:root {
  --bg: #f9f9f9;
  --surface: #ffffff;
  --text: #2c3e50;
  --muted: #667085;
  --border: #e5e7eb;
  --accent: tan;
  --brand-dark: rgb(61, 61, 61);
  --focus: #2c3e50;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--text);
  background:
    radial-gradient(ellipse 120% 80% at 0% 0%, rgba(210, 180, 140, 0.18), transparent 55%),
    radial-gradient(ellipse 90% 60% at 100% 0%, rgba(61, 61, 61, 0.06), transparent 50%),
    var(--bg);
  line-height: 1.6;
  min-height: 100vh;
}

a {
  color: var(--brand-dark);
}

a:hover {
  color: #000;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--brand-dark);
  color: #fff;
  padding: 0.5rem 1rem;
  z-index: 100;
}

.skip-link:focus {
  left: 0.5rem;
  top: 0.5rem;
}

.site-header,
.site-footer,
main {
  width: min(100% - 32px, 960px);
  margin-left: auto;
  margin-right: auto;
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.25rem 0;
  flex-wrap: wrap;
}

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

.brand {
  /* Layout slot for the scaled badge (transform does not affect flow). */
  position: relative;
  display: block;
  flex-shrink: 0;
  width: 168px;
  height: 48px;
  text-decoration: none;
  color: inherit;
}

/*
 * Keep synchronized with src/App.vue `.logo`.
 * Differences that broke visual identity before:
 * - missing transform: scale(1.5)
 * - different font-size / line-height
 * - remote Google Fonts vs app font stack timing
 */
.brand .logo {
  font-family: "Satisfy", cursive;
  font-size: normal;
  /* Isolate from SEO body line-height: 1.6 (App.vue logo inherits browser normal). */
  line-height: normal;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;

  color: whitesmoke;
  background-color: rgb(61, 61, 61);
  border-radius: 5px;
  padding: 5px 10px;
  border: tan 3px solid;

  position: absolute;
  z-index: 10;
  left: 0;
  top: 0;
  display: -ms-flexbox;
  display: flex;
  -ms-flex-direction: row;
  flex-direction: row;
  z-index: 200;
  transform: scale(1.5);
  transform-origin: top left;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15),
              0 2px 4px rgba(0, 0, 0, 0.1);

  white-space: nowrap;
  margin: 0;
}

.site-header nav {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
}

.site-header nav a:not(.button) {
  text-decoration: none;
  color: var(--muted);
}

.site-header nav a:not(.button):hover {
  color: var(--text);
}

main {
  padding: 0.5rem 0 3rem;
}

h1 {
  font-size: clamp(1.75rem, 3vw, 2.25rem);
  line-height: 1.2;
  margin: 0 0 1rem;
  color: var(--brand-dark);
}

h2 {
  font-size: 1.25rem;
  margin: 2rem 0 0.75rem;
  color: var(--brand-dark);
}

.lede {
  font-size: 1.125rem;
  max-width: 42rem;
  margin-top: 0;
}

.muted {
  color: var(--muted);
  font-size: 0.9rem;
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin: 1.25rem 0 1.75rem;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.55rem 1rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--surface);
  text-decoration: none;
  color: var(--text);
  font-weight: 600;
}

.button:hover {
  border-color: #d0d5dd;
}

.button-primary {
  background: var(--brand-dark);
  border-color: var(--brand-dark);
  color: #fff;
}

.button-primary:hover {
  color: #fff;
  filter: brightness(1.08);
}

.button:focus-visible,
a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 2px;
}

.resource-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1rem;
  margin-top: 1.5rem;
}

.resource-card {
  display: block;
  padding: 1.1rem 1.2rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  text-decoration: none;
  color: inherit;
  transition: border-color 0.15s ease;
}

.resource-card:hover {
  border-color: var(--accent);
}

.resource-card h2 {
  margin: 0 0 0.4rem;
  font-size: 1.05rem;
}

.resource-card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.screenshot {
  margin: 1.5rem 0;
}

.screenshot img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface);
}

.screenshot figcaption {
  margin-top: 0.5rem;
  color: var(--muted);
  font-size: 0.9rem;
}

.formula-grid {
  display: grid;
  gap: 1rem;
}

.formula-example {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1rem;
}

.formula-label {
  margin: 0 0 0.5rem;
  font-weight: 600;
}

.formula-example pre {
  margin: 0 0 0.75rem;
  padding: 0.75rem;
  overflow-x: auto;
  background: #f3f4f6;
  border-radius: 6px;
  font-size: 0.9rem;
}

.formula-render {
  overflow-x: auto;
  padding: 0.5rem 0;
}

.copy-latex {
  margin-top: 0.5rem;
  padding: 0.35rem 0.7rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--bg);
  cursor: pointer;
  font: inherit;
}

.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface);
}

table {
  width: 100%;
  border-collapse: collapse;
}

th,
td {
  text-align: left;
  padding: 0.65rem 0.85rem;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}

th {
  background: #f3f4f6;
  font-weight: 600;
}

tr:last-child td {
  border-bottom: none;
}

kbd {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.9em;
  padding: 0.1em 0.35em;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: #f3f4f6;
}

.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  list-style: none;
  padding: 0;
  margin: 0 0 1rem;
  color: var(--muted);
  font-size: 0.95rem;
}

.breadcrumbs li:not(:last-child)::after {
  content: "/";
  margin-left: 0.35rem;
  color: var(--border);
}

.site-footer {
  padding: 2rem 0 3rem;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.95rem;
}

.site-footer nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem;
  margin-bottom: 0.75rem;
}

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

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

.footer-note {
  margin: 0;
}

.not-found .cta-row {
  margin-top: 1.5rem;
}

pre code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

@media (max-width: 640px) {
  .site-header {
    align-items: flex-start;
  }
}