/* ============================================================
   post.css — single-post viewer design system
   Warm "scriptorium" aesthetic, shared with the library reader:
   same 4 theme palettes (light/sepia/dark/olive) and --rdr-*
   variables, so reader_theme / reader_measure / reader_font
   preferences carry across reading articles and books.
   Self-contained: no @import of vars.css.
   ============================================================ */

/* ---------- Base ---------- */

:root {
  /* typography */
  --rdr-font-body:  'Noto Serif SC', 'Songti SC', 'Source Han Serif SC', Georgia, serif;
  --rdr-font-ui:    'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', system-ui, sans-serif;
  --rdr-font-latin: 'EB Garamond', 'Noto Serif SC', Georgia, serif;
  --rdr-font-mono:  'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;

  /* geometry */
  --rdr-topbar-h:   54px;
  --rdr-font-size:  18px;   /* overridden inline from localStorage */
  --rdr-measure:    38em;   /* overridden inline from localStorage */

  --rdr-radius:     10px;
  --rdr-radius-sm:  7px;
  --rdr-motion:     cubic-bezier(0.22, 0.61, 0.36, 1);
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--rdr-font-body);
  font-size: var(--rdr-font-size);
  line-height: 1.85;
  color: var(--rdr-fg);
  background-color: var(--rdr-bg);
  background-image:
    radial-gradient(circle at 16% 10%, var(--rdr-bg-grain) 0, transparent 42%),
    radial-gradient(circle at 84% 82%, var(--rdr-bg-grain) 0, transparent 46%);
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  transition: background-color 0.25s ease, color 0.25s ease;
}

::selection { background: var(--rdr-mark); color: var(--rdr-accent-ink); }

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

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

/* ---------- Theme palettes ---------- */

html[data-theme="light"] {
  color-scheme: light;
  --rdr-bg:           #FAF6EC;
  --rdr-bg-grain:     #F3ECDB;
  --rdr-surface:      #F4EEDF;
  --rdr-surface-2:    #EFE7D4;
  --rdr-fg:           #241B11;
  --rdr-muted:        #6A5C49;
  --rdr-faint:        #8C7B61;
  --rdr-accent:       #8A3517;
  --rdr-accent-ink:   #732A11;
  --rdr-accent-soft:  rgba(138, 53, 23, 0.10);
  --rdr-olive:        #4A6741;
  --rdr-olive-ink:    #3A5133;
  --rdr-olive-soft:   rgba(74, 103, 65, 0.10);
  --rdr-border:       #E2D8C3;
  --rdr-rule:         #D9CDB4;
  --rdr-quote-bg:     #F1E8D3;
  --rdr-mark:         rgba(138, 53, 23, 0.12);
  --rdr-shadow:       rgba(48, 33, 16, 0.13);
  --rdr-shadow-deep:  rgba(48, 33, 16, 0.24);
  --rdr-scrim:        rgba(36, 27, 17, 0.38);
  --rdr-on-accent:    #FBF6EA;
  --rdr-topbar-bg:    rgba(250, 246, 236, 0.88);
  --rdr-error-bg:     #FBEAE3;
  --rdr-error-fg:     #8A3517;
}

html[data-theme="sepia"] {
  color-scheme: light;
  --rdr-bg:           #EFDFBF;
  --rdr-bg-grain:     #E5D0A5;
  --rdr-surface:      #E8D5AE;
  --rdr-surface-2:    #DCC69A;
  --rdr-fg:           #3A2A1A;
  --rdr-muted:        #6B5236;
  --rdr-faint:        #7E6A4E;
  --rdr-accent:       #9A3F1C;
  --rdr-accent-ink:   #7C3113;
  --rdr-accent-soft:  rgba(154, 63, 28, 0.12);
  --rdr-olive:        #5B6B3E;
  --rdr-olive-ink:    #48562F;
  --rdr-olive-soft:   rgba(91, 107, 62, 0.12);
  --rdr-border:       #D8BE8F;
  --rdr-rule:         #CCAE78;
  --rdr-quote-bg:     #E6CFA2;
  --rdr-mark:         rgba(154, 63, 28, 0.14);
  --rdr-shadow:       rgba(58, 42, 26, 0.18);
  --rdr-shadow-deep:  rgba(58, 42, 26, 0.32);
  --rdr-scrim:        rgba(46, 32, 18, 0.46);
  --rdr-on-accent:    #F7EFE0;
  --rdr-topbar-bg:    rgba(239, 223, 191, 0.90);
  --rdr-error-bg:     #F0D8C6;
  --rdr-error-fg:     #8A3517;
}

