:root {
  --paper: #faf8f3;
  --surface: #fffefb;
  --ink: #191b20;
  --ink-soft: #3f434b;
  --muted: #73777f;
  --line: #e4dfd4;
  --line-strong: #cfc8b8;
  --accent: #0e5a57;
  --accent-ink: #0a3f3d;
  --accent-soft: #e7f0ee;
  --code-bg: #15181d;
  --code-ink: #d9dfe8;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  --mono: "Cascadia Code", "SFMono-Regular", Consolas, "Liberation Mono", Menlo,
    monospace;
}

* {
  box-sizing: border-box;
}

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

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

::selection {
  background: #cfe4e0;
  color: #0a3f3d;
}

a {
  color: inherit;
  text-decoration: none;
}

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

h1,
h2,
h3 {
  text-wrap: balance;
}

.wrap {
  width: min(100% - 2.5rem, 68rem);
  margin-inline: auto;
}

.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  z-index: 100;
  background: var(--ink);
  color: var(--paper);
  padding: 0.6rem 1rem;
  border-radius: 0 0 6px 0;
}

.skip-link:focus {
  left: 0;
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 2px;
}

/* ---------- header ---------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  border-bottom: 1px solid var(--line);
  background: rgba(250, 248, 243, 0.88);
  backdrop-filter: blur(10px);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4.5rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.7rem;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 2rem;
  height: 2rem;
  border-radius: 6px;
  background: var(--ink);
  color: var(--paper);
  font-family: var(--mono);
  font-size: 1.05rem;
  font-weight: 700;
  line-height: 1;
}

.brand-text {
  display: flex;
  align-items: baseline;
  gap: 0.45rem;
  font-size: 1.02rem;
  font-weight: 650;
  letter-spacing: -0.01em;
}

.brand-sub {
  font-family: var(--mono);
  font-size: 0.62rem;
  font-weight: 400;
  letter-spacing: 0.08em;
  color: var(--muted);
}

.site-nav {
  display: flex;
  gap: 1.6rem;
  font-size: 0.92rem;
}

.site-nav a {
  position: relative;
  padding: 0.25rem 0;
  color: var(--ink-soft);
}

.site-nav a:hover {
  color: var(--ink);
}

.site-nav a.active {
  color: var(--ink);
  font-weight: 600;
}

.site-nav a.active::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -0.2rem;
  height: 2px;
  background: var(--accent);
}

/* ---------- home hero ---------- */

.hero {
  padding: 5.5rem 0 3.5rem;
  border-bottom: 1px solid var(--line);
}

.eyebrow {
  margin: 0 0 0.8rem;
  font-family: var(--mono);
  font-size: 0.7rem;
  font-weight: 500;
  letter-spacing: 0.18em;
  color: var(--accent);
}

.hero h1 {
  max-width: 20ch;
  margin: 1rem 0 1.4rem;
  font-size: clamp(2.3rem, 5.4vw, 3.9rem);
  font-weight: 680;
  line-height: 1.18;
  letter-spacing: -0.035em;
}

.hero-lead {
  max-width: 40rem;
  margin: 0;
  color: var(--ink-soft);
  font-size: 1.08rem;
  line-height: 1.85;
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1.8rem;
  margin-top: 2.2rem;
  font-family: var(--mono);
  font-size: 0.76rem;
  letter-spacing: 0.02em;
  color: var(--muted);
}

.hero-meta strong {
  color: var(--ink);
  font-weight: 600;
}

/* ---------- home body ---------- */

.home-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 17rem;
  gap: 5rem;
  align-items: start;
  padding: 3.5rem 0 5rem;
}

.section-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 0.4rem;
  padding-bottom: 0.7rem;
  border-bottom: 1px solid var(--ink);
}

.section-head h2 {
  margin: 0;
  font-size: 1.05rem;
  letter-spacing: 0.02em;
}

.section-count {
  font-family: var(--mono);
  font-size: 0.74rem;
  color: var(--muted);
}

.post-item {
  display: grid;
  grid-template-columns: 7.5rem minmax(0, 1fr);
  gap: 1.5rem;
  padding: 1.9rem 0;
  border-bottom: 1px solid var(--line);
}

