:root {
  --bg-main: #0b0f19;
  --bg-card: #131b2e;
  --bg-card-hover: #19243d;
  --bg-hero: linear-gradient(135deg, #111a33 0%, #1a274a 100%);
  --border-color: rgba(255, 255, 255, 0.08);
  --border-highlight: rgba(79, 140, 255, 0.3);
  
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  
  --primary-accent: #3b82f6;
  --primary-glow: rgba(59, 130, 246, 0.25);
  --success-color: #10b981;
  --warning-color: #f59e0b;
  --danger-color: #ef4444;
  --day-color: #facc15;
  --night-color: #818cf8;

  --font-sans: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  --radius-lg: 16px;
  --radius-md: 12px;
  --radius-sm: 8px;
  --radius-full: 9999px;
  
  --shadow-lg: 0 10px 25px -5px rgba(0, 0, 0, 0.5), 0 8px 10px -6px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 30px rgba(59, 130, 246, 0.15);
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--bg-main);
  color: var(--text-primary);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  padding: 30px 20px;
  -webkit-font-smoothing: antialiased;
}

.app-container {
  width: 100%;
  max-width: 1140px;
  display: flex;
  flex-direction: column;
  gap: 28px;
}

/* Header */
.app-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border-color);
}

.logo-area {
  display: flex;
  align-items: center;
  gap: 14px;
}

.logo-icon {
  font-size: 2.2rem;
  background: rgba(255, 255, 255, 0.05);
  padding: 8px 12px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
}

h1 {
  font-size: 1.8rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  background: linear-gradient(90deg, #ffffff, #93c5fd);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.subtitle {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-top: 4px;
}

.subtitle strong {
  color: #60a5fa;
  font-weight: 600;
}

.header-controls {
  display: flex;
  align-items: center;
  gap: 12px;
}

.toggle-group {
  display: inline-flex;
  background: rgba(255, 255, 255, 0.05);
  padding: 4px;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-color);
}

.btn-toggle {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  padding: 6px 14px;
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn-toggle.active {
  background: var(--primary-accent);
  color: #fff;
  box-shadow: 0 2px 8px var(--primary-glow);
}

/* UTC Hero Section */
.utc-hero-section {
  position: relative;
}

.utc-card {
  background: var(--bg-hero);
  border: 1px solid var(--border-highlight);
  border-radius: var(--radius-lg);
  padding: 32px;
  box-shadow: var(--shadow-lg), var(--shadow-glow);
  position: relative;
  overflow: hidden;
}

.utc-card::before {
  content: '';
  position: absolute;
  top: -50%;
  left: 30%;
  width: 350px;
  height: 350px;
  background: radial-gradient(circle, rgba(59, 130, 246, 0.15) 0%, transparent 70%);
  pointer-events: none;
}

.utc-badge-row {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  margin-bottom: 20px;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 5px 12px;
  border-radius: var(--radius-full);
}

.primary-badge {
  background: rgba(59, 130, 246, 0.2);
  color: #93c5fd;
  border: 1px solid rgba(59, 130, 246, 0.4);
}

.offset-badge {
  background: rgba(255, 255, 255, 0.08);
  color: #e2e8f0;
  border: 1px solid var(--border-color);
}

.live-badge {
  background: rgba(16, 185, 129, 0.15);
  color: #34d399;
  border: 1px solid rgba(16, 185, 129, 0.3);
}

.pulse-dot {
  width: 8px;
  height: 8px;
  background-color: #3b82f6;
  border-radius: 50%;
  box-shadow: 0 0 10px #3b82f6;
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% { transform: scale(0.95); opacity: 0.8; }
  50% { transform: scale(1.3); opacity: 1; }
  100% { transform: scale(0.95); opacity: 0.8; }
}

.utc-content {
  text-align: left;
  margin-bottom: 24px;
}

.utc-time-display {
  font-family: var(--font-mono);
  font-size: clamp(3.2rem, 8vw, 5.5rem);
  font-weight: 700;
  color: #ffffff;
  letter-spacing: -0.03em;
  line-height: 1.05;
  text-shadow: 0 0 25px rgba(255, 255, 255, 0.15);
}

.utc-date-display {
  font-size: 1.2rem;
  color: var(--text-secondary);
  margin-top: 8px;
  font-weight: 500;
}

.utc-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.day-progress-container {
  flex-grow: 1;
  max-width: 500px;
}

.day-progress-label {
  display: flex;
  justify-content: space-between;
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 6px;
  font-weight: 500;
}

.progress-bar {
  width: 100%;
  height: 6px;
  background: rgba(255, 255, 255, 0.08);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, #3b82f6, #60a5fa);
  transition: width 0.3s ease;
  border-radius: var(--radius-full);
}

.day-night-icon {
  font-size: 1.8rem;
  filter: drop-shadow(0 0 10px rgba(250, 204, 21, 0.4));
}

