Spend / Save Split Hero

1/**
2 * HeroSplitScreen: a two-story hero for a bank with two products. Two flat
3 * colour fields, "Spend" and "Save", each with its own type voice, product
4 * fragment and call to action. Hovering, focusing or tapping a half springs
5 * it open and squeezes the other; a round seal rides the seam between them.
6 * On phones the halves stack and the tapped one opens.
7 *
8 * Props: brand, spend and save (label, word, lede, cta, fine print), and the
9 * product data (transactions, pot, balance). Each half is a SplitSide.
10 * CSS vars: --fd-spl-spend, --fd-spl-spend-ink, --fd-spl-save, --fd-spl-save-ink.
11 *
12 * Browser support: all evergreen browsers (container query units for the
13 * giant words; fixed sizes otherwise).
14 * Motion: flex-grow with the library spring curve (overshoot), word size
15 * follows via cqw. The savings balance accrues a cent at a time.
16 * prefers-reduced-motion: halves swap size instantly, no accrual ticking.
17 * Accessibility: each half's title is a button with aria-expanded that opens
18 * it; details stay in the accessibility tree when collapsed.
19 */
20import { useEffect, useId, useState } from "react";
21import type { ReactNode } from "react";
22 
23export interface SplitSide {
24  index: string;
25  word: string;
26  lede: ReactNode;
27  cta: { label: string; href: string };
28  fine: ReactNode;
29}
30 
31export interface SplitTxn {
32  merchant: string;
33  place: string;
34  amount: string;
35  roundUp: string;
36  time: string;
37  glyph: string;
38}
39 
40export interface HeroSplitScreenProps {
41  brand?: string;
42  spend?: SplitSide;
43  save?: SplitSide;
44  transactions?: SplitTxn[];
45  pot?: { name: string; saved: number; goal: number; due: string };
46  balance?: number;
47  rate?: string;
48  defaultActive?: "spend" | "save" | null;
49}
50 
51const SPEND: SplitSide = {
52  index: "01",
53  word: "Spend",
54  lede: "A debit card that tells you where the money went before you have left the shop.",
55  cta: { label: "Get the card", href: "#card" },
56  fine: "No fees abroad in 31 countries. Freeze it from your lock screen.",
57};
58 
59const SAVE: SplitSide = {
60  index: "02",
61  word: "Save",
62  lede: "Pots that fill themselves with your spare change, at 2.75% paid every month.",
63  cta: { label: "Open a pot", href: "#pots" },
64  fine: "Deposits protected up to €100,000 by the German deposit scheme.",
65};
66 
67const TXNS: SplitTxn[] = [
68  { merchant: "Bäckerei Rösler", place: "Prenzlauer Berg", amount: "−€3.40", roundUp: "+€0.60", time: "08:12", glyph: "B" },
69  { merchant: "BVG Monatskarte", place: "Berlin AB", amount: "−€58.00", roundUp: "+€0.00", time: "08:40", glyph: "U" },
70  { merchant: "Dussmann", place: "Friedrichstraße", amount: "−€22.75", roundUp: "+€0.25", time: "13:05", glyph: "D" },
71];
72 
73const fmt = (n: number) =>
74  "€" + n.toFixed(2).replace(/\B(?=(\d{3})+(?!\d))/g, ",");
75 
76export function HeroSplitScreen({
77  brand = "Kontor",
78  spend = SPEND,
79  save = SAVE,
80  transactions = TXNS,
81  pot = { name: "Lisbon in June", saved: 1840, goal: 2400, due: "by 14 May" },
82  balance = 4182.36,
83  rate = "2.75% AER",
84  defaultActive = null,
85}: HeroSplitScreenProps) {
86  const [active, setActive] = useState<"spend" | "save" | null>(defaultActive);
87  const [bal, setBal] = useState(balance);
88  const [isTouch, setIsTouch] = useState(false);
89  const ringId = "fd-spl-ring" + useId().replace(/:/g, "");
90 
91  useEffect(() => {
92    const mq = window.matchMedia("(max-width: 760px)");
93    const sync = () => {
94      setIsTouch(mq.matches);
