/* ============================================================================
   GT Course Data Service — landing page styles.
   Consumes ONLY --gt-* semantic tokens (static/gt-tokens.css). No raw color
   values. Component-class naming follows the GT design system conventions
   (.gt-nav, .gt-card, .gt-btn, .gt-badge, .gt-field, .gt-input, .gt-table).
   ============================================================================ */

/* ---------- Reset / base ---------- */

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

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

body {
  margin: 0;
  background: var(--gt-surface-default);
  color: var(--gt-fg-default);
  /* Serif display for headings (set per-element), sans body. */
  font-family: "Segoe UI", system-ui, -apple-system, Roboto, Helvetica,
    Arial, sans-serif;
  line-height: 1.6;
  font-size: 1rem;
}

h1,
h2,
h3,
h4 {
  font-family: Georgia, "Times New Roman", Cambria, serif;
  line-height: 1.2;
  letter-spacing: 0.01em;
  margin: 0 0 0.75rem;
  font-weight: 600;
}

a {
  color: var(--gt-accent-action);
  text-decoration-thickness: 1px;
  text-underline-offset: 2px;
}

a:hover {
  color: var(--gt-accent-brand);
}

code {
  font-family: "Cascadia Mono", Consolas, "SF Mono", Menlo, monospace;
  font-size: 0.9em;
  background: color-mix(in srgb, var(--gt-fg-default) 8%, transparent);
  padding: 0.05rem 0.3rem;
  border-radius: 0.25rem;
}

/* ---------- Layout ---------- */

.gt-nav {
  display: flex;
  align-items: center;
  gap: 0.875rem;
  padding: 0.75rem 1.5rem;
  background: var(--gt-surface-chrome);
  color: var(--gt-fg-on-chrome);
  border-bottom: 1px solid var(--gt-surface-border);
}

.gt-nav__brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--gt-fg-on-chrome);
  text-decoration: none;
  font-weight: 600;
}

.gt-nav__monogram {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.25rem;
  height: 2.25rem;
  font-family: Georgia, "Times New Roman", serif;
  font-weight: 700;
  font-size: 0.9rem;
  letter-spacing: 0.02em;
  color: var(--gt-fg-on-accent);
  background: var(--gt-accent-brand);
  border-radius: 0.25rem;
}

.gt-nav__subtitle {
  margin-left: auto;
  font-size: 0.875rem;
  color: var(--gt-fg-on-chrome);
  opacity: 0.85;
}

.gt-main {
  max-width: 72rem;
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
}

.gt-hero {
  margin-bottom: 2.5rem;
}

.gt-hero h1 {
  font-size: 2.5rem;
}

.gt-hero__lede {
  max-width: 46rem;
  font-size: 1.125rem;
  color: var(--gt-fg-default);
  margin: 0 0 1rem;
}

.gt-hero__sub {
  color: var(--gt-fg-muted);
  max-width: 46rem;
}

.gt-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(16rem, 1fr));
  gap: 1.25rem;
  margin: 1.5rem 0;
}

.gt-section {
  margin: 2.5rem 0;
}

/* ---------- Cards ---------- */

.gt-card {
  padding: 1.5rem;
  background: var(--gt-surface-card);
  color: var(--gt-fg-default);
  border: 1px solid var(--gt-surface-border);
  border-radius: 0.5rem;
  box-shadow: 0 2px 8px
    color-mix(in srgb, var(--gt-fg-default) 12%, transparent);
}

.gt-card h3 {
  margin-top: 0;
}

/* ---------- Buttons ---------- */

.gt-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.5rem 1.25rem;
  font: inherit;
  font-weight: 600;
  border: 1px solid transparent;
  border-radius: 0.375rem;
  cursor: pointer;
  background: var(--gt-accent-action);
  color: var(--gt-fg-on-accent);
}

.gt-btn:hover {
  background: var(--gt-accent-brand);
}

.gt-btn--chrome {
  background: var(--gt-surface-chrome);
  color: var(--gt-fg-on-chrome);
}