.post-meta {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  padding-top: 0.3rem;
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--muted);
}

.post-body h3 {
  margin: 0 0 0.55rem;
  font-size: 1.32rem;
  font-weight: 640;
  line-height: 1.45;
  letter-spacing: -0.015em;
}

.post-body p {
  margin: 0 0 0.9rem;
  color: var(--ink-soft);
  font-size: 0.96rem;
  line-height: 1.8;
}

.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.tag-list li {
  padding: 0.14rem 0.45rem;
  border: 1px solid #cfe0dc;
  border-radius: 3px;
  background: var(--accent-soft);
  color: var(--accent-ink);
  font-family: var(--mono);
  font-size: 0.68rem;
  letter-spacing: 0.03em;
}

.home-aside {
  display: flex;
  flex-direction: column;
  gap: 2.2rem;
  padding-top: 0.4rem;
}

.aside-block h2 {
  margin: 0 0 0.8rem;
  font-family: var(--mono);
  font-size: 0.7rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
}

.aside-block p {
  margin: 0;
  color: var(--ink-soft);
  font-size: 0.9rem;
  line-height: 1.8;
}

.topic-list {
  margin: 0;
  padding: 0;
  list-style: none;
  color: var(--ink-soft);
  font-size: 0.9rem;
}

.topic-list li {
  padding: 0.35rem 0;
  border-bottom: 1px dotted var(--line-strong);
}

.text-link {
  display: inline-block;
  margin-top: 0.7rem;
  color: var(--accent);
  font-size: 0.85rem;
  border-bottom: 1px solid transparent;
}

.text-link:hover {
  border-color: var(--accent);
}

/* ---------- article ---------- */

.article-wrap {
  width: min(100% - 2.5rem, 46rem);
  margin-inline: auto;
  padding: 2.5rem 0 5rem;
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  margin-bottom: 2.6rem;
  font-family: var(--mono);
  font-size: 0.7rem;
  color: var(--muted);
}

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

.breadcrumb .sep {
  color: var(--line-strong);
}

.article-header {
  margin-bottom: 2.4rem;
  padding-bottom: 2.2rem;
  border-bottom: 1px solid var(--line);
}

.article-header h1 {
  margin: 0.9rem 0 1rem;
  font-size: clamp(1.9rem, 4.2vw, 2.9rem);
  font-weight: 680;
  line-height: 1.28;
  letter-spacing: -0.025em;
}

.article-deck {
  margin: 0 0 1.3rem;
  color: var(--ink-soft);
  font-size: 1.02rem;
  line-height: 1.8;
}

.article-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--muted);
}

.article-meta .dot {
  color: var(--line-strong);
}

.prose {
  color: var(--ink-soft);
  font-size: 1.04rem;
  line-height: 1.95;
}

.prose > p {
  margin: 0 0 1.25em;
}

.prose .lead {
  color: var(--ink);
  font-size: 1.12rem;
  line-height: 1.85;
}

.prose h2 {
  margin: 2.8em 0 0.9em;
  padding-bottom: 0.45rem;
  border-bottom: 1px solid var(--line);
  color: var(--ink);
  font-size: 1.42rem;
  font-weight: 650;
  line-height: 1.5;
  letter-spacing: -0.01em;
}

.prose h3 {
  margin: 2em 0 0.6em;
  color: var(--ink);
  font-size: 1.15rem;
}

.prose strong {
  color: var(--ink);
  font-weight: 600;
}

.prose a {
  color: var(--accent);
  border-bottom: 1px solid #b9d4cf;
}

.prose ul,
.prose ol {
  margin: 0 0 1.3em;
  padding-left: 1.35em;
}

.prose li {
  margin: 0.35em 0;
}

.prose li::marker {
  color: var(--accent);
}

.prose blockquote {
  margin: 1.6em 0;
  padding: 0.9em 1.2em;
  border-left: 3px solid var(--accent);
  background: var(--accent-soft);
  color: var(--ink-soft);
}

.prose blockquote p:last-child {
  margin-bottom: 0;
}

.prose code {
  padding: 0.15em 0.38em;
  border-radius: 4px;
  background: #eeeae0;
  color: #2b2f36;
  font-family: var(--mono);
  font-size: 0.86em;
}