95      if (mq.matches) setActive((a) => a ?? "spend");
96    };
97    sync();
98    mq.addEventListener("change", sync);
99    return () => mq.removeEventListener("change", sync);
100  }, []);
101 
102  useEffect(() => {
103    if (window.matchMedia("(prefers-reduced-motion: reduce)").matches) return;
104    let id = 0;
105    const tick = () => {
106      if (!document.hidden) setBal((b) => Math.round((b + 0.01) * 100) / 100);
107      id = window.setTimeout(tick, 1400);
108    };
109    id = window.setTimeout(tick, 1400);
110    return () => window.clearTimeout(id);
111  }, []);
112 
113  const state = active ? `is-${active}` : "is-even";
114  const pct = Math.round((pot.saved / pot.goal) * 100);
115 
116  const enter = (s: "spend" | "save") => {
117    if (!isTouch) setActive(s);
118  };
119 
120  return (
121    <section
122      className={`fd-spl ${state}`}
123      aria-label={`${brand}: ${spend.word} and ${save.word}`}
124      onPointerLeave={(e) => e.pointerType === "mouse" && !isTouch && setActive(defaultActive)}
125    >
126      <style>{css}</style>
127 
128      {/* SPEND */}
129      <div
130        className={`fd-spl-half fd-spl-spend${active === "spend" ? " is-open" : ""}${active === "save" ? " is-shut" : ""}`}
131        onPointerMove={(e) => e.pointerType === "mouse" && active !== "spend" && enter("spend")}
132        onClick={() => isTouch && setActive("spend")}
133        onFocus={() => enter("spend")}
134      >
135        <div className="fd-spl-clip">
136          <header className="fd-spl-top">
137            <a className="fd-spl-logo" href="#top" aria-label={`${brand}, home`}>
138              <svg viewBox="0 0 28 28" width="26" height="26" aria-hidden="true">
139                <rect x="1" y="1" width="26" height="26" rx="6" fill="currentColor" />
140                <path d="M9 7v14M9 14l9-7M12 12l7 9" stroke="#FF5B2E" strokeWidth="2.6" fill="none" strokeLinecap="square" />
141              </svg>
142              <span>{brand.toLowerCase()}</span>
143            </a>
144            <span className="fd-spl-tag">Personal, Business, Kids</span>
145          </header>
146 
147          <div className="fd-spl-body">
148            <button
149              type="button"
150              className="fd-spl-head"
151              aria-expanded={active === "spend"}
152              onClick={() => setActive("spend")}
153            >
154              <span className="fd-spl-idx">{spend.index} / {spend.word}</span>
155              <span className="fd-spl-word fd-spl-word-spend">{spend.word}.</span>
156            </button>
157 
158            <div className="fd-spl-detail">
159              <div className="fd-spl-detail-in">
160              <p className="fd-spl-lede">{spend.lede}</p>
161              <ul className="fd-spl-feed" aria-label="Today on your card">
162                {transactions.map((t) => (
163                  <li key={t.merchant} className="fd-spl-txn">
164                    <span className="fd-spl-glyph" aria-hidden="true">{t.glyph}</span>
165                    <span className="fd-spl-txn-m">
166                      <b>{t.merchant}</b>
167                      <span>{t.place}, {t.time}</span>
168                    </span>
169                    <span className="fd-spl-txn-a">
170                      <b>{t.amount}</b>
171                      <span>{t.roundUp} to Save</span>
172                    </span>
173                  </li>
174                ))}
175              </ul>
176              </div>
177            </div>
178 
179            <div className="fd-spl-foot">
180              <a className="fd-spl-cta fd-spl-cta-spend" href={spend.cta.href}>
