:root {
  --bg: #faf9f6;
  --surface: #ffffff;
  --ink: #1c1b19;
  --ink-soft: #4a4843;
  --ink-faint: #8a877f;
  --rule: #e7e4dc;
  --accent: #6b5e4a;
  --accent-soft: #f0ece3;
  --select-bg: #f6e4a6;
  --select-fg: #1c1b19;
  --max: 720px;
  --serif: Charter, "Iowan Old Style", "Palatino Linotype", Georgia, serif;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  --mono: "SF Mono", "JetBrains Mono", "Cascadia Code", Consolas, monospace;
}

* { box-sizing: border-box; }

/* custom text-selection highlight */
::selection { background: var(--select-bg); color: var(--select-fg); }
::-moz-selection { background: var(--select-bg); color: var(--select-fg); }

/* ---- animations ---- */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(10px); }
  to   { opacity: 1; transform: none; }
}
@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

.site-head { animation: fadeUp 0.5s ease both; }
.note-list li {
  animation: fadeUp 0.45s ease both;
  animation-delay: calc(var(--i, 0) * 55ms + 80ms);
}
.back { animation: fadeIn 0.5s ease both; }
.note-head { animation: fadeUp 0.5s ease both; animation-delay: 0.05s; }
.content { animation: fadeUp 0.55s ease both; animation-delay: 0.14s; }
/* MathJax fades in once typeset, avoiding a layout flash */
mjx-container { animation: fadeIn 0.3s ease both; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-delay: 0ms !important;
    transition-duration: 0.001ms !important;
  }
}

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--serif);
  font-size: 18px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

.wrap {
  max-width: var(--max);
  margin: 0 auto;
  padding: 64px 24px 120px;
}

/* ---- site header ---- */
.site-head {
  border-bottom: 1px solid var(--rule);
  padding-bottom: 28px;
  margin-bottom: 40px;
}
.site-head h1 {
  font-size: 30px;
  margin: 0 0 6px;
  letter-spacing: -0.01em;
}
.site-head p {
  margin: 0;
  color: var(--ink-faint);
  font-family: var(--sans);
  font-size: 15px;
}

/* ---- index list ---- */
.note-list { list-style: none; padding: 0; margin: 0; }
.note-list li { border-bottom: 1px solid var(--rule); }
.note-list a {
  display: block;
  padding: 22px 4px;
  text-decoration: none;
  color: inherit;
  transition: padding-left 0.15s ease;
}
.note-list a:hover { padding-left: 12px; }
.note-list .nt {
  font-size: 21px;
  line-height: 1.3;
  margin-bottom: 4px;
  transition: color 0.18s ease;
}
.note-list a:hover .nt { color: var(--accent); }
.note-list .meta {
  font-family: var(--sans);
  font-size: 13.5px;
  color: var(--ink-faint);
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  align-items: center;
}
.empty { color: var(--ink-faint); font-family: var(--sans); }

/* ---- note page ---- */
.back {
  font-family: var(--sans);
  font-size: 14px;
  color: var(--ink-faint);
  text-decoration: none;
  display: inline-block;
  margin-bottom: 28px;
  transition: color 0.18s ease, transform 0.18s ease;
}
.back:hover { color: var(--accent); transform: translateX(-3px); }

.note-head { margin-bottom: 36px; }
.note-head h1 {
  font-size: 32px;
  line-height: 1.2;
  letter-spacing: -0.015em;
  margin: 0 0 12px;
}
.note-head .byline {
  font-family: var(--sans);
  font-size: 15px;
  color: var(--ink-soft);
  margin: 0 0 10px;
}
.note-head .byline a { color: var(--accent); text-decoration: none; }

/* ---- rendered markdown ---- */
.content { }
.content h1, .content h2, .content h3 {
  font-family: var(--sans);
  letter-spacing: -0.01em;
  line-height: 1.25;
  margin: 1.8em 0 0.5em;
}
.content h1 { font-size: 26px; }
.content h2 {
  font-size: 21px;
  padding-bottom: 6px;
  border-bottom: 1px solid var(--rule);
}
.content h3 { font-size: 17px; color: var(--ink-soft); }
.content p { margin: 0.9em 0; }
.content a { color: var(--accent); }
.content ul, .content ol { padding-left: 1.4em; }
.content li { margin: 0.35em 0; }
.content blockquote {
  margin: 1.2em 0;
  padding: 4px 0 4px 20px;
  border-left: 3px solid var(--accent-soft);
  color: var(--ink-soft);
  font-style: italic;
}
.content code {
  font-family: var(--mono);
  font-size: 0.85em;
  background: var(--accent-soft);
  padding: 1px 6px;
  border-radius: 4px;
}
.content pre {
  background: var(--ink);
  color: #f3f0e9;
  padding: 16px 18px;
  border-radius: 8px;
  overflow-x: auto;
  font-size: 14px;
  line-height: 1.5;
}
.content pre code { background: none; padding: 0; color: inherit; font-size: inherit; }
.content hr { border: none; border-top: 1px solid var(--rule); margin: 2.4em 0; }
.content table {
  border-collapse: collapse;
  width: 100%;
  font-size: 15px;
  font-family: var(--sans);
  margin: 1.2em 0;
}
.content th, .content td { border: 1px solid var(--rule); padding: 8px 12px; text-align: left; }
.content th { background: var(--accent-soft); }
.content img { max-width: 100%; border-radius: 8px; }

mjx-container { overflow-x: auto; overflow-y: hidden; }

.state {
  font-family: var(--sans);
  color: var(--ink-faint);
  padding: 40px 0;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #16151320;
    --bg: #161513;
    --surface: #1e1c19;
    --ink: #ece9e1;
    --ink-soft: #b8b4a8;
    --ink-faint: #807c72;
    --rule: #302d28;
    --accent: #c9b487;
    --accent-soft: #2a2722;
    --select-bg: #4a4023;
    --select-fg: #f4efe3;
  }
  .content pre { background: #0d0c0b; }
}