@charset "UTF-8";
/* 浴衣の着方 — a self-contained page with its own look (not the site template).
   Palette: cotton white, sumi ink, indigo (藍) and a vermilion obi accent (朱).
   Everything is scoped to this page: tokens live on .yk and every rule starts
   with .yk, so no other page is affected. Light and dark follow the site's saved
   theme (data-theme from assets/theme.js) or the system setting without JS. */

.yk {
  color-scheme: light;
  --bg: #fbfaf7;
  --bg-2: #f3f0e9;
  --surface: #ffffff;
  --surface-2: #f7f5f0;
  --tile: #eef0f2;
  --ink: #141a24;
  --ink-2: #4b5363;
  --line: rgba(20, 26, 36, .12);
  --line-strong: rgba(20, 26, 36, .22);
  --indigo: #1f3c66;
  --indigo-ink: #1f3c66;
  --indigo-soft: rgba(31, 60, 102, .08);
  --accent: #b5452c;
  --accent-soft: rgba(181, 69, 44, .09);
  --ochre: #8a6414;
  --ok: #1f5c46;
  --on-accent: #fff;
  --night: #0e1a2e;
  --night-2: #16253f;
  --night-ink: #eef2f8;
  --night-ink-2: #b8c4d6;
  --header-bg: rgba(251, 250, 247, .78);
  --logo-bubble: #1f3c66;
  --logo-door: #fbfaf7;
  --focus: #2f6fd6;
  --sans: "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Noto Sans JP", "Yu Gothic UI", "Meiryo", system-ui, -apple-system, "Segoe UI", sans-serif;
  --serif: "Hiragino Mincho ProN", "Yu Mincho", "Noto Serif JP", "Noto Serif CJK JP", serif;
  --en: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue", "Segoe UI", Roboto, Arial, sans-serif;
  --wrap: 1160px;
  --gutter: clamp(20px, 5vw, 48px);
  --ease: cubic-bezier(.2, .7, .2, 1);
  --header-h: 56px;
  --chapters-h: 48px;
}
:root[data-theme="dark"] .yk {
  color-scheme: dark;
  --bg: #0b0f17;
  --bg-2: #10161f;
  --surface: #151c27;
  --surface-2: #1a2230;
  --tile: #1d2735;
  --ink: #eef1f6;
  --ink-2: #aeb7c6;
  --line: rgba(255, 255, 255, .11);
  --line-strong: rgba(255, 255, 255, .22);
  --indigo: #3a63a0;
  --indigo-ink: #9dbbe6;
  --indigo-soft: rgba(157, 187, 230, .1);
  --accent: #f0896d;
  --accent-soft: rgba(240, 137, 109, .12);
  --ochre: #e2b85e;
  --ok: #7fcfaa;
  --on-accent: #1b0d08;
  --night: #0d1729;
  --night-2: #15233c;
  --header-bg: rgba(11, 15, 23, .76);
  --logo-bubble: #eef1f6;
  --logo-door: #1f3c66;
  --focus: #8fb6ff;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) .yk {
    color-scheme: dark;
    --bg: #0b0f17; --bg-2: #10161f; --surface: #151c27; --surface-2: #1a2230; --tile: #1d2735;
    --ink: #eef1f6; --ink-2: #aeb7c6; --line: rgba(255, 255, 255, .11); --line-strong: rgba(255, 255, 255, .22);
    --indigo: #3a63a0; --indigo-ink: #9dbbe6; --indigo-soft: rgba(157, 187, 230, .1);
    --accent: #f0896d; --accent-soft: rgba(240, 137, 109, .12); --ochre: #e2b85e; --ok: #7fcfaa;
    --night: #0d1729; --night-2: #15233c; --header-bg: rgba(11, 15, 23, .76);
    --logo-bubble: #eef1f6; --logo-door: #1f3c66; --focus: #8fb6ff; --on-accent: #1b0d08;
  }
}

/* Base (this page only) */
html:has(> body.yk) { scroll-behavior: smooth; scroll-padding-top: calc(var(--header-h, 56px) + var(--chapters-h, 48px) + 12px); -webkit-text-size-adjust: 100%; }
.yk, .yk *, .yk *::before, .yk *::after { box-sizing: border-box; }
.yk { margin: 0; min-width: 320px; background: var(--bg); color: var(--ink); font-family: var(--sans); font-size: 17px; line-height: 1.8; letter-spacing: .02em; overflow-x: hidden; -webkit-font-smoothing: antialiased; }
.yk :where(h1, h2, h3, h4, p, ul, ol, dl, dd, figure) { margin: 0; }
.yk :where(ul, ol) { padding: 0; list-style: none; }
.yk img { display: block; max-width: 100%; height: auto; }
.yk picture { display: block; }
.yk svg { display: block; }
.yk a { color: inherit; }
.yk button { font: inherit; color: inherit; cursor: pointer; -webkit-tap-highlight-color: transparent; }
.yk button:disabled { cursor: default; opacity: .4; }
.yk ruby { ruby-position: over; }
.yk rt { font-size: .5em; font-weight: 500; letter-spacing: 0; opacity: .85; }
html.no-furigana .yk rt, html.no-furigana .yk .svg-furigana { display: none; }
.yk [lang="en"] { font-family: var(--en); letter-spacing: 0; }
.yk :focus-visible { outline: 3px solid var(--focus); outline-offset: 3px; border-radius: 8px; }
.yk .sr-only { position: absolute !important; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0; }
.yk ::selection { background: rgba(47, 86, 135, .25); }
.yk-skip { position: absolute; left: 12px; top: -80px; z-index: 100; padding: .6em 1em; border-radius: 10px; background: var(--ink); color: var(--bg) !important; font-weight: 700; text-decoration: none; }
.yk-skip:focus { top: 12px; }
.yk main:focus { outline: none; }
.yk-wrap { max-width: var(--wrap); margin: 0 auto; padding: 0 var(--gutter); }
.yk-center { text-align: center; }
.yk [hidden] { display: none !important; }

/* Japanese first; English follows when the English toggle is on.
   .bi and headings: English on its own line. .swap (labels, buttons): English inline and small. */
.yk .en { color: var(--ink-2); }
.yk .bi > .en, .yk :is(h1, h2, h3, h4, dd) > .en { display: block; }
.yk .bi > .en { margin-top: .3em; font-size: .9em; line-height: 1.55; }
.yk .swap > .en { margin-left: .45em; font-size: .8em; font-weight: 500; }
.yk .en-inline { margin-left: .45em; font-family: var(--en); font-size: .8em; font-weight: 500; color: var(--ink-2); }
html[data-english="off"] .yk .en, html[data-english="off"] .yk .en-inline { display: none !important; }