181                {spend.cta.label}
182                <svg viewBox="0 0 16 16" width="16" height="16" aria-hidden="true"><path d="M3 8h9M8.5 4l4 4-4 4" fill="none" stroke="currentColor" strokeWidth="1.6" /></svg>
183              </a>
184              <p className="fd-spl-fine">{spend.fine}</p>
185            </div>
186          </div>
187        </div>
188        <div className="fd-spl-seal" aria-hidden="true">
189          <svg viewBox="0 0 100 100" width="100" height="100">
190            <defs>
191              <path id={ringId} d="M50,50 m-37,0 a37,37 0 1,1 74,0 a37,37 0 1,1 -74,0" />
192            </defs>
193            <circle cx="50" cy="50" r="49" fill="#1A0F0A" />
194            <text className="fd-spl-seal-t">
195              <textPath href={`#${ringId}`}>ONE ACCOUNT, TWO HALVES, ONE APP, </textPath>
196            </text>
197            <text x="50" y="58" textAnchor="middle" className="fd-spl-seal-or">&amp;</text>
198          </svg>
199        </div>
200      </div>
201 
202      {/* SAVE */}
203      <div
204        className={`fd-spl-half fd-spl-save${active === "save" ? " is-open" : ""}${active === "spend" ? " is-shut" : ""}`}
205        onPointerMove={(e) => e.pointerType === "mouse" && active !== "save" && enter("save")}
206        onClick={() => isTouch && setActive("save")}
207        onFocus={() => enter("save")}
208      >
209        <div className="fd-spl-clip">
210          <header className="fd-spl-top fd-spl-top-r">
211            <a className="fd-spl-login" href="#login">Log in</a>
212            <a className="fd-spl-open" href="#open">Open an account</a>
213          </header>
214 
215          <div className="fd-spl-body">
216            <button
217              type="button"
218              className="fd-spl-head"
219              aria-expanded={active === "save"}
220              onClick={() => setActive("save")}
221            >
222              <span className="fd-spl-idx">{save.index} / {save.word}</span>
223              <span className="fd-spl-word fd-spl-word-save">{save.word}.</span>
224            </button>
225 
226            <div className="fd-spl-detail">
227              <div className="fd-spl-detail-in">
228              <p className="fd-spl-lede">{save.lede}</p>
229              <div className="fd-spl-pot">
230                <div className="fd-spl-pot-row">
231                  <span className="fd-spl-pot-name">{pot.name}</span>
232                  <span className="fd-spl-pot-due">{pct}%, {pot.due}</span>
233                </div>
234                <div className="fd-spl-bar" role="img" aria-label={`${pct}% of ${fmt(pot.goal)} saved`}>
235                  <span style={{ width: `${pct}%` }} />
236                </div>
237                <div className="fd-spl-pot-row fd-spl-pot-nums">
238                  <span>{fmt(pot.saved)}</span>
239                  <span>of {fmt(pot.goal)}</span>
240                </div>
241              </div>
242              <div className="fd-spl-bal">
243                <span className="fd-spl-bal-l">All pots, earning {rate}</span>
244                <span className="fd-spl-bal-v">{fmt(bal)}</span>
245              </div>
246              </div>
247            </div>
248 
249            <div className="fd-spl-foot">
250              <a className="fd-spl-cta fd-spl-cta-save" href={save.cta.href}>
251                {save.cta.label}
252                <svg viewBox="0 0 16 16" width="16" height="16" aria-hidden="true"><path d="M3 8h9M8.5 4l4 4-4 4" fill="none" stroke="currentColor" strokeWidth="1.6" /></svg>
253              </a>
254              <p className="fd-spl-fine">{save.fine}</p>
