@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 300;
  font-display: swap;
  src: url('/assets/fonts/inter-300.woff2') format('woff2');
}
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url('/assets/fonts/inter-400.woff2') format('woff2');
}
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 500;
  font-display: swap;
  src: url('/assets/fonts/inter-500.woff2') format('woff2');
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --left-w: 320px;
  --content-max: 68ch;
  --bg: #F4F1EC;
  --surface: #FAF8F4;
  --text: #1C1A17;
  --text-sub: #6B6760;
  --accent: #5A5490;
  --accent-light: #8880B8;
  --border: rgba(28, 26, 23, 0.11);
  --shadow: rgba(28, 26, 23, 0.07);
  --left-bg: #1D2130;
  --left-text: #ECEFF8;
  --left-sub: rgba(236, 239, 248, 0.72);
  --left-border: rgba(236, 239, 248, 0.14);
  --left-accent: #C4C0E8;
  --font-serif-jp: 'Hiragino Mincho ProN', 'Yu Mincho', 'YuMincho', 'MS PMincho', serif;
  --font-serif-en: 'Crimson Pro', Georgia, serif;
  --font-sans: 'Inter', system-ui, sans-serif;
  --radius: 3px;
  --transition: 0.2s ease;
}

[data-theme="dark"] {
  --bg: #1A1D26;
  --surface: #21243A;
  --text: #E0E4EE;
  --text-sub: #7A8294;
  --accent: #A49ED0;
  --accent-light: #C6C2E4;
  --border: rgba(224, 228, 238, 0.09);
  --shadow: rgba(0, 0, 0, 0.35);
  --left-bg: #090B11;
  --left-text: #E4E8F4;
  --left-sub: rgba(228, 232, 244, 0.68);
  --left-border: rgba(228, 232, 244, 0.12);
}

html {
  background: var(--bg);
  color: var(--text);
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-behavior: smooth;
  overflow-x: hidden;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  line-height: 1.75;
  transition: background var(--transition), color var(--transition);
  -webkit-user-select: none;
  user-select: none;
}

img {
  pointer-events: none;
  -webkit-user-drag: none;
  display: block;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color var(--transition);
}
a:hover {
  color: var(--accent-light);
}

.layout {
  display: flex;
  min-height: 100vh;
}

.left-panel {
  width: var(--left-w);
  flex-shrink: 0;
  background: var(--left-bg);
  background-image: repeating-linear-gradient(
    0deg,
    transparent,
    transparent 3px,
    rgba(255, 255, 255, 0.016) 3px,
    rgba(255, 255, 255, 0.016) 4px
  );
  min-height: 100vh;
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  padding: 2.75rem 2rem 5rem;
  transition: background var(--transition);
  z-index: 100;
}

.left-top {
  flex: 1;
}

.site-name {
  display: block;
  font-family: var(--font-sans);
  font-weight: 200;
  font-size: 0.65rem;
  letter-spacing: 0.45em;
  text-transform: uppercase;
  color: var(--left-sub);
  margin-bottom: 2.25rem;
  text-decoration: none;
  transition: color var(--transition);
}
.site-name:hover {
  color: var(--left-text);
}

.left-hero {
  margin-bottom: 2.5rem;
}
.left-hero-text {
  font-family: var(--font-serif-en);
  font-style: italic;
  font-size: 1.15rem;
  font-weight: 400;
  color: var(--left-text);
  line-height: 1.55;
  margin-bottom: 0.5rem;
}
.left-hero-sub {
  font-family: var(--font-sans);
  font-size: 0.68rem;
  font-weight: 300;
  color: var(--left-sub);
  letter-spacing: 0.04em;
  line-height: 1.9;
}

.left-nav {
  list-style: none;
  margin-bottom: 2rem;
}
.left-nav a {
  display: block;
  font-family: var(--font-sans);
  font-size: 0.66rem;
  font-weight: 400;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--left-sub);
  padding: 0.42rem 0;
  border-bottom: 1px solid var(--left-border);
  transition: color var(--transition);
  text-decoration: none;
}
.left-nav a:hover,
.left-nav a.active {
  color: var(--left-text);
}
.left-nav a.active {
  color: var(--left-accent);
}

