into place visually with no underlying system.

Label

Off-Grid 13px and calc() With Unnamed Constants

Meta

• License: Apache-2.0
• License Provenance: package-authorship-claim

Bad Code

.site-header {
height: 73px;
padding: 13px 21px;
z-index: 999;
}

.site-content {
min-height: calc(100vh - 73px);
margin-top: 7px;
}

.modal {
z-index: 9999;
top: 47px;
}

Why Bad

• 73/13/21/7/47 are not on any 4px or 8px grid — they are pure visual nudges
• calc(100vh - 73px) duplicates the magic 73px — change header height and the layout breaks silently
• z-index values (999, 9999) have no scale; the next dev will write 99999 to win
• No way for the next reader to tell which numbers were intentional vs leftover from debugging
• Pixel-perfect look is fragile — a 14px font bump pushes everything out of alignment again

Good Code

:root {
--header-height: 64px;
--space-sm: 8px;
--space-md: 16px;
--space-lg: 24px;
--z-dropdown: 10;
--z-modal: 40;
}

.site-header {
height: var(--header-height);
padding: var(--space-md) var(--space-lg);
z-index: var(--z-dropdown);
}

.site-content {
min-height: calc(100vh - var(--header-height));
margin-top: var(--space-sm);
}

.modal {
z-index: var(--z-modal);
top: var(--header-height);
}

Why Good

• All values land on an 8px grid — header-height: 64px (8 * 8) is intentional, not accidental
• Single source of truth: change --header-height once, content min-height + modal offset both update
• Z-index scale prevents the 999 → 9999 → 99999 escalation war
• Token names communicate intent: --z-modal is self-documenting, 9999 is not
• Future adjustments happen at the token layer, not scattered through component CSS

Anti Pattern

@community/anti-pattern-magic-numbers

Relations

related: [@community/type-design-token, @community/anti-pattern-hardcoded-pixel-values]

Label

Off-Grid 13px and calc() With Unnamed Constants

Meta

• License: Apache-2.0
• License Provenance: package-authorship-claim

Bad Code

.site-header {
height: 73px;
padding: 13px 21px;
z-index: 999;
}

.site-content {
min-height: calc(100vh - 73px);
margin-top: 7px;
}

.modal {
z-index: 9999;
top: 47px;
}

Why Bad

• 73/13/21/7/47 are not on any 4px or 8px grid — they are pure visual nudges
• calc(100vh - 73px) duplicates the magic 73px — change header height and the layout breaks silently
• z-index values (999, 9999) have no scale; the next dev will write 99999 to win
• No way for the next reader to tell which numbers were intentional vs leftover from debugging
• Pixel-perfect look is fragile — a 14px font bump pushes everything out of alignment again

Good Code

:root {
--header-height: 64px;
--space-sm: 8px;
--space-md: 16px;
--space-lg: 24px;
--z-dropdown: 10;
--z-modal: 40;
}

.site-header {
height: var(--header-height);
padding: var(--space-md) var(--space-lg);
z-index: var(--z-dropdown);
}

.site-content {
min-height: calc(100vh - var(--header-height));
margin-top: var(--space-sm);
}

.modal {
z-index: var(--z-modal);
top: var(--header-height);
}

Why Good

• All values land on an 8px grid — header-height: 64px (8 * 8) is intentional, not accidental
• Single source of truth: change --header-height once, content min-height + modal offset both update
• Z-index scale prevents the 999 → 9999 → 99999 escalation war
• Token names communicate intent: --z-modal is self-documenting, 9999 is not
• Future adjustments happen at the token layer, not scattered through component CSS

Anti Pattern

@community/anti-pattern-magic-numbers