/* ============================================================
   Baolian Design System — Base Styles & Reset
   ============================================================ */

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

body {
  font-family: var(--font-en), var(--font-cn);
  font-size: var(--text-body);
  font-weight: var(--weight-regular);
  line-height: var(--leading-relaxed);
  color: var(--color-text-primary);
  background-color: var(--color-bg-primary);
  overflow-x: hidden;
}

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

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--duration-normal) var(--ease-smooth);
}

a:hover {
  color: var(--color-accent);
}

button {
  font: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

ul, ol {
  list-style: none;
}

/* ── Typography ── */
h1, .h1 {
  font-size: var(--text-h1);
  font-weight: var(--weight-light);
  line-height: var(--leading-tight);
  letter-spacing: var(--tracking-tight);
  color: var(--color-text-primary);
}

h2, .h2 {
  font-size: var(--text-h2);
  font-weight: var(--weight-light);
  line-height: var(--leading-snug);
  letter-spacing: var(--tracking-tight);
  color: var(--color-text-primary);
}

h3, .h3 {
  font-size: var(--text-h3);
  font-weight: var(--weight-regular);
  line-height: var(--leading-snug);
  color: var(--color-text-primary);
}

p {
  font-size: var(--text-body);
  line-height: var(--leading-relaxed);
  color: var(--color-text-secondary);
}

.text-small {
  font-size: var(--text-small);
  line-height: var(--leading-normal);
  color: var(--color-text-muted);
}

/* ── Layout Utilities ── */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--container-padding);
}

.section {
  padding-block: var(--section-padding-y);
}

/* ── Grid System ── */
.grid {
  display: grid;
  gap: var(--gutter);
}

.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

@media (max-width: 1023px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 767px) {
  .grid-2, .grid-3, .grid-4 {
    grid-template-columns: 1fr;
  }
}

/* ── Flex Utilities ── */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.gap-4 { gap: var(--space-4); }
.gap-6 { gap: var(--space-6); }
.gap-8 { gap: var(--space-8); }

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

@media (max-width: 767px) {
  .hide-mobile { display: none !important; }
}

@media (min-width: 768px) {
  .hide-desktop { display: none !important; }
}