Before and after figures

import { ArrowDownRight, ArrowUpRight } from 'lucide-react'
import { Container } from '@/components/ui/layout'

/**
 * Before / after statistics pair
 *
 * The same four measures, twice. Direction is carried by an arrow, a sign and
 * a colour, so the improvement is legible in greyscale — which matters,
 * because this section is the one people screenshot.
 */
const rows = [
  {
    label: 'JavaScript shipped',
    before: '64 kB',
    after: '14 kB',
    delta: -78,
    better: 'down' as const,
  },
  {
    label: 'Largest contentful paint',
    before: '1.5 s',
    after: '0.9 s',
    delta: -41,
    better: 'down' as const,
  },
  {
    label: 'Components maintained',
    before: '4 sets',
    after: '1 set',
    delta: -75,
    better: 'down' as const,
  },
  {
    label: 'Time to a new screen',
    before: '5 days',
    after: '2 days',
    delta: -60,
    better: 'down' as const,
  },
]

export default function ComparisonPairStats() {
  return (
    <section className="border-b border-line bg-surface-sunken py-section">
      <Container>
        <div className="max-w-2xl">
          <h2 className="display-type text-2xl font-semibold text-ink-strong sm:text-3xl">
            Northwind, before and after consolidation.
          </h2>
          <p className="mt-3 text-md text-ink-muted">
            A fictional client, measured across one quarter of migration work.
          </p>
        </div>

        <div className="mt-10 overflow-hidden rounded-xl border border-line bg-surface">
          <div className="grid grid-cols-[1fr_auto_auto_auto] gap-x-4 border-b border-line bg-surface-sunken px-5 py-3 sm:gap-x-8">
            <span className="label-caps text-ink-subtle">Measure</span>
            <span className="label-caps text-right text-ink-subtle">Before</span>
            <span className="label-caps text-right text-ink-subtle">After</span>
            <span className="label-caps text-right text-ink-subtle">Change</span>
          </div>
          <ul>
            {rows.map((row) => {
              const good = row.better === 'down' ? row.delta < 0 : row.delta > 0
              const Icon = row.delta < 0 ? ArrowDownRight : ArrowUpRight
              return (
                <li
                  key={row.label}
                  className="grid grid-cols-[1fr_auto_auto_auto] items-baseline gap-x-4 border-b border-line-subtle px-5 py-3.5 last:border-0 sm:gap-x-8"
                >
                  <span className="text-sm text-ink">{row.label}</span>
                  <span className="text-right font-mono text-sm text-ink-subtle tabular-nums line-through">
                    {row.before}
                  </span>
                  <span className="text-right font-mono text-sm font-semibold text-ink-strong tabular-nums">
                    {row.after}
                  </span>
                  <span
                    className={`flex items-center justify-end gap-0.5 text-right font-mono text-sm tabular-nums ${
                      good ? 'text-success' : 'text-danger'
                    }`}
                  >
                    <Icon className="size-3.5" aria-hidden="true" />
                    {row.delta > 0 ? '+' : ''}
                    {row.delta}%
                  </span>
                </li>
              )
            })}
          </ul>
        </div>
      </Container>
    </section>
  )
}

import type { ElementType, HTMLAttributes, ReactNode } from 'react'
import { cn } from '@/lib/cn'

/**
 * Layout primitives
 *
 * Five zero-JavaScript building blocks that account for the majority of
 * structure in the library. They exist so that spacing decisions are made once,
 * against density tokens, instead of being re-typed as ad-hoc utilities in
 * every section.
 */

export interface ContainerProps extends HTMLAttributes<HTMLDivElement> {
  /** `prose` narrows to a comfortable reading measure. */
  size?: 'prose' | 'narrow' | 'default' | 'wide' | 'full'
  as?: ElementType
  /** Removes the responsive horizontal gutter. */
  bleed?: boolean
}

const containerSizes = {
  prose: 'max-w-[var(--layout-prose-max)]',
  narrow: 'max-w-3xl',
  default: 'max-w-[var(--layout-content-max)]',
  wide: 'max-w-[110rem]',
  full: 'max-w-none',
} as const

export function Container({
  size = 'default',
  as: Tag = 'div',
  bleed = false,
  className,
  children,
  ...props
}: ContainerProps) {
  return (
    <Tag
      className={cn(
        'mx-auto w-full',
        containerSizes[size],
        !bleed && 'px-4 sm:px-6 lg:px-8',
        className,
      )}
      {...props}
    >
      {children}
    </Tag>
  )
}