html[data-theme="dark"] {
  color-scheme: dark;
  --rdr-bg:           #1C1A16;
  --rdr-bg-grain:     #26231C;
  --rdr-surface:      #26221C;
  --rdr-surface-2:    #2F2A22;
  --rdr-fg:           #E9DFCB;
  --rdr-muted:        #B3A78E;
  --rdr-faint:        #8F8672;
  --rdr-accent:       #D07A55;
  --rdr-accent-ink:   #E8A98B;
  --rdr-accent-soft:  rgba(208, 122, 85, 0.14);
  --rdr-olive:        #9DB184;
  --rdr-olive-ink:    #B5C69F;
  --rdr-olive-soft:   rgba(157, 177, 132, 0.14);
  --rdr-border:       #3A352B;
  --rdr-rule:         #453E31;
  --rdr-quote-bg:     #27231C;
  --rdr-mark:         rgba(208, 122, 85, 0.14);
  --rdr-shadow:       rgba(0, 0, 0, 0.35);
  --rdr-shadow-deep:  rgba(0, 0, 0, 0.55);
  --rdr-scrim:        rgba(0, 0, 0, 0.55);
  --rdr-on-accent:    #241B11;
  --rdr-topbar-bg:    rgba(28, 26, 22, 0.86);
  --rdr-error-bg:     #3A2620;
  --rdr-error-fg:     #E8A98B;
}

html[data-theme="olive"] {
  color-scheme: light;
  --rdr-bg:           #F4F3E8;
  --rdr-bg-grain:     #E7E8D4;
  --rdr-surface:      #ECECDC;
  --rdr-surface-2:    #DEDFC6;
  --rdr-fg:           #24301F;
  --rdr-muted:        #55603F;
  --rdr-faint:        #7C8366;
  --rdr-accent:       #3F5C33;
  --rdr-accent-ink:   #2F4726;
  --rdr-accent-soft:  rgba(63, 92, 51, 0.12);
  --rdr-olive:        #6A7B3C;
  --rdr-olive-ink:    #55632F;
  --rdr-olive-soft:   rgba(106, 123, 60, 0.12);
  --rdr-border:       #D6D8BC;
  --rdr-rule:         #C8CBA9;
  --rdr-quote-bg:     #E5E7CC;
  --rdr-mark:         rgba(63, 92, 51, 0.14);
  --rdr-shadow:       rgba(40, 50, 30, 0.14);
  --rdr-shadow-deep:  rgba(40, 50, 30, 0.26);
  --rdr-scrim:        rgba(36, 45, 28, 0.42);
  --rdr-on-accent:    #F4F6E9;
  --rdr-topbar-bg:    rgba(244, 243, 232, 0.90);
  --rdr-error-bg:     #EDE8D6;
  --rdr-error-fg:     #5C4A26;
}

/* ---------- Reading progress ---------- */

#pt-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 2px;
  width: 0%;
  background: linear-gradient(90deg, var(--rdr-olive), var(--rdr-accent));
  z-index: 1200;
  transition: width 0.12s linear;
}

/* ---------- Top bar ---------- */

#pt-topbar {
  position: sticky;
  top: 0;
  z-index: 1000;
  height: var(--rdr-topbar-h);
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 0 20px;
  background: var(--rdr-topbar-bg);
  backdrop-filter: blur(12px) saturate(1.1);
  -webkit-backdrop-filter: blur(12px) saturate(1.1);
  border-bottom: 1px solid var(--rdr-border);
  font-family: var(--rdr-font-ui);
}

#pt-back {
  font-size: 13px;
  color: var(--rdr-muted);
  white-space: nowrap;
  transition: color 0.15s ease;
}
#pt-back:hover { color: var(--rdr-accent); }

#pt-top-title {
  flex: 1;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  font-size: 14px;
  font-weight: 500;
  color: var(--rdr-fg);
  text-align: center;
}

#pt-settings-btn {
  font-family: var(--rdr-font-latin), var(--rdr-font-body);
  font-size: 15px;
  font-weight: 600;
  color: var(--rdr-fg);
  background: var(--rdr-surface);
  border: 1px solid var(--rdr-border);
  border-radius: 18px;
  width: 40px;
  height: 30px;
  cursor: pointer;
  line-height: 1;
  transition: background 0.15s ease, border-color 0.15s ease;
}
#pt-settings-btn:hover,
#pt-settings-btn.open { background: var(--rdr-mark); border-color: var(--rdr-accent); }