.left-controls {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-top: auto;
  padding-top: 1.5rem;
  border-top: 1px solid var(--left-border);
}
.left-controls a {
  font-family: var(--font-sans);
  font-size: 0.58rem;
  font-weight: 400;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--left-sub);
  text-decoration: none;
  transition: color var(--transition);
}
.left-controls a:hover {
  color: var(--left-text);
}
.left-controls a.active {
  color: var(--left-accent);
}

.theme-toggle {
  margin-left: auto;
  background: none;
  border: none;
  cursor: pointer;
  width: 1.75rem;
  height: 1.75rem;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0.5;
  transition: opacity var(--transition);
  padding: 0;
  flex-shrink: 0;
  pointer-events: auto;
}
.theme-toggle:hover {
  opacity: 1;
}
.theme-toggle:focus {
  outline: none;
}
.theme-toggle svg {
  width: 1rem;
  height: 1rem;
  stroke: var(--left-text);
  fill: none;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.theme-toggle .icon-sun { display: none; }
.theme-toggle .icon-moon { display: block; }
[data-theme="dark"] .theme-toggle .icon-sun { display: block; }
[data-theme="dark"] .theme-toggle .icon-moon { display: none; }

.left-copyright {
  font-family: var(--font-sans);
  font-size: 0.52rem;
  letter-spacing: 0.1em;
  color: var(--left-sub);
  padding-top: 0.75rem;
  opacity: 0.7;
}

.page-copyright {
  font-family: var(--font-sans);
  font-size: 0.52rem;
  letter-spacing: 0.1em;
  color: var(--text-sub);
  opacity: 0.7;
  padding-top: 0.75rem;
}

.right-panel {
  flex: 1;
  min-width: 0;
  padding: 3.5rem 5vw 5rem calc(5vw + 1rem);
  max-width: 900px;
}

.progress-bar {
  position: fixed;
  top: 0;
  left: var(--left-w);
  width: calc(100% - var(--left-w));
  height: 2px;
  background: var(--border);
  z-index: 200;
  display: none;
}
.progress-bar__fill {
  height: 100%;
  background: var(--accent);
  width: 0%;
  transition: width 0.1s linear;
}
.is-post .progress-bar {
  display: block;
}

.section-header {
  margin-bottom: 2.5rem;
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--border);
}
.section-label {
  font-family: var(--font-sans);
  font-size: 0.58rem;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--text-sub);
}
.section-meta {
  font-family: var(--font-sans);
  font-size: 0.56rem;
  letter-spacing: 0.12em;
  color: var(--text-sub);
  opacity: 0.6;
  margin-top: 0.4rem;
}

.feed-item {
  padding: 2.25rem 0;
  border-bottom: 1px solid var(--border);
  display: grid;
  grid-template-columns: 7rem 1fr;
  gap: 0 2rem;
  align-items: start;
}
.feed-item:first-child {
  padding-top: 0;
}
.feed-item__meta {
  padding-top: 0.25rem;
}
.feed-item__date {
  display: inline-block;
  font-family: var(--font-sans);
  font-size: 0.58rem;
  letter-spacing: 0.1em;
  color: var(--text-sub);
  margin-bottom: 0.4rem;
  margin-right: 0.4em;
}
.feed-item__lang {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-sans);
  font-size: 0.5rem;
  line-height: 1;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent);
}
.feed-item__pair {
  display: block;
  font-family: var(--font-sans);
  font-size: 0.52rem;
  letter-spacing: 0.1em;
  color: var(--text-sub);
  margin-top: 0.5rem;
  text-decoration: none;
  transition: color var(--transition);
}
.feed-item__pair:hover {
  color: var(--accent);
}
.feed-item__title {
  font-family: var(--font-serif-en);
  font-size: 1.08rem;
  font-weight: 400;
  line-height: 1.42;
  margin-bottom: 0.5rem;
}
.feed-item__title.is-jp {
  font-family: var(--font-serif-jp);
  font-size: 1rem;
  font-weight: 400;
}
.feed-item__title a {
  color: var(--text);
  text-decoration: none;
}
.feed-item__title a:hover {
  color: var(--accent);
}
.feed-item__excerpt {
  font-size: 0.82rem;
  font-family: var(--font-sans);
  color: var(--text-sub);
  line-height: 1.8;
}
.feed-item__excerpt.is-jp {
  font-family: var(--font-serif-jp);
  font-size: 0.81rem;
  line-height: 1.95;
}