/* Header */
.yk-header { position: fixed; inset: 0 0 auto; z-index: 50; display: flex; align-items: center; justify-content: space-between; gap: 12px; height: var(--header-h); padding: 0 max(14px, env(safe-area-inset-right)) 0 max(14px, env(safe-area-inset-left)); background: var(--header-bg); -webkit-backdrop-filter: saturate(180%) blur(20px); backdrop-filter: saturate(180%) blur(20px); transition: box-shadow .3s; }
.yk-header.is-scrolled { box-shadow: 0 1px 0 var(--line); }
.yk-brand { display: flex; align-items: center; gap: 12px; min-width: 0; }
.yk .sy-logo { display: flex; align-items: center; gap: 8px; text-decoration: none; font-weight: 700; color: var(--ink); }
.yk .sy-mark { width: 32px; height: 32px; flex: 0 0 32px; }
.yk .sy-mark .m-bubble { fill: var(--logo-bubble); }
.yk .sy-mark .m-door { fill: var(--logo-door); }
.yk .sy-mark .m-panel { fill: var(--accent); }
.yk .sy-mark .m-knob { fill: var(--logo-bubble); }
.yk .sy-wordmark { font-size: 17px; letter-spacing: .01em; }
.yk .sy-wordmark span { margin: 0 1px; color: var(--accent); }
.yk-back { padding: 5px 12px; border: 1px solid var(--line-strong); border-radius: 999px; font-size: 14px; line-height: 1.5; text-decoration: none; white-space: nowrap; transition: background .2s; }
.yk-back:hover { background: var(--indigo-soft); }
.yk-toolbar { display: flex; align-items: center; gap: 6px; }
.yk-toolbar[hidden] { display: none; }
.yk-toggle { display: inline-flex; align-items: center; gap: 8px; min-height: 36px; padding: 4px 6px 4px 12px; border: 1px solid var(--line-strong); border-radius: 999px; background: transparent; font: 600 13px/1 var(--sans); white-space: nowrap; }
.yk-toggle:hover { background: var(--indigo-soft); }
.yk-toggle[lang="en"] { font-family: var(--en); }
.yk-toggle__switch { position: relative; width: 32px; height: 20px; border-radius: 20px; background: var(--line-strong); transition: background .25s; }
.yk-toggle__switch span { position: absolute; top: 2px; left: 2px; width: 16px; height: 16px; border-radius: 50%; background: #fff; box-shadow: 0 1px 2px rgba(0, 0, 0, .25); transition: transform .25s var(--ease); }
.yk-toggle[aria-pressed="true"] .yk-toggle__switch { background: var(--indigo); }
.yk-toggle[aria-pressed="true"] .yk-toggle__switch span { transform: translateX(12px); }
.yk .theme-toggle { display: inline-grid; place-items: center; width: 36px; height: 36px; padding: 0; border: 1px solid var(--line-strong); border-radius: 50%; background: transparent; color: var(--ink); }
.yk .theme-toggle:hover { background: var(--indigo-soft); }
.yk .theme-toggle__icon { width: 18px; height: 18px; }
.yk .theme-toggle__label { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }

/* Hero */
.yk-hero { padding-top: calc(var(--header-h) + clamp(48px, 9vw, 112px)); background: var(--bg); text-align: center; }
.yk-hero__copy { max-width: 900px; margin: 0 auto; padding: 0 var(--gutter); }
.yk-eyebrow { display: inline-flex; align-items: center; flex-wrap: wrap; justify-content: center; gap: 10px; color: var(--ink-2); font-size: 15px; font-weight: 600; }
.yk-level { padding: 2px 8px; border-radius: 6px; background: var(--accent); color: var(--on-accent); font: 800 12px/1.4 var(--en); letter-spacing: .04em; }
.yk-display { margin-top: 10px; font-family: var(--serif); font-weight: 700; line-height: 1.15; letter-spacing: .04em; }
.yk-display > .jp { display: block; font-size: clamp(60px, 13vw, 148px); }
.yk-display rt { font-size: .2em; font-family: var(--sans); font-weight: 600; letter-spacing: .1em; }
.yk-display > .en { margin-top: 6px; color: var(--ink); font-size: clamp(22px, 2.8vw, 34px); font-weight: 600; letter-spacing: -.01em; font-family: var(--en); }
.yk-hero__lead { max-width: 40em; margin: clamp(22px, 3vw, 32px) auto 0; font-size: clamp(17px, 1.6vw, 20px); line-height: 2; }
.yk-hero__lead > .en { font-size: .86em; }
.yk-hero__cta { display: flex; flex-wrap: wrap; justify-content: center; gap: 12px 22px; margin-top: 30px; }
.yk-btn { display: inline-flex; align-items: center; justify-content: center; gap: .35em; min-height: 48px; padding: 8px 24px; border-radius: 999px; font-weight: 700; font-size: 16px; line-height: 2; text-decoration: none; transition: background .2s, color .2s, transform .2s; }
.yk a.yk-btn--primary { background: var(--indigo); color: #fff; }
.yk-btn--primary .en { color: rgba(255, 255, 255, .82); }
.yk a.yk-btn--primary:hover { background: #17304f; }
:root[data-theme="dark"] .yk a.yk-btn--primary:hover { background: #4a74b3; }
.yk a.yk-btn--ghost { padding-inline: 8px; color: var(--indigo-ink); }
.yk-btn--ghost .en { color: inherit; opacity: .8; }
.yk-btn--ghost:hover { text-decoration: underline; text-underline-offset: .25em; }
.yk-hero__media { position: relative; max-width: 1600px; margin: clamp(44px, 6vw, 80px) auto 0; padding: 0 clamp(0px, 2vw, 24px); }
.yk-hero__media picture { overflow: hidden; border-radius: clamp(0px, 2vw, 28px); background: var(--tile); aspect-ratio: 16 / 8.2; }
.yk-hero__media img { width: 100%; height: 100%; object-fit: cover; object-position: 50% 62%; transform: scale(1.05); transition: transform 2.2s var(--ease); }
.is-loaded .yk-hero__media img { transform: none; }
.yk-caption { margin-top: 10px; color: var(--ink-2); font-size: 13px; line-height: 1.6; text-align: right; padding: 0 var(--gutter); }
.yk-hero .yk-caption { padding-right: clamp(var(--gutter), 3vw, 48px); }
.yk-glance { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); max-width: 900px; margin: clamp(40px, 6vw, 72px) auto 0; padding: 0 var(--gutter) clamp(56px, 8vw, 104px); }
.yk-glance li { display: flex; flex-direction: column; align-items: center; gap: 2px; padding: 0 10px; border-left: 1px solid var(--line); font-size: 14px; line-height: 1.6; color: var(--ink-2); }
.yk-glance li:first-child { border-left: 0; }
.yk-glance .swap > .en { display: block; margin: 0; }
.yk-glance__num { color: var(--ink); font-family: var(--serif); font-size: clamp(30px, 4vw, 44px); font-weight: 700; line-height: 1.5; }
.yk-glance__num small { margin-left: .1em; font-size: .45em; font-family: var(--sans); }
.yk-glance__num rt { font-size: .32em; font-family: var(--sans); }
.yk-in { opacity: 0; transform: translateY(14px); transition: opacity .9s var(--ease) var(--d, 0s), transform .9s var(--ease) var(--d, 0s); }
.is-loaded .yk-in, .no-js .yk-in { opacity: 1; transform: none; }

/* Chapter bar */
.yk-chapters { position: sticky; top: var(--header-h); z-index: 40; height: var(--chapters-h); background: var(--header-bg); -webkit-backdrop-filter: saturate(180%) blur(20px); backdrop-filter: saturate(180%) blur(20px); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.yk-chapters ol { display: flex; justify-content: center; gap: 4px; height: 100%; max-width: var(--wrap); margin: 0 auto; padding: 0 var(--gutter); overflow-x: auto; scrollbar-width: none; overscroll-behavior-x: contain; }
.yk-chapters ol::-webkit-scrollbar { display: none; }
.yk-chapters li { flex: none; display: flex; align-items: center; }
.yk-chapters a { display: inline-flex; align-items: center; min-height: 36px; padding: 2px 14px; border-radius: 999px; color: var(--ink-2); font-size: 14px; font-weight: 600; line-height: 1.4; text-decoration: none; white-space: nowrap; transition: color .2s, background .2s; }
.yk-chapters a rt { font-size: .55em; }
.yk-chapters a:hover { color: var(--ink); background: var(--indigo-soft); }
.yk-chapters a[aria-current] { color: var(--bg); background: var(--ink); }
.yk-chapters a[aria-current] .en { color: inherit; opacity: .8; }

