/* ============================================
   AI Ready SG — Editorial Research Journal
   ============================================ */

:root {
  --bg: #faf9f6;
  --bg-subtle: #f3f1ec;
  --fg: #18181b;
  --fg-secondary: #52525b;
  --fg-muted: #a1a1aa;
  --accent: #e63721;
  --accent-hover: #c7301c;
  --border: #e4e2dd;
  --tag-bg: #eae8e3;
  --tag-fg: #52525b;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111113;
    --bg-subtle: #1a1a1f;
    --fg: #e8e6e1;
    --fg-secondary: #a1a09b;
    --fg-muted: #6b6a66;
    --accent: #ff6b54;
    --accent-hover: #ff8872;
    --border: #2a2a2f;
    --tag-bg: #25252a;
    --tag-fg: #a1a09b;
  }
}

/* --- Reset & Base --- */

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

html {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

body {
  font-family: "Microsoft YaHei", "微软雅黑", "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", "Source Han Sans SC", system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.8;
  color: var(--fg);
  background: var(--bg);
  max-width: 1250px;
  margin: 0 auto;
  padding: 3rem 1.5rem;
}

/* --- Typography --- */

h1, h2, h3, h4 {
  font-family: "Microsoft YaHei", "微软雅黑", "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", "Source Han Sans SC", system-ui, sans-serif;
  font-weight: 700;
  letter-spacing: -0.01em;
  line-height: 1.3;
}

/* --- Links --- */

a {
  color: var(--fg);
  text-decoration: none;
  transition: color 0.15s ease;
}

a:hover {
  color: var(--accent);
}

/* --- Header --- */

header {
  margin-bottom: 3.5rem;
}

header nav {
  display: flex;
  align-items: baseline;
  gap: 1.5rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border);
}

.site-name {
  font-family: "Microsoft YaHei", "微软雅黑", "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", system-ui, sans-serif;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--fg);
  margin-right: auto;
  letter-spacing: -0.02em;
}

.site-name:visited {
  color: var(--fg);
}

.site-name:hover {
  color: var(--accent);
}

header nav a:not(.site-name) {
  font-size: 0.85rem;
  color: var(--fg-muted);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

header nav a:not(.site-name):hover {
  color: var(--fg);
}

/* --- Hero (Index) --- */

.hero {
  margin-bottom: 3.5rem;
}

.hero h1 {
  font-size: 2.8rem;
  line-height: 1.15;
  margin-bottom: 0.75rem;
  letter-spacing: -0.03em;
}

.hero .tagline {
  font-size: 1.05rem;
  color: var(--fg-secondary);
  line-height: 1.6;
}

/* --- Post List (Index) --- */

.post-list {
  list-style: none;
}

.post-list li {
  padding: 2rem 0;
}

.post-list li + li {
  border-top: 1px solid var(--border);
}

.post-list h2 {
  font-size: 1.45rem;
  margin-bottom: 0.4rem;
  line-height: 1.35;
}

.post-list h2 a {
  color: var(--fg);
}

.post-list h2 a:hover {
  color: var(--accent);
}

.post-list .meta {
  font-family: "IBM Plex Mono", "Consolas", "Courier New", monospace;
  font-size: 0.8rem;
  color: var(--fg-muted);
  letter-spacing: 0.02em;
  margin-bottom: 0.5rem;
}

.post-list .tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-bottom: 0.6rem;
}

.post-list .tags span {
  font-family: "IBM Plex Mono", "Consolas", "Courier New", monospace;
  font-size: 0.72rem;
  color: var(--tag-fg);
  background: var(--tag-bg);
  padding: 0.15rem 0.55rem;
  border-radius: 3px;
  letter-spacing: 0.01em;
}

.post-list .excerpt {
  color: var(--fg-secondary);
  font-size: 0.92rem;
  line-height: 1.65;
}

/* --- Post Page --- */

.post-header {
  margin-bottom: 2.5rem;
}

.post-header h1 {
  font-size: 2.2rem;
  line-height: 1.2;
  margin-bottom: 0.75rem;
  letter-spacing: -0.02em;
}

.post-header .meta {
  font-family: "IBM Plex Mono", "Consolas", "Courier New", monospace;
  font-size: 0.82rem;
  color: var(--fg-muted);
  letter-spacing: 0.02em;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--border);
}

