/* ============================================================
   base.css — Reset, tipografía base y armazón de pantallas.
   Responsabilidad: normalizar el navegador y definir el shell
   de la aplicación (contenedor de pantallas + nav inferior).
   ============================================================ */

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

html,
body {
  margin: 0;
  padding: 0;
  height: 100%;
  overflow: hidden;
  background: var(--bg-void);
  color: var(--txt);
  font-family: var(--font-mono);
  font-size: var(--fs-sm);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -webkit-tap-highlight-color: transparent;
  overscroll-behavior: none;
  text-rendering: optimizeLegibility;
}

body {
  position: fixed;
  inset: 0;
  background-image:
    radial-gradient(ellipse 120% 60% at 50% -10%, rgba(0, 240, 255, 0.07), transparent 70%),
    radial-gradient(ellipse 90% 50% at 50% 110%, rgba(168, 85, 247, 0.06), transparent 70%);
  transition: background-image var(--t-slow) var(--ease);
}

button,
input,
textarea,
select {
  font-family: inherit;
  font-size: inherit;
  color: inherit;
}
button {
  cursor: pointer;
  border: 0;
  background: none;
}

h1, h2, h3, h4 {
  margin: 0;
  font-weight: 600;
  color: var(--txt-hi);
  letter-spacing: var(--track-wide);
}
p { margin: 0 0 var(--s3); }

::-webkit-scrollbar { width: 4px; height: 4px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb {
  background: var(--line-hard);
  border-radius: var(--r-pill);
}

/* ---------- Shell ---------- */
#app {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
}

#screens {
  position: relative;
  flex: 1 1 auto;
  min-height: 0;
}

.screen {
  position: absolute;
  inset: 0;
  display: none;
  flex-direction: column;
  overflow-y: auto;
  overflow-x: hidden;
  -webkit-overflow-scrolling: touch;
  padding: calc(var(--safe-t) + var(--s4)) var(--s4) var(--s6);
}
.screen.is-active {
  display: flex;
  animation: screen-in var(--t-mid) var(--ease);
}
.screen--flush {
  padding: 0;
  overflow: hidden;
}

@keyframes screen-in {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: none; }
}

.screen-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--s3);
  margin-bottom: var(--s4);
  padding-bottom: var(--s3);
  border-bottom: 1px solid var(--line-soft);
  flex: 0 0 auto;
}
.screen-title {
  font-size: var(--fs-lg);
  letter-spacing: var(--track-wide);
  color: var(--txt-hi);
  text-transform: uppercase;
}
.screen-sub {
  font-size: var(--fs-nano);
  letter-spacing: var(--track-wide);
  color: var(--txt-ghost);
  text-transform: uppercase;
  white-space: nowrap;
}

/* ---------- Navegación inferior ---------- */
#nav {
  position: relative;
  z-index: var(--z-nav);
  flex: 0 0 auto;
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  height: calc(var(--nav-h) + var(--safe-b));
  padding-bottom: var(--safe-b);
  background: rgba(5, 5, 9, 0.9);
  backdrop-filter: blur(18px) saturate(1.3);
  -webkit-backdrop-filter: blur(18px) saturate(1.3);
  border-top: 1px solid var(--line);
}
.nav-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 3px;
  color: var(--txt-ghost);
  transition: color var(--t-fast) var(--ease);
  position: relative;
  padding: 0 2px;
}
.nav-btn svg { width: 19px; height: 19px; display: block; }
.nav-btn span {
  font-size: 7.5px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  white-space: nowrap;
}
.nav-btn.is-active {
  color: var(--accent);
  text-shadow: 0 0 10px var(--accent-dim);
}
.nav-btn.is-active::before {
  content: "";
  position: absolute;
  top: 0;
  left: 22%;
  right: 22%;
  height: 2px;
  background: var(--accent);
  box-shadow: var(--glow-accent);
}
.nav-btn[data-alert="1"]::after {
  content: "";
  position: absolute;
  top: 8px;
  right: 18%;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--neon-amber);
  box-shadow: var(--glow-amber);
}

/* Utilidades */
.mono { font-family: var(--font-mono); }
.hidden { display: none !important; }
.stack { display: flex; flex-direction: column; gap: var(--s3); }
.row { display: flex; align-items: center; gap: var(--s2); }
.row--wrap { flex-wrap: wrap; }
.grow { flex: 1 1 auto; min-width: 0; }
.center { text-align: center; }
.dim { color: var(--txt-lo); }
.ghost { color: var(--txt-ghost); }
.accent { color: var(--accent); }
.num {
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum";
}