/* ------------------------------------------------------------------
   learn.otaviomiranda.cloud — editorial design system
   ------------------------------------------------------------------ */

:root {
  /* palette */
  --bg:        #fafaf7;   /* warm off-white */
  --bg-soft:   #f3f1ec;   /* cards, code blocks */
  --bg-sink:   #ecead9;   /* highlights, key takeaways */
  --ink:       #1f1d1a;   /* primary text */
  --ink-dim:   #5b574f;   /* secondary text */
  --ink-faint: #8a8478;   /* meta, captions */
  --rule:      #e6e1d8;   /* borders, dividers */
  --rule-soft: #efeae0;
  --accent:    #b14a1a;   /* burnt orange — anthropic-ish */
  --accent-soft: #f4e6d8;

  /* typography */
  --font-serif: "Source Serif 4", "Source Serif Pro", Charter, "Iowan Old Style", Georgia, serif;
  --font-sans:  "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  --font-mono:  "JetBrains Mono", ui-monospace, "SF Mono", Menlo, monospace;

  /* rhythm */
  --step: 8px;
  --reading-width: 68ch;
  --layout-width:  1080px;
}

/* reset --------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 1.65;
  font-feature-settings: "kern", "liga", "calt";
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
img, svg { max-width: 100%; height: auto; display: block; }

/* layout -------------------------------------------------------- */
.page {
  max-width: var(--layout-width);
  margin: 0 auto;
  padding: clamp(32px, 5vw, 72px) clamp(20px, 4vw, 48px) 96px;
}
.page--narrow { max-width: 760px; }

.layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 48px;
}
@media (min-width: 960px) {
  .layout--with-toc {
    grid-template-columns: minmax(0, 1fr) 220px;
  }
  .layout--with-toc .article { order: 1; }
  .layout--with-toc .toc     { order: 2; }
}

/* header -------------------------------------------------------- */
.site-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding-bottom: 24px;
  margin-bottom: 56px;
  border-bottom: 1px solid var(--rule);
  font-size: 14px;
  color: var(--ink-dim);
}
.site-header a {
  color: var(--ink);
  text-decoration: none;
  font-family: var(--font-serif);
  font-size: 18px;
  letter-spacing: -0.01em;
}
.site-header a:hover { color: var(--accent); }
.site-header .crumb { color: var(--ink-faint); }

/* article ------------------------------------------------------- */
.article { min-width: 0; }
.article-meta {
  font-size: 13px;
  color: var(--ink-faint);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-bottom: 12px;
}

/* typography ---------------------------------------------------- */
h1, h2, h3, h4 {
  font-family: var(--font-serif);
  color: var(--ink);
  letter-spacing: -0.015em;
  line-height: 1.2;
  margin: 0 0 16px;
  font-weight: 600;
}
h1 { font-size: clamp(32px, 4.8vw, 44px); margin-bottom: 24px; }
h2 {
  font-size: 26px;
  margin-top: 56px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--rule-soft);
}
h3 { font-size: 20px; margin-top: 36px; }
h4 { font-size: 17px; margin-top: 28px; color: var(--ink-dim); }

.subtitle {
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 20px;
  color: var(--ink-dim);
  margin: 0 0 40px;
  max-width: 56ch;
  font-weight: 400;
}

p { margin: 0 0 18px; max-width: var(--reading-width); }
strong { font-weight: 600; }
em { font-style: italic; }

a {
  color: var(--ink);
  text-decoration: underline;
  text-decoration-color: var(--accent);
  text-decoration-thickness: 1.5px;
  text-underline-offset: 3px;
  transition: color .15s ease;
}
a:hover { color: var(--accent); }

ul, ol { padding-left: 22px; margin: 0 0 18px; max-width: var(--reading-width); }
li { margin-bottom: 6px; }
li::marker { color: var(--ink-faint); }

hr {
  border: none;
  border-top: 1px solid var(--rule);
  margin: 48px 0;
}

/* code ---------------------------------------------------------- */
code {
  font-family: var(--font-mono);
  font-size: 0.92em;
  background: var(--bg-soft);
  padding: 1px 6px;
  border-radius: 3px;
  color: var(--ink);
}
pre {
  background: var(--bg-soft);
  border: 1px solid var(--rule);
  border-radius: 6px;
  padding: 18px 20px;
  overflow-x: auto;
  font-size: 14px;
  line-height: 1.55;
  margin: 24px 0 28px;
  position: relative;
}
pre code {
  background: transparent;
  padding: 0;
  font-size: inherit;
}
.code-meta {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ink-faint);
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin: 28px 0 -8px;
}

