/* Blue Box — Typographic Stylesheet */

/*
 * Font: Cooper* by Indestructible Type
 * A revival of Oswald Cooper's 1920s typeface
 *
 * Design principles:
 * - Generous whitespace
 * - Optimal reading measure (~65ch)
 * - Warm, paper-like background
 * - Quiet navigation
 * - Subtle hierarchy through size and weight
 */

@font-face {
  font-family: 'Cooper';
  src: url('assets/Cooper-Regular.woff2') format('woff2');
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: 'Cooper';
  src: url('assets/Cooper-Italic.woff2') format('woff2');
  font-weight: 400;
  font-style: italic;
  font-display: swap;
}

@font-face {
  font-family: 'Cooper';
  src: url('assets/Cooper-SemiBold.woff2') format('woff2');
  font-weight: 600;
  font-style: normal;
  font-display: swap;
}

:root {
  /* Typography */
  --font-body: 'Cooper', Georgia, 'Times New Roman', serif;
  --font-size-base: 1.125rem;  /* 18px - comfortable reading size */
  --line-height: 1.6;
  --measure: 65ch;

  /* Colors — warm, not clinical */
  --color-text: #2c2c2c;
  --color-text-light: #5c5c5c;
  --color-text-lighter: #888;
  --color-bg: #fffdf9;
  --color-bg-nav: #faf8f4;
  --color-border: #e8e4dc;
  --color-link: #4a4a4a;
  --color-link-hover: #1a1a1a;

  /* Spacing scale */
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2.5rem;
  --space-xl: 4rem;
  --space-2xl: 6rem;
}

* {
  box-sizing: border-box;
}

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

body {
  margin: 0;
  padding: 0;
  font-family: var(--font-body);
  font-size: var(--font-size-base);
  line-height: var(--line-height);
  color: var(--color-text);
  background: var(--color-bg);
  display: flex;
  min-height: 100vh;
}

/* ============================================
   Navigation — quiet, unobtrusive
   ============================================ */

nav {
  width: 260px;
  min-width: 260px;
  padding: var(--space-xl) var(--space-lg);
  background: var(--color-bg-nav);
  border-right: 1px solid var(--color-border);
  overflow-y: auto;
  position: sticky;
  top: 0;
  height: 100vh;
}

nav .site-title {
  font-size: 1.25rem;
  font-weight: 400;
  letter-spacing: -0.01em;
  margin-bottom: var(--space-xl);
  color: var(--color-text);
  text-decoration: none;
  display: block;
}

nav .site-title:hover {
  color: var(--color-link-hover);
}

nav ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

nav > ul > li {
  margin-bottom: var(--space-lg);
}

nav .section-title {
  font-size: 0.875rem;
  font-weight: 400;
  color: var(--color-text-light);
  margin-bottom: var(--space-xs);
  letter-spacing: 0.02em;
}

nav .section-title a {
  color: inherit;
  text-decoration: none;
}

nav .section-title a:hover {
  color: var(--color-text);
}

nav ul ul {
  padding-left: var(--space-sm);
  margin-top: var(--space-xs);
}

nav ul ul li {
  margin: 0.4rem 0;
}

nav a {
  color: var(--color-text-light);
  text-decoration: none;
  font-size: 0.9375rem;
}

nav a:hover {
  color: var(--color-text);
}

/* Visited tracking */
nav a:visited {
  color: var(--color-text-lighter);
}

nav a:visited::after {
  content: " ·";
  color: var(--color-text-lighter);
}

/* Current page */
nav a[aria-current="page"],
nav a.current {
  color: var(--color-text);
}

nav a[aria-current="page"]::after,
nav a.current::after {
  content: none;
}

/* ============================================
   Main content — breathing room
   ============================================ */

main {
  flex: 1;
  padding: var(--space-2xl) var(--space-xl);
  max-width: calc(var(--measure) + var(--space-xl) * 2);
}

main > * {
  max-width: var(--measure);
}

/* Headings */
main h1 {
  font-size: 2rem;
  font-weight: 400;
  margin: 0 0 var(--space-xl) 0;
  line-height: 1.25;
  letter-spacing: -0.02em;
}

main h2 {
  font-size: 1.375rem;
  font-weight: 400;
  margin: var(--space-xl) 0 var(--space-md) 0;
  line-height: 1.3;
  color: var(--color-text);
}

main h3 {
  font-size: 1.125rem;
  font-weight: 600;
  margin: var(--space-lg) 0 var(--space-sm) 0;
  line-height: 1.4;
}

/* Paragraphs — generous spacing */
main p {
  margin: 0 0 var(--space-md) 0;
}

main p + p {
  margin-top: var(--space-md);
}

/* Lists */
main ul, main ol {
  margin: 0 0 var(--space-md) 0;
  padding-left: 1.5em;
}

main li {
  margin: var(--space-xs) 0;
  padding-left: 0.25em;
}

main li::marker {
  color: var(--color-text-light);
}

/* Blockquotes */
main blockquote {
  margin: var(--space-lg) 0;
  padding: 0 0 0 var(--space-md);
  border-left: 2px solid var(--color-border);
  font-style: italic;
  color: var(--color-text-light);
}

