/* === Reset & Base === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial,
    "Hiragino Kaku Gothic ProN", "Hiragino Sans", Meiryo, sans-serif;
  --font-mono: "SF Mono", "Fira Code", "Fira Mono", Menlo, Consolas,
    "Courier New", monospace;
  --measure: 42rem;
  --measure-wide: 54rem;
}

/* Light theme */
[data-theme="light"] {
  --bg: #fafafa;
  --bg-code: #f0f0f0;
  --fg: #2c2c2c;
  --fg-muted: #6b6b6b;
  --fg-link: #1a5a9e;
  --border: #ddd;
}

/* Dark theme */
[data-theme="dark"] {
  --bg: #1a1a1a;
  --bg-code: #252525;
  --fg: #d8d8d8;
  --fg-muted: #909090;
  --fg-link: #6bb3e0;
  --border: #383838;
}

html {
  font-size: 17px;
  line-height: 1.7;
  color: var(--fg);
  background: var(--bg);
  font-family: var(--font-sans);
  -webkit-font-smoothing: antialiased;
}

/* CJK text: slightly smaller font and larger line-height for post body */
:lang(ja) .post-body, :lang(zh) .post-body, :lang(ko) .post-body {
  font-size: 0.92em;
  line-height: 1.9;
}

body {
  max-width: var(--measure-wide);
  margin: 0 auto;
  padding: 2rem 1.5rem;
}

article {
  max-width: var(--measure);
  margin-left: auto;
  margin-right: auto;
}

.post-body {
  text-align: justify;
  hyphens: auto;
}

/* === Typography === */
h1, h2, h3, h4 {
  line-height: 1.3;
  margin-top: 2rem;
  margin-bottom: 0.5rem;
  font-weight: 600;
}

h1 { font-size: 1.6rem; }
h2 { font-size: 1.3rem; }
h3 { font-size: 1.1rem; }

p, ul, ol, blockquote, pre, table {
  margin-bottom: 1.2rem;
}

ul, ol {
  padding-left: 1.5rem;
}

a {
  color: var(--fg-link);
  text-decoration: none;
}
a:hover { text-decoration: underline; }

blockquote {
  border-left: 3px solid var(--border);
  padding-left: 1rem;
  color: var(--fg-muted);
  font-style: normal;
}

code {
  font-family: var(--font-mono);
  font-size: 0.88em;
  background: var(--bg-code);
  padding: 0.15em 0.35em;
  border-radius: 3px;
}

pre {
  background: var(--bg-code);
  padding: 1rem;
  border-radius: 4px;
  border: 1px solid var(--border);
  overflow-x: auto;
}

pre code {
  background: none;
  padding: 0;
  font-size: 0.82em;
}

img {
  max-width: 100%;
  height: auto;
  border-radius: 4px;
}

.post-body img {
  max-width: 75%;
  cursor: zoom-in;
  transition: opacity 0.2s;
  display: block;
  margin-left: auto;
  margin-right: auto;
}
.post-body img:hover {
  opacity: 0.85;
}

.img-modal-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.8);
  z-index: 1000;
  cursor: zoom-out;
  justify-content: center;
  align-items: center;
}
.img-modal-overlay.active {
  display: flex;
}
.img-modal-overlay img {
  max-width: 90vw;
  max-height: 90vh;
  border-radius: 4px;
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.5);
}

table {
  width: 100%;
  border-collapse: collapse;
}
th, td {
  padding: 0.5rem;
  border-bottom: 1px solid var(--border);
  text-align: left;
}
th { font-weight: 600; }

hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 2rem 0;
}

/* === Layout === */
header {
  margin-bottom: 3rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border);
}

nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.site-title {
  font-weight: 600;
  font-size: 1.1rem;
  color: var(--fg);
}
.site-title:hover { text-decoration: none; }

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.2rem;
  font-size: 0.9rem;
}
.nav-links a { color: var(--fg-muted); }
.nav-links a:hover { color: var(--fg); }

.nav-group {
  display: flex;
  gap: 1.2rem;
}
.nav-group + .nav-group {
  padding-left: 1.2rem;
  border-left: 1px solid var(--border);
}

#theme-toggle {
  background: none;
  border: none;
  color: var(--fg-muted);
  cursor: pointer;
  font-size: 1.1rem;
  padding: 0;
}

