/* =====================================================================
   9 to 5 Japanese — shared stylesheet
   Aesthetic: warm washi paper, sumi ink, a single vermilion accent.
   Display: Zen Old Mincho · Body: Zen Kaku Gothic New
   ===================================================================== */

:root {
  --bg: #f4efe4;
  --bg-2: #efe8d9;
  --surface: #fbf8f0;
  --ink: #22201b;
  --ink-mid: #5f584c;
  --line: rgba(34, 32, 27, 0.14);
  --line-soft: rgba(34, 32, 27, 0.08);
  --vermilion: #b8402f;
  --vermilion-deep: #97301f;
  --indigo: #2a3b52;
  --gold: #9a7736;

  --serif: "Zen Old Mincho", "Hiragino Mincho ProN", "Yu Mincho", "Noto Serif JP", serif;
  --sans: "Zen Kaku Gothic New", "Hiragino Kaku Gothic ProN", "Noto Sans JP", system-ui, sans-serif;

  --wrap: 72rem;
  --read: 44rem;
  --radius: 14px;
  --shadow: 0 1px 2px rgba(34, 32, 27, 0.05), 0 18px 40px -28px rgba(34, 32, 27, 0.5);
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: 5.5rem; }

body {
  margin: 0;
  font-family: var(--sans);
  font-weight: 400;
  color: var(--ink);
  background:
    radial-gradient(120% 80% at 85% -10%, #fbf6ec 0%, rgba(251, 246, 236, 0) 55%),
    radial-gradient(90% 60% at 0% 0%, #f7f1e6 0%, rgba(247, 241, 230, 0) 50%),
    var(--bg);
  line-height: 1.72;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  font-variant-ligatures: common-ligatures contextual;
  font-feature-settings: "liga", "calt";
  overflow-x: hidden;
}

/* Paper grain overlay — fixed, non-interactive */
.grain {
  position: fixed;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  opacity: 0.05;
  mix-blend-mode: multiply;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

img { max-width: 100%; height: auto; }

a { color: var(--indigo); text-decoration-thickness: 1px; text-underline-offset: 3px; }

::selection { background: var(--vermilion); color: #fdfaf3; }

.skip {
  position: absolute; left: -999px; top: 0; z-index: 100;
  background: var(--ink); color: var(--bg); padding: 0.6rem 1rem; border-radius: 0 0 8px 0;
}
.skip:focus { left: 0; }

/* ------------------------------------------------------------------ *
   Header / nav
 * ------------------------------------------------------------------ */
.site-head {
  position: sticky; top: 0; z-index: 30;
  display: flex; align-items: center; justify-content: space-between;
  gap: 1rem;
  padding: 0.85rem clamp(1.1rem, 4vw, 3rem);
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line-soft);
}

.brand { display: inline-flex; align-items: center; gap: 0.6rem; text-decoration: none; color: var(--ink); }
.mark { width: 34px; height: 34px; flex: none; }
.mark-ring { fill: none; stroke: var(--ink); stroke-width: 1.5; opacity: 0.55; }
.mark-dot { fill: var(--vermilion); }
.brand:hover .mark-dot { animation: pulse 0.6s var(--ease); }
@keyframes pulse { 50% { transform: scale(0.82); transform-origin: center; } }
.mark { transform-box: fill-box; }

.brand-text { display: flex; flex-direction: column; line-height: 1; }
.brand-en { font-family: var(--serif); font-weight: 700; font-size: 1.02rem; letter-spacing: 0.02em; }
.brand-jp { font-size: 0.66rem; letter-spacing: 0.42em; text-transform: uppercase; color: var(--ink-mid); margin-top: 3px; }

.site-nav { display: flex; align-items: center; gap: clamp(0.9rem, 2vw, 1.9rem); }
.site-nav a {
  font-size: 0.83rem; letter-spacing: 0.04em; text-transform: uppercase;
  color: var(--ink-mid); text-decoration: none; position: relative; padding: 0.3rem 0;
  transition: color 0.25s;
}
.site-nav a::after {
  content: ""; position: absolute; left: 0; bottom: 0; height: 1.5px; width: 100%;
  background: var(--vermilion); transform: scaleX(0); transform-origin: right;
  transition: transform 0.3s var(--ease);
}
.site-nav a:hover, .site-nav a[aria-current="page"] { color: var(--ink); }
.site-nav a:hover::after, .site-nav a[aria-current="page"]::after { transform: scaleX(1); transform-origin: left; }