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

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

main pre {
  font-family: 'SF Mono', 'Monaco', 'Inconsolata', monospace;
  font-size: 0.875rem;
  background: var(--color-bg-nav);
  padding: var(--space-md);
  overflow-x: auto;
  border-radius: 4px;
  margin: var(--space-lg) 0;
  line-height: 1.5;
}

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

/* Links — subtle, text-integrated */
main a {
  color: var(--color-link);
  text-decoration: underline;
  text-decoration-color: var(--color-border);
  text-underline-offset: 0.15em;
}

main a:hover {
  color: var(--color-link-hover);
  text-decoration-color: var(--color-text-light);
}

/* Emphasis */
main strong {
  font-weight: 600;
}

main em {
  font-style: italic;
}

/* Horizontal rules */
/* Gradient transparent - color - transparent */

main hr {
    border: none;
    height: 1px;
    background-image: linear-gradient(to right, rgba(0, 0, 0, 0), rgba(0, 0, 0, 0.75), rgba(0, 0, 0, 0));
    margin: var(--space-xl) 0;
    &:after{
content: "✳︎";
position: absolute;
margin-top: -14px;
padding-inline:1rem;
right: 50%;
background-color: var(--color-bg);
    }
}

/* ============================================
   Page footer
   ============================================ */

main footer {
  margin-top: var(--space-2xl);
  padding-top: var(--space-lg);
  border-top: 1px solid var(--color-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

main footer a {
  color: var(--color-text-lighter);
  font-size: 0.9375rem;
  text-decoration: none;
}

main footer a:hover {
  color: var(--color-text);
}

main footer .prev::before {
  content: "\2190\00a0";
}

main footer .next::after {
  content: "\00a0\2192";
}

/* ============================================
   Figures
   ============================================ */

main figure {
  margin: 0 0 var(--space-xl) 0;
}

main figure img {
  max-width: 100%;
  height: auto;
  border-radius: 4px;
}

main figcaption {
  margin-top: var(--space-xs);
  font-size: 0.875rem;
  color: var(--color-text-lighter);
}

main figcaption a {
  color: inherit;
}

/* ============================================
   Special elements
   ============================================ */

.intro {
  font-size: 1.25rem;
  line-height: 1.5;
  margin-bottom: var(--space-xl);
  color: var(--color-text-light);
}

.genesis {
  background: var(--color-bg-nav);
  padding: var(--space-md) var(--space-lg);
  border-radius: 4px;
  margin: var(--space-lg) 0;
}

.genesis p {
  margin: 0;
  font-size: 0.9375rem;
  color: var(--color-text-light);
}

.method-diagram {
  font-family: 'SF Mono', 'Monaco', 'Inconsolata', monospace;
  font-size: 0.8125rem;
  line-height: 1.6;
  background: var(--color-bg-nav);
  padding: var(--space-md) var(--space-lg);
  border-radius: 4px;
  margin: var(--space-lg) 0;
  white-space: pre;
  overflow-x: auto;
}

/* ============================================
   Timeline
   ============================================ */

.timeline {
  margin-top: var(--space-lg);
}

.event {
  margin-bottom: var(--space-lg);
  padding-left: var(--space-md);
  border-left: 2px solid var(--color-border);
}

.event time {
  display: block;
  font-size: 0.875rem;
  color: var(--color-text-lighter);
  margin-bottom: var(--space-xs);
}

.event h3 {
  margin: 0 0 var(--space-xs) 0;
  font-size: 1.125rem;
  font-weight: 600;
}

.event p {
  margin: 0;
}

.event p + p {
  margin-top: var(--space-sm);
}

/* All events use details/summary */
.event > summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  align-items: baseline;
  gap: var(--space-xs);
}

.event > summary::-webkit-details-marker {
  display: none;
}

.event > summary time {
  font-size: 0.8125rem;
  color: var(--color-text-lighter);
  flex-shrink: 0;
}

.event > summary .summary-title {
  font-size: 0.9375rem;
  color: var(--color-text-light);
}

/* When open: title on its own line */
.event[open] > summary {
  flex-wrap: wrap;
}

.event[open] > summary .summary-title {
  display: block;
  width: 100%;
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--color-text);
  margin-top: var(--space-xs);
}

.event > p {
  margin-top: var(--space-sm);
}

/* ============================================
   Responsive — graceful degradation
   ============================================ */

@media (max-width: 1000px) {
  main {
    padding: var(--space-xl) var(--space-lg);
  }
}

@media (max-width: 800px) {
  body {
    flex-direction: column;
  }

  nav {
    width: 100%;
    min-width: 100%;
    height: auto;
    position: static;
    padding: var(--space-lg);
    border-right: none;
    border-bottom: 1px solid var(--color-border);
  }

  nav .site-title {
    margin-bottom: var(--space-md);
  }

  nav > ul > li {
    margin-bottom: var(--space-md);
  }

  nav ul ul {
    display: none;
  }

  nav .section-title {
    display: inline;
    margin-right: var(--space-md);
  }

  nav > ul {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
  }

  nav > ul > li {
    margin: 0;
  }

  main {
    padding: var(--space-xl) var(--space-lg);
  }
}

@media (max-width: 500px) {
  :root {
    --font-size-base: 1.0625rem;
  }

  main {
    padding: var(--space-lg) var(--space-md);
  }

  main h1 {
    font-size: 1.625rem;
  }

  main h2 {
    font-size: 1.25rem;
  }
}