.post-header {
  margin-bottom: 3rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--border);
}
.post-header__meta {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1.25rem;
}
.post-header__date {
  font-family: var(--font-sans);
  font-size: 0.6rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--text-sub);
}
.post-header__tag {
  font-family: var(--font-sans);
  font-size: 0.55rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--accent);
  text-decoration: none;
}
.post-header__tag:hover {
  color: var(--accent-light);
}
.post-header__title {
  font-family: var(--font-serif-en);
  font-size: clamp(1.5rem, 3vw, 2.1rem);
  font-weight: 400;
  line-height: 1.25;
  letter-spacing: -0.01em;
  color: var(--text);
  margin-bottom: 0.75rem;
}
.post-header__title.is-jp {
  font-family: var(--font-serif-jp);
  font-size: clamp(1.4rem, 2.8vw, 1.95rem);
  line-height: 1.35;
  font-weight: 500;
}
.post-header__author {
  font-family: var(--font-sans);
  font-size: 0.62rem;
  letter-spacing: 0.1em;
  color: var(--text-sub);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.post-header__author a {
  color: var(--text-sub);
  text-decoration: none;
}
.post-header__author a:hover {
  color: var(--accent);
}
.post-header__readtime {
  color: var(--accent);
  opacity: 0.7;
}
.post-header__pair {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  margin-top: 1rem;
  font-family: var(--font-sans);
  font-size: 0.6rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--text-sub);
  text-decoration: none;
  padding: 0.35rem 0.8rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: all var(--transition);
}
.post-header__pair:hover {
  color: var(--accent);
  border-color: var(--accent);
}

.post-header,
.post-body,
.post-nav {
  max-width: 68ch;
}

.post-body {
  font-family: var(--font-serif-en);
  font-size: 1.05rem;
  font-weight: 400;
  line-height: 2.05;
  color: var(--text);
}
.post-body.is-jp {
  font-family: var(--font-serif-jp);
  font-size: 0.97rem;
  line-height: 2.1;
  letter-spacing: 0.02em;
}
.post-body p {
  margin-bottom: 1.7em;
}
.post-body p:last-child {
  margin-bottom: 0;
}
.post-body h2 {
  font-family: var(--font-sans);
  font-size: 0.65rem;
  letter-spacing: 0.25em;
  text-transform: uppercase;
  color: var(--text-sub);
  margin: 3em 0 1.5em;
  padding-bottom: 0.75em;
  border-bottom: 1px solid var(--border);
}
.post-body blockquote {
  font-family: var(--font-serif-en);
  font-size: 1.02rem;
  font-style: italic;
  border-left: 2px solid var(--accent);
  padding-left: 1.5rem;
  margin: 2em 0;
  color: var(--text-sub);
}
.post-body a {
  color: var(--accent);
  text-decoration: underline;
  text-underline-offset: 3px;
}
.post-body img {
  width: 100%;
  height: auto;
  margin: 2em 0;
  border-radius: var(--radius);
}
.post-body hr {
  border: none;
  height: auto;
  text-align: center;
  margin: 2.75em 0;
  overflow: visible;
}
.post-body hr::after {
  content: '· · ·';
  font-size: 0.9rem;
  letter-spacing: 0.65em;
  padding-left: 0.65em;
  color: var(--text-sub);
  font-family: var(--font-serif-en);
  font-style: italic;
}

.post-body:not(.is-jp) p.dropcap-p::first-letter {
  font-family: var(--font-serif-en);
  font-size: 3.9rem;
  font-weight: 600;
  float: left;
  line-height: 0.78;
  margin: 0.08em 0.12em 0 0;
  color: var(--text);
  padding-top: 0.05em;
}

