/* =============================================================
   base.css — Reset, layout base y tipografía. Mobile-first.
   ============================================================= */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { -webkit-text-size-adjust: 100%; }

body {
  font-family: var(--font-sans);
  font-size: var(--fs-base);
  font-weight: var(--fw-regular);
  color: var(--text);
  background-color: var(--bg);
  line-height: 1.5;
  min-height: 100vh;
  min-height: 100dvh;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
  transition: background-color var(--transition), color var(--transition);
}

h1, h2, h3, h4 { font-weight: var(--fw-bold); line-height: 1.2; color: var(--text); }
h1 { font-size: var(--fs-2xl); }
h2 { font-size: var(--fs-xl); }
h3 { font-size: var(--fs-lg); }

a { color: var(--primary); text-decoration: none; }
button { font-family: inherit; cursor: pointer; border: none; background: none; color: inherit; }
img { max-width: 100%; display: block; }
input, select, textarea { font-family: inherit; font-size: var(--fs-base); }
ul { list-style: none; }

/* ---- Contenedor de página mobile-first ---- */
.app-shell {
  width: 100%;
  max-width: var(--content-max);
  margin: 0 auto;
  padding: 0 var(--space-4);
  padding-bottom: calc(var(--nav-height) + var(--space-8));
  min-height: 100vh;
  min-height: 100dvh;
}

.page-section { margin-top: var(--space-5); }

.section-title {
  font-size: var(--fs-sm);
  font-weight: var(--fw-semibold);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-muted);
  margin-bottom: var(--space-3);
  padding-left: var(--space-1);
}

/* ---- Utilidades ---- */
.text-muted { color: var(--text-muted); }
.text-secondary { color: var(--text-secondary); }
.text-income { color: var(--income); }
.text-expense { color: var(--expense); }
.text-center { text-align: center; }
.hidden { display: none !important; }
.flex { display: flex; }
.flex-between { display: flex; align-items: center; justify-content: space-between; }
.flex-center { display: flex; align-items: center; justify-content: center; }
.gap-2 { gap: var(--space-2); }
.gap-3 { gap: var(--space-3); }
.gap-4 { gap: var(--space-4); }
.full-width { width: 100%; }
.mt-2 { margin-top: var(--space-2); }
.mt-4 { margin-top: var(--space-4); }
.mb-4 { margin-bottom: var(--space-4); }

/* ---- Estados vacíos ---- */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-10) var(--space-4);
  text-align: center;
  color: var(--text-muted);
}
.empty-state i { font-size: 2.5rem; color: var(--border-strong); }
.empty-state p { font-size: var(--fs-sm); }

/* ---- Skeleton loading ---- */
.skeleton {
  background: linear-gradient(90deg, var(--surface-2) 25%, var(--surface-3) 50%, var(--surface-2) 75%);
  background-size: 200% 100%;
  animation: shimmer 1.4s infinite;
  border-radius: var(--radius-sm);
}
@keyframes shimmer { 0% { background-position: 200% 0; } 100% { background-position: -200% 0; } }

/* ---- Spinner ---- */
.spinner {
  width: 20px; height: 20px;
  border: 2.5px solid rgba(255,255,255,0.4);
  border-top-color: #fff;
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
  display: inline-block;
}
.spinner.dark { border-color: var(--border-strong); border-top-color: var(--primary); }
@keyframes spin { to { transform: rotate(360deg); } }

/* ---- Animaciones de entrada ---- */
@keyframes fadeInUp { from { opacity: 0; transform: translateY(16px); } to { opacity: 1; transform: translateY(0); } }
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }
.animate-in { animation: fadeInUp 0.4s ease both; }

/* ---- Accesibilidad ---- */
:focus-visible { outline: 2px solid var(--primary); outline-offset: 2px; }
::selection { background: var(--primary); color: var(--on-primary); }

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

/* ---- Scrollbar discreta ---- */
::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-thumb { background: var(--border-strong); border-radius: var(--radius-full); }
::-webkit-scrollbar-track { background: transparent; }