/* =====================================================================
   Ling Zhang's Blog — global stylesheet
   Inspired by the WordPress "Twenty Twenty" theme (accent #cd2653,
   centered single column, large readable type).

   This is the ONE place for global look & feel. Individual posts contain
   NO styling of their own — restyling the whole blog means editing this
   file (and the header/footer includes) only.
   ===================================================================== */

:root {
  --accent: #cd2653;
  --accent-dark: #b31e46;
  --text: #202020;
  --text-muted: #6d6d6d;
  --bg: #f5f5f3;
  --bg-content: #ffffff;
  --bg-reading: #f4ecdd;   /* beige reading surface for single posts */
  --border: #e2e2e2;
  --max-text: 46rem;     /* single-post reading column */
  --max-wide: 64rem;     /* header / lists / archive       */
  --serif: Georgia, "Songti SC", "SimSun", serif;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue",
          "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

/* ---- base ---------------------------------------------------------- */
* { box-sizing: border-box; }
html { font-size: 18px; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--sans);
  font-size: 1.05rem;
  line-height: 1.7;
  color: var(--text);
  background: var(--bg-reading);   /* beige content surface, site-wide */
}
img { max-width: 100%; height: auto; }
a { color: var(--accent); text-decoration: none; }
a:hover, a:focus { color: var(--accent-dark); text-decoration: underline; }

.container { width: 92%; max-width: var(--max-wide); margin: 0 auto; }

/* ---- site header --------------------------------------------------- */
.site-header {
  background: var(--bg-content);
  border-bottom: 1px solid var(--border);
  padding: 1.4rem 0 1rem;
  text-align: center;
}
.site-header .avatar {
  width: 108px; height: 108px; border-radius: 50%;
  object-fit: cover; display: block; margin: 0 auto .7rem;
  box-shadow: 0 2px 10px rgba(0,0,0,.12);
}
.site-title {
  font-size: 1.9rem; font-weight: 700; letter-spacing: -.02em;
  margin: 0 0 .4rem;
}
.site-title a { color: var(--text); }
.site-title a:hover { color: var(--accent); text-decoration: none; }
.site-bio { color: var(--text-muted); font-size: .95rem; margin: 0 0 .3rem; }
.site-social { margin: .1rem 0 0; }
.site-social a { font-size: .9rem; }

/* Single blog entry: brand + nav merged into one compact sticky top bar,
   pinned to the top of the viewport while reading. */
.site-topbar {
  background: var(--bg-content);
  border-bottom: 1px solid var(--border);
  position: sticky; top: 0; z-index: 20;
}
.site-topbar .container {
  position: relative;
  display: flex; align-items: center;
  gap: 1rem; padding: .5rem 0;
}
.site-topbar .brand {
  display: inline-flex; align-items: center; gap: .6rem; flex-shrink: 0;
  transition: opacity .2s ease;
}
.site-topbar .brand:hover { text-decoration: none; }
/* On pages that ALSO show the full banner (home/archive/about), the sticky
   bar's mini brand stays hidden until the banner scrolls out of view — so
   the avatar never appears twice at once. topbar.js toggles .is-visible.
   (Kept as visibility:hidden, not display:none, so nav stays centered and
   the toggle stays right.) Post pages have no banner, so their brand is
   always shown. */
body:not(.layout-post) .site-topbar .brand { opacity: 0; visibility: hidden; }
body:not(.layout-post) .site-topbar .brand.is-visible { opacity: 1; visibility: visible; }
.site-topbar .avatar {
  width: 40px; height: 40px; border-radius: 50%; object-fit: cover;
  box-shadow: 0 1px 5px rgba(0,0,0,.12);
}
.site-topbar .site-title {
  font-size: 1.15rem; font-weight: 700; color: var(--text); letter-spacing: -.01em;
}
.site-topbar .brand:hover .site-title { color: var(--accent); }
/* Nav centered across the top bar, independent of the brand's width. */
.site-topbar .topbar-nav {
  position: absolute; left: 50%; transform: translateX(-50%);
  display: flex; gap: 1.4rem; white-space: nowrap;
}
.site-topbar .topbar-nav a {
  color: var(--text); font-weight: 600; font-size: .9rem;
  text-transform: uppercase; letter-spacing: .04em;
}
.site-topbar .topbar-nav a:hover { color: var(--accent); text-decoration: none; }