.nav-cta {
  border: 1px solid var(--line); border-radius: 999px; padding: 0.4rem 0.95rem !important;
  color: var(--ink) !important;
}
.nav-cta::after { display: none; }
.nav-cta:hover { background: var(--ink); color: var(--bg) !important; border-color: var(--ink); }

.nav-toggle { display: none; }

/* ------------------------------------------------------------------ *
   Layout scaffolding
 * ------------------------------------------------------------------ */
main { position: relative; z-index: 2; }

section { padding-inline: clamp(1.1rem, 4vw, 3rem); }

.eyebrow, .hero-kicker {
  font-size: 0.75rem; letter-spacing: 0.34em; text-transform: uppercase; color: var(--vermilion-deep);
  font-weight: 700; margin: 0;
}

/* ------------------------------------------------------------------ *
   Hero
 * ------------------------------------------------------------------ */
.hero {
  position: relative;
  max-width: var(--wrap); margin: 0 auto;
  padding-top: clamp(3rem, 8vw, 6rem); padding-bottom: clamp(2rem, 5vw, 3.5rem);
}
.hero-inner { max-width: 40rem; position: relative; z-index: 2; }
.hero-title {
  font-family: var(--serif); font-weight: 900;
  font-size: clamp(2.6rem, 7vw, 5rem); line-height: 1.04; letter-spacing: -0.015em;
  margin: 1rem 0 1.4rem;
  text-wrap: balance;
}
.hero-title em { font-style: italic; font-weight: 600; color: var(--vermilion); display: block; }
.hero-sub { font-size: clamp(1.05rem, 2.2vw, 1.28rem); color: var(--ink-mid); max-width: 34rem; margin: 0 0 2rem; }
.hero-sub strong { color: var(--ink); font-weight: 700; }

.hero-cta { display: flex; flex-wrap: wrap; gap: 0.9rem; }
.btn {
  display: inline-flex; align-items: center; gap: 0.5rem;
  font-size: 0.95rem; font-weight: 700; letter-spacing: 0.01em;
  padding: 0.85rem 1.6rem; border-radius: 999px; text-decoration: none;
  transition: transform 0.2s var(--ease), background 0.25s, box-shadow 0.25s, color 0.25s;
}
.btn-primary { background: var(--vermilion); color: #fdfaf3; box-shadow: 0 12px 24px -14px var(--vermilion); }
.btn-primary:hover { background: var(--vermilion-deep); transform: translateY(-2px); }
.btn-ghost { color: var(--ink); border: 1px solid var(--line); }
.btn-ghost:hover { border-color: var(--ink); transform: translateY(-2px); }

/* Hero decoration — hinomaru circle + faded kanji */
.hero-deco { position: absolute; inset: 0; z-index: 1; pointer-events: none; overflow: hidden; }
.hero-circle {
  position: absolute; top: -6%; right: -4%;
  width: clamp(15rem, 34vw, 30rem); aspect-ratio: 1; border-radius: 50%;
  background: radial-gradient(circle at 38% 35%, #d5563f 0%, var(--vermilion) 45%, var(--vermilion-deep) 100%);
  opacity: 0.10;
}
.hero-kanji {
  position: absolute; top: 4%; right: 4%;
  font-family: var(--serif); font-weight: 900; font-size: clamp(11rem, 28vw, 24rem);
  color: var(--ink); opacity: 0.05; line-height: 0.8; user-select: none;
}

.hero-stats {
  position: relative; z-index: 2;
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px;
  background: var(--line-soft); border: 1px solid var(--line-soft); border-radius: var(--radius);
  overflow: hidden; margin-top: clamp(2.5rem, 6vw, 4rem);
}
.stat { background: var(--surface); padding: 1.4rem 1.5rem; display: flex; flex-direction: column; gap: 0.15rem; }
.stat-n { font-family: var(--serif); font-weight: 700; font-size: clamp(1.8rem, 4vw, 2.6rem); line-height: 1; color: var(--ink); }
.stat-u { font-size: 0.8rem; letter-spacing: 0.16em; text-transform: uppercase; color: var(--vermilion-deep); font-weight: 700; }
.stat-d { font-size: 0.88rem; color: var(--ink-mid); margin-top: 0.35rem; }

