/* ============================================================
   Claude-like Hugo Theme — main.css
   Light + Dark mode, serif body, warm accent palette
   ============================================================ */

/* ---------- Tokens (light) ---------- */
:root {
  --side-bar-bg-color: #f5f2ec;
  --control-text-color: #72695e;
  --text-color: #2b2621;
  --bg-color: #faf9f5;
  --surface-color: #f6f3ed;
  --select-text-bg-color: #e8ddd0;
  --item-hover-bg-color: rgba(194, 113, 62, 0.08);
  --active-file-bg-color: rgba(194, 113, 62, 0.12);
  --active-file-border-color: #d6b79b;
  --code-bg-color: #fcfcfa;
  --code-text-color: #1c1815;
  --code-border-color: #e9e2d8;
  --border-color: #ddd5ca;
  --accent-color: #bc6a3a;
  --accent-hover: #9d552d;
  --heading-color: #1c1815;
  --quote-bg-color: #f3ede5;
  --quote-border-color: #d8cbbb;
  --quote-text-color: #625950;
  --table-border-strong-color: #cbb9a6;
  --table-row-border-color: rgba(114, 105, 94, 0.26);
  --table-hover-color: rgba(188, 106, 58, 0.05);
  --code-muted-color: #6f665d;
  --code-keyword-color: #7b2ff7;
  --code-string-color: #2f8f2f;
  --code-number-color: #c06a2a;
  --code-symbol-color: #2c5ec6;
  --inline-code-color: #b14a40;
  --inline-code-bg-color: #f2eeea;
  --inline-code-border-color: #d7cec5;

  --font-body: "Anthropic Serif", Georgia, "Times New Roman", "Songti SC",
    "Noto Serif CJK SC", "Source Han Serif SC", "PingFang SC",
    "Hiragino Sans GB", serif;
  --font-ui: "PingFang SC", "Hiragino Sans GB", "Noto Sans CJK SC",
    "Source Han Sans SC", "Microsoft YaHei", "Segoe UI", sans-serif;
  --font-mono: Menlo, Monaco, "SF Mono", Consolas, "Sarasa Mono SC",
    "Cascadia Code", monospace;

  --nav-height: 60px;
  --content-width: 780px;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --transition: 0.18s ease;
}

/* ---------- Tokens (dark) ---------- */
@media (prefers-color-scheme: dark) {
  :root {
    --side-bar-bg-color: #171411;
    --control-text-color: #a7998b;
    --text-color: #ddd4ca;
    --bg-color: #151210;
    --surface-color: #181512;
    --select-text-bg-color: #5a4234;
    --item-hover-bg-color: rgba(213, 149, 103, 0.1);
    --active-file-bg-color: rgba(213, 149, 103, 0.14);
    --active-file-border-color: #cb8f63;
    --code-bg-color: #1d1917;
    --code-text-color: #e8dfd5;
    --code-border-color: #332b25;
    --border-color: #2f2924;
    --accent-color: #d59567;
    --accent-hover: #efb892;
    --heading-color: #f2e9df;
    --quote-bg-color: #1c1815;
    --quote-border-color: #4c4037;
    --quote-text-color: #d0c2b4;
    --table-border-strong-color: #5a4c41;
    --table-row-border-color: rgba(232, 223, 213, 0.14);
    --table-hover-color: rgba(213, 149, 103, 0.06);
    --code-muted-color: #9f8f81;
    --code-keyword-color: #b899ff;
    --code-string-color: #81cb82;
    --code-number-color: #d9a56f;
    --code-symbol-color: #89b1ea;
    --inline-code-color: #e1a092;
    --inline-code-bg-color: #241d19;
    --inline-code-border-color: #3a3029;
  }
}

/* ---------- Reset & Base ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-behavior: smooth;
  background-color: var(--bg-color);
}

body {
  font-family: var(--font-body);
  color: var(--text-color);
  background-color: var(--bg-color);
  line-height: 1.62;
  font-weight: 400;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ---------- Nav ---------- */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--nav-height);
  background-color: var(--bg-color);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.nav-inner {
  max-width: calc(var(--content-width) + 64px);
  margin: 0 auto;
  padding: 0 32px;
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.site-title {
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 1.05rem;
  color: var(--heading-color);
  text-decoration: none;
  letter-spacing: 0;
  flex-shrink: 0;
  transition: color var(--transition);
}
.site-title:hover { color: var(--accent-color); }

