/* ============================================================================
   Layout — app shell (sidebar desktop, bottom-nav mobile)
   Mobile-first: bottom-nav by default, sidebar from min-width 768px.
   ============================================================================ */

/* App shell -------------------------------------------------------------- */
.app-shell {
  display: grid;
  grid-template-areas:
    "topbar"
    "main"
    "bottom";
  grid-template-rows: var(--topbar-h) 1fr var(--bottom-nav-h);
  grid-template-columns: 1fr;
  min-height: 100vh;
  min-height: 100dvh;
  background: var(--color-bg);
}

.app-topbar {
  grid-area: topbar;
  position: sticky;
  top: 0;
  z-index: var(--z-sticky);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  padding: 0 var(--content-pad-x);
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  height: var(--topbar-h);
}

.app-topbar__brand {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-weight: var(--fw-semibold);
  font-size: var(--fs-1);
  color: var(--color-text);
  letter-spacing: var(--tracking-tight);
}

.app-topbar__brand-mark {
  width: 28px;
  height: 28px;
  border-radius: var(--radius-sm);
  background: var(--color-primary);
  color: var(--color-text-on-primary);
  display: grid;
  place-items: center;
  font-size: 12px;
  font-weight: var(--fw-bold);
  letter-spacing: 0.04em;
}

.app-topbar__actions {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.app-main {
  grid-area: main;
  padding: var(--space-5) var(--content-pad-x);
  padding-bottom: calc(var(--space-7) + var(--bottom-nav-h));
  overflow-x: hidden;
}

.app-main__inner {
  max-width: var(--content-max);
  margin: 0 auto;
}

.app-sidebar {
  display: none; /* mobile: hidden */
}

.app-bottom {
  grid-area: bottom;
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: var(--z-sticky);
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  padding-bottom: env(safe-area-inset-bottom, 0);
}

/* Page header ---------------------------------------------------------- */
.page-header {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--space-4);
  margin-bottom: var(--space-5);
}

.page-header__title {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.page-header h1 {
  font-size: var(--fs-4);
  font-weight: var(--fw-semibold);
  letter-spacing: var(--tracking-tight);
}

.page-header__subtitle {
  color: var(--color-muted);
  font-size: var(--fs--1);
}

.page-header__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

/* Grids ---------------------------------------------------------------- */
.grid {
  display: grid;
  gap: var(--space-4);
}

.grid--2 { grid-template-columns: 1fr; }
.grid--3 { grid-template-columns: 1fr; }
.grid--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }

.stack {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.cluster {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  align-items: center;
}

.row {
  display: flex;
  gap: var(--space-3);
  align-items: center;
}

.spacer { flex: 1 1 auto; }

/* Container ----------------------------------------------------------- */
.container {
  max-width: var(--content-max);
  margin: 0 auto;
  padding: 0 var(--content-pad-x);
}

.container--narrow { max-width: 640px; }
.container--medium { max-width: 880px; }

/* Auth shell — centered card ------------------------------------------ */
.auth-shell {
  min-height: 100vh;
  min-height: 100dvh;
  display: grid;
  place-items: center;
  padding: var(--space-5);
  background: var(--color-bg);
}

.auth-card {
  width: 100%;
  max-width: 420px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-3);
  padding: var(--space-6);
}

.auth-card__brand {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin-bottom: var(--space-5);
}

.auth-card__brand-mark {
  width: 40px;
  height: 40px;
  border-radius: var(--radius);
  background: var(--color-primary);
  color: var(--color-text-on-primary);
  display: grid;
  place-items: center;
  font-weight: var(--fw-bold);
  letter-spacing: 0.04em;
  font-size: 14px;
}

.auth-card__title {
  font-size: var(--fs-3);
  font-weight: var(--fw-semibold);
  letter-spacing: var(--tracking-tight);
  margin-bottom: var(--space-2);
}

.auth-card__subtitle {
  color: var(--color-muted);
  font-size: var(--fs--1);
  margin-bottom: var(--space-5);
}

.auth-card__footer {
  margin-top: var(--space-5);
  padding-top: var(--space-4);
  border-top: 1px solid var(--color-border);
  text-align: center;
  font-size: var(--fs--1);
  color: var(--color-muted);
}

/* Desktop layout — sidebar takes over =================================== */
@media (min-width: 768px) {
  .app-shell {
    grid-template-areas:
      "sidebar topbar"
      "sidebar main";
    grid-template-rows: var(--topbar-h) 1fr;
    grid-template-columns: var(--sidebar-w) minmax(0, 1fr);
  }

  .app-sidebar {
    grid-area: sidebar;
    display: flex;
    flex-direction: column;
    position: sticky;
    top: 0;
    height: 100vh;
    height: 100dvh;
    background: var(--color-surface);
    border-right: 1px solid var(--color-border);
    overflow-y: auto;
  }

  .app-bottom {
    display: none;
  }

  .app-main {
    padding: var(--space-6) var(--content-pad-x);
  }

  .grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .grid--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
}

@media (min-width: 1024px) {
  .app-main {
    padding: var(--space-7) var(--space-7);
  }
}