.post-nav {
  display: flex;
  justify-content: space-between;
  margin-top: 3rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
  font-size: 0.85rem;
}
.post-nav-prev, .post-nav-next {
  max-width: 45%;
}
.post-nav-next {
  margin-left: auto;
  text-align: right;
}

footer {
  margin-top: 4rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
  color: var(--fg-muted);
  font-size: 0.85rem;
}

footer .license {
  font-size: 0.78rem;
  margin-top: 0.2rem;
}

main > h1:first-child { margin-top: 0; }

/* === Table of Contents === */
.toc {
  margin-bottom: 2rem;
  padding: 1rem 1.2rem;
  border: 1px solid var(--border);
  border-radius: 4px;
  font-size: 0.9rem;
}

.toc summary {
  font-weight: 600;
  cursor: pointer;
  color: var(--fg-muted);
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.toc ol {
  margin-top: 0.6rem;
  margin-bottom: 0;
  padding-left: 1.2rem;
}

.toc li {
  margin-bottom: 0.25rem;
}

.toc a {
  color: var(--fg-muted);
}
.toc a:hover {
  color: var(--fg);
}

/* === Projects === */
.projects h2 {
  margin-top: 0;
}

.project-list {
  list-style: none;
  padding: 0;
}

.project-list li {
  margin-bottom: 0;
}

.project-list li:nth-child(odd) .project-item {
  background: var(--bg-code);
}

.project-list li:nth-child(even) .project-item {
  background: var(--bg);
}

.project-item {
  display: flex;
  flex-direction: column;
  padding: 1rem;
  border-radius: 4px;
  color: var(--fg);
  text-decoration: none;
}
.project-item:hover {
  text-decoration: none;
}
.project-item:hover .project-name {
  color: var(--fg-link);
}

.project-item img {
  width: auto;
  max-width: 100%;
  object-fit: contain;
  align-self: flex-start;
  border-radius: 0;
  margin-bottom: 0.3rem;
}

.project-text {
  font-size: 0.88rem;
  color: var(--fg-muted);
}

.project-name {
  font-weight: 600;
  color: var(--fg);
}

.projects-more {
  font-size: 0.85rem;
  margin-top: 0.5rem;
}

/* === Search === */
#search-input {
  width: 100%;
  padding: 0.6rem 0.8rem;
  font-size: 1rem;
  font-family: var(--font-sans);
  color: var(--fg);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 4px;
  margin-bottom: 1.5rem;
}
#search-input:focus {
  outline: none;
  border-color: var(--fg-muted);
}
.search-hint {
  font-size: 0.82rem;
  color: var(--fg-muted);
  margin-top: -1rem;
  margin-bottom: 1.5rem;
}

/* === Post list === */
.post-list {
  list-style: none;
  padding: 0;
}

.post-list li {
  margin-bottom: 1rem;
  display: flex;
  gap: 1rem;
  align-items: baseline;
  flex-wrap: wrap;
}

.post-list time {
  color: var(--fg-muted);
  font-size: 0.85rem;
  white-space: nowrap;
  min-width: 6rem;
}

.index-tags {
  margin-left: auto;
  display: none;
}

.index-tag {
  font-size: 0.72rem;
  color: var(--fg-muted);
  background: var(--bg-code);
  border: 1px solid var(--border);
  padding: 0.15rem 0.4rem;
  border-radius: 3px;
  text-decoration: none;
  margin-left: 0.3rem;
}
.index-tag:hover {
  color: var(--fg);
  text-decoration: none;
}

@media (min-width: 700px) {
  .index-tags {
    display: inline;
  }
}

/* === Post === */
.meta {
  color: var(--fg-muted);
  font-size: 0.9rem;
  margin-bottom: 1rem;
}
.meta .updated {
  margin-left: 0.5em;
  font-size: 0.85rem;
}

.lang-nav {
  display: inline-flex;
  gap: 0;
  font-size: 0.75rem;
  margin-bottom: 1.5rem;
  border: 1px solid var(--border);
  border-radius: 3px;
  overflow: hidden;
}
.lang-nav a,
.lang-nav .lang-current {
  padding: 0.2rem 0.5rem;
  color: var(--fg-muted);
  text-decoration: none;
  border-right: 1px solid var(--border);
}
.lang-nav a:last-child,
.lang-nav .lang-current:last-child {
  border-right: none;
}
.lang-nav a:hover {
  background: var(--bg-code);
  color: var(--fg);
}
.lang-current {
  font-weight: 600;
  color: var(--fg);
  background: var(--bg-code);
}