/* ------------------------------------------------------------------ *
   Creed strip
 * ------------------------------------------------------------------ */
.creed {
  max-width: var(--wrap); margin: clamp(3rem, 7vw, 5rem) auto;
  border-top: 1px solid var(--line); border-bottom: 1px solid var(--line);
  padding-block: clamp(2rem, 5vw, 3.2rem);
}
.creed p {
  font-family: var(--serif); font-size: clamp(1.3rem, 3vw, 2rem); line-height: 1.5;
  max-width: 46rem; margin: 0; color: var(--ink-mid); font-weight: 500;
}
.creed-lead { color: var(--ink); font-weight: 700; }

/* ------------------------------------------------------------------ *
   Roadmap
 * ------------------------------------------------------------------ */
.roadmap { max-width: var(--wrap); margin: 0 auto; padding-bottom: clamp(3rem, 8vw, 6rem); }
.section-head { max-width: 40rem; margin-bottom: clamp(2rem, 5vw, 3rem); }
.section-head h2 { font-family: var(--serif); font-weight: 700; font-size: clamp(2rem, 5vw, 3.2rem); margin: 0.5rem 0 0.7rem; letter-spacing: -0.01em; text-wrap: balance; }
.section-sub { color: var(--ink-mid); font-size: 1.05rem; margin: 0; }

.track { margin-top: clamp(2.5rem, 6vw, 4rem); }
.track-head { display: flex; align-items: baseline; gap: 1.2rem; flex-wrap: wrap; margin-bottom: 1.4rem; }
.track-head h3 {
  font-family: var(--serif); font-weight: 700; font-size: 1.5rem; margin: 0;
  position: relative; padding-left: 1.1rem;
}
.track-head h3::before {
  content: ""; position: absolute; left: 0; top: 0.15em; bottom: 0.15em; width: 4px;
  background: var(--vermilion); border-radius: 2px;
}
.track-head p { margin: 0; color: var(--ink-mid); font-size: 0.95rem; }

.track-cards { display: grid; gap: 1rem; }

.card {
  display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 1.2rem;
  background: var(--surface); border: 1px solid var(--line-soft); border-radius: var(--radius);
  padding: 1.3rem 1.5rem; text-decoration: none; color: var(--ink);
  box-shadow: 0 1px 2px rgba(34,32,27,0.03);
  transition: transform 0.28s var(--ease), box-shadow 0.28s var(--ease), border-color 0.28s;
}
.card:hover { transform: translateY(-3px); box-shadow: var(--shadow); border-color: var(--line); }
.card-n { font-family: var(--serif); font-weight: 700; font-size: 1.5rem; color: var(--vermilion); opacity: 0.65; min-width: 2ch; }
.card-body { display: flex; flex-direction: column; gap: 0.25rem; }
.card-title { font-family: var(--serif); font-weight: 700; font-size: 1.22rem; line-height: 1.25; }
.card-ex { color: var(--ink-mid); font-size: 0.92rem; line-height: 1.5; }
.card-meta { font-size: 0.74rem; letter-spacing: 0.12em; text-transform: uppercase; color: var(--gold); margin-top: 0.2rem; }
.card-arrow { font-size: 1.3rem; color: var(--ink-mid); transition: transform 0.28s var(--ease), color 0.28s; }
.card:hover .card-arrow { transform: translateX(5px); color: var(--vermilion); }

/* ------------------------------------------------------------------ *
   Article pages
 * ------------------------------------------------------------------ */
.progress { position: sticky; top: 0; z-index: 25; height: 3px; background: transparent; }
.progress span { display: block; height: 100%; width: 0; background: var(--vermilion); transition: width 0.1s linear; }