255            </div>
256          </div>
257        </div>
258      </div>
259    </section>
260  );
261}
262 
263const css = `
264.fd-spl, .fd-spl *, .fd-spl *::before, .fd-spl *::after { box-sizing: border-box; }
265.fd-spl :where(p, a, ul, li, b, span, div, header, button, svg) {
266  margin: 0; padding: 0; border: 0; background: none; font: inherit; color: inherit;
267  letter-spacing: inherit; text-decoration: none; list-style: none; text-align: inherit;
268}
269.fd-spl {
270  --fd-ease-out: cubic-bezier(0.22, 1, 0.36, 1);
271  --fd-ease-in-out: cubic-bezier(0.65, 0, 0.35, 1);
272  --fd-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
273  --fd-dur-1: 120ms; --fd-dur-2: 240ms; --fd-dur-3: 420ms; --fd-dur-4: 700ms;
274  --fd-spl-spend: #FF5B2E;
275  --fd-spl-spend-ink: #1A0F0A;
276  --fd-spl-save: #0E3B2D;
277  --fd-spl-save-ink: #F1E8D3;
278  --fd-spl-brass: #E1B85C;
279  --fd-spl-sans: "SF Pro Display", ui-sans-serif, -apple-system, BlinkMacSystemFont, "Inter", "Segoe UI", Roboto, sans-serif;
280  --fd-spl-serif: "Iowan Old Style", "Palatino Linotype", Palatino, "Book Antiqua", Georgia, serif;
281  --fd-spl-mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, monospace;
282  position: relative; display: flex; min-height: 880px; margin: 0; padding: 0; overflow: hidden;
283  font: 400 15px/1.45 var(--fd-spl-sans); color: var(--fd-spl-spend-ink); background: var(--fd-spl-save);
284}
285.fd-spl-half {
286  position: relative; flex: 1 1 0; min-width: 0; container-type: inline-size; display: flex; flex-direction: column;
287  transition: flex-grow var(--fd-dur-4) var(--fd-spring);
288}
289.fd-spl.is-spend .fd-spl-spend, .fd-spl.is-save .fd-spl-save { flex-grow: 1.85; }
290.fd-spl-spend { background: var(--fd-spl-spend); color: var(--fd-spl-spend-ink); z-index: 2; }
291.fd-spl-save { background: var(--fd-spl-save); color: var(--fd-spl-save-ink); z-index: 1; }
292.fd-spl-clip { position: relative; flex: 1 1 auto; overflow: hidden; display: flex; flex-direction: column; padding: 0 44px 40px; }
293 
294.fd-spl-top { display: flex; align-items: center; justify-content: space-between; gap: 16px; height: 84px; white-space: nowrap; }
295.fd-spl-top-r { justify-content: flex-end; }
296.fd-spl-logo { display: inline-flex; align-items: center; gap: 10px; color: var(--fd-spl-spend-ink); }
297.fd-spl-logo svg { display: block; }
298.fd-spl-logo span { font: 800 24px/1 var(--fd-spl-sans); letter-spacing: -0.04em; }
299.fd-spl-tag { font: 500 12px/1 var(--fd-spl-mono); letter-spacing: 0.02em; transition: opacity var(--fd-dur-2); }
300.fd-spl-login { font: 500 15px/1 var(--fd-spl-sans); padding: 10px 6px; }
301.fd-spl-login:hover { text-decoration: underline; text-underline-offset: 4px; }
302.fd-spl-open { font: 600 14px/1 var(--fd-spl-sans); padding: 12px 18px; border-radius: 9999px; background: var(--fd-spl-save-ink); color: var(--fd-spl-save); transition: transform var(--fd-dur-2) var(--fd-spring); }
303.fd-spl-open:active { transform: scale(0.96); transition-duration: var(--fd-dur-1); }
304 
305.fd-spl-body { flex: 1; display: flex; flex-direction: column; justify-content: flex-end; gap: 28px; min-width: 0; }
306.fd-spl-head { appearance: none; cursor: default; display: flex; flex-direction: column; align-items: flex-start; gap: 14px; text-align: left; color: inherit; background: none; border: 0; padding: 0; width: 100%; }
307.fd-spl-idx { font: 500 12px/1 var(--fd-spl-mono); letter-spacing: 0.06em; text-transform: uppercase; }
308.fd-spl-word { display: block; white-space: nowrap; }
309.fd-spl-word-spend { font: 900 clamp(4.5rem, 25.5cqw, 15rem)/0.8 var(--fd-spl-sans); letter-spacing: -0.065em; margin-left: -0.05em; }
