/* MathBuddy informational site — static, local-only styles. */

:root {
  --color-bg: #ffffff;
  --color-bg-alt: #f5f7fa;
  --color-text: #1c2530;
  --color-text-muted: #4b5563;
  --color-border: #d7dde5;
  --color-primary: #1a5fb4;
  --color-primary-dark: #123f7a;
  --color-focus: #b3261e;
  --color-callout-bg: #fff8e6;
  --color-callout-border: #e0b100;
  --max-width: 46rem;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #14181f;
    --color-bg-alt: #1c222c;
    --color-text: #e8edf3;
    --color-text-muted: #a9b4c2;
    --color-border: #313b48;
    --color-primary: #6ba8f0;
    --color-primary-dark: #9cc4f5;
    --color-focus: #ff8a80;
    --color-callout-bg: #2a2410;
    --color-callout-border: #8a6d00;
  }
}

* {
  box-sizing: border-box;
}

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

body {
  margin: 0;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: -apple-system, "Segoe UI", system-ui, Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.6;
  font-size: 1rem;
}

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

a:hover {
  color: var(--color-primary-dark);
}

:focus-visible {
  outline: 3px solid var(--color-focus);
  outline-offset: 2px;
}

.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  background: var(--color-bg);
  color: var(--color-text);
  padding: 0.75rem 1rem;
  z-index: 100;
  border: 2px solid var(--color-primary);
}

.skip-link:focus {
  left: 1rem;
  top: 1rem;
}

header.site-header {
  border-bottom: 1px solid var(--color-border);
  background: var(--color-bg-alt);
}

.site-header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1rem 1.25rem;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
}

.site-brand {
  font-weight: 700;
  font-size: 1.15rem;
  text-decoration: none;
  color: var(--color-text);
}

nav.site-nav ul {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem;
  margin: 0;
  padding: 0;
}

nav.site-nav a {
  text-decoration: none;
  font-weight: 600;
}

nav.site-nav a:hover,
nav.site-nav a:focus-visible {
  text-decoration: underline;
}

main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 2rem 1.25rem 3rem;
}

h1 {
  font-size: 1.9rem;
  margin-top: 0;
}

h2 {
  font-size: 1.3rem;
  margin-top: 2.25rem;
}

h3 {
  font-size: 1.05rem;
  margin-top: 1.5rem;
}

p,
ul,
ol {
  color: var(--color-text);
}

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

.tagline {
  color: var(--color-text-muted);
  font-size: 1.05rem;
}

.status-line {
  display: inline-block;
  border: 1px solid var(--color-border);
  background: var(--color-bg-alt);
  border-radius: 999px;
  padding: 0.3rem 0.9rem;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-text-muted);
  margin: 0.75rem 0 1.25rem;
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin: 1.5rem 0;
}

.btn {
  display: inline-block;
  text-decoration: none;
  padding: 0.7rem 1.25rem;
  border-radius: 6px;
  font-weight: 600;
  border: 2px solid transparent;
}

.btn-primary {
  background: var(--color-primary);
  color: #ffffff;
  border-color: var(--color-primary);
}

.btn-primary:hover,
.btn-primary:focus-visible {
  background: var(--color-primary-dark);
  border-color: var(--color-primary-dark);
  color: #ffffff;
}

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

.btn-secondary:hover,
.btn-secondary:focus-visible {
  background: var(--color-bg-alt);
}

.callout {
  background: var(--color-callout-bg);
  border: 1px solid var(--color-callout-border);
  border-radius: 6px;
  padding: 1rem 1.25rem;
  margin: 1.5rem 0;
}

.callout p:last-child {
  margin-bottom: 0;
}

.card {
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 1.25rem;
  margin: 1rem 0;
  background: var(--color-bg-alt);
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0;
}

th,
td {
  text-align: left;
  padding: 0.5rem 0.6rem;
  border-bottom: 1px solid var(--color-border);
  vertical-align: top;
}

footer.site-footer {
  border-top: 1px solid var(--color-border);
  margin-top: 2rem;
}

.site-footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1.5rem 1.25rem;
  color: var(--color-text-muted);
  font-size: 0.9rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
}

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

@media (max-width: 480px) {
  .site-header-inner {
    flex-direction: column;
    align-items: flex-start;
  }

  nav.site-nav ul {
    gap: 0.9rem;
  }

  h1 {
    font-size: 1.55rem;
  }
}