/* Spark Languages marketing + deep-link site.
   Self-contained, no external resources. Theme-aware (light + dark). */

:root {
  color-scheme: light dark;
  --bg: #ffffff;
  --fg: #1c1c1e;
  --muted: #6b6b70;
  --card: #f5f5f7;
  --border: #e2e2e6;
  --accent: #0a6cff;
  --accent-fg: #ffffff;
  --radius: 14px;
  --maxw: min(94vw, 96rem);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f0f11;
    --fg: #f2f2f4;
    --muted: #9a9aa2;
    --card: #1b1b1f;
    --border: #2c2c31;
    --accent: #4c93ff;
  }
}

* { box-sizing: border-box; }

html, body { margin: 0; padding: 0; }

body {
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.55 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  padding: 1.5rem;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.hero {
  max-width: var(--maxw);
  margin: 3rem auto 2rem;
  text-align: center;
}

.brand {
  font-weight: 600;
  letter-spacing: 0.01em;
  color: var(--muted);
  margin: 0 0 0.75rem;
}
.brand a { color: inherit; }

.hero h1 {
  font-size: clamp(1.5rem, 3.4vw, 2.4rem);
  line-height: 1.25;
  font-weight: 700;
  margin: 0 auto;
}

.language-apps {
  max-width: 46rem;
  margin: 0 auto;
  width: 100%;
  text-align: center;
}

.language-apps .bubble {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: calc(var(--radius) + 10px);
  padding: 1rem 1.25rem;
}

.language-apps .bubble .card {
  background: var(--bg);
  text-align: center;
}

.language-apps h2 {
  font-size: 1.6rem;
  margin: 0 0 0.75rem;
}

.language-apps .intro {
  color: var(--muted);
  max-width: 58ch;
  margin: 0 auto 2rem;
}

.grid {
  max-width: var(--maxw);
  margin: 0 auto;
  width: 100%;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(16rem, 1fr));
  gap: 1.25rem;
  text-align: left;
}

.language-apps .grid {
  max-width: 100%;
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
}
.card h2 { margin: 0 0 0.5rem; font-size: 1.3rem; }
.card p { margin: 0 0 1rem; color: var(--fg); }
.card .cta { margin: 0; }

.note {
  grid-column: 1 / -1;
  text-align: center;
  color: var(--muted);
  font-size: 0.95rem;
  margin: 0.5rem 0 0;
}

.btn {
  display: inline-block;
  padding: 0.65rem 1.15rem;
  border-radius: 999px;
  border: 1px solid var(--border);
  font-weight: 600;
  color: var(--fg);
  background: transparent;
}
.btn:hover { text-decoration: none; border-color: var(--accent); }
.btn-primary {
  background: var(--accent);
  color: var(--accent-fg);
  border-color: var(--accent);
}
.btn-primary:hover { color: var(--accent-fg); opacity: 0.92; }
.btn-disabled {
  color: var(--muted);
  cursor: default;
  opacity: 0.7;
}

.redirect {
  max-width: 32rem;
  margin: 4rem auto;
  text-align: center;
  flex: 1;
}
.redirect h1 { font-size: 1.5rem; margin: 0.5rem 0 1.5rem; }
.redirect .muted { color: var(--muted); margin-top: 2rem; }
.redirect .cta { display: flex; gap: 0.75rem; justify-content: center; flex-wrap: wrap; }

.spinner {
  width: 2rem;
  height: 2rem;
  margin: 1.5rem auto;
  border: 3px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }
@media (prefers-reduced-motion: reduce) { .spinner { animation: none; } }

.footer {
  max-width: var(--maxw);
  margin: 3rem auto 0;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  text-align: center;
  color: var(--muted);
  font-size: 0.9rem;
  width: 100%;
}
.footer a { color: var(--muted); }