/* ══════════════════════════════════════════════════════════════════════════
   ee-base.css — Education Engine Shared Layout
   Nav, footer, hero, containers, cards, code blocks, scroll cards.
   Uses --fn-* tokens exclusively (legacy vars via ee-compat.css).
   Zero telemetry. Zero external dependencies. Native fonts only.
   ══════════════════════════════════════════════════════════════════════════ */

/* ── Reset ─────────────────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  font-family: var(--fn-font-body);
  font-size: 16px;
  line-height: 1.6;
  color: var(--fn-text);
  background: var(--fn-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body { min-height: 100vh; }

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

/* ── Container ─────────────────────────────────────────────────────────── */
.container { max-width: 960px; margin: 0 auto; padding: 0 20px; }

section { padding: 40px 0; }

/* ── Navigation ────────────────────────────────────────────────────────── */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--fn-surface);
  border-bottom: 1px solid var(--fn-border);
  backdrop-filter: blur(8px);
}

.nav-inner {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
}

.logo {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--fn-text-bright);
  text-decoration: none;
  letter-spacing: 0.01em;
}
.logo span { color: var(--fn-accent); }

.nav-links {
  display: flex;
  align-items: center;
  list-style: none;
  gap: 6px;
}

.nav-links a {
  padding: 6px 12px;
  font-size: 0.88rem;
  color: var(--fn-text-dim);
  border-radius: var(--fn-radius-md);
  transition: color 0.15s, background 0.15s;
}
.nav-links a:hover {
  color: var(--fn-text-bright);
  background: var(--fn-surface2);
}

/* Theme button in nav */
.theme-btn {
  background: none;
  border: 1px solid var(--fn-border);
  color: var(--fn-text-dim);
  font-size: 0.78rem;
  padding: 4px 10px;
  border-radius: var(--fn-radius-md);
  cursor: pointer;
  font-family: inherit;
  letter-spacing: 0.04em;
  transition: all 0.15s;
}
.theme-btn:hover {
  border-color: var(--fn-accent);
  color: var(--fn-accent);
}

/* Mobile menu */
.mobile-menu-btn {
  display: none;
  background: none;
  border: 1px solid var(--fn-border);
  border-radius: 6px;
  color: var(--fn-text-bright);
  font-size: 1.3rem;
  padding: 6px 10px;
  cursor: pointer;
  line-height: 1;
}

/* ── Hero ──────────────────────────────────────────────────────────────── */
.hero {
  text-align: center;
  padding: 60px 20px 40px;
}

.hero h1 {
  font-size: 2.4rem;
  font-weight: 800;
  color: var(--fn-text-bright);
  letter-spacing: -0.02em;
  margin-bottom: 12px;
  line-height: 1.2;
}

.hero .accent { color: var(--fn-accent); }

.tagline {
  font-size: 1.1rem;
  color: var(--fn-text-dim);
  max-width: 540px;
  margin: 0 auto;
  line-height: 1.6;
}

/* ── Section Titles ────────────────────────────────────────────────────── */
.section-title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--fn-text-bright);
  margin-bottom: 12px;
}
.section-subtitle {
  color: var(--fn-text-dim);
  font-size: 0.95rem;
  margin-bottom: 24px;
  max-width: 640px;
}
.section-center { text-align: center; }

/* ── Card Grid ─────────────────────────────────────────────────────────── */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 16px;
}

.card {
  background: var(--fn-surface);
  border: 1px solid var(--fn-border);
  border-radius: var(--fn-radius-lg);
  padding: 24px;
  transition: border-color 0.15s;
}
.card:hover { border-color: var(--fn-accent); }

.card h3 {
  font-size: 1.05rem;
  color: var(--fn-text-bright);
  margin-bottom: 8px;
}
.card p {
  color: var(--fn-text-dim);
  font-size: 0.9rem;
  line-height: 1.6;
}
.card-icon {
  font-size: 1.8rem;
  display: block;
  margin-bottom: 12px;
}

/* ── Scroll Cards ──────────────────────────────────────────────────────── */
.scroll-card {
  background: var(--fn-surface);
  border: 1px solid var(--fn-border);
  border-radius: var(--fn-radius-lg);
  padding: 20px 24px;
  margin-bottom: 12px;
}
.scroll-card h3 {
  color: var(--fn-text-bright);
  font-size: 1rem;
  margin-bottom: 8px;
}
.scroll-card p {
  color: var(--fn-text-dim);
  font-size: 0.9rem;
  line-height: 1.7;
}
.scroll-type {
  display: inline-block;
  font-size: 0.68rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 2px 8px;
  border-radius: var(--fn-radius-full);
  background: var(--fn-accent-glow);
  color: var(--fn-accent);
  margin-bottom: 8px;
}

/* ── Code Blocks ───────────────────────────────────────────────────────── */
.code-block {
  background: var(--fn-bg);
  border: 1px solid var(--fn-border);
  border-radius: var(--fn-radius-md);
  padding: 16px 20px;
  font-family: var(--fn-font-mono);
  font-size: 0.88rem;
  line-height: 1.5;
  color: var(--fn-text);
  overflow-x: auto;
}
.code-block .cmd { color: var(--fn-accent); }
.code-block .string { color: var(--fn-success); }

/* ── Buttons ───────────────────────────────────────────────────────────── */
.btn-primary {
  display: inline-block;
  padding: 12px 24px;
  background: var(--fn-accent);
  color: var(--fn-bg);
  font-weight: 700;
  font-size: 0.95rem;
  border: none;
  border-radius: var(--fn-radius-md);
  cursor: pointer;
  text-decoration: none;
  transition: opacity 0.15s;
  font-family: inherit;
}
.btn-primary:hover { opacity: 0.85; color: var(--fn-bg); }

.btn-secondary {
  display: inline-block;
  padding: 10px 20px;
  background: transparent;
  color: var(--fn-accent);
  font-size: 0.9rem;
  border: 1px solid var(--fn-accent);
  border-radius: var(--fn-radius-md);
  cursor: pointer;
  text-decoration: none;
  transition: all 0.15s;
  font-family: inherit;
}
.btn-secondary:hover {
  background: var(--fn-accent-glow);
  color: var(--fn-text-bright);
}

.cta-group {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}

/* ── Footer ────────────────────────────────────────────────────────────── */
.site-footer {
  text-align: center;
  padding: 32px 20px;
  border-top: 1px solid var(--fn-border);
  margin-top: 40px;
  color: var(--fn-text-ghost);
  font-size: 0.85rem;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px 20px;
  margin-bottom: 12px;
}
.footer-links a {
  color: var(--fn-text-dim);
  font-size: 0.82rem;
}
.footer-links a:hover { color: var(--fn-accent); }

/* ── Responsive ────────────────────────────────────────────────────────── */
@media (max-width: 640px) {
  .hero h1 { font-size: 1.8rem; }
  .tagline { font-size: 0.95rem; }
  section { padding: 28px 0; }
  .card-grid { grid-template-columns: 1fr; }
}

@media (max-width: 480px) {
  .mobile-menu-btn { display: block; }
  .nav-links {
    display: none;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--fn-surface);
    padding: 12px 16px;
    border-bottom: 1px solid var(--fn-border);
    gap: 4px;
    z-index: 50;
  }
  .nav-links.nav-open { display: flex; }
  .nav-links li { width: 100%; }
  .nav-links a, .nav-links button {
    display: block;
    width: 100%;
    padding: 12px;
    text-align: left;
    font-size: 0.95rem;
  }
  .nav-inner { position: relative; }
}