/* ---- primary nav --------------------------------------------------- */
.site-nav {
  background: var(--bg-content);
  border-bottom: 1px solid var(--border);
  position: sticky; top: 0; z-index: 10;
}
.site-nav ul {
  list-style: none; margin: 0 auto; padding: .6rem 0;
  display: flex; gap: 1.6rem; justify-content: center; flex-wrap: wrap;
}
.site-nav a {
  color: var(--text); font-weight: 600; font-size: .95rem;
  text-transform: uppercase; letter-spacing: .04em;
}
.site-nav a:hover { color: var(--accent); text-decoration: none; }
.site-nav .container { position: relative; }

/* ---- language toggle (中文 | English) ------------------------------ */
.lang-toggle {
  display: inline-flex; align-items: center; gap: .4rem;
  font-size: .8rem; white-space: nowrap;
}
.lang-toggle a {
  color: var(--text-muted); font-weight: 600;
  text-transform: none; letter-spacing: 0;
}
.lang-toggle a:hover { color: var(--accent); text-decoration: none; }
.lang-toggle a.active { color: var(--accent); cursor: default; }
.lang-toggle .sep { color: var(--border); }
/* Full labels by default; the short 中 / EN variants show on phones. */
.lang-toggle .lt-short { display: none; }
/* On the home banner nav, pin the toggle to the right of the centered links. */
.site-nav .lang-toggle {
  position: absolute; right: 0; top: 50%; transform: translateY(-50%);
}
/* On the single-post sticky bar, the toggle rides the far right. */
.site-topbar .lang-toggle { margin-left: auto; flex-shrink: 0; }

/* ---- main / article ------------------------------------------------ */
.site-main { padding: 2.6rem 0 3.5rem; }
/* Single blog entry: less headroom so the article body leads. */
.layout-post .site-main { padding-top: 1.4rem; }
.layout-post .post-header { margin-top: 0; }
/* Content areas inherit the beige body; only the chrome (header/nav/footer)
   stays white. */
.post { background: transparent; }

.post-header { max-width: var(--max-text); margin: 0 auto 1.6rem; }
.post-title { font-size: 2.1rem; line-height: 1.2; margin: 0 0 .5rem; font-weight: 800; }
.post-title a { color: var(--text); }
.post-meta { color: var(--text-muted); font-size: .85rem; text-transform: uppercase; letter-spacing: .05em; }

.post-content {
  max-width: var(--max-text); margin: 0 auto;
  font-size: 1.12rem; line-height: 1.8;
  overflow-wrap: break-word;
}
.post-content p { margin: 0 0 1.3rem; }
.post-content h2 { font-size: 1.5rem; margin: 2rem 0 .8rem; }
.post-content h3 { font-size: 1.25rem; margin: 1.6rem 0 .6rem; }
.post-content img { border-radius: 2px; }
.post-content a { text-decoration: underline; text-decoration-thickness: 1px; text-underline-offset: 2px; }
.post-content blockquote {
  margin: 1.5rem 0; padding: .4rem 0 .4rem 1.2rem;
  border-left: 3px solid var(--accent); color: var(--text-muted); font-style: italic;
}
.post-content pre, .post-content code {
  font-family: "SF Mono", Menlo, Consolas, monospace; font-size: .9em;
}
.post-content pre {
  background: #f3f3f3; padding: 1rem; overflow-x: auto; border-radius: 4px;
}
.post-content table { border-collapse: collapse; max-width: 100%; overflow-x: auto; display: block; }
.post-content td, .post-content th { border: 1px solid var(--border); padding: .4rem .6rem; }
/* legacy WP alignment helpers */
.aligncenter, img.aligncenter { display: block; margin-left: auto; margin-right: auto; }
.alignright { float: right; margin: 0 0 1rem 1.5rem; }
.alignleft  { float: left;  margin: 0 1.5rem 1rem 0; }
[align="center"] { text-align: center; }

/* ---- archived comments -------------------------------------------- */
.archived-comments { max-width: var(--max-text); margin: 3rem auto 0; padding-top: 1.6rem; border-top: 1px solid var(--border); }
.comments-title { font-size: 1.4rem; margin: 0 0 .3rem; }
.comments-note { color: var(--text-muted); font-size: .85rem; margin: 0 0 1.4rem; }
.comment-list { list-style: none; margin: 0; padding: 0; }
.comment { padding: 1rem 0; border-bottom: 1px solid var(--border); }
.comment-meta { margin-bottom: .3rem; }
.comment-author { font-weight: 700; }
.comment-date { color: var(--text-muted); font-size: .8rem; margin-left: .7rem; }
.comment-body { font-size: 1rem; }
.comment-body p { margin: 0 0 .6rem; }
.giscus-wrap { max-width: var(--max-text); margin: 2.5rem auto 0; }

