/* wangcong.org - "engineer's ledger"
   Serif prose, mono metadata, spruce green accent, hairline rules. */

:root {
  --paper: #FDFDFB;
  --ink: #22272C;
  --muted: #6B7378;
  --accent: #0E6B54;
  --accent-dark: #094A3A;
  --rule: #E6E4DD;
  --code-bg: #F5F4EF;
  --serif: "Source Serif 4", "Source Serif Pro", Georgia, "Liberation Serif",
           "DejaVu Serif", "Noto Serif CJK SC", "Source Han Serif SC",
           "Songti SC", SimSun, serif;
  --mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, Consolas,
          "Noto Sans Mono CJK SC", monospace;
}

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

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

body {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--serif);
  font-size: 1.0625rem;
  line-height: 1.75;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.wrapper {
  width: 100%;
  max-width: 44rem;
  margin: 0 auto;
  padding: 0 1.25rem;
}

main.wrapper {
  flex: 1;
  padding-top: 3rem;
  padding-bottom: 4rem;
}

::selection {
  background: #D8E8E1;
}

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

.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  background: var(--paper);
  padding: 0.5rem 1rem;
  font-family: var(--mono);
  font-size: 0.8125rem;
}

.skip-link:focus {
  left: 0;
  z-index: 10;
}

/* ---------- Links ---------- */

a {
  color: var(--accent);
  text-decoration: underline;
  text-decoration-color: rgba(14, 107, 84, 0.35);
  text-underline-offset: 3px;
  transition: color 120ms ease, text-decoration-color 120ms ease;
}

a:hover {
  color: var(--accent-dark);
  text-decoration-color: currentColor;
}

/* ---------- Header ---------- */

.site-header {
  border-bottom: 1px solid var(--rule);
}

.header-inner {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
  padding-top: 2rem;
  padding-bottom: 1.25rem;
}

.site-title {
  font-family: var(--mono);
  font-size: 1rem;
  font-weight: 500;
  letter-spacing: 0.01em;
  color: var(--ink);
  text-decoration: none;
}

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

.site-nav {
  display: flex;
  gap: 1.25rem;
}

.site-nav .page-link {
  font-family: var(--mono);
  font-size: 0.8125rem;
  color: var(--muted);
  text-decoration: none;
}

.site-nav .page-link:hover {
  color: var(--accent);
}

/* ---------- Ledger metadata (shared) ---------- */

.post-meta,
.post-date {
  font-family: var(--mono);
  font-size: 0.8125rem;
  letter-spacing: 0.02em;
  color: var(--muted);
}

/* ---------- Home ---------- */

.home > h1 {
  font-size: 1.5rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin-bottom: 1rem;
}

.post-preview {
  display: grid;
  grid-template-columns: 6.5rem 1fr;
  gap: 0.35rem 1.5rem;
  padding: 1.75rem 0;
  border-top: 1px solid var(--rule);
}

.post-preview:first-child {
  border-top: none;
}

.post-preview .post-meta {
  padding-top: 0.45rem;
}

.post-preview h2 {
  font-size: 1.25rem;
  font-weight: 600;
  line-height: 1.35;
  letter-spacing: -0.01em;
}

.post-preview h2 a {
  color: var(--ink);
  text-decoration: none;
}

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

.post-excerpt {
  margin-top: 0.5rem;
  font-size: 0.9375rem;
  line-height: 1.65;
  color: var(--muted);
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.post-excerpt p {
  margin: 0;
}

.read-more {
  display: inline-block;
  margin-top: 0.65rem;
  font-family: var(--mono);
  font-size: 0.8125rem;
  text-decoration: none;
}

.read-more:hover {
  text-decoration: underline;
}

.all-posts {
  margin-top: 1.5rem;
  padding-top: 1.75rem;
  border-top: 1px solid var(--rule);
  font-family: var(--mono);
  font-size: 0.875rem;
}

/* ---------- Archive ---------- */

.archive-year {
  font-family: var(--mono);
  font-size: 0.9375rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  color: var(--ink);
  margin: 2.5rem 0 0.75rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--rule);
}

.archive-year:first-of-type {
  margin-top: 1rem;
}

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

.archive-list li {
  display: grid;
  grid-template-columns: 4rem 1fr;
  gap: 1.25rem;
  padding: 0.3rem 0;
  line-height: 1.55;
}

