:root {
  --bg: #ffffff;
  --bg-soft: #f6f7f9;
  --fg: #1a1d21;
  --fg-soft: #5c6570;
  --line: #e6e8eb;
  --accent: #2563eb;
  --code-bg: #f2f4f7;
  --radius: 10px;
  --max: 44rem;
}

[data-theme='dark'] {
  --bg: #16181c;
  --bg-soft: #1d2026;
  --fg: #e7e9ec;
  --fg-soft: #9aa3ad;
  --line: #2c3138;
  --accent: #7ea6ff;
  --code-bg: #22262d;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme='light']) {
    --bg: #16181c;
    --bg-soft: #1d2026;
    --fg: #e7e9ec;
    --fg-soft: #9aa3ad;
    --line: #2c3138;
    --accent: #7ea6ff;
    --code-bg: #22262d;
  }
}

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB',
    'Microsoft YaHei', 'Noto Sans SC', sans-serif;
  font-size: 16.5px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

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

a:hover {
  text-decoration: underline;
}

.site-header,
main,
.site-footer {
  width: 100%;
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 1.25rem;
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding-top: 1.5rem;
  padding-bottom: 1.5rem;
  flex-wrap: wrap;
}

.brand {
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--fg);
  letter-spacing: -0.01em;
}

.site-header nav {
  display: flex;
  align-items: center;
  gap: 1.1rem;
  font-size: 0.92rem;
}

.site-header nav a {
  color: var(--fg-soft);
}

.site-header nav a:hover {
  color: var(--fg);
  text-decoration: none;
}

#theme-toggle {
  border: 1px solid var(--line);
  background: transparent;
  color: var(--fg-soft);
  border-radius: 999px;
  width: 2rem;
  height: 2rem;
  cursor: pointer;
  font-size: 0.9rem;
  line-height: 1;
  transition: border-color 0.15s, color 0.15s;
}

#theme-toggle:hover {
  border-color: var(--fg-soft);
  color: var(--fg);
}

main {
  padding-bottom: 3rem;
  min-height: 60vh;
}

.intro {
  padding: 1rem 0 2rem;
  border-bottom: 1px solid var(--line);
  margin-bottom: 2rem;
}

.intro h1 {
  font-size: 1.9rem;
  margin: 0 0 0.35rem;
  letter-spacing: -0.02em;
}

.intro p {
  margin: 0;
  color: var(--fg-soft);
}

.post-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.post-list li {
  padding: 1.35rem 0;
  border-bottom: 1px solid var(--line);
}

.post-list li:last-child {
  border-bottom: 0;
}

.post-link {
  display: block;
  color: inherit;
}

.post-link:hover {
  text-decoration: none;
}

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

.post-list h2 {
  font-size: 1.18rem;
  margin: 0 0 0.3rem;
  letter-spacing: -0.01em;
  transition: color 0.15s;
}

.post-list p {
  margin: 0;
  color: var(--fg-soft);
  font-size: 0.95rem;
}

.meta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-top: 0.5rem;
  font-size: 0.85rem;
  color: var(--fg-soft);
  flex-wrap: wrap;
}

.tags {
  display: inline-flex;
  gap: 0.4rem;
  flex-wrap: wrap;
}

.tag {
  background: var(--bg-soft);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 0.05rem 0.6rem;
  font-size: 0.78rem;
}

.post h1 {
  font-size: 1.85rem;
  line-height: 1.35;
  letter-spacing: -0.02em;
  margin: 0.5rem 0 0.75rem;
}

.post > .meta {
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--line);
  margin-bottom: 2rem;
}

.prose > :first-child {
  margin-top: 0;
}

.prose h2 {
  font-size: 1.35rem;
  margin: 2.2rem 0 0.8rem;
  letter-spacing: -0.01em;
}

.prose h3 {
  font-size: 1.12rem;
  margin: 1.8rem 0 0.6rem;
}

.prose p,
.prose ul,
.prose ol {
  margin: 0 0 1.1rem;
}

.prose ul,
.prose ol {
  padding-left: 1.4rem;
}

.prose li {
  margin: 0.3rem 0;
}

.prose blockquote {
  margin: 1.4rem 0;
  padding: 0.2rem 0 0.2rem 1rem;
  border-left: 3px solid var(--line);
  color: var(--fg-soft);
}

.prose img {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius);
}

.prose code {
  background: var(--code-bg);
  border-radius: 5px;
  padding: 0.15em 0.4em;
  font-size: 0.88em;
  font-family: ui-monospace, SFMono-Regular, 'SF Mono', Menlo, Consolas, 'Liberation Mono', monospace;
}

.prose pre {
  background: var(--code-bg);
  border-radius: var(--radius);
  padding: 1rem 1.1rem;
  overflow-x: auto;
  margin: 1.4rem 0;
  line-height: 1.6;
}

.prose pre code {
  background: none;
  padding: 0;
  font-size: 0.86rem;
}

.prose hr {
  border: 0;
  border-top: 1px solid var(--line);
  margin: 2.5rem 0;
}

.table-wrap {
  margin: 1.4rem 0;
  overflow-x: auto;
}

.prose table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.93rem;
}

.prose th,
.prose td {
  border: 1px solid var(--line);
  padding: 0.5rem 0.7rem;
  text-align: left;
}

.prose th {
  background: var(--bg-soft);
  font-weight: 600;
}

.back {
  margin-top: 3rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--line);
  font-size: 0.92rem;
}

.empty {
  color: var(--fg-soft);
}

.site-footer {
  padding-top: 1.5rem;
  padding-bottom: 2.5rem;
  border-top: 1px solid var(--line);
  color: var(--fg-soft);
  font-size: 0.85rem;
}

.site-footer p {
  margin: 0;
}

@media (max-width: 600px) {
  body {
    font-size: 16px;
  }
  .intro h1 {
    font-size: 1.6rem;
  }
  .post h1 {
    font-size: 1.5rem;
  }
}