/* Shared section typography */
.yk-chapter { padding: clamp(80px, 11vw, 150px) 0; }
.yk-head { max-width: 820px; margin: 0 auto clamp(40px, 6vw, 72px); text-align: center; }
.yk-head--left { margin: 0; text-align: left; }
.yk-kicker { display: inline-flex; align-items: baseline; flex-wrap: wrap; gap: 10px; margin-bottom: 14px; color: var(--accent); font-size: 14px; font-weight: 700; letter-spacing: .08em; }
.yk-kicker .en { color: var(--ink-2); letter-spacing: .01em; }
.yk-kicker__no { font: 700 13px/1 var(--en); letter-spacing: .1em; color: var(--ink-2); }
.yk-h2 > .jp, .yk-display > .jp { display: block; word-break: auto-phrase; text-wrap: balance; }
.yk-h2 { font-size: clamp(28px, calc(5.4vw + 8px), 64px); font-weight: 800; line-height: 1.3; letter-spacing: .01em; word-break: auto-phrase; text-wrap: balance; }
.yk-h2 > .en { margin-top: .35em; font-size: clamp(18px, 1.9vw, 23px); font-weight: 600; line-height: 1.4; letter-spacing: -.005em; }
.yk-h2--sm { font-size: clamp(30px, 4.2vw, 48px); }
.yk-lead { max-width: 40em; margin: 22px auto 0; font-size: clamp(17px, 1.5vw, 19px); line-height: 2; color: var(--ink); }
.yk-head--left .yk-lead { margin-left: 0; }
.yk h3 { font-size: 21px; font-weight: 800; line-height: 1.5; }
.yk h3 > .en { margin-top: 2px; font-size: 14px; font-weight: 600; line-height: 1.4; }

/* Rule — the one dark chapter */
.yk-rule { padding: clamp(88px, 12vw, 160px) 0; background: radial-gradient(120% 90% at 50% 0%, var(--night-2), var(--night) 70%); color: var(--night-ink); }
.yk-rule .en, .yk-rule .en-inline { color: var(--night-ink-2); }
.yk-rule .yk-kicker { color: #f3a48c; }
.yk-rule__head { text-align: center; }
.yk-rule__title { font-family: var(--serif); font-weight: 700; line-height: 1.1; letter-spacing: .06em; }
.yk-rule__title > .jp { display: block; font-size: clamp(84px, 19vw, 220px); }
.yk-rule__title rt { font-size: .18em; font-family: var(--sans); letter-spacing: .1em; }
.yk-rule__title > .en { margin-top: 10px; font-size: clamp(20px, 2.4vw, 30px); font-weight: 600; font-family: var(--en); letter-spacing: -.01em; color: var(--night-ink) !important; }
.yk-rule__motto { margin-top: 22px; font-size: clamp(20px, 2.4vw, 28px); font-weight: 700; }
.yk-rule__motto > .en { font-size: .65em; font-weight: 500; }
.yk-rule__compare { display: grid; grid-template-columns: repeat(2, minmax(0, 320px)); justify-content: center; gap: clamp(16px, 3vw, 32px); margin-top: clamp(48px, 6vw, 72px); }
.yk-rule .compare { padding: 22px 16px 18px; border-radius: 24px; background: #f7f5f0; color: #141a24; }
.yk-rule .compare .en { color: #4b5363; }
.yk-rule .compare--ok { box-shadow: inset 0 0 0 3px #4fae86; }
.yk-rule .compare--ng { box-shadow: inset 0 0 0 3px #e0765a; opacity: .92; }
.yk-rule .compare--ok strong { color: #1f6a4c; }
.yk-rule .compare--ng strong { color: #a83d24; }
.yk-rule__points { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: clamp(20px, 3vw, 40px); max-width: 1040px; margin: clamp(56px, 7vw, 88px) auto 0; }
.yk-rule__points li { padding-top: 20px; border-top: 1px solid rgba(255, 255, 255, .2); font-size: 17px; line-height: 1.9; }
.yk-rule__icon { display: block; margin-bottom: 10px; color: #f3a48c; font-family: var(--serif); font-size: 30px; font-weight: 700; line-height: 1.2; }
.yk-rule__icon--y { font-family: Georgia, serif; font-style: italic; font-size: 36px; }
.yk-rule__warning { display: grid; gap: 4px; max-width: 1040px; margin: clamp(40px, 5vw, 56px) auto 0; padding: 22px 26px 22px 64px; border-radius: 20px; background: rgba(224, 118, 90, .16); box-shadow: inset 0 0 0 1px rgba(243, 164, 140, .45); font-size: clamp(17px, 1.6vw, 20px); font-weight: 700; position: relative; }
.yk-rule__warning::before { content: "!"; position: absolute; left: 22px; top: 22px; display: grid; place-items: center; width: 28px; height: 28px; border-radius: 50%; background: #e0765a; color: #fff; font: 800 16px/1 var(--en); }
.yk-rule__warning > .en { font-weight: 500; }
.yk-rule__note { max-width: 1040px; margin: 18px auto 0; font-size: 15px; color: var(--night-ink-2); text-align: center; }
.yk-rule__note > .jp { color: var(--night-ink); }

/* Compare figures (shared) */
.yk .compare { margin: 0; text-align: center; }
.yk .compare svg { width: 100%; max-width: 240px; height: auto; margin: 0 auto; color: inherit; }
.yk .compare figcaption { margin-top: 8px; font-size: 16px; line-height: 1.6; }
.yk .compare figcaption strong { display: block; font-size: 15px; }
.yk .compare figcaption > .en { display: block; font-size: 13px; }

/* Ryokan steps */
.yk-ryokan { background: var(--bg); }
.yk-steps { display: grid; grid-template-columns: repeat(6, minmax(0, 1fr)); gap: clamp(14px, 2vw, 24px); }
.yk-step { grid-column: span 2; display: flex; flex-direction: column; overflow: hidden; border-radius: 28px; background: var(--surface); box-shadow: 0 1px 0 var(--line), 0 0 0 1px var(--line); }
.yk-step--key { grid-column: span 2; }
.yk-step:nth-child(4) { grid-column: 1 / span 3; }
.yk-step--wide { grid-column: 4 / span 3; }
.yk-step__art { display: grid; place-items: center; min-height: 260px; padding: 24px; background: var(--tile); }
.yk-step__art svg { width: 100%; max-width: 150px; height: auto; max-height: 230px; }
.yk-step__art .size-art { max-width: 132px; }
.yk-step:nth-child(4) .yk-step__art svg { max-width: 150px; }
.yk-step--key .yk-step__art { background: linear-gradient(180deg, var(--tile), var(--indigo-soft)); }
.yk .pair-art { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; width: 100%; max-width: 300px; }
.yk .pair-art figure { text-align: center; }
.yk .pair-art svg { max-width: 130px; margin: 0 auto; }
.yk .pair-art figcaption { margin-top: 4px; color: var(--ink-2); font-size: 13px; font-weight: 700; }
.yk-step__body { padding: 22px 26px 28px; }
.yk-step__num { color: var(--accent); font: 700 13px/1 var(--en); letter-spacing: .14em; }
.yk-step h3 { margin-top: 10px; }
.yk-step__body > .bi { margin-top: 10px; font-size: 16px; line-height: 1.9; }
.yk-cold { display: grid; grid-template-columns: minmax(0, 260px) minmax(0, 1fr); align-items: center; gap: clamp(24px, 4vw, 56px); margin-top: clamp(24px, 3vw, 32px); padding: clamp(24px, 4vw, 48px); border-radius: 28px; background: linear-gradient(135deg, #3b2a22, #20160f); color: #f6ecdf; }
.yk-cold .en { color: #dcc8b4; }
.yk-cold .yk-kicker { color: #f0b48a; }
.yk-cold__art { display: grid; place-items: center; padding: 14px; border-radius: 20px; background: rgba(255, 255, 255, .08); }
.yk-cold__art svg { width: 100%; max-width: 170px; height: auto; color: #f6ecdf; }
.yk-cold h3 { font-size: clamp(22px, 2.6vw, 30px); }
.yk-cold__body > .bi { margin-top: 14px; font-size: 17px; line-height: 1.9; }