export interface StackProps extends HTMLAttributes<HTMLDivElement> {
  direction?: 'row' | 'column'
  gap?: 'none' | 'xs' | 'sm' | 'md' | 'lg' | 'xl'
  align?: 'start' | 'center' | 'end' | 'stretch' | 'baseline'
  justify?: 'start' | 'center' | 'end' | 'between' | 'around'
  wrap?: boolean
  as?: ElementType
}

const gapMap = {
  none: 'gap-0',
  xs: 'gap-1',
  sm: 'gap-2',
  md: 'gap-gap',
  lg: 'gap-stack',
  xl: 'gap-8',
} as const

const alignMap = {
  start: 'items-start',
  center: 'items-center',
  end: 'items-end',
  stretch: 'items-stretch',
  baseline: 'items-baseline',
} as const

const justifyMap = {
  start: 'justify-start',
  center: 'justify-center',
  end: 'justify-end',
  between: 'justify-between',
  around: 'justify-around',
} as const

export function Stack({
  direction = 'column',
  gap = 'md',
  align,
  justify,
  wrap = false,
  as: Tag = 'div',
  className,
  children,
  ...props
}: StackProps) {
  return (
    <Tag
      className={cn(
        'flex',
        direction === 'column' ? 'flex-col' : 'flex-row',
        gapMap[gap],
        align && alignMap[align],
        justify && justifyMap[justify],
        wrap && 'flex-wrap',
        className,
      )}
      {...props}
    >
      {children}
    </Tag>
  )
}

export interface GridProps extends HTMLAttributes<HTMLDivElement> {
  /** Column count at the largest breakpoint; smaller breakpoints step down. */
  cols?: 1 | 2 | 3 | 4 | 5 | 6
  gap?: StackProps['gap']
  as?: ElementType
  /** Auto-fit tracks with a minimum width instead of a fixed column count. */
  minItemWidth?: string
}

const colMap = {
  1: 'grid-cols-1',
  2: 'grid-cols-1 sm:grid-cols-2',
  3: 'grid-cols-1 sm:grid-cols-2 lg:grid-cols-3',
  4: 'grid-cols-1 sm:grid-cols-2 lg:grid-cols-4',
  5: 'grid-cols-2 sm:grid-cols-3 lg:grid-cols-5',
  6: 'grid-cols-2 sm:grid-cols-3 lg:grid-cols-6',
} as const

export function Grid({
  cols = 3,
  gap = 'lg',
  as: Tag = 'div',
  minItemWidth,
  className,
  style,
  children,
  ...props
}: GridProps) {
  return (
    <Tag
      className={cn('grid', minItemWidth ? undefined : colMap[cols], gapMap[gap], className)}
      style={
        minItemWidth
          ? {
              ...style,
              gridTemplateColumns: `repeat(auto-fit, minmax(min(${minItemWidth}, 100%), 1fr))`,
            }
          : style
      }
      {...props}
    >
      {children}
    </Tag>
  )
}

export interface DividerProps extends HTMLAttributes<HTMLDivElement> {
  orientation?: 'horizontal' | 'vertical'
  /** Renders a centred text label interrupting the rule. */
  label?: ReactNode
  weight?: 'subtle' | 'default' | 'strong'
}

const dividerWeight = {
  subtle: 'border-line-subtle',
  default: 'border-line',
  strong: 'border-line-strong',
} as const

export function Divider({
  orientation = 'horizontal',
  label,
  weight = 'default',
  className,
  ...props
}: DividerProps) {
  if (orientation === 'vertical') {
    return (
      <div
        role="separator"
        aria-orientation="vertical"
        className={cn('h-full w-px self-stretch border-l', dividerWeight[weight], className)}
        {...props}
      />
    )
  }

  if (label) {
    return (
      <div className={cn('flex items-center gap-3', className)} {...props}>
        <span className={cn('h-px flex-1 border-t', dividerWeight[weight])} role="separator" />
        <span className="label-caps text-ink-subtle">{label}</span>
        <span className={cn('h-px flex-1 border-t', dividerWeight[weight])} aria-hidden="true" />
      </div>
    )
  }

  return (
    <div
      role="separator"
      className={cn('w-full border-t', dividerWeight[weight], className)}
      {...props}
    />
  )
}