/* ============================================================
   AirPulse — Modern Glassmorphism CSS Design System
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Outfit:wght@400;600;700;800&display=swap');

:root {
  /* Color Palette */
  --bg-primary: #0B0F17;
  --bg-surface: rgba(18, 24, 38, 0.75);
  --bg-card: rgba(26, 34, 52, 0.65);
  --border-glass: rgba(255, 255, 255, 0.1);
  --border-glow: rgba(59, 130, 246, 0.3);
  
  --text-primary: #F8FAFC;
  --text-secondary: #94A3B8;
  --text-muted: #64748B;
  
  --accent-blue: #3B82F6;
  --accent-cyan: #06B6D4;
  --accent-purple: #8B5CF6;
  
  /* AQI Severity Colors */
  --aqi-good: #10B981;
  --aqi-satisfactory: #84CC16;
  --aqi-moderate: #F59E0B;
  --aqi-poor: #F97316;
  --aqi-very-poor: #EF4444;
  --aqi-severe: #991B1B;

  /* Typography */
  --font-heading: 'Outfit', -apple-system, sans-serif;
  --font-body: 'Inter', -apple-system, sans-serif;
}

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

body {
  background-color: var(--bg-primary);
  background-image: 
    radial-gradient(at 0% 0%, rgba(59, 130, 246, 0.15) 0px, transparent 50%),
    radial-gradient(at 100% 100%, rgba(139, 92, 246, 0.12) 0px, transparent 50%);
  color: var(--text-primary);
  font-family: var(--font-body);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
}

/* --- Layout Container --- */
.app-container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 2rem 1.5rem;
  width: 100%;
}

/* --- Navbar / Header --- */
.header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 2.5rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border-glass);
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.brand-logo {
  width: 42px;
  height: 42px;
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-cyan));
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  box-shadow: 0 0 20px rgba(59, 130, 246, 0.4);
}

.brand-title {
  font-family: var(--font-heading);
  font-size: 1.75rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  background: linear-gradient(to right, #FFFFFF, var(--text-secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.brand-badge {
  font-size: 0.75rem;
  padding: 0.2rem 0.6rem;
  border-radius: 20px;
  background: rgba(59, 130, 246, 0.15);
  color: var(--accent-blue);
  border: 1px solid rgba(59, 130, 246, 0.3);
  font-weight: 600;
  text-transform: uppercase;
}

/* --- City Selector Pills --- */
.city-nav {
  display: flex;
  gap: 0.75rem;
  margin-bottom: 2rem;
  flex-wrap: wrap;
}

.city-pill {
  background: var(--bg-surface);
  border: 1px solid var(--border-glass);
  color: var(--text-secondary);
  padding: 0.65rem 1.5rem;
  border-radius: 30px;
  font-family: var(--font-heading);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.25s ease;
  backdrop-filter: blur(12px);
}

.city-pill:hover {
  color: var(--text-primary);
  border-color: var(--accent-blue);
  transform: translateY(-2px);
}

.city-pill.active {
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
  color: #FFFFFF;
  border-color: transparent;
  box-shadow: 0 4px 20px rgba(59, 130, 246, 0.35);
}

/* --- Hero Metrics Grid --- */
.hero-grid {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: 1.5rem;
  margin-bottom: 2rem;
}

@media (max-width: 900px) {
  .hero-grid {
    grid-template-columns: 1fr;
  }
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border-glass);
  backdrop-filter: blur(16px);
  border-radius: 20px;
  padding: 1.75rem;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
  transition: border-color 0.3s ease;
}

.card:hover {
  border-color: var(--border-glow);
}

.current-aqi-card {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  position: relative;
  overflow: hidden;
}

.card-label {
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.city-name-header {
  font-family: var(--font-heading);
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 1rem;
}

.aqi-number-container {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  margin: 1rem 0;
}

.aqi-number {
  font-family: var(--font-heading);
  font-size: 4.5rem;
  font-weight: 800;
  line-height: 1;
  letter-spacing: -0.03em;
}

.aqi-unit {
  font-size: 1.25rem;
  color: var(--text-muted);
  font-weight: 500;
}

.aqi-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  border-radius: 30px;
  font-weight: 700;
  font-size: 0.95rem;
  align-self: flex-start;
  color: #FFFFFF;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

.weather-stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
  margin-top: 1.5rem;
}

@media (max-width: 600px) {
  .weather-stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.weather-stat-box {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.06);
  padding: 1rem;
  border-radius: 14px;
  text-align: center;
}

.weather-stat-value {
  font-family: var(--font-heading);
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-top: 0.25rem;
}

.weather-stat-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
}

/* --- Forecast Chart Card --- */
.chart-card {
  display: flex;
  flex-direction: column;
}

.chart-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.25rem;
}

.chart-title {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 700;
}

.chart-container {
  position: relative;
  flex-grow: 1;
  min-height: 280px;
}

/* --- Footer --- */
.footer {
  margin-top: auto;
  padding-top: 2rem;
  border-top: 1px solid var(--border-glass);
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--text-muted);
  font-size: 0.85rem;
  flex-wrap: wrap;
  gap: 1rem;
}

.meta-status {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--aqi-good);
  box-shadow: 0 0 10px var(--aqi-good);
}