/* ==================== BASE ==================== */
:root {
  --bg-primary: #000000;
  --bg-secondary: #0a0a12;
  --bg-tertiary: #14141f;
  --bg-card: #16162a;
  --text-primary: #ffffff;
  --text-secondary: #a0a0b0;
  --text-muted: #606070;
  --accent-primary: #00d4ff;
  --accent-cyan: #00eaff;
  --success: #00ff88;
  --danger: #ff4466;
  --focus-ring: #00d4ff;
  --focus-glow: rgba(0, 212, 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; }

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

.header {
  display: flex;
  align-items: center;
  padding: 14px 20px;
  background: var(--bg-secondary);
  gap: 12px;
  flex-shrink: 0;
}
.header h1 { font-size: 22px; font-weight: 600; flex: 1; }
.header-meta { font-size: 13px; color: var(--text-secondary); }
.back-btn {
  background: transparent;
  color: var(--text-primary);
  font-size: 22px;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  border: 2px solid transparent;
}

.content {
  flex: 1;
  padding: 12px 20px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

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

/* --- Tabs --- */
.tabs {
  display: flex;
  gap: 6px;
  padding: 8px 20px 0;
  background: var(--bg-secondary);
  flex-shrink: 0;
}
.tab {
  flex: 1;
  padding: 10px 12px;
  background: var(--bg-tertiary);
  border-radius: var(--radius-sm) var(--radius-sm) 0 0;
  color: var(--text-secondary);
  font-size: 14px;
  font-weight: 600;
  text-align: center;
  letter-spacing: 0.3px;
  text-transform: uppercase;
}
.tab.active {
  color: var(--accent-primary);
  background: var(--bg-card);
}
.tab:focus {
  background: var(--bg-card);
}

/* --- Nav Bar --- */
.nav-bar {
  display: flex;
  gap: 8px;
  padding: 10px 20px;
  background: var(--bg-secondary);
  flex-shrink: 0;
}
.nav-item {
  flex: 1;
  padding: 12px 14px;
  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: #000; }
.nav-item.primary:focus { background: #33ddff; }

/* --- Coin list --- */
.coin-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  max-height: 420px;
  overflow-y: auto;
  padding-right: 2px;
}

.coin-card {
  display: grid;
  grid-template-columns: 44px 1fr auto auto;
  align-items: center;
  gap: 10px;
  padding: 12px 14px;
  background: var(--bg-card);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  text-align: left;
  min-height: 60px;
  width: 100%;
}
.coin-card:focus { background: #1d1d33; }

.coin-symbol {
  font-size: 14px;
  font-weight: 700;
  color: var(--accent-cyan);
  letter-spacing: 0.5px;
  text-transform: uppercase;
  text-align: center;
}
.coin-main { min-width: 0; }
.coin-name {
  font-size: 14px;
  font-weight: 500;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.coin-price {
  font-size: 18px;
  font-weight: 700;
  color: var(--text-primary);
  font-variant-numeric: tabular-nums;
}

.change-badge {
  padding: 4px 8px;
  border-radius: 999px;
  font-size: 13px;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  min-width: 60px;
  text-align: center;
}
.change-badge.up {
  background: rgba(0, 255, 136, 0.15);
  color: var(--success);
}
.change-badge.down {
  background: rgba(255, 68, 102, 0.15);
  color: var(--danger);
}
.change-badge.neutral {
  background: rgba(0, 212, 255, 0.15);
  color: var(--accent-cyan);
}

.coin-star {
  font-size: 18px;
  color: var(--text-muted);
  padding: 0 4px;
}
.coin-star.filled { color: #ffd166; }

/* --- Skeleton --- */
.skeleton {
  min-height: 60px;
  border: 1px solid var(--bg-tertiary);
  background: linear-gradient(90deg, var(--bg-card) 0%, var(--bg-tertiary) 50%, var(--bg-card) 100%);
  background-size: 200% 100%;
  animation: shimmer 1.4s linear infinite;
  border-radius: var(--radius-md);
}
@keyframes shimmer {
  0%   { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

/* --- Loading / error / empty --- */
.loading-container {
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.error-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  padding: 32px 20px;
  text-align: center;
}
.error-icon { font-size: 44px; color: var(--danger); }
.error-message { font-size: 15px; color: var(--text-secondary); }

.empty-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 40px 20px;
  text-align: center;
}
.empty-icon { font-size: 44px; color: var(--text-muted); }
.empty-message { font-size: 16px; color: var(--text-primary); }
.empty-hint { font-size: 13px; color: var(--text-secondary); }

.hidden { display: none !important; }

/* ==================== DETAIL SCREEN ==================== */
.detail-hero {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 20px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
}
.detail-symbol {
  font-size: 14px;
  font-weight: 700;
  color: var(--accent-cyan);
  letter-spacing: 1px;
  text-transform: uppercase;
}
.detail-name {
  font-size: 18px;
  color: var(--text-secondary);
}
.detail-price {
  font-size: 44px;
  font-weight: 700;
  color: var(--text-primary);
  font-variant-numeric: tabular-nums;
  margin-top: 4px;
}

.stat-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}
.stat-card {
  background: var(--bg-tertiary);
  border-radius: var(--radius-md);
  padding: 14px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.stat-wide { grid-column: span 2; }
.stat-label {
  font-size: 12px;
  color: var(--text-secondary);
  letter-spacing: 0.4px;
  text-transform: uppercase;
  font-weight: 600;
}
.stat-value {
  font-size: 18px;
  font-weight: 600;
  color: var(--text-primary);
  font-variant-numeric: tabular-nums;
}