html, body {
  margin: 0;
  padding: 0;
  overflow-x: hidden;
  width: 100%;
  max-width: 100vw;
  box-sizing: border-box;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, sans-serif;
  background: #f9fafb;
  color: #111;
}
header {
  padding: 1.5rem 1rem 0;
}
h1 {
  font-size: 1.5rem;
  margin: 0;
}
.subtitle {
  color: #555;
  font-size: 1rem;
  margin-top: 0.25rem;
}
.card-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr)); /* 🔑 предотвращает "перетягивание" */
  gap: 1rem;
  padding: 1rem;
}
.card {
  background: #e0f2fe;
  border-radius: 12px;
  padding: 1rem;
  text-align: center;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.2s ease;
}
.card:hover {
  background: #bae6fd;
}
.card.locked {
  background: #e5e7eb;
  cursor: default;
  opacity: 0.6;
}
.card.completed {
  background: #bbf7d0;
}
.back-button {
  font-size: 1rem;
  background: none;
  border: none;
  color: #3b82f6;
  cursor: pointer;
  margin-bottom: 1rem;
}
.practice-container {
  padding: 0 1rem 2rem;
}
.skill-name {
  font-size: 1.2rem;
  margin-bottom: 1rem;
  color: #111827;
}
.section-text {
  margin: 1rem 0;
  font-size: 1rem;
  line-height: 1.6;
}
.section-text.strong {
  font-weight: 600;
}
.section-text.dim {
  color: #6b7280;
}
.section-text.italic {
  font-style: italic;
}
.complete-button {
  background: #22c55e;
  color: white;
  border: none;
  border-radius: 10px;
  padding: 0.8rem 1.2rem;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  margin-top: 2rem;
}