/* Festival */
.yk-festival { background: var(--bg-2); }
.yk-festival__open { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); align-items: center; gap: clamp(32px, 6vw, 88px); }
.yk-photo { margin: 0; }
.yk-photo picture { overflow: hidden; border-radius: 28px; background: var(--tile); }
.yk-photo img { width: 100%; height: 100%; object-fit: cover; }
.yk-photo--bows picture { aspect-ratio: 1; }
.yk-photo .yk-caption { padding: 0; }
.yk-compare-wm { display: grid; grid-template-columns: minmax(0, 380px) minmax(0, 1fr); align-items: center; gap: clamp(28px, 6vw, 88px); margin-top: clamp(64px, 9vw, 120px); }
.yk-photo--pair picture { aspect-ratio: 4 / 5.6; }
.yk-photo--pair img { object-position: 50% 30%; }
.yk-diff { display: grid; gap: 16px; margin-top: 4px; }
.yk-diff > div { padding: 24px 26px; border-radius: 24px; background: var(--surface); box-shadow: 0 0 0 1px var(--line); }
.yk-diff dt { font-size: 22px; font-weight: 800; }
.yk-diff dd { margin-top: 8px; font-size: 16px; line-height: 1.9; }
.yk-diff .yk-diff__tag { display: inline-block; margin-top: 14px; padding: 4px 14px; border-radius: 999px; background: var(--indigo-soft); color: var(--indigo-ink); font-size: 14px; font-weight: 700; }
.yk-diff .yk-diff__tag .en { color: inherit; opacity: .85; }
.yk-lesson-wrap { margin-top: clamp(64px, 9vw, 120px); text-align: center; }

/* Track switch (segmented control) */
.yk .track-switch { display: inline-flex; gap: 4px; padding: 4px; border-radius: 999px; background: var(--surface); box-shadow: 0 0 0 1px var(--line); }
.yk .track-button { min-width: 8.5rem; min-height: 46px; padding: 6px 20px; border: 0; border-radius: 999px; background: transparent; line-height: 1.3; transition: background .2s, color .2s; }
.yk .track-button .jp { display: block; font-weight: 700; line-height: 1.6; }
.yk .track-button .en { display: block; font-size: 12px; }
.yk .track-button[aria-pressed="true"] { background: var(--ink); color: var(--bg); }
.yk .track-button[aria-pressed="true"] .en { color: inherit; opacity: .8; }

/* Festival lesson stage */
.yk .lesson { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); grid-template-areas: "art text" "art nav" "markers markers"; grid-template-rows: 1fr auto auto; margin-top: 24px; overflow: hidden; border-radius: 32px; background: var(--surface); box-shadow: 0 0 0 1px var(--line), 0 30px 60px -40px rgba(14, 26, 46, .35); text-align: left; }
.yk .lesson:focus { outline: none; }
.yk .lesson__art { grid-area: art; position: relative; min-height: 36rem; padding: 22px; background: var(--tile); color: var(--ink); }
.yk .figure-topline { display: flex; justify-content: space-between; align-items: center; color: var(--ink-2); font-size: 13px; font-weight: 700; }
.yk .view-pill { padding: 3px 12px; border-radius: 999px; background: var(--surface); }
.yk .figure-number { font: 600 14px/1 var(--en); letter-spacing: .06em; }
.yk .main-illustration svg { width: 100%; height: auto; max-height: 32rem; margin: 0 auto; }
.yk .figure-callout { position: absolute; top: 38%; left: 18px; max-width: 9.5rem; padding: 8px 12px; border-radius: 16px; background: var(--surface); box-shadow: 0 6px 20px -10px rgba(0, 0, 0, .35); font-size: 13px; line-height: 1.35; }
.yk .figure-callout .jp { display: block; font-family: var(--serif); font-size: 24px; font-weight: 700; line-height: 1.6; }
.yk .figure-callout .en { display: block; }
.yk .figure-callout.callout-right { right: 18px; left: auto; }
.yk .secondary-callout { top: 55%; }
.yk .back-inset { position: absolute; right: 14px; bottom: 64px; width: 9rem; padding: 8px; border-radius: 16px; background: var(--surface); box-shadow: 0 6px 20px -10px rgba(0, 0, 0, .35); text-align: center; font-size: 12px; line-height: 1.4; }
.yk .back-inset svg { width: 100%; height: auto; }
.yk .back-inset .en { display: block; }
.yk .replay-button { position: absolute; bottom: 16px; left: 18px; min-height: 40px; padding: 4px 16px; border: 0; border-radius: 999px; background: var(--surface); box-shadow: 0 0 0 1px var(--line); font-size: 14px; font-weight: 700; }
.yk .replay-button:hover { box-shadow: 0 0 0 1px var(--line-strong); }
.yk .lesson__nav { grid-area: nav; display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 16px clamp(18px, 3vw, 36px) 22px; }
.yk .button { display: inline-flex; align-items: center; justify-content: center; gap: 8px; min-height: 46px; padding: 8px 20px; border: 0; border-radius: 999px; background: var(--surface-2); box-shadow: 0 0 0 1px var(--line); font-weight: 700; line-height: 1.4; }
.yk .button .swap > .en { margin-left: .35em; }
.yk .button-primary { background: var(--indigo); color: #fff; box-shadow: none; }
.yk .button-primary .en { color: rgba(255, 255, 255, .85); }
.yk .button-primary:hover { filter: brightness(1.12); }
.yk .button-quiet:hover:not(:disabled) { box-shadow: 0 0 0 1px var(--line-strong); }
.yk .step-count { color: var(--ink-2); font: 600 15px/1 var(--en); font-variant-numeric: tabular-nums; }
.yk .lesson__text { grid-area: text; padding: clamp(24px, 4vw, 44px) clamp(18px, 3vw, 36px) 8px; }
.yk .step-kicker { color: var(--accent); font-size: 13px; font-weight: 700; letter-spacing: .08em; }
.yk .step-word { margin-top: 6px; }
.yk .step-word .jp { display: block; font-family: var(--serif); font-size: clamp(40px, 5vw, 60px); font-weight: 700; line-height: 1.4; }
.yk .step-word .en { display: block; font-size: 14px; }
.yk .step-heading { margin-top: 12px; font-size: 24px; }
.yk .step-explanation { margin-top: 10px; font-size: 18px; line-height: 1.9; }
.yk .instruction-tip { margin-top: 18px; padding: 14px 18px; border-radius: 16px; background: var(--indigo-soft); font-size: 16px; line-height: 1.8; }
.yk .important-note { margin-top: 18px; padding: 18px; border-radius: 20px; background: var(--accent-soft); box-shadow: inset 0 0 0 1px color-mix(in srgb, var(--accent) 35%, transparent); }
.yk .important-note h4 { color: var(--accent); font-size: 17px; }
.yk .important-note h4 > .en { display: block; font-size: 13px; }
.yk .overlap-comparisons { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 14px; }
.yk .important-note .compare { padding: 10px 8px; border-radius: 14px; background: #f7f5f0; color: #141a24; }
.yk .important-note .compare .en { color: #4b5363; }
.yk .important-note .compare svg { max-width: 150px; }
.yk .compare--ok strong { color: #1f6a4c; }
.yk .compare--ng strong { color: #a83d24; }
.yk .knot-steps { display: grid; gap: 10px; margin-top: 18px; counter-reset: knot; }
.yk .knot-steps li { position: relative; padding-left: 40px; counter-increment: knot; line-height: 1.8; }
.yk .knot-steps li::before { content: counter(knot); position: absolute; top: 4px; left: 0; display: grid; place-items: center; width: 28px; height: 28px; border-radius: 50%; background: var(--indigo); color: #fff; font: 800 13px/1 var(--en); }
.yk .checklist { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 18px; }
.yk .checklist li { padding: 4px 14px; border-radius: 999px; background: var(--indigo-soft); font-size: 15px; line-height: 1.6; }
.yk .checklist li::before { content: "✓ "; color: var(--ok); font-weight: 800; }
.yk .checklist .bi > .en { display: inline; margin: 0 0 0 .4em; font-size: .82em; }
.yk .lesson__markers { grid-area: markers; padding: 18px clamp(18px, 3vw, 36px) 22px; border-top: 1px solid var(--line); }
.yk .progress-track { height: 4px; overflow: hidden; border-radius: 4px; background: var(--line); }
.yk #progress-fill { width: 12.5%; height: 100%; border-radius: 4px; background: var(--accent); transition: width .35s var(--ease); }
.yk .step-markers { display: grid; grid-template-columns: repeat(8, minmax(0, 1fr)); gap: 6px; margin-top: 14px; }
.yk .step-marker { display: grid; justify-items: center; align-content: start; gap: 8px; min-height: 46px; padding: 4px 2px; border: 0; border-radius: 14px; background: transparent; font-size: 12px; line-height: 1.35; }
.yk .step-marker:hover { background: var(--indigo-soft); }
.yk .marker-number { display: grid; place-items: center; width: 30px; height: 30px; border-radius: 50%; box-shadow: inset 0 0 0 1px var(--line-strong); font: 700 13px/1 var(--en); }
.yk .step-marker.is-done .marker-number { background: var(--indigo-soft); box-shadow: inset 0 0 0 1px var(--indigo-ink); color: var(--indigo-ink); }
.yk .step-marker[aria-current="step"] .marker-number { background: var(--ink); color: var(--bg); box-shadow: none; }
.yk .marker-label { color: var(--ink-2); }
.yk .marker-label .swap > .en { display: block; margin: 0; font-size: .9em; }
.yk .celebration { position: absolute; inset: 0; overflow: hidden; pointer-events: none; }
.yk .celebration i { position: absolute; top: 18%; left: var(--x); width: 5px; height: 10px; border-radius: 1px; background: var(--c); animation: yk-confetti 1.9s var(--delay) ease-out both; }