310.fd-spl-word-save { font: italic 400 clamp(4.5rem, 34cqw, 17rem)/0.8 var(--fd-spl-serif); letter-spacing: -0.045em; margin-left: -0.03em; color: var(--fd-spl-save-ink); }
311 
312.fd-spl-detail { display: grid; grid-template-rows: 1fr; max-width: 520px; margin-bottom: 0; transition: grid-template-rows var(--fd-dur-4) var(--fd-ease-out), opacity var(--fd-dur-3) var(--fd-ease-out), margin var(--fd-dur-4) var(--fd-ease-out); }
313.fd-spl-detail-in { display: flex; flex-direction: column; gap: 22px; min-height: 0; overflow: hidden; }
314.fd-spl-half.is-shut .fd-spl-detail { grid-template-rows: 0fr; opacity: 0; margin-bottom: -28px; pointer-events: none; }
315.fd-spl-half.is-shut .fd-spl-tag { opacity: 0; }
316.fd-spl-lede { font: 500 clamp(1.125rem, 1.6vw, 1.375rem)/1.3 var(--fd-spl-sans); letter-spacing: -0.012em; max-width: 30ch; }
317.fd-spl-save .fd-spl-lede { font: 400 clamp(1.25rem, 1.8vw, 1.5rem)/1.3 var(--fd-spl-serif); }
318 
319.fd-spl-feed { display: flex; flex-direction: column; border-top: 2px solid var(--fd-spl-spend-ink); }
320.fd-spl-txn { display: grid; grid-template-columns: 34px 1fr auto; align-items: center; gap: 14px; padding: 11px 0; border-bottom: 1px solid rgba(26,15,10,0.28); }
321.fd-spl-glyph { display: grid; place-items: center; width: 34px; height: 34px; border-radius: 50%; background: var(--fd-spl-spend-ink); color: var(--fd-spl-spend); font: 800 14px/1 var(--fd-spl-sans); }
322.fd-spl-txn-m, .fd-spl-txn-a { display: flex; flex-direction: column; gap: 3px; min-width: 0; }
323.fd-spl-txn-a { text-align: right; align-items: flex-end; }
324.fd-spl-txn b { font: 600 15px/1.2 var(--fd-spl-sans); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
325.fd-spl-txn-a b { font: 600 15px/1.2 var(--fd-spl-mono); }
326.fd-spl-txn span span, .fd-spl-txn-m > span, .fd-spl-txn-a > span { font: 400 12px/1.2 var(--fd-spl-mono); opacity: 0.78; white-space: nowrap; }
327 
328.fd-spl-pot { padding: 16px 0 0; border-top: 1px solid rgba(241,232,211,0.4); }
329.fd-spl-pot-row { display: flex; justify-content: space-between; gap: 12px; }
330.fd-spl-pot-name { font: 600 15px/1.2 var(--fd-spl-sans); }
331.fd-spl-pot-due { font: 400 12px/1.4 var(--fd-spl-mono); opacity: 0.8; }
332.fd-spl-bar { position: relative; display: block; height: 10px; margin: 12px 0 10px; border-radius: 9999px; background: rgba(241,232,211,0.16); overflow: hidden; }
333.fd-spl-bar span { position: absolute; left: 0; top: 0; bottom: 0; display: block; border-radius: 9999px; background: var(--fd-spl-brass); }
334.fd-spl-pot-nums { font: 400 13px/1.2 var(--fd-spl-mono); }
335.fd-spl-bal { display: flex; justify-content: space-between; align-items: baseline; gap: 16px; padding-top: 16px; border-top: 1px solid rgba(241,232,211,0.4); }
336.fd-spl-bal-l { font: 400 12px/1.3 var(--fd-spl-mono); opacity: 0.8; }
337.fd-spl-bal-v { font: 400 40px/1 var(--fd-spl-serif); letter-spacing: -0.025em; font-variant-numeric: tabular-nums; color: var(--fd-spl-brass); }
338 
339.fd-spl-foot { display: flex; align-items: center; gap: 20px; flex-wrap: wrap; }
340.fd-spl-cta {
341  display: inline-flex; align-items: center; gap: 12px; height: 54px; padding: 0 26px; border-radius: 9999px; white-space: nowrap;
342  font: 700 16px/1 var(--fd-spl-sans); transition: transform var(--fd-dur-2) var(--fd-spring), background var(--fd-dur-1);
343}
344.fd-spl-cta svg { display: block; transition: transform var(--fd-dur-2) var(--fd-ease-out); }
345.fd-spl-cta:hover svg { transform: translateX(4px); }
346.fd-spl-cta:active { transform: scale(0.96); transition-duration: var(--fd-dur-1); }
