* {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
}

body {
  margin: 0;
  font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial;
  background: #0f0f12;
  color: #f1f5f9;
}

.container {
  min-height: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 2rem 1.25rem 1.5rem;
  gap: 1.5rem;
}

.main-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1.5rem;
  flex: 1;
  width: 100%;
}

.visualmente-oculto {
  position: absolute !important;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.sos-btn {
  --size: min(70vmin, 22rem);
  width: var(--size);
  height: var(--size);
  border-radius: 9999px;
  border: 0;
  background: radial-gradient(circle at 30% 30%, #ff4d4f, #cc0000 60%);
  color: #fff;
  font-weight: 800;
  font-size: clamp(3rem, 12vmin, 6rem);
  letter-spacing: 0.1em;
  text-shadow: 0 2px 8px rgba(0, 0, 0, 0.35);
  box-shadow: 0 12px 40px rgba(255, 0, 0, 0.25), inset 0 -8px 16px rgba(0, 0, 0, 0.35);
  cursor: pointer;
  transition: transform 0.08s ease, box-shadow 0.2s ease, filter 0.2s ease;
  animation: pulse 1.5s infinite ease-in-out;
}

.sos-btn:active {
  transform: scale(0.98);
  filter: brightness(0.95);
}

.sos-btn.sent {
  background: radial-gradient(circle at 30% 30%, #22c55e, #15803d 60%);
  box-shadow: 0 12px 40px rgba(34, 197, 94, 0.25), inset 0 -8px 16px rgba(0, 0, 0, 0.35);
  animation: none;
}

@keyframes pulse {
  0% {
    box-shadow: 0 0 0 0 rgba(239, 68, 68, 0.6), 0 12px 40px rgba(255, 0, 0, 0.25),
      inset 0 -8px 16px rgba(0, 0, 0, 0.35);
  }
  70% {
    box-shadow: 0 0 0 24px rgba(239, 68, 68, 0), 0 12px 40px rgba(255, 0, 0, 0.25),
      inset 0 -8px 16px rgba(0, 0, 0, 0.35);
  }
  100% {
    box-shadow: 0 0 0 0 rgba(239, 68, 68, 0), 0 12px 40px rgba(255, 0, 0, 0.25),
      inset 0 -8px 16px rgba(0, 0, 0, 0.35);
  }
}

.status {
  min-height: 1.5rem;
  text-align: center;
  font-size: 0.95rem;
  color: #cbd5e1;
  max-width: 36rem;
}

.install-btn {
  padding: 0.75rem 1rem;
  font-weight: 700;
  border: 0;
  border-radius: 999px;
  background: #1f2937;
  color: #e5e7eb;
  cursor: pointer;
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.25);
}

.install-btn:hover {
  filter: brightness(1.1);
}

.bottom-nav {
  width: min(100%, 420px);
  display: flex;
  gap: 0.75rem;
  padding: 0.75rem;
  border-radius: 14px;
  background: rgba(2, 6, 23, 0.55);
  backdrop-filter: blur(6px);
  border: 1px solid rgba(148, 163, 184, 0.15);
}

.nav-btn {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.65rem 1rem;
  font-size: 0.95rem;
  border-radius: 10px;
  border: none;
  background: transparent;
  color: #e2e8f0;
  cursor: pointer;
  text-decoration: none;
  transition: background 0.15s ease, color 0.15s ease, transform 0.15s ease;
}

.nav-btn:hover {
  background: rgba(148, 163, 184, 0.15);
  color: #fff;
}

.nav-btn:active {
  transform: translateY(1px);
}

.nav-btn.active,
.nav-btn[aria-current="page"] {
  background: linear-gradient(135deg, rgba(34, 211, 238, 0.2), rgba(99, 102, 241, 0.25));
  color: #38bdf8;
}

.settings-placeholder {
  width: min(100%, 420px);
  padding: 2rem;
  border-radius: 20px;
  background: rgba(15, 23, 42, 0.75);
  box-shadow: 0 12px 32px rgba(15, 23, 42, 0.35);
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  text-align: center;
}

.settings-title {
  margin: 0;
  font-size: 1.4rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: #e2e8f0;
}

.settings-empty {
  margin: 0;
  font-size: 0.95rem;
  color: #cbd5e1;
}

.footer {
  text-align: center;
  color: #94a3b8;
  opacity: 0.8;
  font-size: 0.85rem;
  margin-top: 1rem;
}

@media (min-width: 768px) {
  .bottom-nav {
    width: min(100%, 520px);
  }
}