/* Underneath and feet */
.yk-under { background: var(--bg-2); padding-top: 0; }
.yk-bento { display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); gap: clamp(14px, 2vw, 24px); }
.yk-tile { overflow: hidden; padding: clamp(24px, 3vw, 36px); border-radius: 28px; background: var(--surface); box-shadow: 0 0 0 1px var(--line); }
.yk-tile--photo { display: grid; grid-template-columns: minmax(0, 1fr); grid-template-rows: auto 1fr; padding: 0; }
.yk-tile--photo picture { aspect-ratio: 16 / 7; }
.yk-tile--photo img { width: 100%; height: 100%; object-fit: cover; object-position: 50% 55%; }
.yk-tile__body { padding: clamp(24px, 3vw, 36px); }
.yk-list { display: grid; gap: 14px; margin-top: 16px; }
.yk-list li { position: relative; padding-left: 18px; font-size: 16px; line-height: 1.85; }
.yk-list li::before { content: ""; position: absolute; left: 0; top: .8em; width: 6px; height: 6px; border-radius: 50%; background: var(--accent); }

/* Etiquette */
.yk-etiquette { background: var(--bg); }
.yk-etiquette__grid { display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); gap: clamp(32px, 6vw, 88px); align-items: start; }
.yk-etiquette .yk-head--left { position: sticky; top: calc(var(--header-h) + var(--chapters-h) + 32px); }
.yk-legend { display: flex; flex-wrap: wrap; align-items: center; gap: 6px 10px; margin-top: 26px; color: var(--ink-2); font-size: 14px; }
.yk-mark { display: inline-grid; place-items: center; width: 24px; height: 24px; border-radius: 50%; color: #fff; font-size: 13px; font-weight: 800; }
.yk-mark--ok, .yk .manner--ok .manner__mark { background: var(--ok); }
.yk-mark--check, .yk .manner--check .manner__mark { background: var(--ochre); }
.yk-mark--no, .yk .manner--no .manner__mark { background: var(--accent); }
:root[data-theme="dark"] .yk .yk-mark, :root[data-theme="dark"] .yk .manner__mark { color: #0b0f17; }
.yk .manners { display: grid; border-top: 1px solid var(--line); }
.yk .manner { display: grid; grid-template-columns: 7.5rem minmax(0, 1fr); gap: 18px; padding: 24px 0; border-bottom: 1px solid var(--line); }
.yk .manner__mark { align-self: start; justify-self: start; display: inline-flex; align-items: center; gap: 6px; padding: 3px 12px; border-radius: 999px; color: #fff; font-size: 13px; font-weight: 800; letter-spacing: .04em; white-space: nowrap; }
.yk .manner__mark .swap > .en { color: inherit; margin-left: .3em; }
.yk .manner h3 { font-size: 19px; }
.yk .manner .bi { margin-top: 6px; font-size: 16px; line-height: 1.85; }