347.fd-spl-cta-spend { background: var(--fd-spl-spend-ink); color: var(--fd-spl-spend); }
348.fd-spl-cta-save { background: var(--fd-spl-brass); color: var(--fd-spl-save); }
349.fd-spl-fine { font: 400 12px/1.4 var(--fd-spl-mono); max-width: 34ch; transition: opacity var(--fd-dur-2); }
350.fd-spl-half.is-shut .fd-spl-fine { opacity: 0; }
351 
352.fd-spl-seal {
353  position: absolute; top: 50%; right: -50px; width: 100px; height: 100px; margin-top: -50px; z-index: 5; pointer-events: none;
354  color: var(--fd-spl-spend);
355}
356.fd-spl-seal svg { display: block; width: 100%; height: 100%; animation: fd-spl-spin 24s linear infinite; }
357.fd-spl-seal-t { font: 600 9.2px/1 ui-monospace, "SF Mono", Menlo, monospace; letter-spacing: 0.16em; fill: #FFD9C9; }
358.fd-spl-seal-or { font: italic 400 30px/1 "Iowan Old Style", Palatino, Georgia, serif; fill: #E1B85C; }
359@keyframes fd-spl-spin { to { transform: rotate(360deg); } }
360 
361.fd-spl :focus-visible { outline: 2px solid currentColor; outline-offset: 3px; border-radius: 6px; }
362.fd-spl-cta:focus-visible { outline-offset: 4px; border-radius: 9999px; }
363 
364@media (max-width: 760px) {
365  .fd-spl { flex-direction: column; min-height: 844px; }
366  .fd-spl-half, .fd-spl.is-spend .fd-spl-spend, .fd-spl.is-save .fd-spl-save { flex: 0 0 auto; transition: none; }
367  .fd-spl .fd-spl-half.is-open { flex: 1 0 auto; }
368  .fd-spl-half.is-shut { cursor: pointer; }
369  .fd-spl-clip { padding: 0 16px 28px; }
370  .fd-spl-top { height: 64px; }
371  .fd-spl-tag { display: none; }
372  .fd-spl-save .fd-spl-top { display: none; }
373  .fd-spl-save .fd-spl-clip { padding-top: 40px; }
374  .fd-spl-logo span { font-size: 22px; }
375  .fd-spl-body { gap: 18px; justify-content: flex-end; }
376  .fd-spl-spend.is-shut .fd-spl-clip { padding-bottom: 44px; }
377  .fd-spl-head { cursor: pointer; flex-direction: row; align-items: flex-end; justify-content: space-between; }
378  .fd-spl-head .fd-spl-idx { display: none; }
379  .fd-spl-word-spend { font-size: 6rem; }
380  .fd-spl-word-save { font-size: 6.4rem; }
381  .fd-spl-detail { transition: opacity var(--fd-dur-3) var(--fd-ease-out); }
382  .fd-spl-half.is-shut .fd-spl-detail, .fd-spl-half.is-shut .fd-spl-fine, .fd-spl-half.is-shut .fd-spl-idx { display: none; }
383  .fd-spl-half.is-shut .fd-spl-body { flex-direction: row; align-items: center; justify-content: space-between; gap: 12px; }
384  .fd-spl-half.is-shut .fd-spl-head { width: auto; }
385  .fd-spl-half.is-shut .fd-spl-word-spend { font-size: 3.6rem; }
386  .fd-spl-half.is-shut .fd-spl-word-save { font-size: 3.9rem; }
387  .fd-spl-half.is-shut .fd-spl-cta { height: 44px; padding: 0 18px; font-size: 14px; }
388  .fd-spl-half.is-open .fd-spl-detail { animation: fd-spl-in var(--fd-dur-3) var(--fd-ease-out) both; }
389  .fd-spl-lede, .fd-spl-save .fd-spl-lede { font-size: 1.0625rem; }
390  .fd-spl-txn:nth-child(3) { display: none; }
391  .fd-spl-bal-v { font-size: 32px; }
392  .fd-spl-cta { height: 50px; }
393  .fd-spl-foot { gap: 12px; }
394  .fd-spl-seal { top: auto; bottom: -30px; right: 16px; margin-top: 0; width: 60px; height: 60px; }
395  .fd-spl-seal-t { display: none; }
396}
397@keyframes fd-spl-in { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: none; } }
398@media (prefers-reduced-motion: reduce) {
399  .fd-spl-half, .fd-spl-detail, .fd-spl-tag, .fd-spl-fine, .fd-spl-cta, .fd-spl-cta svg, .fd-spl-open { transition: none; }
400  .fd-spl-seal svg { animation: none; }
401  .fd-spl-half.is-open .fd-spl-detail { animation: none; }
402}
403`;
404 
405export function Demo() {
406  return <HeroSplitScreen />;
407}