/* base.css — Reset + global typography + utility cơ bản
   Phải được load sau tokens.css để có biến.
*/

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 80px; /* tránh header sticky che tiêu đề khi anchor */
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-weight: var(--weight-regular);
  font-size: var(--text-base);
  line-height: var(--leading-normal);
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  margin: 0 0 var(--space-3);
  font-weight: var(--weight-bold);
  line-height: var(--leading-tight);
  letter-spacing: var(--tracking-tight);
  color: var(--color-text);
}

h1 {
  font-size: var(--text-4xl);
}

h2 {
  font-size: var(--text-3xl);
}

h3 {
  font-size: var(--text-2xl);
}

h4 {
  font-size: var(--text-xl);
}

p {
  margin: 0 0 var(--space-4);
}

a {
  color: var(--color-navy-700);
  text-decoration: none;
  transition: color var(--duration-fast) var(--ease-out);
}

a:hover,
a:focus-visible {
  color: var(--color-gold-600);
}

img,
svg {
  display: block;
  max-width: 100%;
  height: auto;
}

button,
input,
select,
textarea {
  font: inherit;
  color: inherit;
}

button {
  cursor: pointer;
  background: none;
  border: none;
  padding: 0;
}

ul,
ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 2px;
  border-radius: 4px;
}

/* ===== Utility ===== */

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  top: -64px;
  left: var(--space-4);
  padding: var(--space-3) var(--space-5);
  background: var(--color-navy-900);
  color: var(--color-text-on-dark);
  border-radius: var(--radius-sm);
  font-weight: var(--weight-semibold);
  z-index: var(--z-modal);
  transition: top var(--duration-fast) var(--ease-out);
}

.skip-link:focus {
  top: var(--space-3);
  color: var(--color-text-on-dark);
}

.is-gold {
  color: var(--color-gold-500);
}

.is-muted {
  color: var(--color-text-muted);
}

.text-uppercase {
  text-transform: uppercase;
  letter-spacing: var(--tracking-wide);
  font-size: var(--text-sm);
  font-weight: var(--weight-semibold);
}

/* Reveal animation (kích hoạt qua JS) */
.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition:
    opacity var(--duration-slow) var(--ease-out-expo),
    transform var(--duration-slow) var(--ease-out-expo);
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  .reveal {
    opacity: 1;
    transform: none;
  }
}