.post { max-width: var(--read); margin: 0 auto; padding: clamp(2.5rem, 6vw, 4.5rem) clamp(1.1rem, 4vw, 2rem) clamp(3rem, 7vw, 5rem); }
.post-head { margin-bottom: 2.2rem; }
.kicker { display: flex; align-items: center; gap: 0.7rem; font-size: 0.78rem; letter-spacing: 0.2em; text-transform: uppercase; color: var(--vermilion-deep); font-weight: 700; }
.kicker-n { font-family: var(--serif); font-size: 1.05rem; letter-spacing: 0; background: var(--vermilion); color: #fdfaf3; width: 2rem; height: 2rem; border-radius: 50%; display: inline-flex; align-items: center; justify-content: center; }
.post-head h1 { font-family: var(--serif); font-weight: 700; font-size: clamp(2.1rem, 5.5vw, 3.4rem); line-height: 1.08; letter-spacing: -0.01em; margin: 1rem 0 1rem; text-wrap: balance; }
.post-meta { display: flex; align-items: center; gap: 0.7rem; color: var(--ink-mid); font-size: 0.9rem; }
.post-meta .dot { width: 4px; height: 4px; border-radius: 50%; background: var(--ink-mid); opacity: 0.5; }

.tags { list-style: none; display: flex; flex-wrap: wrap; gap: 0.5rem; padding: 0; margin: 1.3rem 0 0; }
.tags li { font-size: 0.74rem; letter-spacing: 0.05em; color: var(--ink-mid); border: 1px solid var(--line); border-radius: 999px; padding: 0.2rem 0.7rem; }

/* Prose */
.prose { font-size: 1.05rem; hyphens: none; }
.prose > *:first-child { margin-top: 0; }
.prose p { margin: 0 0 1.3rem; text-wrap: pretty; }
.prose h2 { font-family: var(--serif); font-weight: 700; font-size: clamp(1.5rem, 3.5vw, 2rem); line-height: 1.2; margin: 2.6rem 0 1rem; letter-spacing: -0.01em; text-wrap: balance; }
.prose h3 { font-family: var(--serif); font-weight: 700; font-size: 1.35rem; margin: 2rem 0 0.8rem; text-wrap: balance; }
.prose h2 + p, .prose h3 + p { margin-top: 0; }
.prose a { color: var(--indigo); text-decoration: underline; text-decoration-color: color-mix(in srgb, var(--indigo) 35%, transparent); transition: text-decoration-color 0.2s; }
.prose a:hover { text-decoration-color: var(--indigo); }
.prose strong { font-weight: 700; color: var(--ink); }
.prose ul, .prose ol { margin: 0 0 1.4rem; padding-left: 1.3rem; }
.prose li { margin-bottom: 0.55rem; padding-left: 0.3rem; }
.prose ul li::marker { color: var(--vermilion); }
.prose ol li::marker { color: var(--vermilion); font-family: var(--serif); font-weight: 700; }
.prose hr { border: none; height: 1px; background: var(--line); margin: 2.6rem auto; width: 60%; }
.prose blockquote { border-left: 3px solid var(--vermilion); margin: 1.6rem 0; padding: 0.3rem 0 0.3rem 1.3rem; color: var(--ink-mid); font-family: var(--serif); font-size: 1.15rem; font-style: italic; }

/* Pager */
.pager { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; margin-top: 3rem; padding-top: 2rem; border-top: 1px solid var(--line); }
.pager a { display: flex; flex-direction: column; gap: 0.25rem; text-decoration: none; padding: 1rem 1.2rem; border: 1px solid var(--line-soft); border-radius: var(--radius); background: var(--surface); transition: border-color 0.25s, transform 0.25s var(--ease); }
.pager a:hover { border-color: var(--vermilion); transform: translateY(-2px); }
.pager span { font-size: 0.72rem; letter-spacing: 0.16em; text-transform: uppercase; color: var(--ink-mid); }
.pager strong { font-family: var(--serif); font-size: 1.05rem; color: var(--ink); line-height: 1.25; }
.pager-next { text-align: right; grid-column: 2; }

.back-link { margin-top: 2rem; }
.back-link a { font-size: 0.9rem; color: var(--ink-mid); text-decoration: none; }
.back-link a:hover { color: var(--vermilion); }