.prose pre {
  margin: 1.5em 0;
  padding: 1.15rem 1.3rem;
  overflow-x: auto;
  border: 1px solid #23272f;
  border-radius: 8px;
  background: var(--code-bg);
  color: var(--code-ink);
  font-size: 0.84rem;
  line-height: 1.65;
}

.prose pre code {
  padding: 0;
  border-radius: 0;
  background: none;
  color: inherit;
  font-size: 1em;
}

.prose table {
  width: 100%;
  margin: 1.5em 0;
  border-collapse: collapse;
  font-size: 0.92rem;
}

.prose th,
.prose td {
  padding: 0.55rem 0.7rem;
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

.prose th {
  background: #f3efe6;
  color: var(--ink);
  font-weight: 600;
}

.article-end {
  margin-top: 3rem;
  padding-top: 1.6rem;
  border-top: 1px solid var(--line);
}

.article-end p {
  margin: 0 0 1rem;
  color: var(--muted);
  font-size: 0.86rem;
  line-height: 1.8;
}

.post-nav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-top: 2.5rem;
}

.post-nav a {
  padding: 1rem 1.1rem;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
}

.post-nav a:hover {
  border-color: var(--accent);
}

.post-nav span {
  display: block;
  margin-bottom: 0.35rem;
  font-family: var(--mono);
  font-size: 0.66rem;
  color: var(--muted);
}

.post-nav strong {
  font-size: 0.95rem;
  font-weight: 600;
}

.post-nav .next {
  text-align: right;
}

.post-nav .empty {
  border: 1px dashed var(--line);
  border-radius: 8px;
}

/* ---------- about ---------- */

.about-wrap {
  width: min(100% - 2.5rem, 46rem);
  margin-inline: auto;
  padding: 4rem 0 5rem;
}

.page-header {
  margin-bottom: 2.2rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--line);
}

.page-header h1 {
  margin: 0.7rem 0 0.8rem;
  font-size: clamp(2rem, 4.5vw, 2.9rem);
  font-weight: 680;
  letter-spacing: -0.03em;
}

.page-lead {
  margin: 0;
  color: var(--ink-soft);
  font-size: 1.05rem;
}

.about-prose h2:first-of-type {
  margin-top: 0;
}

/* ---------- footer ---------- */

.site-footer {
  padding: 2rem 0 2.5rem;
  border-top: 1px solid var(--line);
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 1rem;
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.02em;
  color: var(--muted);
}

.footer-inner p {
  margin: 0;
}

.footer-icp a {
  color: inherit;
  text-decoration: none;
  border-bottom: 1px solid var(--line);
}

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

/* ---------- responsive ---------- */

@media (max-width: 900px) {
  .home-grid {
    grid-template-columns: 1fr;
    gap: 3rem;
  }

  .home-aside {
    padding-top: 2rem;
    border-top: 1px solid var(--line);
  }

  .hero {
    padding: 4rem 0 2.8rem;
  }
}

@media (max-width: 640px) {
  .wrap,
  .article-wrap,
  .about-wrap {
    width: calc(100% - 2rem);
  }

  .header-inner {
    height: 4rem;
  }

  .brand-sub {
    display: none;
  }

  .site-nav {
    gap: 1.1rem;
    font-size: 0.88rem;
  }

  .hero h1 {
    font-size: 2.05rem;
  }

  .hero-meta {
    gap: 1rem;
  }

  .post-item {
    grid-template-columns: 1fr;
    gap: 0.5rem;
  }

  .post-meta {
    flex-direction: row;
    gap: 0.8rem;
    padding-top: 0;
  }

  .article-wrap,
  .about-wrap {
    padding-top: 1.5rem;
  }

  .post-nav {
    grid-template-columns: 1fr;
  }

  .post-nav .next {
    text-align: left;
  }
}

@media print {
  .site-header,
  .site-footer,
  .post-nav {
    display: none;
  }

  body {
    background: #fff;
  }

  .article-wrap {
    width: 100%;
    padding: 0;
  }

  .prose pre {
    white-space: pre-wrap;
    border: 1px solid #ccc;
    background: #f5f5f5;
    color: #000;
  }
}