05Price digits as the hero

<main class="stage">
  <div class="price is-demo">
    <p class="price__plan">Pro plan</p>
    <div class="price__amount">
      <span class="price__currency">₩</span>
      <span class="price__num" aria-hidden="true"></span>
      <span class="price__sr">$19/mo · $190/yr</span>
    </div>
    <p class="price__suffix">/ mo</p>
  </div>
</main>

@use "../../../../site/static/demo-tokens" as *;

$duration: $dur-loop;                              // 월간 ↔ 연간 가격이 한 번 굴러가는 주기
$easing: $ease-out;
$color: $subject-cream;                            // 가격 숫자 색

@include stage($stage-ink);

// @property: 정수 커스텀 속성이라야 애니메이션 중간값도 정수로 보간된다 (03 과 같은 기법)
@property --num {
  syntax: '<integer>';
  initial-value: 19000;
  inherits: false;
}

.price {
  text-align: center;

  &__plan {
    margin: 0 0 $sp-2;
    color: rgba($subject-cream, .7);
    font-weight: 700;
    font-size: clamp(12px, 3vw, 14px);
    line-height: 1;
    text-transform: uppercase;
    letter-spacing: .06em;
  }

  &__amount {
    display: flex;
    align-items: flex-start;
    justify-content: center;
    gap: $sp-1;
  }

  &__currency {
    color: $color;
    font-weight: 700;
    font-size: clamp(18px, 5vw, 28px);
    line-height: 1.4;
  }

  &__num {
    --num: 19000;
    counter-reset: num var(--num);
    display: block;
    font-weight: 800;
    font-size: clamp(32px, 10vw, 56px);
    line-height: 1;
    font-variant-numeric: tabular-nums;
    color: $color;

    &::before { content: counter(num); }
  }

  // counter() 는 스크린 리더가 못 읽는다 — 실제 값을 시각적으로만 숨겨 따로 둔다
  &__sr {
    position: absolute;
    width: 1px; height: 1px;
    overflow: hidden;
    clip-path: inset(50%);
    white-space: nowrap;
  }

  &__suffix {
    margin: $sp-2 0 0;
    color: rgba($subject-cream, .6);
    font-weight: 600;
    font-size: clamp(12px, 3vw, 14px);
    line-height: 1;
  }
}

.price.is-demo .price__num {
  animation: price-roll $duration $easing infinite;
}

@keyframes price-roll {
  0%, 10%   { --num: 19000; }
  45%, 55%  { --num: 190000; }
  90%, 100% { --num: 19000; }
}

@media (prefers-reduced-motion: reduce) {
  .price.is-demo .price__num { animation: none; --num: 19000; }
}

html, body {
  margin: 0;
  overflow: hidden;
}

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #17141a;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

@property --num {
  syntax: "<integer>";
  initial-value: 19000;
  inherits: false;
}
.price {
  text-align: center;
}
.price__plan {
  margin: 0 0 8px;
  color: rgba(255, 247, 230, 0.7);
  font-weight: 700;
  font-size: clamp(12px, 3vw, 14px);
  line-height: 1;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}
.price__amount {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  gap: 4px;
}
.price__currency {
  color: #fff7e6;
  font-weight: 700;
  font-size: clamp(18px, 5vw, 28px);
  line-height: 1.4;
}
.price__num {
  --num: 19000;
  counter-reset: num var(--num);
  display: block;
  font-weight: 800;
  font-size: clamp(32px, 10vw, 56px);
  line-height: 1;
  font-variant-numeric: tabular-nums;
  color: #fff7e6;
}
.price__num::before {
  content: counter(num);
}
.price__sr {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
}
.price__suffix {
  margin: 8px 0 0;
  color: rgba(255, 247, 230, 0.6);
  font-weight: 600;
  font-size: clamp(12px, 3vw, 14px);
  line-height: 1;
}

.price.is-demo .price__num {
  animation: price-roll 2s ease-out infinite;
}

@keyframes price-roll {
  0%, 10% {
    --num: 19000;
  }
  45%, 55% {
    --num: 190000;
  }
  90%, 100% {
    --num: 19000;
  }
}
@media (prefers-reduced-motion: reduce) {
  .price.is-demo .price__num {
    animation: none;
    --num: 19000;
  }
}

import type { CSSProperties } from "react";
import styles from "./KineticPricing.module.scss";

export type KineticPricingProps = {
  planName?: string;
  currency?: string;
  monthly?: number;
  yearly?: number;
  suffix?: string;
  /** 월간 ↔ 연간 가격이 한 번 굴러가는 주기(기본 2000ms) */
  duration?: number;
  easing?: string;
  color?: string;
};

type Vars = CSSProperties & {
  "--duration"?: string; "--easing"?: string; "--color"?: string;
  "--num-from"?: number; "--num-to"?: number;
};

export default function KineticPricing({
  planName = "Pro plan",
  currency = "$",
  monthly = 19,
  yearly = 190,
  suffix = "/ mo",
  duration = 2000,
  easing = "ease-out",
  color = "#fff7e6",
}: KineticPricingProps) {
  const vars: Vars = {
    "--duration": `${duration}ms`, "--easing": easing, "--color": color,
    "--num-from": monthly, "--num-to": yearly,
  };

  return (
    <div className={styles.stage} style={vars}>
      <div className={styles.price}>
        <p className={styles.plan}>{planName}</p>
        <div className={styles.amount}>
          <span className={styles.currency}>{currency}</span>
          <span className={styles.num} aria-hidden="true" />
          <span className={styles.sr}>{currency}{monthly}{suffix} · {currency}{yearly}/yr</span>
        </div>
        <p className={styles.suffix}>{suffix}</p>
      </div>
    </div>
  );
}