.ai-notice {
  font-size: 0.82rem;
  color: var(--fg-muted);
  background: var(--bg-code);
  padding: 0.5rem 0.8rem;
  border-radius: 4px;
  margin-bottom: 1.5rem;
}

.tags { margin-left: 1rem; }
.tags a {
  font-size: 0.78rem;
  margin-right: 0.3rem;
  padding: 0.1rem 0.5rem;
  border-radius: 9999px;
  text-decoration: none;
  color: var(--fg-muted);
  background: var(--bg-code);
  border: 1px solid var(--border);
}
.tags a:hover { border-color: var(--fg-muted); text-decoration: none; }
.tags a::before { content: "#"; }

/* Tag colors (light) */
[data-theme="light"] :is(.tags a, .index-tag, .tag-cloud a)[href*="/software/"] { background: #e8f4fd; border-color: #c4dff0; }
[data-theme="light"] :is(.tags a, .index-tag, .tag-cloud a)[href*="/ai/"] { background: #fce4ec; border-color: #f0c4d0; }
[data-theme="light"] :is(.tags a, .index-tag, .tag-cloud a)[href*="/linguistics/"] { background: #e8f5e9; border-color: #c8e6c9; }
[data-theme="light"] :is(.tags a, .index-tag, .tag-cloud a)[href*="/nlp/"] { background: #fff3e0; border-color: #ffe0b2; }
[data-theme="light"] :is(.tags a, .index-tag, .tag-cloud a)[href*="/education/"] { background: #f3e5f5; border-color: #e1bee7; }
[data-theme="light"] :is(.tags a, .index-tag, .tag-cloud a)[href*="/music/"] { background: #fce4ec; border-color: #f8bbd0; }
[data-theme="light"] :is(.tags a, .index-tag, .tag-cloud a)[href*="/guitar/"] { background: #fce4ec; border-color: #f8bbd0; }
[data-theme="light"] :is(.tags a, .index-tag, .tag-cloud a)[href*="/research/"] { background: #e0f2f1; border-color: #b2dfdb; }
[data-theme="light"] :is(.tags a, .index-tag, .tag-cloud a)[href*="/books/"] { background: #fff8e1; border-color: #ffecb3; }
[data-theme="light"] :is(.tags a, .index-tag, .tag-cloud a)[href*="/meta/"] { background: #f5f5f5; border-color: #e0e0e0; }

/* Tag colors (dark) */
[data-theme="dark"] :is(.tags a, .index-tag, .tag-cloud a)[href*="/software/"] { background: #1a2a3a; border-color: #2a3a4a; }
[data-theme="dark"] :is(.tags a, .index-tag, .tag-cloud a)[href*="/ai/"] { background: #3a1a2a; border-color: #4a2a3a; }
[data-theme="dark"] :is(.tags a, .index-tag, .tag-cloud a)[href*="/linguistics/"] { background: #1a3a1a; border-color: #2a4a2a; }
[data-theme="dark"] :is(.tags a, .index-tag, .tag-cloud a)[href*="/nlp/"] { background: #3a2a1a; border-color: #4a3a2a; }
[data-theme="dark"] :is(.tags a, .index-tag, .tag-cloud a)[href*="/education/"] { background: #2a1a3a; border-color: #3a2a4a; }
[data-theme="dark"] :is(.tags a, .index-tag, .tag-cloud a)[href*="/music/"], [data-theme="dark"] :is(.tags a, .index-tag, .tag-cloud a)[href*="/guitar/"] { background: #3a1a2a; border-color: #4a2a3a; }
[data-theme="dark"] :is(.tags a, .index-tag, .tag-cloud a)[href*="/research/"] { background: #1a3a3a; border-color: #2a4a4a; }
[data-theme="dark"] :is(.tags a, .index-tag, .tag-cloud a)[href*="/books/"] { background: #3a3a1a; border-color: #4a4a2a; }
[data-theme="dark"] :is(.tags a, .index-tag, .tag-cloud a)[href*="/meta/"] { background: #2a2a2a; border-color: #3a3a3a; }