/* ---------- Settings panel ---------- */

#pt-settings {
  position: fixed;
  top: calc(var(--rdr-topbar-h) + 12px);
  right: 20px;
  z-index: 1100;
  width: 268px;
  padding: 18px;
  background: var(--rdr-surface);
  border: 1px solid var(--rdr-border);
  border-radius: var(--rdr-radius);
  box-shadow: 0 18px 44px -12px var(--rdr-shadow-deep), 0 4px 10px -6px var(--rdr-shadow);
  font-family: var(--rdr-font-ui);
  opacity: 0;
  transform: translateY(-8px) scale(0.98);
  transform-origin: top right;
  pointer-events: none;
  transition: opacity 0.18s ease, transform 0.18s ease;
}
body.pt-settings-open #pt-settings {
  opacity: 1;
  transform: none;
  pointer-events: auto;
}

.pt-setting-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 14px;
}
.pt-setting-row:last-child { margin-bottom: 0; }

.pt-setting-label {
  font-size: 12px;
  color: var(--rdr-muted);
  letter-spacing: 0.04em;
  flex-shrink: 0;
}

.pt-setting-group {
  display: flex;
  align-items: center;
  gap: 10px;
}

.pt-setting-group button {
  font-family: var(--rdr-font-latin), var(--rdr-font-body);
  font-size: 14px;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  border: 1px solid var(--rdr-border);
  background: transparent;
  color: var(--rdr-fg);
  cursor: pointer;
  transition: all 0.15s ease;
}
.pt-setting-group button:hover {
  border-color: var(--rdr-accent);
  color: var(--rdr-accent);
  background: var(--rdr-mark);
}

.pt-setting-group span {
  font-size: 13px;
  color: var(--rdr-faint);
  min-width: 40px;
  text-align: center;
}

.pt-seg {
  display: flex;
  gap: 5px;
}
.pt-seg button {
  font-family: var(--rdr-font-ui);
  font-size: 11px;
  padding: 4px 11px;
  border-radius: 14px;
  border: 1px solid var(--rdr-border);
  background: transparent;
  color: var(--rdr-fg);
  cursor: pointer;
  transition: all 0.15s ease;
}
.pt-seg button:hover { border-color: var(--rdr-accent); color: var(--rdr-accent); }
.pt-seg button.active {
  background: var(--rdr-mark);
  border-color: var(--rdr-accent);
  color: var(--rdr-accent);
  font-weight: 600;
}
html[data-theme="olive"] .pt-seg button[data-theme="olive"] {
  background: var(--rdr-accent);
  color: var(--rdr-on-accent);
  font-weight: 600;
}

/* ---------- Article ---------- */

#pt-main {
  display: block;
}

#pt-article {
  max-width: var(--rdr-measure);
  margin: 0 auto;
  padding: 48px 24px 80px;
}

.pt-article-header { margin-bottom: 44px; }

.pt-eyebrow {
  font-family: var(--rdr-font-latin), var(--rdr-font-body);
  font-size: 12px;
  font-style: italic;
  color: var(--rdr-olive);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.pt-eyebrow::before {
  content: "";
  width: 24px;
  height: 1px;
  background: var(--rdr-olive);
}

.pt-title {
  font-family: var(--rdr-font-body);
  font-size: clamp(26px, 4vw, 38px);
  font-weight: 600;
  color: var(--rdr-fg);
  line-height: 1.3;
  margin-bottom: 24px;
  letter-spacing: 0.01em;
}

.pt-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px;
  font-family: var(--rdr-font-ui);
  font-size: 13px;
  color: var(--rdr-faint);
}
.pt-meta .pt-author-info { display: flex; align-items: center; gap: 8px; }
.pt-meta .pt-author-avatar {
  width: 26px;
  height: 26px;
  border-radius: 50%;
  background: var(--rdr-surface);
  border: 1px solid var(--rdr-border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--rdr-font-latin);
  font-size: 12px;
  font-weight: 600;
  color: var(--rdr-accent);
}
.pt-meta time {
  font-family: var(--rdr-font-latin), var(--rdr-font-body);
  font-size: 14px;
  font-style: italic;
  color: var(--rdr-muted);
  letter-spacing: 0.03em;
}
.pt-meta .pt-sep { color: var(--rdr-rule); font-size: 12px; }
.pt-meta .pt-categories { display: flex; gap: 8px; flex-wrap: wrap; }
.pt-cat-tag {
  font-family: var(--rdr-font-ui);
  font-size: 11px;
  font-weight: 600;
  color: var(--rdr-olive-ink);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 3px 10px;
  border: 1px solid var(--rdr-border);
  border-radius: 999px;
  background: var(--rdr-surface);
}