.archive-list .post-date {
  padding-top: 0.2rem;
}

.archive-list a {
  color: var(--ink);
  text-decoration: none;
}

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

/* ---------- Post & page ---------- */

.post-header {
  margin-bottom: 2.25rem;
}

.post-header .post-meta {
  margin-bottom: 0.75rem;
}

.post-title {
  font-size: 1.9rem;
  font-weight: 600;
  line-height: 1.25;
  letter-spacing: -0.015em;
}

.post-content > * + * {
  margin-top: 1.1rem;
}

.post-content h2 {
  font-size: 1.35rem;
  font-weight: 600;
  line-height: 1.35;
  letter-spacing: -0.01em;
  margin-top: 2.5rem;
}

.post-content h3 {
  font-size: 1.125rem;
  font-weight: 600;
  margin-top: 2rem;
}

.post-content h4 {
  font-size: 1rem;
  font-weight: 600;
  margin-top: 1.75rem;
}

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

.post-content li + li {
  margin-top: 0.35rem;
}

.post-content blockquote {
  border-left: 2px solid var(--accent);
  padding-left: 1.25rem;
  color: var(--muted);
}

.post-content img {
  max-width: 100%;
  height: auto;
}

.post-content hr {
  border: none;
  border-top: 1px solid var(--rule);
  margin: 2.5rem auto;
  width: 5rem;
}

.post-content table {
  border-collapse: collapse;
  width: 100%;
  display: block;
  overflow-x: auto;
  font-size: 0.9375rem;
}

.post-content th {
  font-family: var(--mono);
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: 0.03em;
  text-align: left;
}

.post-content th,
.post-content td {
  border-bottom: 1px solid var(--rule);
  padding: 0.5rem 1rem 0.5rem 0;
}

/* ---------- Code ---------- */

code {
  font-family: var(--mono);
  font-size: 0.85em;
}

p code,
li code,
h2 code,
h3 code,
td code {
  background: var(--code-bg);
  padding: 0.1em 0.35em;
  border-radius: 3px;
}

pre {
  background: var(--code-bg);
  border-radius: 6px;
  padding: 1rem 1.25rem;
  overflow-x: auto;
  line-height: 1.6;
}

pre code {
  font-size: 0.8125rem;
  background: none;
  padding: 0;
}

/* Rouge syntax highlighting: restrained, harmonized with the accent */

.highlight .c, .highlight .c1, .highlight .cm, .highlight .cp, .highlight .cs {
  color: #98A0A6;
  font-style: italic;
}

.highlight .k, .highlight .kd, .highlight .kn, .highlight .kr,
.highlight .kt, .highlight .kc, .highlight .kp, .highlight .ow {
  color: var(--accent);
}

.highlight .s, .highlight .s1, .highlight .s2, .highlight .sb,
.highlight .sc, .highlight .sd, .highlight .se, .highlight .sh,
.highlight .si, .highlight .sr, .highlight .ss, .highlight .sx {
  color: #9C5B1D;
}

.highlight .m, .highlight .mi, .highlight .mf, .highlight .mh,
.highlight .mo, .highlight .il {
  color: #9C5B1D;
}

.highlight .nf, .highlight .fm, .highlight .nc, .highlight .nn {
  color: #38598C;
}

.highlight .gp {
  color: var(--muted);
}

.highlight .err {
  color: inherit;
  background: none;
}

/* ---------- Footer ---------- */

.site-footer {
  border-top: 1px solid var(--rule);
}

.footer-inner {
  padding-top: 1.75rem;
  padding-bottom: 2.5rem;
}

.footer-inner p {
  font-family: var(--mono);
  font-size: 0.75rem;
  line-height: 1.7;
  color: var(--muted);
}

.footer-inner p + p {
  margin-top: 0.5rem;
}

.footer-inner a {
  color: var(--muted);
  text-decoration-color: rgba(107, 115, 120, 0.4);
}

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

/* ---------- Responsive ---------- */

@media (max-width: 40rem) {
  body {
    font-size: 1rem;
  }

  .post-title {
    font-size: 1.55rem;
  }

  .post-preview {
    grid-template-columns: 1fr;
    gap: 0.15rem;
    padding: 1.4rem 0;
  }

  .post-preview .post-meta {
    padding-top: 0;
  }

  .archive-list li {
    grid-template-columns: 3.5rem 1fr;
    gap: 0.9rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  * {
    transition: none !important;
  }
}