:root {
  --bg: #0f1020;
  --surface: #1b1d31;
  --border: #2c2f49;
  --text: #f1f2ff;
  --muted: #9a9dbb;
  --accent: #7c5cff;
  --tab-bg: #242743;
}

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

body {
  font-family: "Segoe UI", system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  align-items: flex-end;
  justify-content: center;
}

.app {
  width: 100%;
  max-width: 640px;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
}

.content {
  flex: 1;
  position: relative;
  padding: 2rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

.panel {
  position: absolute;
  max-width: 480px;
  width: 90%;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 2rem;
  opacity: 0;
  transform: translateY(16px);
  pointer-events: none;
  transition: opacity 0.35s ease, transform 0.35s ease;
}

.panel.active {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

.panel h2 {
  font-size: 1.5rem;
  margin-bottom: 0.75rem;
  color: var(--accent);
}

.panel p {
  color: var(--muted);
  line-height: 1.6;
}

.tab-bar {
  position: relative;
  display: flex;
  background: var(--surface);
  border-top: 1px solid var(--border);
  padding: 0.75rem;
}

.tab {
  flex: 1;
  background: none;
  border: none;
  color: var(--muted);
  font-size: 0.85rem;
  font-weight: 600;
  padding: 0.9rem 0.25rem;
  cursor: pointer;
  z-index: 1;
  transition: color 0.3s ease;
  border-radius: 12px;
}

.tab.active {
  color: var(--accent);
}

.indicator {
  position: absolute;
  top: 0.75rem;
  bottom: 0.75rem;
  left: 0;
  width: 20%;
  background: var(--tab-bg);
  border: 1px solid var(--accent);
  border-radius: 12px;
  transition: transform 0.35s cubic-bezier(0.34, 1.4, 0.64, 1);
  pointer-events: none;
}

.indicator.left-0 { transform: translateX(0%); }
.indicator.left-1 { transform: translateX(100%); }
.indicator.left-2 { transform: translateX(200%); }
.indicator.left-3 { transform: translateX(300%); }
.indicator.left-4 { transform: translateX(400%); }