/* ============================================================
   LAYOUT — Shell, contenedores, grid utilitario
   ============================================================ */

.app-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  grid-template-rows: var(--header-height) auto;
  width: 100%;
  min-width: 0;
  min-height: 100vh;
  overflow-x: clip;
  background: var(--bg-primary);
}

.app-main {
  width: 100%;
  min-width: 0;
  padding-top: var(--space-4);
  padding-bottom: var(--space-6);
}

.container {
  width: 100%;
  min-width: 0;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--space-4);
  padding-right: var(--space-4);
}

@media (min-width: 768px) {
  .container {
    padding-left: var(--space-6);
    padding-right: var(--space-6);
  }
}

@media (min-width: 1280px) {
  .container {
    padding-left: var(--space-8);
    padding-right: var(--space-8);
  }
}

.page-header {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  margin-bottom: var(--space-6);
  padding: 0 0 var(--space-4) var(--space-4);
  border-bottom: 1px solid var(--border-color);
}

.page-header::before {
  content: "";
  position: absolute;
  top: 0.2rem;
  bottom: var(--space-4);
  left: 0;
  width: 3px;
  border-radius: var(--radius-full);
  background: linear-gradient(180deg, var(--accent), color-mix(in srgb, var(--accent) 24%, transparent));
}

@media (min-width: 768px) {
  .page-header {
    flex-direction: row;
    align-items: flex-end;
    justify-content: space-between;
  }
}

.page-title {
  font-size: var(--text-xl);
  font-weight: var(--font-bold);
  color: var(--text-primary);
  line-height: var(--leading-tight);
  letter-spacing: -0.025em;
}

.page-subtitle {
  max-width: 54rem;
  margin-top: var(--space-1);
  font-size: var(--text-sm);
  color: var(--text-secondary);
  line-height: 1.45;
}

/* Grid utilitario */
.grid-1 { display: grid; grid-template-columns: 1fr; gap: var(--space-4); }
.grid-2 { display: grid; grid-template-columns: 1fr; gap: var(--space-4); }
.grid-3 { display: grid; grid-template-columns: 1fr; gap: var(--space-4); }
.grid-4 { display: grid; grid-template-columns: 1fr; gap: var(--space-4); }

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

@media (min-width: 1024px) {
  .grid-3 { grid-template-columns: repeat(3, 1fr); }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 1280px) {
  .grid-4 { grid-template-columns: repeat(4, 1fr); }
}

/* Dashboard split */
.dashboard-split {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-4);
}

@media (min-width: 1024px) {
  .dashboard-split {
    grid-template-columns: 1fr 1fr;
  }
}

/* Stack */
.stack-2 { display: flex; flex-direction: column; gap: var(--space-2); }
.stack-3 { display: flex; flex-direction: column; gap: var(--space-3); }
.stack-4 { display: flex; flex-direction: column; gap: var(--space-4); }
.stack-6 { display: flex; flex-direction: column; gap: var(--space-6); }

/* Row responsive */
.row-responsive {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

@media (min-width: 768px) {
  .row-responsive {
    flex-direction: row;
    align-items: center;
  }
}

/* Section */
.section-title {
  font-size: var(--text-lg);
  font-weight: var(--font-semibold);
  color: var(--text-primary);
  line-height: var(--leading-tight);
  letter-spacing: -0.015em;
  margin-bottom: var(--space-3);
}

/* Card grid */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(16rem, 1fr));
  gap: var(--space-4);
}

/* Scroll container */
.scroll-x {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.scroll-y {
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
}

@media (max-width: 767px) {
  .grid-4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 640px) {
  .app-main { padding-top: var(--space-3); }
  .container { padding-left: var(--space-3); padding-right: var(--space-3); }
  .page-header { gap: var(--space-3); margin-bottom: var(--space-4); padding: 0 0 var(--space-3) var(--space-3); }
  .page-header::before { bottom: var(--space-3); }
  .page-header > .btn-group { display: flex; flex-wrap: nowrap; width: 100%; padding-bottom: var(--space-1); overflow-x: auto; scrollbar-width: thin; }
  .page-header > .btn-group > .btn { flex: 0 0 auto; justify-content: center; min-height: 2.25rem; }
  .page-title { font-size: var(--text-lg); }
  .grid-1, .grid-2, .grid-3, .grid-4, .dashboard-split, .card-grid { gap: var(--space-3); }
}