/* --- Markdown Body Overrides --- */

.markdown-body {
  --fontStack-sansSerif: "Microsoft YaHei", "微软雅黑", "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", "Source Han Sans SC", system-ui, sans-serif;
  font-family: "Microsoft YaHei", "微软雅黑", "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", "Source Han Sans SC", system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.8;
  color: var(--fg);
  background: transparent;
}

.markdown-body h1,
.markdown-body h2,
.markdown-body h3,
.markdown-body h4 {
  font-family: "Microsoft YaHei", "微软雅黑", "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", "Source Han Sans SC", system-ui, sans-serif !important;
  font-weight: 700 !important;
  letter-spacing: -0.01em;
  color: var(--fg);
  border-bottom: none;
  padding-bottom: 0;
}

.markdown-body h2 {
  margin-top: 2rem;
  padding-bottom: 0.3rem;
  border-bottom: 1px solid var(--border);
}

.markdown-body a {
  color: var(--accent);
}

.markdown-body a:hover {
  text-decoration: underline;
}

.markdown-body blockquote {
  border-left-color: var(--accent);
  color: var(--fg-secondary);
}

.markdown-body table {
  display: table;
  width: 100%;
  overflow: auto;
}

.markdown-body table th,
.markdown-body table td {
  font-size: 0.85rem;
}

.markdown-body hr {
  background-color: var(--border);
}

.markdown-body code,
.markdown-body pre {
  font-family: "IBM Plex Mono", "Consolas", "Liberation Mono", "Courier New", monospace;
}

/* Dark mode overrides for github-markdown */
@media (prefers-color-scheme: dark) {
  .markdown-body {
    color-scheme: dark;
    --color-fg-default: var(--fg);
    --color-canvas-default: transparent;
    --color-canvas-subtle: var(--bg-subtle);
    --color-border-default: var(--border);
    --color-border-muted: var(--border);
    --color-accent-fg: var(--accent);
  }
}

@media (prefers-color-scheme: light) {
  .markdown-body {
    color-scheme: light;
    --color-fg-default: var(--fg);
    --color-canvas-default: transparent;
    --color-canvas-subtle: var(--bg-subtle);
    --color-border-default: var(--border);
    --color-border-muted: var(--border);
    --color-accent-fg: var(--accent);
  }
}

/* --- Footer --- */

footer {
  margin-top: 4rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  color: var(--fg-muted);
  font-size: 0.8rem;
  font-family: "IBM Plex Mono", "Consolas", "Courier New", monospace;
  letter-spacing: 0.02em;
}

/* --- Responsive --- */

@media (max-width: 768px) {
  body {
    padding: 1.5rem 1rem;
    font-size: 15px;
  }

  header {
    margin-bottom: 2rem;
  }

  header nav {
    padding-bottom: 1rem;
  }

  .site-name {
    font-size: 1.25rem;
  }

  .hero {
    margin-bottom: 2rem;
  }

  .hero h1 {
    font-size: 1.8rem;
  }

  .hero .tagline {
    font-size: 0.95rem;
  }

  .post-header {
    margin-bottom: 1.5rem;
  }

  .post-header h1 {
    font-size: 1.5rem;
  }

  .post-header .meta {
    padding-bottom: 1.25rem;
  }

  .post-list li {
    padding: 1.25rem 0;
  }

  .post-list h2 {
    font-size: 1.15rem;
  }

  .post-list .excerpt {
    font-size: 0.85rem;
  }

  .markdown-body {
    font-size: 15px;
  }

  .markdown-body table {
    font-size: 0.8rem;
  }

  .markdown-body h2 {
    font-size: 1.3rem;
  }

  .markdown-body h3 {
    font-size: 1.1rem;
  }

  footer {
    margin-top: 2.5rem;
  }
}

@media (max-width: 480px) {
  body {
    padding: 1rem 0.75rem;
    font-size: 14px;
  }

  .hero h1 {
    font-size: 1.5rem;
  }

  .post-header h1 {
    font-size: 1.3rem;
  }

  .post-list h2 {
    font-size: 1.05rem;
  }

  .post-list .tags {
    gap: 0.3rem;
  }

  .post-list .tags span {
    font-size: 0.65rem;
  }

  .markdown-body {
    font-size: 14px;
    overflow-wrap: break-word;
    word-break: break-word;
  }
}