@font-face {
  font-family: "Spectral";
  src: url("/fonts/spectral-400.woff2") format("woff2");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: "Spectral";
  src: url("/fonts/spectral-400-italic.woff2") format("woff2");
  font-weight: 400;
  font-style: italic;
  font-display: swap;
}

@font-face {
  font-family: "Spectral";
  src: url("/fonts/spectral-600.woff2") format("woff2");
  font-weight: 600;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: "Spectral";
  src: url("/fonts/spectral-700.woff2") format("woff2");
  font-weight: 700;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: "Inter";
  src: url("/fonts/inter.woff2") format("woff2-variations"),
       url("/fonts/inter.woff2") format("woff2");
  font-weight: 100 900;
  font-style: normal;
  font-display: swap;
}

:root {
  --bg: #ffffff;
  --soft: #faf7f1;
  --ink: #1a1a1a;
  --muted: #555555;
  --rule: #d8d4cc;
  --accent: #6a4a1f;

  --max-width: 68ch;
  --wide: 78ch;

  --serif: "Spectral", Georgia, "Iowan Old Style", "Palatino Linotype", serif;
  --sans: "Inter", -apple-system, "Segoe UI", Helvetica, Arial, sans-serif;
  --mono: "SF Mono", Consolas, "Courier New", monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d0d10;
    --soft: #1a1a20;
    --ink: #e8e6df;
    --muted: #9a978d;
    --rule: #2a2a30;
    --accent: #d6a458;
  }
}

* { box-sizing: border-box; }

html {
  font-size: 18px;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  font-family: var(--serif);
  font-size: 1.05rem;
  line-height: 1.6;
  color: var(--ink);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

.wrap {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.wrap-wide {
  max-width: var(--wide);
  margin: 0 auto;
  padding: 0 1.5rem;
}

main {
  padding: 2rem 0 5rem;
}

h1, h2, h3, h4 {
  font-family: var(--serif);
  color: var(--ink);
  line-height: 1.2;
  font-weight: 700;
  margin: 1.8em 0 0.5em;
}

h1 {
  font-size: 2rem;
  margin-top: 0;
}

h2 {
  font-size: 1.4rem;
  border-bottom: 1px solid var(--rule);
  padding-bottom: 0.25em;
}

h3 {
  font-size: 1.15rem;
  color: var(--accent);
}

h4 {
  font-family: var(--sans);
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-weight: 600;
}

p, ul, ol { margin: 0 0 0.85em; }

a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid var(--rule);
  transition: border-color 120ms ease;
}

a:hover { border-bottom-color: var(--accent); }

strong { font-weight: 700; }
em { font-style: italic; }

code, pre {
  font-family: var(--mono);
  font-size: 0.9em;
}

code {
  background: var(--soft);
  padding: 0.1em 0.35em;
  border-radius: 3px;
}

pre {
  background: var(--soft);
  border-left: 3px solid var(--accent);
  padding: 0.75em 1em;
  line-height: 1.5;
  overflow-x: auto;
}

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

blockquote {
  margin: 1.2em 0;
  padding: 0.3em 1rem;
  border-left: 3px solid var(--accent);
  color: var(--muted);
  font-style: italic;
}

hr {
  border: none;
  border-top: 1px solid var(--rule);
  margin: 2.5rem 0;
}

img, svg, video { max-width: 100%; height: auto; }

/* Masthead */
header.site {
  border-bottom: 1px solid var(--rule);
  background: var(--bg);
}

header.site .inner {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  max-width: var(--wide);
  margin: 0 auto;
  padding: 1.15rem 1.5rem;
}

header.site .brand {
  font-family: var(--serif);
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--ink);
  border-bottom: none;
  letter-spacing: -0.005em;
}

header.site .brand:hover { color: var(--accent); }

header.site nav {
  font-family: var(--sans);
  font-size: 0.78rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

header.site nav a {
  color: var(--muted);
  border-bottom: none;
  margin-left: 1.5rem;
}

header.site nav a:hover { color: var(--accent); }

/* Footer */
footer.site {
  border-top: 1px solid var(--rule);
  margin-top: 5rem;
  padding: 1.5rem 0 2.5rem;
  font-family: var(--sans);
  color: var(--muted);
  font-size: 0.82rem;
}

footer.site .inner {
  max-width: var(--wide);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Lesson end nav — "All lessons" link at the bottom of each lesson */
.lesson-end {
  padding: 2rem 1.5rem 3rem;
  text-align: center;
  font-family: var(--sans);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.lesson-end a {
  color: var(--accent);
  border-bottom: none;
}

.lesson-end a:hover {
  border-bottom: 1px solid var(--accent);
}

/* Small uppercase label */
.eyebrow {
  font-family: var(--sans);
  font-size: 0.78rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--accent);
  display: block;
}

@media (max-width: 560px) {
  html { font-size: 17px; }
  header.site .inner { padding: 1rem; }
  header.site nav a { margin-left: 1rem; }
}