/* ------------------------------------------------------------------ *
   Footer
 * ------------------------------------------------------------------ */
.site-foot { position: relative; z-index: 2; background: var(--bg-2); border-top: 1px solid var(--line); margin-top: 4rem; }
.foot-inner { max-width: var(--wrap); margin: 0 auto; padding: clamp(2.5rem, 6vw, 3.5rem) clamp(1.1rem, 4vw, 3rem); display: grid; grid-template-columns: 1.4fr 1fr; gap: 2rem 1.5rem; align-items: start; }
.foot-brand { display: flex; align-items: center; gap: 0.7rem; }
.foot-brand strong { font-family: var(--serif); font-size: 1.15rem; display: block; }
.foot-brand span { font-size: 0.88rem; color: var(--ink-mid); }
.foot-nav { display: flex; flex-wrap: wrap; gap: 0.4rem 1.4rem; }
.foot-nav a { font-size: 0.88rem; color: var(--ink-mid); text-decoration: none; }
.foot-nav a:hover { color: var(--vermilion); }
.foot-note { grid-column: 1 / -1; margin: 1rem 0 0; padding-top: 1.5rem; border-top: 1px solid var(--line-soft); font-family: var(--serif); font-size: 1.02rem; color: var(--ink-mid); }
.foot-note .muted { font-family: var(--sans); font-size: 0.8rem; opacity: 0.75; display: inline-block; margin-top: 0.4rem; }

/* ------------------------------------------------------------------ *
   Reveal animation
 * ------------------------------------------------------------------ */
.reveal { opacity: 0; transform: translateY(18px); transition: opacity 0.7s var(--ease), transform 0.7s var(--ease); }
.reveal.in { opacity: 1; transform: none; }
.reveal-root .prose > * { opacity: 0; transform: translateY(12px); animation: rise 0.6s var(--ease) forwards; }
.reveal-root.ready .prose > * { animation-delay: calc(var(--i, 0) * 0ms); }

@keyframes rise { to { opacity: 1; transform: none; } }

/* Staggered post-load reveal for header bits */
.page-post .post-head > * { opacity: 0; transform: translateY(14px); animation: rise 0.6s var(--ease) forwards; }
.page-post .kicker { animation-delay: 0.05s; }
.page-post .post-head h1 { animation-delay: 0.13s; }
.page-post .post-meta { animation-delay: 0.22s; }
.page-post .tags { animation-delay: 0.3s; }

.hero-inner > * { opacity: 0; transform: translateY(16px); animation: rise 0.7s var(--ease) forwards; }
.hero-kicker { animation-delay: 0.05s; }
.hero-title { animation-delay: 0.14s; }
.hero-sub { animation-delay: 0.26s; }
.hero-cta { animation-delay: 0.38s; }

/* ------------------------------------------------------------------ *
   Responsive
 * ------------------------------------------------------------------ */
@media (max-width: 760px) {
  .nav-toggle {
    display: inline-flex; flex-direction: column; gap: 5px; justify-content: center;
    width: 42px; height: 42px; background: none; border: 1px solid var(--line); border-radius: 10px; cursor: pointer;
  }
  .nav-toggle span { display: block; width: 18px; height: 2px; background: var(--ink); margin: 0 auto; transition: transform 0.3s var(--ease), opacity 0.3s; }
  .nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
  .nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
  .nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

  .site-nav {
    position: absolute; top: 100%; left: 0; right: 0;
    flex-direction: column; align-items: flex-start; gap: 0.4rem;
    background: var(--surface); border-bottom: 1px solid var(--line);
    padding: 1rem clamp(1.1rem, 4vw, 3rem) 1.4rem;
    clip-path: inset(0 0 100% 0); opacity: 0; pointer-events: none;
    transition: clip-path 0.35s var(--ease), opacity 0.25s;
  }
  .site-nav.open { clip-path: inset(0 0 0 0); opacity: 1; pointer-events: auto; }
  .site-nav a { font-size: 0.95rem; padding: 0.5rem 0; }
  .nav-cta { margin-top: 0.4rem; }

  .hero-stats { grid-template-columns: 1fr; }
  .card { grid-template-columns: auto 1fr; }
  .card-arrow { display: none; }
  .pager { grid-template-columns: 1fr; }
  .foot-inner { grid-template-columns: 1fr; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.001ms !important; transition-duration: 0.001ms !important; scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; }
}

/* ------------------------------------------------------------------ *
   Table of contents
 * ------------------------------------------------------------------ */
.post-shell { max-width: var(--wrap); margin: 0 auto; }

