/* billgraham.io — base stylesheet
   Typography-first, no framework. Light/dark follows system preference. */

:root {
  --font-serif: Charter, "Bitstream Charter", "Sitka Text", Cambria, "Iowan Old Style", Georgia, serif;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;

  --bg: #faf9f7;
  --text: #1c1c1a;
  --text-secondary: #5c5850;
  --border: #e2ddd4;
  --accent: #9c3f1c;
  --accent-contrast: #ffffff;

  --content-width: 38rem;
  --gutter: 1.25rem;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #17171a;
    --text: #e8e6e1;
    --text-secondary: #aaa69d;
    --border: #333230;
    --accent: #e39a68;
    --accent-contrast: #17171a;
  }
}

* {
  box-sizing: border-box;
}

html {
  font-size: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-serif);
  font-size: 1.125rem;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

@media (prefers-reduced-motion: no-preference) {
  a, .btn {
    transition: color 0.15s ease, background-color 0.15s ease, border-color 0.15s ease;
  }
}

/* Layout */

.site-header,
.site-footer,
main {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.site-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
  padding-top: 2rem;
  padding-bottom: 1.5rem;
  font-family: var(--font-sans);
}

.site-title {
  font-size: 1.0625rem;
  font-weight: 600;
  letter-spacing: 0.01em;
}

.site-title a {
  text-decoration: none;
  color: var(--text);
}

.site-nav {
  display: flex;
  gap: 1.25rem;
  font-size: 0.9375rem;
}

.site-nav a {
  text-decoration: none;
  color: var(--text-secondary);
}

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

main {
  padding-top: 1rem;
  padding-bottom: 4rem;
  min-height: 60vh;
}

.site-footer {
  border-top: 1px solid var(--border);
  padding-top: 1.75rem;
  padding-bottom: 2.5rem;
  font-family: var(--font-sans);
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.footer-signup {
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 1rem 1.25rem;
  margin-bottom: 1.5rem;
}

.footer-signup__label {
  display: block;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-secondary);
  margin-bottom: 0.6rem;
}

.footer-signup-form {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.footer-signup-form input[type="email"] {
  flex: 1 1 12rem;
  padding: 0.55rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: 5px;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 0.9375rem;
}

.footer-signup-form input[type="email"]::placeholder {
  color: var(--text-secondary);
}

.footer-signup-form button {
  padding: 0.55rem 1.1rem;
  border: 1px solid var(--accent);
  border-radius: 5px;
  background: var(--accent);
  color: var(--accent-contrast);
  font-family: var(--font-sans);
  font-size: 0.9375rem;
  font-weight: 600;
  cursor: pointer;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.footer-meta {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem 1rem;
}

/* Typography */

h1, h2, h3 {
  font-family: var(--font-serif);
  font-weight: 600;
  line-height: 1.25;
  margin-top: 2rem;
  margin-bottom: 0.75rem;
}

h1 {
  font-size: 1.875rem;
}

h2 {
  font-size: 1.4rem;
}

h3 {
  font-size: 1.15rem;
}

p {
  margin: 0 0 1.25rem;
}

a {
  color: var(--accent);
}

a:hover {
  text-decoration-thickness: 2px;
}

ul, ol {
  padding-left: 1.4rem;
  margin: 0 0 1.25rem;
}

blockquote {
  margin: 1.5rem 0;
  padding-left: 1rem;
  border-left: 3px solid var(--border);
  color: var(--text-secondary);
  font-style: italic;
}

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

code, pre, kbd, samp {
  font-family: var(--font-mono);
  font-size: 0.875em;
}

code {
  background: color-mix(in srgb, var(--text) 6%, transparent);
  padding: 0.15em 0.35em;
  border-radius: 4px;
}

pre {
  background: color-mix(in srgb, var(--text) 6%, transparent);
  padding: 1rem;
  border-radius: 6px;
  overflow-x: auto;
}

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

img, iframe {
  max-width: 100%;
}

/* Homepage */

.intro {
  font-size: 1.0625rem;
  color: var(--text-secondary);
  margin-bottom: 2.5rem;
}

.publication-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.publication-item {
  padding: 1.5rem 0;
  border-top: 1px solid var(--border);
}

.publication-item:first-child {
  border-top: none;
}

.publication-item__title {
  font-size: 1.2rem;
  font-weight: 600;
  margin: 0 0 0.35rem;
}

.publication-item__title a {
  text-decoration: none;
  color: var(--text);
}

.publication-item__title a:hover {
  color: var(--accent);
}

.publication-item__date {
  font-family: var(--font-sans);
  font-size: 0.8125rem;
  color: var(--text-secondary);
  display: block;
  margin-bottom: 0.5rem;
}

.publication-item__excerpt {
  color: var(--text-secondary);
  margin: 0;
}

/* Publication page */

.pub-header {
  margin-bottom: 1.5rem;
}

.pub-date {
  font-family: var(--font-sans);
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.pub-media {
  margin: 1.75rem 0;
}

.video-embed {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  border-radius: 6px;
  overflow: hidden;
  background: color-mix(in srgb, var(--text) 8%, transparent);
}

.video-embed iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

.pub-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin: 1.5rem 0 2rem;
  font-family: var(--font-sans);
}

.btn {
  display: inline-block;
  padding: 0.6rem 1.1rem;
  border-radius: 5px;
  font-size: 0.9375rem;
  font-weight: 600;
  text-decoration: none;
  border: 1px solid var(--accent);
}

.btn-primary {
  background: var(--accent);
  color: var(--accent-contrast);
}

.btn-secondary {
  background: transparent;
  color: var(--accent);
}

.pub-body {
  margin-top: 2rem;
}

/* About page */

.page-title {
  margin-top: 1rem;
}