/* ============================================
   ZHICAI Layout — layout.css
   Grid System + Responsive Utilities
   ============================================ */

/* --- Grid System --- */
.grid {
  display: grid;
  gap: var(--space-6);
}

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

.grid-auto-fit {
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.grid-auto-fill {
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
}

/* --- Flex Utilities --- */
.flex        { display: flex; }
.flex-col    { flex-direction: column; }
.flex-wrap   { flex-wrap: wrap; }
.items-center    { align-items: center; }
.items-start     { align-items: flex-start; }
.items-end       { align-items: flex-end; }
.justify-center  { justify-content: center; }
.justify-between { justify-content: space-between; }
.justify-end     { justify-content: flex-end; }
.gap-2  { gap: var(--space-2); }
.gap-4  { gap: var(--space-4); }
.gap-6  { gap: var(--space-6); }
.gap-8  { gap: var(--space-8); }
.gap-10 { gap: var(--space-10); }
.gap-12 { gap: var(--space-12); }

/* --- Two Column Layout --- */
.split-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-16);
  align-items: center;
}

.split-layout.reverse {
  direction: rtl;
}

.split-layout.reverse > * {
  direction: ltr;
}

/* --- Spacing Utilities --- */
.mt-4  { margin-top: var(--space-4); }
.mt-8  { margin-top: var(--space-8); }
.mt-12 { margin-top: var(--space-12); }
.mt-16 { margin-top: var(--space-16); }
.mb-4  { margin-bottom: var(--space-4); }
.mb-8  { margin-bottom: var(--space-8); }
.mb-12 { margin-bottom: var(--space-12); }
.mb-16 { margin-bottom: var(--space-16); }
.mx-auto { margin-left: auto; margin-right: auto; }
.pt-4  { padding-top: var(--space-4); }
.pb-4  { padding-bottom: var(--space-4); }

/* --- Responsive Breakpoints --- */
@media (max-width: 1024px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .split-layout { grid-template-columns: 1fr; gap: var(--space-10); }
  .split-layout.reverse { direction: ltr; }

  .lg-hidden { display: none !important; }
}

@media (max-width: 768px) {
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .grid-2 { grid-template-columns: 1fr; }

  :root {
    --container-pad: var(--space-4);
    --nav-height: 64px;
  }

  .md-hidden { display: none !important; }
  .md-block { display: block !important; }
}

@media (max-width: 480px) {
  .grid-3 { grid-template-columns: 1fr; }

  .sm-hidden { display: none !important; }
}