.pt-featured {
  width: 100%;
  margin: 28px 0 0;
  border-radius: var(--rdr-radius);
  overflow: hidden;
  border: 1px solid var(--rdr-border);
  box-shadow: 0 14px 40px -18px var(--rdr-shadow-deep);
}
.pt-featured img {
  width: 100%;
  height: auto;
  max-height: 460px;
  object-fit: cover;
  display: block;
}

/* ---------- Body typography ---------- */

.pt-body {
  font-family: var(--rdr-font-body);
  line-height: 1.95;
  text-align: justify;
  text-justify: inter-ideograph;
  word-break: break-word;
}

.pt-body p { margin: 0 0 1.15em; }
.pt-body p + p { text-indent: 2em; }

.pt-body h2 {
  position: relative;
  margin: 2em 0 0.85em;
  padding-left: 0.75em;
  font-family: var(--rdr-font-latin), var(--rdr-font-body);
  font-size: 1.42em;
  font-weight: 600;
  line-height: 1.5;
  color: var(--rdr-accent-ink);
  text-align: left;
}
.pt-body h2::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.2em;
  bottom: 0.2em;
  width: 3px;
  border-radius: 2px;
  background: linear-gradient(180deg, var(--rdr-accent) 0%, var(--rdr-olive) 100%);
}

.pt-body h3 {
  margin: 1.7em 0 0.7em;
  font-family: var(--rdr-font-latin), var(--rdr-font-body);
  font-size: 1.2em;
  font-weight: 600;
  line-height: 1.5;
  color: var(--rdr-olive-ink);
  text-align: left;
}

.pt-body h4 {
  margin: 1.5em 0 0.6em;
  font-size: 1.05em;
  font-weight: 600;
  color: var(--rdr-faint);
  text-align: left;
}

.pt-body strong { color: var(--rdr-accent-ink); font-weight: 700; }
.pt-body em { font-style: italic; }

.pt-body a {
  color: var(--rdr-accent);
  border-bottom: 1px solid var(--rdr-accent-soft);
  transition: color 0.15s ease, border-color 0.15s ease;
}
.pt-body a:hover { color: var(--rdr-accent-ink); border-bottom-color: var(--rdr-accent); }

.pt-body blockquote {
  margin: 1.7em 0;
  padding: 1.05em 1.5em;
  background: var(--rdr-quote-bg);
  border-left: 3px solid var(--rdr-accent);
  border-radius: 0 var(--rdr-radius) var(--rdr-radius) 0;
  color: var(--rdr-muted);
  font-family: var(--rdr-font-latin), var(--rdr-font-body);
  font-size: 1.02em;
}
.pt-body blockquote p:last-child { margin-bottom: 0; }
.pt-body blockquote p + p { text-indent: 0; }

.pt-body hr {
  position: relative;
  height: 1px;
  width: min(70%, 13em);
  margin: 2.8em auto;
  border: none;
  background: linear-gradient(90deg, transparent 0%, var(--rdr-rule) 50%, transparent 100%);
}
.pt-body hr::after {
  content: "✦";
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  padding: 0 0.7em;
  background: var(--rdr-bg);
  color: var(--rdr-accent);
  font-size: 0.85em;
}

.pt-body ol,
.pt-body ul {
  margin: 0 0 1.3em;
  padding-left: 0;
  list-style: none;
}
.pt-body li { margin: 0.5em 0; line-height: 1.85; }
.pt-body ul li { position: relative; padding-left: 1.5em; }
.pt-body ul li::before {
  content: "";
  position: absolute;
  left: 0.35em;
  top: 0.72em;
  width: 0.42em;
  height: 0.42em;
  border-radius: 50%;
  background: var(--rdr-olive);
}
.pt-body ol { counter-reset: pt-list; }
.pt-body ol li {
  counter-increment: pt-list;
  position: relative;
  padding-left: 1.7em;
}
.pt-body ol li::before {
  content: counter(pt-list) ".";
  position: absolute;
  left: 0;
  top: 0;
  font-family: var(--rdr-font-latin), var(--rdr-font-body);
  font-weight: 600;
  color: var(--rdr-accent);
}