.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
  list-style: none;
}

.nav-links a {
  font-family: var(--font-ui);
  font-size: 0.875rem;
  font-weight: 400;
  color: var(--control-text-color);
  text-decoration: none;
  padding: 5px 10px;
  border-radius: var(--radius-sm);
  transition: color var(--transition), background var(--transition);
}
.nav-links a:hover,
.nav-links a.active {
  color: var(--accent-color);
  background: var(--item-hover-bg-color);
}

/* Hamburger */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
  color: var(--control-text-color);
}
.nav-toggle svg { display: block; }

/* ---------- Layout ---------- */
.site-main {
  flex: 1;
  width: 100%;
  max-width: calc(var(--content-width) + 64px);
  margin: 0 auto;
  padding: 48px 32px 96px;
}

/* ---------- Homepage ---------- */
.home-hero {
  padding: 56px 0 40px;
  border-bottom: 1px solid var(--border-color);
  margin-bottom: 48px;
}

.home-hero h1 {
  font-size: 2rem;
  line-height: 1.18;
  font-weight: 600;
  color: var(--heading-color);
  margin-bottom: 12px;
}

.home-hero p {
  font-size: 1.08rem;
  color: var(--control-text-color);
  max-width: 520px;
  line-height: 1.6;
}

.section-heading {
  font-family: var(--font-ui);
  font-size: 0.78rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--control-text-color);
  margin-bottom: 20px;
}

/* ---------- Post list ---------- */
.post-list {
  list-style: none;
}

.post-list-item {
  padding: 22px 0;
  border-bottom: 1px solid var(--border-color);
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 8px 24px;
  align-items: start;
}
.post-list-item:last-child { border-bottom: 0; }

.post-list-title {
  font-family: var(--font-body);
  font-size: 1.06rem;
  font-weight: 600;
  color: var(--heading-color);
  text-decoration: none;
  line-height: 1.36;
  transition: color var(--transition);
}
.post-list-title:hover { color: var(--accent-color); }

.post-list-summary {
  font-size: 0.9rem;
  color: var(--control-text-color);
  line-height: 1.55;
  grid-column: 1;
  margin-top: 4px;
}

.post-meta {
  font-family: var(--font-ui);
  font-size: 0.8rem;
  color: var(--control-text-color);
  white-space: nowrap;
  margin-top: 4px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.post-tag {
  display: inline-block;
  background: var(--item-hover-bg-color);
  color: var(--accent-color);
  font-size: 0.73rem;
  font-family: var(--font-ui);
  font-weight: 500;
  border-radius: 99px;
  padding: 2px 8px;
  letter-spacing: 0.01em;
  text-decoration: none;
  transition: background var(--transition);
}
.post-tag:hover { background: var(--active-file-bg-color); }

/* ---------- Single post ---------- */
.post-header {
  padding-bottom: 28px;
  border-bottom: 1px solid var(--border-color);
  margin-bottom: 36px;
}

.post-title {
  font-family: var(--font-body);
  font-size: 1.84em;
  line-height: 1.16;
  font-weight: 600;
  color: var(--heading-color);
  margin-bottom: 14px;
  margin-top: 0;
}

.post-meta-full {
  font-family: var(--font-ui);
  font-size: 0.83rem;
  color: var(--control-text-color);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
}

.post-meta-full .sep {
  width: 3px;
  height: 3px;
  background: var(--control-text-color);
  border-radius: 50%;
  opacity: 0.5;
}

/* ---------- Prose content ---------- */
.post-content {
  font-family: var(--font-body);
  color: var(--text-color);
  line-height: 1.62;
}

.post-content h1,
.post-content h2,
.post-content h3,
.post-content h4,
.post-content h5,
.post-content h6 {
  font-family: var(--font-body);
  font-weight: 600;
  line-height: 1.3;
  color: var(--heading-color);
  margin-top: 1.7em;
  margin-bottom: 0.6em;
}

.post-content h1 { font-size: 1.84em; }
.post-content h2 { font-size: 1.48em; border-bottom: 1px solid var(--border-color); padding-bottom: 0.3em; }
.post-content h3 { font-size: 1.24em; }
.post-content h4 { font-size: 1.12em; }
.post-content h5 { font-size: 1em; }
.post-content h6 { font-size: 1em; color: var(--control-text-color); }

.post-content p,
.post-content blockquote,
.post-content ul,
.post-content ol,
.post-content dl,
.post-content table {
  margin: 0.85em 0;
}

