You build a tournament bracket with a popular React library. In Chrome it's perfect — neat columns, clean connector lines. Then you open it on an iPhone, or in Safari, or inside your Capacitor app… and every match is crammed into the top-left corner, stacked on top of the round headers.

If you've ever shipped a bracket to iOS, you've probably seen this exact bug. Here's why it happens — and a tiny library that fixes it for good.

The symptom

It looks fine everywhere Chromium runs (Chrome, Edge, Android WebView) and completely broken everywhere WebKit runs:

• Safari (macOS and iOS)
• iOS WKWebView
• Capacitor / Cordova apps
• Electron-on-WebKit

The matches don't just shift a little — they all render at coordinate (0,0) of the bracket, piling on top of each other and the headers.

The cause: SVG <foreignObject> in WebKit

Most React bracket libraries — @g-loot/react-tournament-brackets, react-tournament-bracket, and friends — render the bracket as an SVG and place each match's HTML inside a <foreignObject> positioned with x/y attributes.

WebKit has a long-standing bug: it ignores x, y, and transform on <foreignObject> and positions the content relative to the top-level <svg> instead of the foreignObject's own coordinates. Every match therefore collapses to the origin.

And there's no CSS escape hatch — x, y, and transform are all ignored on foreignObject in Safari, so you can't nudge the content back into place. I even tried patching a library to wrap each match in a <g transform="translate(x,y)"> instead of a nested <svg x y>; WebKit ignores ancestor transforms for foreignObject positioning too. The SVG approach is simply a dead end on WebKit.

The fix: don't use SVG at all

A bracket is really just columns of cards joined by connector lines — and both are expressible in plain CSS.

Here's the key insight. Put each round in a flex column where every match sits in an equal flex: 1 slot. Because each round has half the matches of the previous one, a match's slot spans exactly two feeder slots — so the two feeders land at 25% and 75% of that slot, and the match itself at 50%:

Round 1 slot   Round 2 slot
┌──────────┐
│ Match A  │──┐   25%
├──────────┤  ├─►┌──────────┐
│ Match B  │──┘  │ Winner   │   50%
└──────────┘     └──────────┘
┌──────────┐
│ Match C  │──┐   75%
│   ...    │

Draw the connector elbow with a few absolutely-positioned, bordered <div>s at those same 25 / 50 / 75% offsets, and the tree stays perfectly aligned at any height — with zero JavaScript measuring and no SVG. Because it's all flexbox and borders, it renders identically on Chromium, Firefox, and WebKit.

bracketkit

I packaged this up as bracketkit — a headless, pure-CSS tournament bracket for React:

• 🍏 Works in Safari / WebKit — no SVG, no foreignObject.
• 🧩 Headless — you render the match card; bracketkit owns layout + connectors. No theme objects, no design lock-in.
• 🪶 ~4 KB, zero dependencies — ESM + CJS + first-class TypeScript types.
• ⚡ SSR-safe — no measurement, correct on the first server render.
• 🎨 Style it any way — plain CSS, Tailwind, or a drop-in shadcn/ui component.

Quick start

npm i bracketkit

import { Bracket, type BracketRound } from "bracketkit"

type Match = { id: string; home: string; away: string; homeScore?: number; awayScore?: number }

const rounds: BracketRound<Match>[] = [
  {
    id: "sf",
    name: "Semi-finals",
    matches: [
      { id: "sf1", home: "Lions", away: "Bears", homeScore: 2, awayScore: 1 },
      { id: "sf2", home: "Hawks", away: "Wolves", homeScore: 0, awayScore: 3 },
    ],
  },
  { id: "f", name: "Final", matches: [{ id: "f1", home: "Lions", away: "Wolves" }] },
]

export function Playoffs() {
  return (
    <div style={{ overflowX: "auto", color: "#64748b" /* connector color */ }}>
      <Bracket
        rounds={rounds}
        renderRoundHeader={(round) => <h3>{round.name}</h3>}
        renderMatch={(m) => (
          <div className="match-card">
            <div>{m.home} — {m.homeScore ?? "–"}</div>
            <div>{m.away} — {m.awayScore ?? "–"}</div>
          </div>
        )}
      />
    </div>
  )
}

Theming

bracketkit ships no visual styling beyond layout. Connectors inherit currentColor and expose two CSS variables; every part has a data-* hook:

[data-bracket-root] {
  --bracket-connector-color: #64748b;
  --bracket-connector-width: 2px;
}
[data-bracket-match] { /* your card wrapper */ }

Prefer shadcn/ui?

npx shadcn@latest add https://hrmasss.github.io/bracketkit/r/bracket.json

You get a styled, batteries-included <Bracket> using your shadcn tokens — and you own the code.

Try it

• 🔗 Live demo & docs: https://hrmasss.github.io/bracketkit/
• 📦 npm: https://www.npmjs.com/package/bracketkit
• ⭐ GitHub: https://github.com/hrmasss/bracketkit

If you've fought the Safari foreignObject bug, I'd love to know whether this saves you the headache. Issues and PRs welcome.