/* Toolbar & Scrubber */
.toolbar-section {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.search-and-add {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.select-wrapper {
  flex: 1;
  min-width: 260px;
  position: relative;
}

select {
  width: 100%;
  background: var(--bg-card);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  padding: 12px 16px;
  border-radius: var(--radius-md);
  font-family: var(--font-sans);
  font-size: 0.95rem;
  appearance: none;
  cursor: pointer;
  outline: none;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

select:focus {
  border-color: var(--primary-accent);
  box-shadow: 0 0 0 3px var(--primary-glow);
}

.select-wrapper::after {
  content: '▼';
  font-size: 0.7rem;
  color: var(--text-muted);
  position: absolute;
  right: 16px;
  top: 50%;
  transform: translateY(-50%);
  pointer-events: none;
}

.btn {
  padding: 12px 20px;
  border-radius: var(--radius-md);
  font-family: var(--font-sans);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
  border: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}

.btn-primary {
  background: var(--primary-accent);
  color: #ffffff;
}

.btn-primary:hover {
  background: #2563eb;
  box-shadow: 0 4px 14px var(--primary-glow);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.06);
  color: var(--text-secondary);
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  color: #fff;
}

.btn-small {
  background: rgba(239, 68, 68, 0.15);
  color: #f87171;
  border: 1px solid rgba(239, 68, 68, 0.3);
  padding: 4px 10px;
  font-size: 0.75rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn-small:hover {
  background: rgba(239, 68, 68, 0.25);
  color: #fff;
}

/* Time Scrubber Card */
.scrubber-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 16px 20px;
}

.scrubber-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
  font-size: 0.9rem;
}

#scrubber-value-label {
  color: #60a5fa;
  margin-left: 6px;
  font-family: var(--font-mono);
}

input[type=range] {
  width: 100%;
  height: 8px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 4px;
  outline: none;
  appearance: none;
  cursor: pointer;
}

input[type=range]::-webkit-slider-thumb {
  appearance: none;
  width: 20px;
  height: 20px;
  background: var(--primary-accent);
  border: 3px solid #fff;
  border-radius: 50%;
  cursor: pointer;
  box-shadow: 0 0 10px rgba(59, 130, 246, 0.8);
  transition: transform 0.1s ease;
}

input[type=range]::-webkit-slider-thumb:hover {
  transform: scale(1.15);
}

.scrubber-markers {
  display: flex;
  justify-content: space-between;
  margin-top: 8px;
  font-size: 0.75rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

/* Clocks Section */
.clocks-section {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.section-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.section-header h2 {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
}

.clocks-count {
  font-size: 0.85rem;
  color: var(--text-muted);
  background: rgba(255, 255, 255, 0.05);
  padding: 4px 10px;
  border-radius: var(--radius-full);
}

.clocks-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 18px;
}

/* Individual Clock Card */
.clock-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 20px;
  transition: transform 0.2s ease, border-color 0.2s ease, background 0.2s ease;
  position: relative;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.clock-card:hover {
  transform: translateY(-2px);
  border-color: rgba(255, 255, 255, 0.2);
  background: var(--bg-card-hover);
}

.card-top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 14px;
}

.city-info h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 2px;
  color: #fff;
}

.city-info .country-name {
  font-size: 0.82rem;
  color: var(--text-muted);
}

.card-actions {
  display: flex;
  align-items: center;
  gap: 6px;
}

.btn-remove {
  background: transparent;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  padding: 4px;
  border-radius: var(--radius-sm);
  font-size: 1.1rem;
  line-height: 1;
  transition: all 0.2s ease;
}

.btn-remove:hover {
  color: var(--danger-color);
  background: rgba(239, 68, 68, 0.1);
}

.card-body {
  margin-bottom: 16px;
}

.card-time {
  font-family: var(--font-mono);
  font-size: 2.2rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: #fff;
  line-height: 1.1;
}

.card-date {
  font-size: 0.88rem;
  color: var(--text-secondary);
  margin-top: 6px;
}

.card-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 12px;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.card-diff-badge {
  font-size: 0.78rem;
  font-family: var(--font-mono);
  font-weight: 600;
  padding: 3px 8px;
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.06);
  color: #cbd5e1;
}

.card-diff-badge.ahead {
  color: #38bdf8;
  background: rgba(56, 189, 248, 0.1);
  border: 1px solid rgba(56, 189, 248, 0.2);
}

.card-diff-badge.behind {
  color: #fb923c;
  background: rgba(251, 146, 60, 0.1);
  border: 1px solid rgba(251, 146, 60, 0.2);
}

.card-diff-badge.equal {
  color: #94a3b8;
}

.card-daynight-tag {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 0.78rem;
  font-weight: 600;
}

.card-daynight-tag.day {
  color: var(--day-color);
}

.card-daynight-tag.night {
  color: var(--night-color);
}

/* Footer */
.app-footer {
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-muted);
  padding: 20px 0 10px;
  border-top: 1px solid var(--border-color);
  line-height: 1.5;
}

/* Responsiveness */
@media (max-width: 680px) {
  .app-header {
    flex-direction: column;
    align-items: flex-start;
  }
  
  .header-controls {
    width: 100%;
    justify-content: space-between;
  }

  .utc-card {
    padding: 20px;
  }

  .utc-time-display {
    font-size: 2.8rem;
  }

  .clocks-grid {
    grid-template-columns: 1fr;
  }
}