.post-nav {
  margin-top: 4rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}
.post-nav__item {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  text-decoration: none;
  padding: 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: border-color var(--transition);
}
.post-nav__item:hover {
  border-color: var(--accent);
}
.post-nav__item--next {
  text-align: right;
}
.post-nav__dir {
  font-family: var(--font-sans);
  font-size: 0.52rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--text-sub);
}
.post-nav__title {
  font-size: 0.88rem;
  color: var(--text);
  line-height: 1.4;
}
.post-nav__title.is-jp {
  font-family: var(--font-serif-jp);
}

.about-body {
  font-family: var(--font-sans);
  font-size: 0.95rem;
  line-height: 1.95;
  color: var(--text);
  max-width: var(--content-max);
}
.about-block {
  margin-bottom: 2.5rem;
  padding-bottom: 2.5rem;
  border-bottom: 1px solid var(--border);
}
.about-block:last-child {
  border-bottom: none;
  margin-bottom: 0;
  padding-bottom: 0;
}
.about-block--lead p,
.about-block p {
  font-family: var(--font-serif-jp);
  font-size: 0.97rem;
  line-height: 2.1;
  letter-spacing: 0.02em;
  margin-bottom: 0;
}
.about-block--lead p:lang(en),
.about-block p:lang(en) {
  font-family: var(--font-serif-en);
  font-size: 1.05rem;
  line-height: 2.05;
  letter-spacing: 0;
}
.about-section-label {
  font-family: var(--font-sans);
  font-size: 0.55rem;
  font-weight: 500;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--text-sub);
  margin-top: 1.75rem;
  margin-bottom: 0.5rem;
}
.about-block .about-section-label:first-child {
  margin-top: 0;
}
.about-author-line {
  font-size: 0.88rem;
  line-height: 2.0;
  color: var(--text);
}
.about-author-line small {
  font-size: 0.78rem;
  color: var(--text-sub);
  font-style: normal;
}
.about-author-line a {
  color: var(--text);
  text-decoration: none;
  border-bottom: 1px solid var(--border);
  transition: border-color var(--transition), color var(--transition);
}
.about-author-line a:hover {
  color: var(--accent);
  border-color: var(--accent);
}
.about-body strong {
  font-weight: 500;
  color: var(--text);
}

.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 2.5rem;
  height: 2.5rem;
  background: rgba(44, 42, 38, 0.75);
  color: #fff;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-sans);
  font-size: 0.8rem;
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition), visibility var(--transition), background var(--transition);
  z-index: 300;
  pointer-events: auto;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.18);
}
.back-to-top.is-visible {
  opacity: 1;
  visibility: visible;
}
.back-to-top:hover {
  background: rgba(44, 42, 38, 0.95);
}
[data-theme="dark"] .back-to-top { background: rgba(210, 214, 222, 0.12); }
[data-theme="dark"] .back-to-top:hover { background: rgba(210, 214, 222, 0.22); }

details.left-verified {
  margin: 0;
  padding: 0;
}
details.left-verified > summary {
  list-style: none;
  display: flex;
  align-items: center;
  gap: 0.42em;
  cursor: pointer;
  font-family: var(--font-sans);
  font-size: 0.52rem;
  letter-spacing: 0.1em;
  color: var(--left-sub);
  padding-top: 0.75rem;
  opacity: 0.7;
  transition: opacity 0.2s;
  -webkit-user-select: none;
  user-select: none;
}
details.left-verified > summary::-webkit-details-marker { display: none; }
details.left-verified > summary::marker { display: none; }
details.left-verified > summary:hover { opacity: 1; }
details.left-verified[open] > summary { opacity: 1; }
details.left-verified > summary .ots-icon {
  width: 0.82rem;
  height: 0.82rem;
  stroke: var(--left-sub);
  fill: none;
  stroke-width: 1.5;
  stroke-linecap: round;
  stroke-linejoin: round;
  flex-shrink: 0;
  pointer-events: none;
}
.ots-detail {
  font-family: var(--font-sans);
  font-size: 0.5rem;
  letter-spacing: 0.04em;
  line-height: 1.9;
  color: var(--left-sub);
  padding: 0.6rem 0 0 1.22rem;
  opacity: 0.82;
}
.ots-detail a {
  color: var(--left-accent);
  text-decoration: none;
  display: inline-block;
  margin-top: 0.45em;
  opacity: 0.75;
  transition: opacity 0.2s;
}
.ots-detail a:hover {
  opacity: 1;
}

