/* NDH Academy — Base reset & typography */

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font-body);
  font-size: var(--font-size-base);
  line-height: var(--line-height-body);
  color: var(--text-primary);
  background: var(--bg-page);
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul { margin: 0; padding: 0; list-style: none; }
button { font-family: inherit; cursor: pointer; }
h1, h2, h3, h4 {
  font-family: var(--font-heading);
  line-height: var(--line-height-heading);
  font-weight: var(--font-weight-semibold);
  margin: 0;
  letter-spacing: -0.01em;
}
p { margin: 0; }

.container {
  width: 100%;
  max-width: 1200px;
  margin-inline: auto;
  padding-inline: var(--space-6);
}

/* Khoảng cách giữa section >= 2x khoảng cách nội bộ (ui-rules.md #4) */
.section { padding-block: var(--space-32); }
.section--tight { padding-block: var(--space-24); }
@media (max-width: 768px) {
  .section { padding-block: var(--space-24); }
  .section--tight { padding-block: var(--space-16); }
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-primary-600);
}
.eyebrow::before {
  content: '';
  width: 18px;
  height: 1.5px;
  background: var(--color-primary-500);
}

.section-head { max-width: 640px; margin-bottom: var(--space-12); }
.section-head--center { margin-inline: auto; text-align: center; }
.section-title { font-size: var(--font-size-4xl); margin-top: var(--space-3); }
.section-desc { margin-top: var(--space-3); color: var(--text-secondary); font-size: var(--font-size-lg); }

.text-center { text-align: center; }
.visually-hidden {
  position: absolute; width: 1px; height: 1px; overflow: hidden;
  clip: rect(0 0 0 0); white-space: nowrap;
}

::selection { background: var(--color-primary-200); color: var(--color-neutral-900); }

/* focus state rõ ràng cho accessibility */
a:focus-visible, button:focus-visible, input:focus-visible, textarea:focus-visible {
  outline: 2px solid var(--color-primary-400);
  outline-offset: 2px;
}