.post-body h2:first-child { margin-top: 1.5rem; }

/* === Tag cloud === */
.tag-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  list-style: none;
  padding: 0;
}

.tag-cloud a {
  display: inline-block;
  padding: 0.2rem 0.6rem;
  border: 1px solid var(--border);
  border-radius: 9999px;
  font-size: 0.9rem;
  color: var(--fg-muted);
  background: var(--bg-code);
  text-decoration: none;
}
.tag-cloud a:hover { border-color: var(--fg-muted); text-decoration: none; }
.tag-cloud a:hover {
  color: var(--fg);
  border-color: var(--fg-muted);
  text-decoration: none;
}

/* === Responsive === */
@media (max-width: 600px) {
  html { font-size: 16px; }
  body { padding: 1rem 1.2rem; }
  .nav-links { gap: 0.8rem; }
  .nav-group { gap: 0.8rem; }
  .nav-group + .nav-group { padding-left: 0.8rem; }
  .post-list li { flex-direction: column; gap: 0.1rem; }
  .post-list time { min-width: auto; }
}

/* === YouTube embed === */
.video-container {
  position: relative;
  padding-bottom: 56.25%;
  height: 0;
  overflow: hidden;
  margin-bottom: 1.2rem;
}
.video-container iframe {
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 100%;
  border: 0;
}

