:root {
  --bg-primary: #000000; /* transparent on additive display */
  --bg-secondary: #0a0a0f;
  --bg-tertiary: #14141f;
  --bg-card: #1a1a2e;
  --text-primary: #ffffff;
  --text-secondary: #a0a0b0;
  --text-muted: #606070;
  --accent-primary: #b9c2ff;
  --accent-secondary: #e8ecff;
  --focus-ring: #b9c2ff;
  --focus-glow: rgba(185, 194, 255, 0.4);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  width: 600px;
  height: 600px;
  overflow: hidden;
}

#app { width: 100%; height: 100%; position: relative; }

/* --- Screens --- */
.screen {
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  position: absolute;
  top: 0;
  left: 0;
}
.screen.hidden { display: none; }

/* --- Header --- */
.header {
  display: flex;
  align-items: center;
  padding: 16px 20px;
  background: var(--bg-secondary);
  gap: 12px;
  flex-shrink: 0;
}
.header h1 { font-size: 22px; font-weight: 600; flex: 1; }
.header-meta { font-size: 14px; color: var(--accent-secondary); font-weight: 600; }
.back-btn {
  background: transparent;
  color: var(--text-primary);
  font-size: 22px;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  border: 2px solid transparent;
}

/* --- Content Area --- */
.content {
  flex: 1;
  padding: 16px 20px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.home-content { align-items: center; justify-content: center; gap: 8px; }

/* --- Focus States --- */
.focusable { transition: all 0.15s ease; border: 2px solid transparent; cursor: pointer; min-height: 44px; }
.focusable:focus { outline: none; border-color: var(--focus-ring); box-shadow: 0 0 20px var(--focus-glow); }

/* --- Nav Bar --- */
.nav-bar { display: flex; gap: 8px; padding: 12px 20px; background: var(--bg-secondary); flex-shrink: 0; }
.nav-item {
  flex: 1;
  padding: 14px 16px;
  background: var(--bg-tertiary);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-size: 15px;
  font-weight: 500;
  text-align: center;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}
.nav-item:focus { background: var(--bg-card); }
.nav-item.primary { background: var(--accent-primary); color: #0a0a14; }
.nav-item.primary:focus { background: var(--accent-secondary); }

/* --- Moon Canvas --- */
#moon-canvas, #browse-canvas { display: block; }

.phase-name { font-size: 26px; font-weight: 700; color: var(--text-primary); margin-top: 4px; }
.phase-sub { font-size: 14px; color: var(--text-secondary); }
.hint-text { font-size: 14px; color: var(--accent-secondary); text-align: center; margin-top: 2px; }
.browse-date { font-size: 15px; color: var(--text-secondary); }

.hidden { display: none !important; }