.pt-body code {
  font-family: var(--rdr-font-mono);
  font-size: 0.86em;
  padding: 0.18em 0.42em;
  border: 1px solid var(--rdr-border);
  border-radius: 5px;
  background: var(--rdr-surface-2);
  color: var(--rdr-accent-ink);
  word-break: break-word;
}
.pt-body pre {
  margin: 1.5em 0;
  padding: 1.1em 1.3em;
  overflow-x: auto;
  border: 1px solid var(--rdr-border);
  border-radius: var(--rdr-radius);
  background: var(--rdr-surface);
  line-height: 1.7;
  text-align: left;
}
.pt-body pre code {
  padding: 0;
  border: none;
  background: none;
  color: var(--rdr-fg);
  font-size: 0.88em;
}

.pt-body table {
  width: 100%;
  margin: 1.5em 0;
  border-collapse: collapse;
  font-size: 0.95em;
  text-align: left;
}
.pt-body th,
.pt-body td {
  padding: 0.6em 0.9em;
  border: 1px solid var(--rdr-border);
}
.pt-body th {
  background: var(--rdr-surface);
  color: var(--rdr-accent-ink);
  font-weight: 600;
}

.pt-body img {
  max-width: 100%;
  height: auto;
  border-radius: var(--rdr-radius);
  margin: 0.5em auto;
  display: block;
}

.pt-body audio {
  display: block;
  width: min(100%, 32em);
  margin: 1.4em auto;
}

.pt-body video {
  display: block;
  max-width: 100%;
  height: auto;
  margin: 1.4em auto;
  border-radius: var(--rdr-radius);
}

/* sup/sub passthrough (footnote-style markers from source) */
.pt-body sup,
.pt-body sub {
  font-family: var(--rdr-font-latin), var(--rdr-font-body);
  font-size: 0.75em;
  color: var(--rdr-accent);
}

/* ---------- Page nav ---------- */

.pt-pagenav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-top: 56px;
  padding-top: 28px;
  border-top: 1px solid var(--rdr-rule);
  font-family: var(--rdr-font-ui);
}
.pt-nav-link {
  display: block;
  padding: 16px 18px;
  background: var(--rdr-surface);
  border: 1px solid var(--rdr-border);
  border-radius: var(--rdr-radius);
  transition: border-color 0.15s ease, transform 0.15s ease;
}
.pt-nav-link:hover {
  border-color: var(--rdr-accent);
  transform: translateY(-2px);
}
.pt-nav-link .pt-nav-dir {
  display: block;
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--rdr-faint);
  margin-bottom: 5px;
  text-transform: uppercase;
}
.pt-nav-link .pt-nav-title {
  display: block;
  font-size: 14px;
  color: var(--rdr-fg);
  line-height: 1.5;
}
.pt-nav-link.is-next { text-align: right; }
.pt-nav-link.is-disabled {
  opacity: 0.45;
  pointer-events: none;
}

.pt-back-list {
  display: inline-block;
  margin-top: 28px;
  font-family: var(--rdr-font-ui);
  font-size: 13px;
  color: var(--rdr-muted);
  transition: color 0.15s ease;
}
.pt-back-list:hover { color: var(--rdr-accent); }

/* ---------- Back to top ---------- */

#pt-back-top {
  position: fixed;
  right: 24px;
  bottom: 28px;
  z-index: 900;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 1px solid var(--rdr-border);
  background: var(--rdr-surface);
  color: var(--rdr-accent);
  font-size: 18px;
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transform: translateY(8px);
  transition: opacity 0.2s ease, transform 0.2s ease, border-color 0.15s ease;
}
#pt-back-top.pt-show { opacity: 1; pointer-events: auto; transform: none; }
#pt-back-top:hover { border-color: var(--rdr-accent); }

/* ---------- Error ---------- */

.pt-error {
  max-width: var(--rdr-measure);
  margin: 3em auto;
  padding: 1.3em 1.6em;
  border: 1px solid var(--rdr-accent);
  border-radius: var(--rdr-radius);
  background: var(--rdr-error-bg);
  color: var(--rdr-error-fg);
  font-family: var(--rdr-font-ui);
  font-size: 0.95em;
}
.pt-error a { color: var(--rdr-accent); border-bottom: 1px solid var(--rdr-accent-soft); }

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

@media (max-width: 640px) {
  #pt-topbar { padding: 0 12px; gap: 10px; }
  #pt-top-title { text-align: left; }
  #pt-article { padding: 32px 18px 64px; }
  .pt-pagenav { grid-template-columns: 1fr; }
  .pt-nav-link.is-next { text-align: left; }
}