.toc {
  background: var(--surface); border: 1px solid var(--line-soft); border-radius: var(--radius);
  padding: 0.3rem 1.1rem; margin: clamp(1.5rem, 5vw, 2.5rem) auto 0; max-width: var(--read);
}
.toc summary {
  cursor: pointer; list-style: none; font-family: var(--serif); font-weight: 700;
  font-size: 0.95rem; color: var(--ink); padding: 0.7rem 0; letter-spacing: 0.02em;
}
.toc summary::-webkit-details-marker { display: none; }
.toc summary::before { content: "\203A"; display: inline-block; margin-right: 0.55rem; color: var(--vermilion); transition: transform 0.25s var(--ease); }
.toc[open] summary::before { transform: rotate(90deg); }
.toc ol { list-style: none; counter-reset: toc; margin: 0 0 0.6rem; padding: 0; }
.toc li a {
  display: block; position: relative; padding: 0.34rem 0 0.34rem 1.7rem; margin-left: 0.1rem;
  font-size: 0.9rem; line-height: 1.35; color: var(--ink-mid); text-decoration: none;
  border-left: 2px solid var(--line-soft); transition: color 0.2s, border-color 0.2s;
}
.toc li a::before {
  counter-increment: toc; content: counter(toc, decimal-leading-zero);
  position: absolute; left: 0.5rem; top: 0.5rem; font-family: var(--serif); font-size: 0.7rem;
  color: var(--vermilion); opacity: 0.6;
}
.toc li a:hover { color: var(--ink); border-left-color: var(--vermilion); }
.toc li a.active { color: var(--vermilion); border-left-color: var(--vermilion); }

@media (min-width: 1024px) {
  .post-shell {
    display: grid; grid-template-columns: 15rem minmax(0, var(--read)); justify-content: center;
    gap: clamp(2rem, 4vw, 4rem); align-items: start; padding-top: clamp(2.5rem, 6vw, 4.5rem);
  }
  .post-shell .post { padding-top: 0; }
  .toc { position: sticky; top: 5.5rem; margin: 0; max-width: none; background: none; border: none; padding: 0; }
  .toc summary { border-bottom: 1px solid var(--line); }
}

/* Heading offset for anchored scroll targets */
.prose h2, .prose h3 { scroll-margin-top: 5.5rem; }

/* ------------------------------------------------------------------ *
   Back-to-top button
 * ------------------------------------------------------------------ */
.to-top {
  position: fixed; right: clamp(1rem, 3vw, 2rem); bottom: clamp(1rem, 3vw, 2rem); z-index: 35;
  width: 46px; height: 46px; border-radius: 50%; border: 1px solid var(--line);
  background: var(--surface); color: var(--ink); cursor: pointer; box-shadow: var(--shadow);
  display: grid; place-items: center; opacity: 0; transform: translateY(12px); pointer-events: none;
  transition: opacity 0.3s var(--ease), transform 0.3s var(--ease), background 0.25s, color 0.25s, border-color 0.25s;
}
.to-top svg { width: 20px; height: 20px; }
.to-top.show { opacity: 1; transform: none; pointer-events: auto; }
.to-top:hover { background: var(--vermilion); color: #fdfaf3; border-color: var(--vermilion); }

/* ------------------------------------------------------------------ *
   404
 * ------------------------------------------------------------------ */
.notfound {
  position: relative; overflow: hidden; max-width: var(--wrap); margin: 0 auto;
  min-height: 62vh; display: flex; flex-direction: column; justify-content: center;
  padding-block: clamp(3rem, 10vw, 7rem);
}
.notfound-inner { position: relative; z-index: 2; max-width: 34rem; }
.notfound h1 { font-family: var(--serif); font-weight: 700; font-size: clamp(2.4rem, 6vw, 4rem); line-height: 1.05; margin: 1rem 0; }
.notfound-sub { color: var(--ink-mid); font-size: 1.1rem; margin: 0 0 2rem; }
.notfound-kanji {
  position: absolute; right: -2%; top: 50%; transform: translateY(-50%);
  font-family: var(--serif); font-weight: 900; font-size: clamp(14rem, 40vw, 34rem);
  color: var(--vermilion); opacity: 0.07; line-height: 0.8; z-index: 1; user-select: none;
}

@media (max-width: 760px) {
  .toc { margin-top: clamp(1.2rem, 5vw, 2rem); }
}