.post-content a {
  color: var(--accent-color);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition), color var(--transition);
}
.post-content a:hover {
  color: var(--accent-hover);
  border-bottom-color: currentColor;
}

.post-content strong, .post-content b {
  font-family: var(--font-ui);
  font-weight: 700;
  color: var(--heading-color);
}

.post-content hr {
  border: none;
  border-top: 1px solid var(--border-color);
  margin: 28px 0;
  opacity: 0.75;
}

.post-content ul, .post-content ol { padding-left: 1.5rem; }
.post-content li { padding-left: 0.15rem; margin-bottom: 0.2em; }
.post-content ul li::marker,
.post-content ol li::marker { color: var(--control-text-color); }

.post-content blockquote {
  border-left: 2px solid var(--quote-border-color);
  background-color: var(--quote-bg-color);
  padding: 0.6rem 1.1rem;
  color: var(--quote-text-color);
  border-radius: var(--radius-md);
  font-style: italic;
}
.post-content blockquote p { margin: 0; }

.post-content img {
  max-width: 100%;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  margin: 12px 0;
}

/* Code */
.post-content code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  color: var(--inline-code-color);
  background: var(--inline-code-bg-color);
  border: 1px solid var(--inline-code-border-color);
  border-radius: 999px;
  padding: 0.08em 0.44em 0.1em;
}

.post-content pre {
  font-family: var(--font-mono);
  background: var(--code-bg-color);
  border: 1px solid var(--code-border-color);
  border-radius: var(--radius-md);
  padding: 1rem 1.1rem;
  overflow-x: auto;
  font-size: 0.9em;
  line-height: 1.56;
  margin: 20px 0;
}
.post-content pre code {
  all: unset;
  font-family: var(--font-mono);
  font-size: inherit;
  color: var(--code-text-color);
}

/* Syntax highlight tokens */
.post-content .keyword, .post-content .kw { color: var(--code-keyword-color); }
.post-content .string, .post-content .s  { color: var(--code-string-color); }
.post-content .number, .post-content .nb { color: var(--code-number-color); }
.post-content .comment, .post-content .c { color: var(--code-muted-color); font-style: italic; }
.post-content .symbol, .post-content .nv { color: var(--code-symbol-color); }

/* Chroma highlight classes */
.highlight .k, .highlight .kd, .highlight .kn, .highlight .kp, .highlight .kr, .highlight .kt { color: var(--code-keyword-color); }
.highlight .s, .highlight .s1, .highlight .s2, .highlight .sb, .highlight .sc, .highlight .sd, .highlight .se, .highlight .sh, .highlight .si, .highlight .sx { color: var(--code-string-color); }
.highlight .m, .highlight .mb, .highlight .mf, .highlight .mh, .highlight .mi, .highlight .ml, .highlight .mo { color: var(--code-number-color); }
.highlight .c, .highlight .c1, .highlight .cm, .highlight .cs { color: var(--code-muted-color); font-style: italic; }
.highlight .n, .highlight .na, .highlight .nb, .highlight .nc, .highlight .nd, .highlight .ni, .highlight .ne, .highlight .nf, .highlight .nl, .highlight .nn, .highlight .nx, .highlight .py { color: var(--code-symbol-color); }
.highlight .o, .highlight .ow { color: var(--code-text-color); }
.highlight pre { background: transparent !important; border: 0; padding: 0; margin: 0; }

/* Tables */
.post-content table {
  width: 100%;
  border-collapse: collapse;
  border-top: 1px solid var(--table-border-strong-color);
  border-bottom: 1px solid var(--table-border-strong-color);
  font-size: 0.93rem;
}
.post-content thead tr { border-bottom: 1px solid var(--table-border-strong-color); }
.post-content tbody tr { border-bottom: 1px solid var(--table-row-border-color); }
.post-content tbody tr:last-child { border-bottom: 0; }
.post-content tbody tr:hover td { background: var(--table-hover-color); }
.post-content th {
  font-weight: 600;
  color: var(--heading-color);
  padding: 11px 18px 10px 0;
  text-align: left;
  vertical-align: bottom;
}
.post-content td {
  padding: 11px 18px 11px 0;
  vertical-align: top;
  line-height: 1.56;
}

/* ---------- Post footer nav ---------- */
.post-nav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-top: 56px;
  padding-top: 32px;
  border-top: 1px solid var(--border-color);
}

