/* === Reset & Base === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg: #F5F5F0;
  --bg-secondary: #EAEAE5;
  --card-bg: #FFFFFF;
  --text: #1A1A1A;
  --text-secondary: #6B7280;
  --accent: #D4AF37;
  --accent-light: #F0E6C0;
  --green: #16A34A;
  --green-bg: #DCFCE7;
  --red: #DC2626;
  --red-bg: #FEE2E2;
  --border: #E5E7EB;
  --shadow: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.06);
  --shadow-lg: 0 4px 12px rgba(0,0,0,0.1);
  --radius: 12px;
  --transition: 0.3s ease;
  --font-sans: 'Segoe UI', system-ui, -apple-system, sans-serif;
}

[data-theme="dark"] {
  --bg: #0F0F0F;
  --bg-secondary: #1A1A1A;
  --card-bg: #1E1E1E;
  --text: #F0F0F0;
  --text-secondary: #9CA3AF;
  --accent-light: #3D3520;
  --green-bg: #14532D;
  --red-bg: #7F1D1D;
  --border: #333333;
  --shadow: 0 1px 3px rgba(0,0,0,0.3);
  --shadow-lg: 0 4px 12px rgba(0,0,0,0.4);
}

html { font-size: 16px; }
body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
  min-height: 100vh;
  transition: background var(--transition), color var(--transition);
}

/* === Header === */
.header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 1.5rem;
  background: var(--card-bg);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow);
  position: sticky;
  top: 0;
  z-index: 100;
  transition: background var(--transition);
}

.header-left { display: flex; align-items: center; gap: 1rem; flex-wrap: wrap; }

.logo {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 0.4rem;
}
.logo-icon { color: var(--accent); font-size: 1.4rem; }

.update-status {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--green);
  display: inline-block;
  transition: background var(--transition);
}
.status-dot.error { background: var(--red); }
.status-dot.loading { background: var(--accent); animation: pulse 1s infinite; }

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}

.theme-toggle {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.5rem 0.7rem;
  cursor: pointer;
  font-size: 1.2rem;
  color: var(--text);
  transition: background var(--transition), transform 0.2s;
}
.theme-toggle:hover { transform: scale(1.1); }
.theme-toggle:active { transform: scale(0.95); }

/* === Main === */
.main { max-width: 1200px; margin: 0 auto; padding: 1.5rem; }

/* === Price Cards === */
.price-section { margin-bottom: 2rem; }

.price-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1rem;
}

.price-card {
  background: var(--card-bg);
  border-radius: var(--radius);
  padding: 1.25rem;
  box-shadow: var(--shadow);
  border-left: 4px solid var(--accent);
  transition: background var(--transition), box-shadow 0.2s, transform 0.2s;
  position: relative;
  overflow: hidden;
}
.price-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-2px); }

.price-card.flash {
  animation: flash-gold 0.6s ease;
}
@keyframes flash-gold {
  0% { background: var(--accent-light); }
  100% { background: var(--card-bg); }
}

.card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
}

.card-type {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--accent);
}

.card-badge {
  font-size: 0.7rem;
  padding: 0.2rem 0.5rem;
  border-radius: 4px;
  font-weight: 600;
}
.card-badge.up { background: var(--green-bg); color: var(--green); }
.card-badge.down { background: var(--red-bg); color: var(--red); }
.card-badge.neutral { background: var(--bg-secondary); color: var(--text-secondary); }

.price-row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: 0.5rem 0;
  border-bottom: 1px solid var(--border);
}
.price-row:last-child { border-bottom: none; }

.price-label {
  font-size: 0.85rem;
  color: var(--text-secondary);
  font-weight: 500;
}

.price-value {
  font-size: 1.3rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

.price-change {
  font-size: 0.8rem;
  font-weight: 600;
  margin-top: 0.5rem;
  text-align: right;
}
.price-change.up { color: var(--green); }
.price-change.down { color: var(--red); }
.price-change.neutral { color: var(--text-secondary); }

/* === Skeleton Loading === */
.skeleton-card {
  background: var(--card-bg);
  border-radius: var(--radius);
  padding: 1.25rem;
  box-shadow: var(--shadow);
  border-left: 4px solid var(--border);
}

.skeleton-line {
  height: 1rem;
  background: linear-gradient(90deg, var(--bg-secondary) 25%, var(--border) 50%, var(--bg-secondary) 75%);
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
  border-radius: 4px;
  margin-bottom: 0.75rem;
}
.skeleton-line.short { width: 40%; }
.skeleton-line.medium { width: 70%; }
.skeleton-line.tall { height: 1.5rem; }

@keyframes shimmer {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

/* === Error Banner === */
.error-banner {
  background: var(--red-bg);
  color: var(--red);
  padding: 0.75rem 1rem;
  border-radius: var(--radius);
  margin-bottom: 1rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.9rem;
}

.error-banner button {
  background: var(--red);
  color: #fff;
  border: none;
  padding: 0.4rem 1rem;
  border-radius: 6px;
  cursor: pointer;
  font-weight: 600;
  font-size: 0.85rem;
}
.error-banner button:hover { opacity: 0.9; }

/* === Chart Section === */
.chart-section {
  background: var(--card-bg);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: var(--shadow);
  transition: background var(--transition);
}

.chart-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 1rem;
}

.chart-title {
  font-size: 1.1rem;
  font-weight: 600;
}

.chart-controls {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.type-selector, .timeframe-selector {
  display: flex;
  gap: 0.25rem;
  background: var(--bg-secondary);
  border-radius: 8px;
  padding: 0.2rem;
}

.type-btn, .tf-btn {
  background: transparent;
  border: none;
  padding: 0.4rem 0.8rem;
  border-radius: 6px;
  cursor: pointer;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-secondary);
  transition: all 0.2s;
}
.type-btn:hover, .tf-btn:hover { color: var(--text); }
.type-btn.active, .tf-btn.active {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 1px 3px rgba(212,175,55,0.3);
}

.chart-container {
  position: relative;
  width: 100%;
  aspect-ratio: 2 / 1;
  min-height: 250px;
}

.chart-loading, .chart-error {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: 0.9rem;
  color: var(--text-secondary);
}

/* === Footer === */
.footer {
  text-align: center;
  padding: 1.5rem;
  font-size: 0.8rem;
  color: var(--text-secondary);
  border-top: 1px solid var(--border);
  margin-top: 2rem;
}
.footer-note { margin-top: 0.3rem; font-style: italic; opacity: 0.7; }

/* === Responsive === */
@media (max-width: 640px) {
  .header { padding: 0.75rem 1rem; }
  .logo { font-size: 1.05rem; }
  .main { padding: 1rem; }
  .price-grid { grid-template-columns: 1fr; }
  .chart-header { flex-direction: column; align-items: flex-start; }
  .chart-container { aspect-ratio: 4/3; }
  .price-value { font-size: 1.15rem; }
}

@media (min-width: 641px) and (max-width: 1024px) {
  .price-grid { grid-template-columns: repeat(2, 1fr); }
}