/* Common mistakes */
.yk-mistakes { background: linear-gradient(180deg, var(--bg) 0, color-mix(in srgb, var(--accent) 7%, var(--bg)) 100%); }
.yk-mistakes__list { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: clamp(14px, 2vw, 24px); }
.yk-mistake { position: relative; padding: 28px 26px 26px; border-radius: 28px; background: var(--surface); box-shadow: 0 0 0 1px var(--line); }
.yk-mistake__no { display: grid; place-items: center; width: 34px; height: 34px; margin-bottom: 14px; border-radius: 50%; background: var(--accent); color: var(--on-accent); font: 800 16px/1 var(--en); }
:root[data-theme="dark"] .yk .yk-mistake__no { color: #0b0f17; }
.yk-mistake h3 { font-size: 21px; }
.yk-mistake > .bi, .yk-mistake__body > .bi { margin-top: 10px; font-size: 16px; line-height: 1.85; }
.yk .yk-fix { position: relative; margin-top: 12px; padding: 10px 14px 10px 40px; border-radius: 14px; background: color-mix(in srgb, var(--ok) 10%, transparent); color: var(--ink); font-weight: 700; }
.yk .yk-fix::before { content: "✓"; position: absolute; left: 14px; top: 10px; color: var(--ok); font-weight: 800; }
.yk .yk-fix > .en { margin-top: 0; font-weight: 500; }
.yk-mistake--lead { grid-column: 1 / -1; display: grid; grid-template-columns: minmax(0, 300px) minmax(0, 1fr); align-items: center; gap: clamp(20px, 4vw, 56px); padding: clamp(24px, 4vw, 44px); background: var(--night); color: var(--night-ink); box-shadow: none; }
.yk-mistake--lead .en { color: var(--night-ink-2); }
.yk-mistake--lead h3 { font-family: var(--serif); font-size: clamp(36px, 5vw, 60px); line-height: 1.3; }
.yk-mistake--lead h3 > .en { font-family: var(--en); font-size: 16px; }
.yk-mistake--lead .yk-mistake__no { background: #e0765a; color: #fff; }
.yk-mistake--lead .yk-fix { background: rgba(79, 174, 134, .18); color: var(--night-ink); }
.yk-mistake--lead .yk-fix::before { color: #7fcfaa; }
.yk-mistake__art { padding: 16px; border-radius: 22px; background: #f7f5f0; color: #141a24; box-shadow: inset 0 0 0 3px #e0765a; }
.yk-mistake__art svg { width: 100%; max-width: 260px; height: auto; margin: 0 auto; }

/* Words */
.yk-words { background: var(--bg); }
.yk-banner { margin: 0 0 clamp(24px, 3vw, 32px); }
.yk-banner picture { overflow: hidden; border-radius: 28px; aspect-ratio: 21 / 8; background: var(--tile); }
.yk-banner img { width: 100%; height: 100%; object-fit: cover; object-position: 50% 45%; }
.yk .vocab { display: grid; grid-template-columns: minmax(0, 340px) minmax(0, 1fr); gap: clamp(20px, 3vw, 40px); align-items: start; padding: clamp(20px, 3vw, 36px); border-radius: 28px; background: var(--surface); box-shadow: 0 0 0 1px var(--line); }
.yk .vocab__figure { display: grid; place-items: center; padding: 18px; border-radius: 22px; background: var(--tile); color: var(--ink); }
.yk .parts-stage { position: relative; width: min(100%, 290px); }
.yk #parts-illustration svg { width: 100%; height: auto; }
.yk .hotspot { position: absolute; display: grid; place-items: center; width: 44px; height: 44px; padding: 0; border: 0; border-radius: 50%; background: transparent; transform: translate(-50%, -50%); }
.yk .hotspot > span { display: grid; place-items: center; width: 32px; height: 32px; border-radius: 50%; background: #fff; color: #1f3c66; box-shadow: 0 0 0 2px #1f3c66, 0 4px 10px rgba(0, 0, 0, .2); font: 800 14px/1 var(--en); transition: transform .2s var(--ease); }
.yk .hotspot:hover > span { transform: scale(1.08); }
.yk .hotspot[aria-pressed="true"] > span { background: var(--accent); color: var(--on-accent); box-shadow: 0 0 0 2px #fff, 0 4px 10px rgba(0, 0, 0, .25); }
.yk .vocab-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(min(100%, 8.5rem), 1fr)); gap: 10px; }
@media (max-width: 500px) { .yk .vocab-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 8px; } }
.yk .vocab-card { padding: 10px 14px 12px; border-radius: 16px; background: var(--surface-2); box-shadow: 0 0 0 1px var(--line); transition: box-shadow .2s, background .2s; }
.yk .vocab-card.is-active { background: var(--accent-soft); box-shadow: 0 0 0 2px var(--accent); }
.yk .vocab-card__word { display: block; font-family: var(--serif); font-size: 26px; font-weight: 700; line-height: 1.8; }
.yk .vocab-card__meaning { display: block; font-size: 13px; line-height: 1.45; }
.yk .vocab-card__meaning b { color: var(--ink); }
.yk .phrases { margin-top: clamp(14px, 2vw, 24px); padding: clamp(24px, 3vw, 40px); border-radius: 28px; background: var(--night); color: var(--night-ink); }
.yk .phrases .en { color: var(--night-ink-2); }
.yk .phrases h3 { font-size: clamp(22px, 2.6vw, 30px); }
.yk .phrases ol { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px 40px; margin-top: 22px; counter-reset: phrase; }
.yk .phrases ol li { position: relative; padding-left: 44px; font-size: 19px; line-height: 1.8; counter-increment: phrase; }
.yk .phrases ol li::before { content: counter(phrase); position: absolute; top: 4px; left: 0; display: grid; place-items: center; width: 30px; height: 30px; border-radius: 50%; background: rgba(255, 255, 255, .12); color: #f3a48c; font: 800 13px/1 var(--en); }
.yk .phrases .speak-button { color: var(--night-ink-2); }

/* Practice */
.yk-practice { background: var(--bg-2); }
.yk .quiz { max-width: 820px; margin: 0 auto; padding: clamp(24px, 4vw, 44px); border-radius: 32px; background: var(--surface); box-shadow: 0 0 0 1px var(--line), 0 30px 60px -40px rgba(14, 26, 46, .35); }
.yk .quiz__top { display: flex; justify-content: space-between; align-items: baseline; }
.yk .quiz__top .yk-kicker { margin: 0; }
.yk .quiz__count { color: var(--ink-2); font: 600 15px/1 var(--en); font-variant-numeric: tabular-nums; }
.yk .quiz__question { margin-top: 10px; font-size: clamp(21px, 2.4vw, 26px); line-height: 1.6; }
.yk .quiz__question:focus { outline: none; }
.yk .quiz__question:focus-visible { outline: 3px solid var(--focus); }
.yk .quiz__question > .en { font-size: 15px; }
.yk .quiz__listen { margin-top: 16px; }
.yk .listen-button svg { width: 18px; height: 18px; fill: currentColor; }
.yk .quiz__options { display: grid; gap: 10px; margin-top: 22px; }
.yk .quiz__options.is-pictures { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.yk .quiz__option-row { display: flex; align-items: center; gap: 6px; }
.yk .quiz-option { position: relative; display: flex; flex: 1; align-items: center; gap: 14px; min-height: 56px; padding: 10px 18px; border: 0; border-radius: 18px; background: var(--surface-2); box-shadow: 0 0 0 1px var(--line); color: var(--ink); text-align: left; line-height: 1.45; transition: box-shadow .2s; }
.yk .quiz-option:hover:not(:disabled) { box-shadow: 0 0 0 2px var(--indigo-ink); }
.yk .quiz-option:disabled { opacity: 1; }
.yk .quiz-option .jp { display: block; font-size: 18px; line-height: 1.8; }
.yk .quiz-option .en { display: block; font-size: 13px; }
.yk .option-letter { flex: none; display: grid; place-items: center; width: 28px; height: 28px; border-radius: 50%; box-shadow: inset 0 0 0 1px var(--line-strong); color: var(--ink-2); font: 800 13px/1 var(--en); }
.yk .quiz-option.has-diagram { flex-direction: column; gap: 6px; padding: 10px; background: #f7f5f0; color: #141a24; }
.yk .quiz-option.has-diagram .option-letter { color: #4b5363; box-shadow: inset 0 0 0 1px rgba(20, 26, 36, .25); }
.yk .quiz-option.has-diagram svg { width: 100%; height: auto; }
.yk .option-result { margin-left: auto; font-weight: 800; }
.yk .quiz-option.correct { box-shadow: 0 0 0 2px var(--ok); background: color-mix(in srgb, var(--ok) 10%, var(--surface)); }
.yk .quiz-option.correct .option-result { color: var(--ok); }
.yk .quiz-option.incorrect { box-shadow: 0 0 0 2px var(--accent); background: var(--accent-soft); }
.yk .quiz-option.incorrect .option-result { color: var(--accent); }
.yk .quiz-option.has-diagram.correct .option-result { color: #1f6a4c; }
.yk .quiz-option.has-diagram.incorrect .option-result { color: #a83d24; }
.yk .has-diagram .option-result { position: absolute; top: 8px; right: 10px; }
.yk .quiz__feedback { min-height: 1.5rem; margin-top: 18px; color: var(--ok); font-weight: 700; }
.yk .quiz__feedback.is-incorrect { color: var(--accent); }
.yk .quiz__feedback > .en { display: block; font-weight: 500; font-size: 15px; }
.yk .quiz__footer { display: flex; justify-content: space-between; align-items: center; gap: 16px; margin-top: 18px; }
.yk .text-button { min-height: 44px; padding: 4px; border: 0; background: none; color: var(--ink-2); font-weight: 700; text-decoration: underline; text-underline-offset: .25em; }