.post-nav-item {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 16px 18px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  text-decoration: none;
  transition: border-color var(--transition), background var(--transition);
  background: var(--surface-color);
}
.post-nav-item:hover {
  border-color: var(--active-file-border-color);
  background: var(--quote-bg-color);
}
.post-nav-item.next { text-align: right; }

.post-nav-label {
  font-family: var(--font-ui);
  font-size: 0.73rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--accent-color);
}

.post-nav-title {
  font-family: var(--font-body);
  font-size: 0.94rem;
  font-weight: 600;
  color: var(--heading-color);
  line-height: 1.36;
}

/* ---------- Tags / Taxonomy pages ---------- */
.tag-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 24px;
}

.tag-cloud-item {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  background: var(--surface-color);
  border: 1px solid var(--border-color);
  color: var(--text-color);
  font-family: var(--font-ui);
  font-size: 0.85rem;
  border-radius: 99px;
  padding: 5px 14px;
  text-decoration: none;
  transition: border-color var(--transition), color var(--transition), background var(--transition);
}
.tag-cloud-item:hover {
  border-color: var(--active-file-border-color);
  color: var(--accent-color);
  background: var(--active-file-bg-color);
}
.tag-cloud-count {
  font-size: 0.72rem;
  color: var(--control-text-color);
}

/* ---------- About / Static pages ---------- */
.page-header {
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border-color);
  margin-bottom: 32px;
}

.page-title {
  font-size: 1.84em;
  font-weight: 600;
  color: var(--heading-color);
  line-height: 1.16;
}

/* ---------- 404 ---------- */
.error-page {
  text-align: center;
  padding: 80px 0;
}
.error-code {
  font-family: var(--font-body);
  font-size: 5rem;
  font-weight: 600;
  color: var(--border-color);
  line-height: 1;
  margin-bottom: 16px;
}
.error-page h1 { font-size: 1.5rem; margin-bottom: 12px; }
.error-page p { color: var(--control-text-color); margin-bottom: 28px; }

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--border-color);
  padding: 28px 32px;
  font-family: var(--font-ui);
  font-size: 0.8rem;
  color: var(--control-text-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.footer-links {
  display: flex;
  gap: 16px;
  list-style: none;
}
.footer-links a {
  color: var(--control-text-color);
  text-decoration: none;
  transition: color var(--transition);
}
.footer-links a:hover { color: var(--accent-color); }

/* ---------- Utility ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-ui);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--accent-color);
  text-decoration: none;
  border: 1px solid var(--active-file-border-color);
  background: var(--active-file-bg-color);
  border-radius: var(--radius-sm);
  padding: 7px 14px;
  transition: background var(--transition), border-color var(--transition);
  cursor: pointer;
}
.btn:hover {
  background: var(--item-hover-bg-color);
  border-color: var(--accent-color);
}

/* TOC */
.toc {
  background: var(--quote-bg-color);
  border-radius: var(--radius-md);
  padding: 18px 20px;
  margin-bottom: 32px;
  font-size: 0.88rem;
}
.toc-title {
  font-family: var(--font-ui);
  font-weight: 600;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--control-text-color);
  margin-bottom: 10px;
}
.toc nav ul { list-style: none; padding: 0; }
.toc nav li { padding: 2px 0; }
.toc nav a {
  color: var(--control-text-color);
  text-decoration: none;
  transition: color var(--transition);
}
.toc nav a:hover { color: var(--accent-color); }

/* ---------- Responsive ---------- */
@media (max-width: 768px) {
  .site-main { padding: 32px 20px 72px; }

  .nav-inner { padding: 0 20px; }

  .nav-links {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: var(--bg-color);
    border-bottom: 1px solid var(--border-color);
    flex-direction: column;
    align-items: flex-start;
    padding: 12px 20px 16px;
    gap: 2px;
  }
  .nav-links.open { display: flex; }
  .nav-toggle { display: flex; }

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

  .post-nav { grid-template-columns: 1fr; }
  .post-nav-item.next { text-align: left; }

  .home-hero h1 { font-size: 1.6rem; }

  .site-footer { flex-direction: column; align-items: flex-start; gap: 12px; }
}

@media (min-width: 1400px) {
  :root { --content-width: 820px; }
}
@media (min-width: 1800px) {
  :root { --content-width: 880px; }
}

/* ---------- Reading progress bar ---------- */
#reading-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 0%;
  height: 2px;
  background: var(--accent-color);
  z-index: 200;
  transition: width 0.1s linear;
  opacity: 0.85;
}