:root {
  --color-bg: #ffffff;
  --color-surface: #f8f9fa;
  --color-border: #e5e7eb;
  --color-primary: #2563eb;
  --color-primary-hover: #1d4ed8;
  --color-text: #1f2937;
  --color-text-heading: #111827;
  --color-text-muted: #6b7280;
  --color-success: #059669;
  --color-warning: #d97706;
  --color-danger: #dc2626;
  --max-width: 960px;
  --radius: 8px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  line-height: 1.7;
  color: var(--color-text);
  background: var(--color-bg);
}

.container { max-width: var(--max-width); margin: 0 auto; padding: 0 20px; }

/* Header */
header {
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  padding: 16px 0;
  position: sticky; top: 0; z-index: 100;
}
header .container { display: flex; justify-content: space-between; align-items: center; }
header .logo { font-size: 1.25rem; font-weight: 700; color: var(--color-primary); text-decoration: none; }
header nav a { color: var(--color-text-muted); text-decoration: none; margin-left: 24px; font-size: 0.9rem; }
header nav a:hover { color: var(--color-primary); }

/* Hero */
.hero { padding: 60px 0; text-align: center; background: var(--color-surface); }
.hero h1 { font-size: 2rem; color: var(--color-text-heading); margin-bottom: 12px; }
.hero p { color: var(--color-text-muted); font-size: 1.1rem; max-width: 600px; margin: 0 auto; }

/* Language cards */
.lang-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 24px; padding: 48px 0; }
.lang-card {
  border: 1px solid var(--color-border); border-radius: var(--radius); padding: 24px;
  transition: box-shadow 0.2s; text-decoration: none; color: inherit; display: block;
}
.lang-card:hover { box-shadow: 0 4px 16px rgba(0,0,0,0.08); border-color: var(--color-primary); }
.lang-card .flag { font-size: 2rem; margin-bottom: 8px; }
.lang-card h2 { font-size: 1.25rem; color: var(--color-text-heading); margin-bottom: 8px; }
.lang-card p { color: var(--color-text-muted); font-size: 0.9rem; }

/* Content pages */
.content { padding: 48px 0; }
.content h1 { font-size: 1.75rem; color: var(--color-text-heading); margin-bottom: 8px; }
.content h2 { font-size: 1.25rem; color: var(--color-text-heading); margin: 32px 0 12px; padding-bottom: 8px; border-bottom: 2px solid var(--color-border); }
.content h3 { font-size: 1.1rem; color: var(--color-text-heading); margin: 24px 0 8px; }
.content p { margin-bottom: 12px; }
.content ul, .content ol { margin: 8px 0 16px 24px; }
.content li { margin-bottom: 6px; }

/* Info boxes */
.info-box {
  background: #eff6ff; border-left: 4px solid var(--color-primary);
  padding: 16px 20px; border-radius: 0 var(--radius) var(--radius) 0; margin: 20px 0;
}
.info-box.warning { background: #fffbeb; border-left-color: var(--color-warning); }
.info-box.success { background: #ecfdf5; border-left-color: var(--color-success); }

/* Tables */
table { width: 100%; border-collapse: collapse; margin: 20px 0; font-size: 0.9rem; }
th, td { padding: 10px 14px; text-align: left; border-bottom: 1px solid var(--color-border); }
th { background: var(--color-surface); font-weight: 600; color: var(--color-text-heading); }

/* FAQ */
.faq-item { border: 1px solid var(--color-border); border-radius: var(--radius); margin-bottom: 12px; overflow: hidden; }
.faq-q { padding: 16px 20px; font-weight: 600; cursor: pointer; display: flex; justify-content: space-between; align-items: center; }
.faq-q:hover { background: var(--color-surface); }
.faq-a { padding: 0 20px 16px; color: var(--color-text-muted); display: none; }
.faq-item.open .faq-a { display: block; }

/* Breadcrumb */
.breadcrumb { color: var(--color-text-muted); font-size: 0.85rem; margin-bottom: 24px; }
.breadcrumb a { color: var(--color-primary); text-decoration: none; }
.breadcrumb a:hover { text-decoration: underline; }

/* CTA */
.cta-box {
  background: var(--color-primary); color: #fff; text-align: center;
  padding: 32px 24px; border-radius: var(--radius); margin: 40px 0;
}
.cta-box h2 { color: #fff; border: none; margin-top: 0; }

/* Footer */
footer {
  background: var(--color-surface); border-top: 1px solid var(--color-border);
  padding: 32px 0; margin-top: 48px; color: var(--color-text-muted); font-size: 0.85rem; text-align: center;
}
footer a { color: var(--color-primary); text-decoration: none; }

/* CEFR Table */
.cefr-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; margin: 20px 0; }
.cefr-level { background: var(--color-surface); padding: 16px; border-radius: var(--radius); text-align: center; }
.cefr-level .label { font-weight: 700; font-size: 1.1rem; color: var(--color-primary); }
.cefr-level .desc { font-size: 0.8rem; color: var(--color-text-muted); margin-top: 4px; }

@media (max-width: 640px) {
  .hero h1 { font-size: 1.5rem; }
  .lang-grid { grid-template-columns: 1fr; }
  .cefr-grid { grid-template-columns: 1fr; }
  header nav a { margin-left: 12px; font-size: 0.8rem; }
}