/* === Syntax Highlighting (Rouge) === */
.highlight { border-radius: 4px; padding: 1rem; overflow-x: auto; margin-bottom: 1.2rem; border: 1px solid var(--border); }
.highlight pre { margin: 0; border: none; padding: 0; background: none; }
.highlight code { background: none; padding: 0; font-size: 0.82em; }
.highlight table td { padding: 5px; }
.highlight table pre { margin: 0; }
.highlight, .highlight .w {
  color: #24292f;
  background-color: #f6f8fa;
}
.highlight .k, .highlight .kd, .highlight .kn, .highlight .kp, .highlight .kr, .highlight .kt, .highlight .kv {
  color: #cf222e;
}
.highlight .gr {
  color: #f6f8fa;
}
.highlight .gd {
  color: #82071e;
  background-color: #ffebe9;
}
.highlight .nb {
  color: #953800;
}
.highlight .nc {
  color: #953800;
}
.highlight .no {
  color: #953800;
}
.highlight .nn {
  color: #953800;
}
.highlight .sr {
  color: #116329;
}
.highlight .na {
  color: #116329;
}
.highlight .nt {
  color: #116329;
}
.highlight .gi {
  color: #116329;
  background-color: #dafbe1;
}
.highlight .ges {
  font-weight: bold;
  font-style: italic;
}
.highlight .kc {
  color: #0550ae;
}
.highlight .l, .highlight .ld, .highlight .m, .highlight .mb, .highlight .mf, .highlight .mh, .highlight .mi, .highlight .il, .highlight .mo, .highlight .mx {
  color: #0550ae;
}
.highlight .sb {
  color: #0550ae;
}
.highlight .bp {
  color: #0550ae;
}
.highlight .ne {
  color: #0550ae;
}
.highlight .nl {
  color: #0550ae;
}
.highlight .py {
  color: #0550ae;
}
.highlight .nv, .highlight .vc, .highlight .vg, .highlight .vi, .highlight .vm {
  color: #0550ae;
}
.highlight .o, .highlight .ow {
  color: #0550ae;
}
.highlight .gh {
  color: #0550ae;
  font-weight: bold;
}
.highlight .gu {
  color: #0550ae;
  font-weight: bold;
}
.highlight .s, .highlight .sa, .highlight .sc, .highlight .dl, .highlight .sd, .highlight .s2, .highlight .se, .highlight .sh, .highlight .sx, .highlight .s1, .highlight .ss {
  color: #0a3069;
}
.highlight .nd {
  color: #8250df;
}
.highlight .nf, .highlight .fm {
  color: #8250df;
}
.highlight .err {
  color: #f6f8fa;
  background-color: #82071e;
}
.highlight .c, .highlight .ch, .highlight .cd, .highlight .cm, .highlight .cp, .highlight .cpf, .highlight .c1, .highlight .cs {
  color: #6e7781;
}
.highlight .gl {
  color: #6e7781;
}
.highlight .gt {
  color: #6e7781;
}
.highlight .ni {
  color: #24292f;
}
.highlight .si {
  color: #24292f;
}
.highlight .ge {
  color: #24292f;
  font-style: italic;
}
.highlight .gs {
  color: #24292f;
  font-weight: bold;
}
[data-theme="dark"] .highlight table td { padding: 5px; }
[data-theme="dark"] .highlight table pre { margin: 0; }
[data-theme="dark"] .highlight, [data-theme="dark"] .highlight .w {
  color: #fbf1c7;
  background-color: #282828;
}
[data-theme="dark"] .highlight .err {
  color: #fb4934;
  background-color: #282828;
  font-weight: bold;
}
[data-theme="dark"] .highlight .c, [data-theme="dark"] .highlight .ch, [data-theme="dark"] .highlight .cd, [data-theme="dark"] .highlight .cm, [data-theme="dark"] .highlight .cpf, [data-theme="dark"] .highlight .c1, [data-theme="dark"] .highlight .cs {
  color: #928374;
  font-style: italic;
}
[data-theme="dark"] .highlight .cp {
  color: #8ec07c;
}
[data-theme="dark"] .highlight .nt {
  color: #fb4934;
}
[data-theme="dark"] .highlight .o, [data-theme="dark"] .highlight .ow {
  color: #fbf1c7;
}
[data-theme="dark"] .highlight .p, [data-theme="dark"] .highlight .pi {
  color: #fbf1c7;
}
[data-theme="dark"] .highlight .gi {
  color: #b8bb26;
  background-color: #282828;
}
[data-theme="dark"] .highlight .gd {
  color: #fb4934;
  background-color: #282828;
}
[data-theme="dark"] .highlight .gh {
  color: #b8bb26;
  font-weight: bold;
}
[data-theme="dark"] .highlight .ge {
  font-style: italic;
}
[data-theme="dark"] .highlight .ges {
  font-weight: bold;
  font-style: italic;
}
[data-theme="dark"] .highlight .gs {
  font-weight: bold;
}
[data-theme="dark"] .highlight .k, [data-theme="dark"] .highlight .kn, [data-theme="dark"] .highlight .kp, [data-theme="dark"] .highlight .kr, [data-theme="dark"] .highlight .kv {
  color: #fb4934;
}
[data-theme="dark"] .highlight .kc {
  color: #d3869b;
}
[data-theme="dark"] .highlight .kt {
  color: #fabd2f;
}
[data-theme="dark"] .highlight .kd {
  color: #fe8019;
}
[data-theme="dark"] .highlight .s, [data-theme="dark"] .highlight .sb, [data-theme="dark"] .highlight .sc, [data-theme="dark"] .highlight .dl, [data-theme="dark"] .highlight .sd, [data-theme="dark"] .highlight .s2, [data-theme="dark"] .highlight .sh, [data-theme="dark"] .highlight .sx, [data-theme="dark"] .highlight .s1 {
  color: #b8bb26;
  font-style: italic;
}
[data-theme="dark"] .highlight .si {
  color: #b8bb26;
  font-style: italic;
}
[data-theme="dark"] .highlight .sr {
  color: #b8bb26;
  font-style: italic;
}
[data-theme="dark"] .highlight .sa {
  color: #fb4934;
}
[data-theme="dark"] .highlight .se {
  color: #fe8019;
}
[data-theme="dark"] .highlight .nn {
  color: #8ec07c;
}
[data-theme="dark"] .highlight .nc {
  color: #8ec07c;
}
[data-theme="dark"] .highlight .no {
  color: #d3869b;
}
[data-theme="dark"] .highlight .na {
  color: #b8bb26;
}
[data-theme="dark"] .highlight .m, [data-theme="dark"] .highlight .mb, [data-theme="dark"] .highlight .mf, [data-theme="dark"] .highlight .mh, [data-theme="dark"] .highlight .mi, [data-theme="dark"] .highlight .il, [data-theme="dark"] .highlight .mo, [data-theme="dark"] .highlight .mx {
  color: #d3869b;
}
[data-theme="dark"] .highlight .ss {
  color: #83a598;
}