/* Paper HTML Styles - Dark mode compatible */
:root {
  --bg: #ffffff;
  --text: #111111;
  --text-muted: #666666;
  --border: #e5e5e5;
  --code-bg: #f5f5f5;
  --link: #0066cc;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111111;
    --text: #f5f5f5;
    --text-muted: #999999;
    --border: #333333;
    --code-bg: #1a1a1a;
    --link: #66b3ff;
  }
}

* {
  box-sizing: border-box;
}

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
  line-height: 1.7;
  color: var(--text);
  background: var(--bg);
  max-width: 720px;
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
}

/* Header */
header {
  margin-bottom: 3rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--border);
}

h1.title {
  font-size: 1.75rem;
  font-weight: 700;
  line-height: 1.3;
  margin: 0 0 1rem;
}

.author {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin: 0;
}

/* Headings */
h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  line-height: 1.3;
  margin-top: 2.5rem;
  margin-bottom: 1rem;
}

h1 { font-size: 1.5rem; }
h2 { font-size: 1.35rem; }
h3 { font-size: 1.15rem; }
h4 { font-size: 1rem; }

/* Paragraphs */
p {
  margin: 0 0 1.25rem;
}

/* Links */
a {
  color: var(--link);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

/* Lists */
ul, ol {
  margin: 0 0 1.25rem;
  padding-left: 1.5rem;
}

li {
  margin-bottom: 0.5rem;
}

/* Blockquotes */
blockquote {
  margin: 1.5rem 0;
  padding: 1rem 1.5rem;
  border-left: 3px solid var(--border);
  background: var(--code-bg);
  font-style: italic;
}

blockquote p:last-child {
  margin-bottom: 0;
}

/* Code */
code {
  font-family: 'SF Mono', Menlo, Monaco, monospace;
  font-size: 0.875em;
  background: var(--code-bg);
  padding: 0.15em 0.4em;
  border-radius: 3px;
}

pre {
  background: var(--code-bg);
  padding: 1rem;
  overflow-x: auto;
  border-radius: 6px;
  margin: 1.5rem 0;
}

pre code {
  background: none;
  padding: 0;
}

/* Tables */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-size: 0.9rem;
}

th, td {
  padding: 0.75rem;
  text-align: left;
  border-bottom: 1px solid var(--border);
}

th {
  font-weight: 600;
}

/* Math - MathJax */
.MathJax {
  font-size: 1.1em !important;
}

.MathJax_Display {
  margin: 1.5rem 0 !important;
  overflow-x: auto;
}


/* Table of contents */
#TOC {
  background: var(--code-bg);
  padding: 1.5rem;
  border-radius: 6px;
  margin-bottom: 2rem;
}

#TOC ul {
  list-style: none;
  padding-left: 0;
  margin: 0;
}

#TOC ul ul {
  padding-left: 1.25rem;
  margin-top: 0.5rem;
}

#TOC li {
  margin-bottom: 0.4rem;
}

#TOC a {
  color: var(--text);
}

/* Footnotes */
.footnotes {
  margin-top: 3rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  font-size: 0.9rem;
}

.footnote-ref {
  font-size: 0.8em;
  vertical-align: super;
}

/* Abstract */
header + p:first-of-type,
blockquote:first-of-type {
  font-size: 1.05rem;
  color: var(--text-muted);
}

/* Section numbering visual hierarchy */
.header-section-number {
  color: var(--text-muted);
  margin-right: 0.5rem;
}

/* Back to top link */
.back-link {
  display: inline-block;
  margin-top: 2rem;
  padding: 0.5rem 1rem;
  background: var(--code-bg);
  border-radius: 4px;
  font-size: 0.875rem;
}