.gt-btn--chrome:hover {
  background: var(--gt-accent-action);
  color: var(--gt-fg-on-accent);
}

/* ---------- Forms ---------- */

.gt-field {
  display: flex;
  flex-direction: column;
  gap: 0.375rem;
}

.gt-field > label {
  font-weight: 600;
}

.gt-input {
  padding: 0.5rem 0.75rem;
  font: inherit;
  background: var(--gt-surface-card);
  color: var(--gt-fg-default);
  border: 1px solid var(--gt-surface-border);
  border-radius: 0.375rem;
}

.gt-input::placeholder {
  color: var(--gt-fg-muted);
}

.gt-form-row {
  display: flex;
  align-items: flex-end;
  gap: 0.75rem;
  flex-wrap: wrap;
}

/* ---------- Badges ---------- */

.gt-badge {
  display: inline-block;
  padding: 0.125rem 0.625rem;
  font-size: 0.875rem;
  font-weight: 600;
  border-radius: 9999px;
  border: 1px solid var(--gt-surface-border);
  background: transparent;
  color: var(--gt-fg-default);
}

.gt-badge--ok {
  background: color-mix(in srgb, var(--gt-status-success) 15%, var(--gt-surface-default));
  color: var(--gt-status-success);
  border-color: var(--gt-status-success);
}

.gt-badge--error {
  background: color-mix(in srgb, var(--gt-status-alert) 15%, var(--gt-surface-default));
  color: var(--gt-status-alert);
  border-color: var(--gt-status-alert);
}

.gt-badge--warn {
  background: color-mix(in srgb, var(--gt-accent-brand) 15%, var(--gt-surface-default));
  color: var(--gt-fg-default);
  border-color: var(--gt-accent-brand);
}

/* ---------- Source-check widget ---------- */

.gt-source-check {
  margin-top: 2rem;
}

.gt-source-check__output {
  margin-top: 1rem;
  min-height: 3rem;
}

.gt-source-check__loading {
  color: var(--gt-fg-muted);
  font-style: italic;
}

.gt-source-check__error {
  color: var(--gt-status-alert);
}

.gt-source-check__sample {
  display: block;
  white-space: pre-wrap;
  word-break: break-word;
  font-family: "Cascadia Mono", Consolas, monospace;
  font-size: 0.85rem;
  background: var(--gt-surface-default);
  border: 1px solid var(--gt-surface-border);
  border-radius: 0.375rem;
  padding: 0.75rem;
  margin-top: 0.75rem;
}

.gt-source-check__meta {
  color: var(--gt-fg-muted);
  font-size: 0.875rem;
  margin-top: 0.5rem;
}

/* ---------- Tables ---------- */

.gt-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--gt-surface-card);
  color: var(--gt-fg-default);
}

.gt-table th,
.gt-table td {
  padding: 0.5rem 0.75rem;
  text-align: left;
  border-bottom: 1px solid var(--gt-surface-border);
  vertical-align: top;
}

.gt-table th {
  background: var(--gt-surface-chrome);
  color: var(--gt-fg-on-chrome);
  font-weight: 600;
}

.gt-table tbody tr:nth-child(even) {
  background: var(--gt-surface-default);
}

.gt-table code {
  background: none;
  padding: 0;
}

/* ---------- Footer ---------- */

.gt-footer {
  margin-top: 3rem;
  padding: 1.5rem;
  border-top: 1px solid var(--gt-surface-border);
  color: var(--gt-fg-muted);
  font-size: 0.875rem;
}

.gt-footer a {
  color: var(--gt-fg-muted);
}

.gt-footer a:hover {
  color: var(--gt-fg-default);
}

/* ---------- Focus visibility (WCAG 2.2) ---------- */

.gt-btn:focus-visible,
.gt-input:focus-visible,
a:focus-visible {
  outline: 2px solid var(--gt-accent-action);
  outline-offset: 2px;
}