/* callouts ------------------------------------------------------ */
.callout {
  margin: 28px 0;
  padding: 18px 22px;
  border-left: 3px solid var(--rule);
  background: var(--bg-soft);
  border-radius: 0 6px 6px 0;
  max-width: var(--reading-width);
}
.callout > :last-child { margin-bottom: 0; }
.callout-label {
  display: block;
  font-family: var(--font-sans);
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin-bottom: 6px;
  font-weight: 600;
}
.callout--insight { border-left-color: var(--accent); background: var(--accent-soft); }
.callout--insight .callout-label { color: var(--accent); }
.callout--warn    { border-left-color: #c47a1d; background: #faf0e1; }
.callout--warn    .callout-label { color: #a35c10; }

/* key takeaway -------------------------------------------------- */
.takeaway {
  margin: 36px 0;
  padding: 24px 28px;
  background: var(--bg-sink);
  border-radius: 8px;
  font-family: var(--font-serif);
  font-size: 19px;
  line-height: 1.5;
  color: var(--ink);
  max-width: var(--reading-width);
}
.takeaway-label {
  display: block;
  font-family: var(--font-sans);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin-bottom: 10px;
  font-weight: 600;
}

/* figure -------------------------------------------------------- */
figure {
  margin: 32px 0;
  max-width: var(--reading-width);
}
figcaption {
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 14px;
  color: var(--ink-dim);
  margin-top: 10px;
  text-align: center;
}
.figure-frame {
  border: 1px solid var(--rule);
  border-radius: 6px;
  padding: 24px;
  background: #fff;
}

/* table --------------------------------------------------------- */
.table-wrap { overflow-x: auto; margin: 24px 0; max-width: var(--reading-width); }
table {
  border-collapse: collapse;
  width: 100%;
  font-size: 15px;
}
th, td {
  text-align: left;
  padding: 10px 14px;
  border-bottom: 1px solid var(--rule);
  vertical-align: top;
}
th {
  font-family: var(--font-sans);
  font-weight: 600;
  color: var(--ink-dim);
  font-size: 12px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  border-bottom: 1.5px solid var(--ink);
}

/* TOC ----------------------------------------------------------- */
.toc {
  font-size: 14px;
  line-height: 1.55;
}
@media (min-width: 960px) {
  .toc {
    position: sticky;
    top: 32px;
    align-self: start;
    border-left: 1px solid var(--rule);
    padding-left: 20px;
    margin-top: 28px;
  }
}
.toc-label {
  font-family: var(--font-sans);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-faint);
  font-weight: 600;
  margin-bottom: 12px;
}
.toc ol { list-style: none; padding: 0; margin: 0; }
.toc li { margin-bottom: 8px; }
.toc a {
  color: var(--ink-dim);
  text-decoration: none;
  display: block;
}
.toc a:hover { color: var(--accent); }
.toc .toc-sub { padding-left: 14px; margin-top: 6px; font-size: 13px; }

/* index card list (landing) ------------------------------------ */
.studies { list-style: none; padding: 0; margin: 40px 0 0; }
.studies li {
  border-bottom: 1px solid var(--rule);
  padding: 20px 0;
}
.studies li:first-child { border-top: 1px solid var(--rule); }
.study-link {
  display: block;
  text-decoration: none;
  color: var(--ink);
}
.study-link:hover .study-title { color: var(--accent); }
.study-title {
  font-family: var(--font-serif);
  font-size: 22px;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin-bottom: 4px;
  transition: color .15s ease;
}
.study-meta {
  font-size: 13px;
  color: var(--ink-faint);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-bottom: 6px;
}
.study-desc {
  color: var(--ink-dim);
  font-size: 15px;
  max-width: 60ch;
}

/* footer -------------------------------------------------------- */
.site-footer {
  margin-top: 96px;
  padding-top: 24px;
  border-top: 1px solid var(--rule);
  font-size: 13px;
  color: var(--ink-faint);
  display: flex;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
}
.site-footer a { color: var(--ink-dim); text-decoration: none; }
.site-footer a:hover { color: var(--accent); }

/* utilities ----------------------------------------------------- */
.lede { font-size: 19px; line-height: 1.55; color: var(--ink-dim); max-width: 60ch; margin-bottom: 32px; }
.dim  { color: var(--ink-dim); }
.faint { color: var(--ink-faint); }
.mono { font-family: var(--font-mono); }