/* ---- home feed (full body per entry) ------------------------------- */
.post-feed { }
.feed-entry { padding: 2.2rem 0 2.6rem; border-bottom: 1px solid var(--border); }
.feed-entry:first-child { padding-top: .3rem; }
.feed-entry .post-title { font-size: 1.75rem; }
.feed-entry .post-title a { color: var(--text); }
.feed-entry .post-title a:hover { color: var(--accent); text-decoration: none; }
.read-more { max-width: var(--max-text); margin: 1.2rem auto 0; }
.read-more a { font-weight: 600; text-transform: uppercase; letter-spacing: .04em; font-size: .85rem; }

/* Home-feed truncation. The link is hidden by default and revealed only on
   entries the clamp JS marks .is-clamped (body taller than the preview limit).
   So the link means "there is more body to read" — never tied to comments.
   With JS off, no entry is clamped: long posts render in full, no link. */
.read-more { display: none; }
.feed-entry.is-clamped .read-more { display: block; }

.feed-entry.is-clamped .post-content {
  max-height: 22rem;
  overflow: hidden;
  position: relative;
}
.feed-entry.is-clamped .post-content::after {
  content: "";
  position: absolute; left: 0; right: 0; bottom: 0; height: 5.5rem;
  background: linear-gradient(to bottom, rgba(244, 236, 221, 0), var(--bg-reading));
  pointer-events: none;
}

/* ---- post lists (archive / year) ----------------------------------- */
.post-list { max-width: var(--max-wide); margin: 0 auto; list-style: none; padding: 0; }
.post-list-item { padding: 1.3rem 0; border-bottom: 1px solid var(--border); }
.post-list-item .entry-title { font-size: 1.35rem; margin: 0 0 .2rem; }
.post-list-item .entry-meta { color: var(--text-muted); font-size: .8rem; text-transform: uppercase; letter-spacing: .04em; }
.post-list-item .entry-excerpt { color: #444; margin: .4rem 0 0; }

.archive-year { max-width: var(--max-wide); margin: 2.4rem auto 0; }
.archive-year h2 { font-size: 1.6rem; color: var(--accent); border-bottom: 2px solid var(--border); padding-bottom: .3rem; }
.archive-list { list-style: none; padding: 0; margin: 0; }
.archive-list li { display: flex; gap: 1rem; padding: .35rem 0; }
.archive-list .a-date { color: var(--text-muted); font-variant-numeric: tabular-nums; min-width: 5.5rem; font-size: .9rem; }

/* ---- gallery (special collections) --------------------------------- */
.gallery { max-width: var(--max-wide); margin: 1.5rem auto 0; display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 1.2rem; }
.gallery figure { margin: 0; }
.gallery a { display: block; background: var(--bg-content); border: 1px solid var(--border);
  border-radius: 4px; overflow: hidden; }
.gallery img { display: block; width: 100%; height: 180px; object-fit: cover;
  transition: transform .2s ease; }
.gallery a:hover img { transform: scale(1.03); }
.gallery figcaption { font-size: .8rem; color: var(--text-muted); margin-top: .4rem; text-align: center; }

/* ---- pagination ---------------------------------------------------- */
.pagination { max-width: var(--max-wide); margin: 2.5rem auto 0; display: flex; justify-content: space-between; align-items: center; }
.pagination a, .pagination span { font-weight: 600; }
.pagination .page-num { color: var(--text-muted); font-weight: 400; font-size: .9rem; }

/* ---- footer -------------------------------------------------------- */
.site-footer {
  border-top: 1px solid var(--border); background: var(--bg-content);
  text-align: center; padding: 2rem 0; color: var(--text-muted); font-size: .85rem;
}
.site-footer a { color: var(--text-muted); text-decoration: underline; }

/* ---- responsive ---------------------------------------------------- */
@media (max-width: 640px) {
  html { font-size: 17px; }
  .post-title { font-size: 1.7rem; }
  .post-content { font-size: 1.05rem; }
  /* On phones the compact sticky bar shows the avatar only (the brand text
     "Ling Zhang's Blog" crowds the nav), and the language toggle uses the
     short 中 | EN labels. Desktop is unchanged. */
  .site-topbar .brand .site-title { display: none; }
  .lang-toggle .lt-full { display: none; }
  .lang-toggle .lt-short { display: inline; }
}