/* Keep going, credits, footer */
.yk-more { padding: clamp(72px, 9vw, 120px) 0; background: var(--bg); }
.yk-more__title { text-align: center; font-size: clamp(28px, 3.6vw, 40px); font-weight: 800; line-height: 1.4; }
.yk-more__title > .en { font-size: 17px; font-weight: 600; }
.yk-links { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; max-width: 920px; margin: 32px auto 40px; }
.yk-links a { position: relative; display: block; padding: 18px 52px 18px 22px; border-radius: 20px; background: var(--surface); box-shadow: 0 0 0 1px var(--line); font-weight: 700; line-height: 1.7; text-decoration: none; transition: box-shadow .2s, transform .2s; }
.yk-links a:hover { box-shadow: 0 0 0 2px var(--indigo-ink); }
.yk-links .swap > .en { display: block; margin: 2px 0 0; font-size: 14px; }
.yk-lv { display: inline-block; margin-right: 10px; padding: 3px 7px; border-radius: 6px; background: var(--indigo); color: #fff; font: 800 12px/1 var(--en); vertical-align: 2px; }
.yk-lv--place { background: var(--accent); }
:root[data-theme="dark"] .yk .yk-lv--place { color: #0b0f17; }
.yk-arr { position: absolute; right: 22px; top: 50%; transform: translateY(-50%); color: var(--accent); }
.yk-credits { padding: 36px 0; background: var(--bg-2); color: var(--ink-2); font-size: 14px; border-top: 1px solid var(--line); }
.yk-credits summary { display: flex; align-items: center; gap: 10px; cursor: pointer; list-style: none; }
.yk-credits summary::-webkit-details-marker { display: none; }
.yk-credits summary::before { content: "+"; color: var(--accent); font: 800 20px/1 var(--en); }
.yk-credits details[open] summary::before { content: "−"; }
.yk-credits h2 { display: inline; color: var(--ink); font-size: 16px; font-weight: 700; }
.yk-credits__h { margin-top: 18px; color: var(--ink); font-size: 14px !important; }
.yk .credit-list { margin-top: 8px; padding-left: 20px; list-style: disc; line-height: 1.7; }
.yk .credit-list a { color: var(--indigo-ink); }
.yk .credit-note { margin-top: 14px; }
.yk-foot { padding: 28px 0 calc(28px + env(safe-area-inset-bottom)); background: var(--bg-2); border-top: 1px solid var(--line); font-size: 15px; }
.yk-foot__row { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 14px 24px; }
.yk-foot a { text-decoration: none; }
.yk-foot a:hover { text-decoration: underline; text-underline-offset: .25em; }
.yk-noscript { padding: 48px 0; background: var(--bg-2); }
.yk-noscript ol { display: grid; gap: 10px; margin: 10px 0 20px; padding-left: 22px; list-style: decimal; }
.yk-noscript h3 { margin-top: 20px; }
.no-js .yk-toolbar { display: none; }

/* Tap-to-hear buttons from speech.js: 32px, 44px on touch screens. */
.yk .speak-button { display: inline-grid; place-items: center; width: 32px; height: 32px; margin-inline-start: .2em; padding: 0; border: 0; border-radius: 50%; background: none; color: var(--ink-2); vertical-align: middle; line-height: 1; }
.yk .speak-button svg { width: 18px; height: 18px; }
.yk .speak-button:hover, .yk .speakable.is-speaking > .speak-button, .yk .speak-button.is-speaking { color: var(--accent); background: var(--accent-soft); }
.yk .speakable { cursor: pointer; }
.yk .speakable.is-speaking { color: var(--accent); }
.yk .is-speaking .speak-wave { animation: yk-pulse .9s ease-in-out infinite; }
.yk-rule .speak-button, .yk-cold .speak-button, .yk-mistake--lead .speak-button { color: var(--night-ink-2); }
.yk-display .speak-button, .yk-rule__title .speak-button { display: flex; align-items: center; justify-content: center; width: 44px; height: 44px; margin: 2px auto 0; }
.yk-display .speak-button svg { width: 24px; height: 24px; }
@media (pointer: coarse) { .yk .speak-button { width: 44px; height: 44px; margin-block: -6px; } }

/* Motion: entrances only, once; all off with reduced motion. */
.js .yk [data-reveal] { opacity: 0; transform: translateY(24px); transition: opacity .8s var(--ease), transform .8s var(--ease); }
.js .yk [data-reveal].is-in { opacity: 1; transform: none; }
.yk .main-illustration.is-entering { animation: yk-figure-in .45s ease both; }
.yk .content-enter { animation: yk-content-in .3s ease both; }
.yk .motion-arrow { stroke-dasharray: 8 5; animation: yk-arrow 1.8s linear 2; }
.yk .fabric-enter { animation: yk-fabric .8s ease-out both; }
.yk .yukata-stage-3 .fabric-enter { --fabric-from: -30px; }
.yk .yukata-stage-4 .fabric-enter { --fabric-from: 30px; }
.yk .part-glow { animation: yk-glow 1.8s ease-in-out 2; }
.yk [data-art] .motion-arrow, .yk [data-art] .fabric-enter, .yk [data-art] .part-glow { animation: none; }
@keyframes yk-figure-in { from { opacity: .3; transform: translateY(5px); } to { opacity: 1; transform: none; } }
@keyframes yk-content-in { from { opacity: .2; transform: translateX(7px); } to { opacity: 1; transform: none; } }
@keyframes yk-arrow { to { stroke-dashoffset: -52; } }
@keyframes yk-fabric { from { opacity: .6; transform: translateX(var(--fabric-from, 8px)); } to { opacity: 1; transform: none; } }
@keyframes yk-glow { 50% { filter: brightness(1.13); } }
@keyframes yk-confetti { 0% { opacity: 0; transform: translateY(-20px) rotate(0); } 15% { opacity: 1; } 100% { opacity: 0; transform: translateY(310px) rotate(200deg); } }
@keyframes yk-pulse { 50% { opacity: .3; } }
@media (prefers-reduced-motion: reduce) {
  html:has(> body.yk) { scroll-behavior: auto; }
  .yk *, .yk *::before, .yk *::after { animation: none !important; transition: none !important; }
  .yk .yk-in, .js .yk [data-reveal] { opacity: 1 !important; transform: none !important; }
  .yk .yk-hero__media img { transform: none !important; }
}