.page-verified {
  font-family: var(--font-sans);
  font-size: 0.52rem;
  letter-spacing: 0.1em;
  color: var(--text-sub);
  opacity: 0.7;
  margin-top: 2.5rem;
  padding-top: 0.75rem;
}

.lang-filter {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  margin-bottom: 2.25rem;
}
.lang-btn {
  background: none;
  border: 0.5px solid var(--border);
  border-radius: 2px;
  padding: 0.3rem 0.8rem;
  font-family: var(--font-sans);
  font-size: 0.55rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--text-sub);
  cursor: pointer;
  transition: color 0.2s, border-color 0.2s;
  line-height: 1;
  outline: none;
  -webkit-user-select: none;
  user-select: none;
}
.lang-btn:hover {
  color: var(--text);
  border-color: var(--text-sub);
}
.lang-btn.active {
  color: var(--accent);
  border-color: var(--accent);
}

.menu-toggle { display: none; }
.menu-icon-close { display: none; }

@media (max-width: 860px) {
  :root { --left-w: 100%; }

  .layout {
    flex-direction: column;
  }

  .left-panel {
    width: 100%;
    height: auto;
    min-height: auto;
    padding: 1.1rem 1.5rem 0.9rem;
    flex-direction: row;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.75rem;
    background: var(--left-bg);
  }

  .left-top { display: contents; }
  .left-hero { display: none; }

  .site-name {
    margin-bottom: 0;
    font-size: 0.7rem;
  }

  .left-nav {
    display: none;
    width: 100%;
    margin-bottom: 0;
  }
  .left-nav.is-open {
    display: block;
  }

  .left-controls {
    margin-top: 0;
    padding-top: 0;
    border-top: none;
  }

  .menu-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.35rem;
    color: var(--left-text);
    transition: color var(--transition), opacity var(--transition);
    pointer-events: auto;
    flex-shrink: 0;
  }
  .menu-toggle:hover { opacity: 0.75; }

  .menu-icon,
  .menu-icon-close {
    width: 20px;
    height: 20px;
    display: block;
    transition: opacity 0.2s ease, transform 0.2s ease;
  }
  .menu-icon-close { display: none; }
  .menu-toggle.is-active .menu-icon { display: none; }
  .menu-toggle.is-active .menu-icon-close { display: block; }

  .left-copyright { display: none; }

  .right-panel { padding: 2rem 1.5rem 4rem; }

  .progress-bar { left: 0; width: 100%; }

  .feed-item {
    grid-template-columns: 1fr;
    gap: 0.5rem;
  }
  .feed-item__meta {
    display: flex;
    flex-direction: row;
    align-items: center;
    gap: 0.5rem;
    padding-top: 0;
    flex-wrap: nowrap;
  }
  .feed-item__date {
    margin-bottom: 0;
    line-height: 1;
  }
  .feed-item__lang {
    display: inline-flex;
    align-items: center;
    line-height: 1;
    padding: 0.11rem 0.32rem;
    margin-top: 0;
    flex-shrink: 0;
  }
  .feed-item__pair { display: none; }

  .post-nav { grid-template-columns: 1fr; }
  .post-nav__item--next { text-align: left; }

  .back-to-top {
    bottom: 1.25rem;
    right: 1.25rem;
  }
}

@media (max-width: 860px) and (orientation: portrait) {
  .left-panel {
    position: sticky;
    top: 0;
    z-index: 200;
  }
  .section-header {
    position: sticky;
    top: var(--header-h, 56px);
    z-index: 190;
    background: var(--bg);
    padding-top: 0.85rem;
    padding-bottom: 0.85rem;
    margin-bottom: 1.5rem;
    border-bottom: 1px solid var(--border);
  }
  .progress-bar {
    top: 0;
    z-index: 300;
  }
  html {
    scroll-padding-top: calc(var(--header-h, 56px) + 3rem);
  }
}