/* Responsive */
@media (max-width: 1080px) {
  .yk-steps { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .yk-step, .yk-step--key, .yk-step:nth-child(4) { grid-column: span 1; }
  .yk-step--wide { grid-column: 1 / -1; flex-direction: row; }
  .yk-step--wide .yk-step__art { flex: 1; }
  .yk-step--wide .yk-step__body { flex: 1; align-self: center; }
  .yk-rule__points { grid-template-columns: minmax(0, 1fr); max-width: 640px; }
  .yk-mistakes__list { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .yk-bento { grid-template-columns: minmax(0, 1fr); }
  .yk .phrases ol { grid-template-columns: minmax(0, 1fr); }
}
@media (max-width: 900px) {
  .yk-festival__open, .yk-compare-wm, .yk-etiquette__grid { grid-template-columns: minmax(0, 1fr); }
  .yk-etiquette .yk-head--left { position: static; }
  .yk-compare-wm .yk-photo--pair { max-width: 340px; margin: 0 auto; }
  .yk .vocab { grid-template-columns: minmax(0, 1fr); }
  .yk .vocab__figure { justify-self: center; width: min(100%, 360px); }
  .yk-cold { grid-template-columns: minmax(0, 180px) minmax(0, 1fr); }
}
@media (max-width: 760px) {
  .yk { font-size: 16px; }
  .yk .lesson { grid-template-columns: minmax(0, 1fr); grid-template-areas: "art" "nav" "text" "markers"; grid-template-rows: auto; border-radius: 24px; }
  .yk .lesson__art { min-height: 0; padding: 12px 12px 58px; }
  .yk .main-illustration svg { max-height: min(40vh, 21rem); }
  .yk .figure-callout { top: 30%; left: 8px; max-width: 7.2rem; padding: 6px 9px; font-size: 12px; }
  .yk .figure-callout .jp { font-size: 19px; }
  .yk .figure-callout.callout-right { right: 8px; }
  .yk .secondary-callout { top: 52%; }
  .yk .back-inset { right: 8px; bottom: 10px; width: 6.6rem; }
  .yk .replay-button { bottom: 10px; left: 10px; }
  .yk .lesson__nav { padding: 12px; border-bottom: 1px solid var(--line); }
  .yk .lesson__text { padding: 20px 18px 10px; }
  .yk .step-word .jp { font-size: 40px; }
  .yk .step-explanation { font-size: 17px; }
  .yk .marker-label { display: none; }
  .yk .step-markers { gap: 2px; }
  .yk .quiz__options.is-pictures { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 6px; }
  .yk-links { grid-template-columns: minmax(0, 1fr); }
  .yk .manner { grid-template-columns: minmax(0, 1fr); gap: 10px; padding: 20px 0; }
}
@media (max-width: 699px) {
  .yk-hero__media { padding: 0 16px; }
  .yk-hero__media picture { aspect-ratio: 4 / 5; border-radius: 24px; }
  .yk-hero__media img { object-position: 50% 50%; }
  .yk-glance { grid-template-columns: repeat(3, minmax(0, 1fr)); padding-inline: 12px; }
  .yk-glance li { padding: 0 6px; font-size: 12px; }
  .yk-steps { grid-template-columns: minmax(0, 1fr); }
  .yk-step, .yk-step--wide { grid-column: auto; flex-direction: row; border-radius: 22px; }
  .yk-step__art { flex: 0 0 36%; min-height: 0; padding: 14px 8px; }
  .yk-step__art svg { max-height: 170px; }
  .yk-step__body { flex: 1; padding: 18px 18px 20px; }
  .yk-step--wide { flex-direction: column; }
  .yk-step--wide .yk-step__art { flex: none; }
  .yk-cold { grid-template-columns: minmax(0, 1fr); text-align: left; }
  .yk-cold__art { max-width: 200px; }
  .yk-mistakes__list { grid-template-columns: minmax(0, 1fr); }
  .yk-mistake--lead { grid-template-columns: minmax(0, 1fr); }
  .yk-mistake__art { max-width: 280px; }
  .yk-tile--photo picture { aspect-ratio: 3 / 2; }
  .yk-banner picture { aspect-ratio: 16 / 9; border-radius: 22px; }
  .yk-photo picture { border-radius: 22px; }
  .yk-rule__compare { gap: 12px; }
  .yk-rule .compare { padding: 14px 8px 12px; border-radius: 18px; }
  .yk .compare figcaption { font-size: 14px; }
  .yk-rule__warning { padding: 18px 18px 18px 56px; }
  .yk-rule__warning::before { left: 16px; top: 18px; }
}
/* Header on phones: one row, never overlapping. The wordmark goes first,
   then the back link shortens to "← Ryokan", then the toggles lose their switches. */
@media (max-width: 720px) {
  .yk { --header-h: 52px; --chapters-h: 46px; }
  .yk-header { gap: 8px; padding-inline: max(10px, env(safe-area-inset-left)) max(10px, env(safe-area-inset-right)); }
  .yk .sy-wordmark { display: none; }
  .yk-brand { gap: 8px; }
  .yk .sy-mark { width: 30px; height: 30px; flex-basis: 30px; }
  .yk-back { padding: 4px 10px; font-size: 13px; }
  .yk-toggle { gap: 6px; min-height: 34px; padding: 3px 4px 3px 10px; font-size: 12px; }
  .yk-toggle__switch { width: 28px; height: 18px; }
  .yk-toggle__switch span { width: 14px; height: 14px; }
  .yk-toggle[aria-pressed="true"] .yk-toggle__switch span { transform: translateX(10px); }
  .yk .theme-toggle { width: 34px; height: 34px; }
  .yk-chapters ol { justify-content: flex-start; padding: 0 10px; }
  .yk-chapters a { padding: 2px 11px; font-size: 13px; }
}
@media (max-width: 500px) {
  .yk-back__more { display: none; }
}
@media (max-width: 420px) {
  .yk-toolbar { gap: 4px; }
  .yk-toggle { padding: 3px 10px; min-height: 34px; }
  .yk-toggle__switch { display: none; }
  .yk-toggle[aria-pressed="true"] { background: var(--ink); color: var(--bg); border-color: var(--ink); }
  .yk-toggle[aria-pressed="false"] .yk-toggle__label { text-decoration: line-through; text-decoration-thickness: 1px; opacity: .7; }
  .yk-chapters .swap > .en { display: none; }
}
@media (max-width: 350px) {
  .yk-header { gap: 6px; padding-inline: 8px; }
  .yk-back { padding: 4px 7px; font-size: 12px; }
  .yk-toolbar { gap: 3px; }
  .yk-toggle { padding: 3px 7px; font-size: 11.5px; }
  .yk .theme-toggle { width: 32px; height: 32px; }
}
@media print {
  .yk-header, .yk-chapters, .yk .speak-button, .yk .replay-button { display: none; }
  .js .yk [data-reveal] { opacity: 1; transform: none; }
}