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

 body {
     font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
     background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
     min-height: 100vh;
     padding: 20px;
 }

 .container {
     max-width: 1400px;
     margin: 0 auto;
 }

 .header {
     text-align: center;
     color: white;
     margin-bottom: 40px;
 }

 .header h1 {
     font-size: 2.5rem;
     margin-bottom: 10px;
     text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
 }

 .header p {
     font-size: 1.1rem;
     opacity: 0.9;
 }

 .stats-grid {
     display: grid;
     grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
     gap: 20px;
     margin-bottom: 40px;
 }

 .chart-section {
     background: rgba(255, 255, 255, 0.95);
     border-radius: 16px;
     padding: 24px;
     box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
     backdrop-filter: blur(10px);
     border: 1px solid rgba(255, 255, 255, 0.2);
     margin-bottom: 40px;
 }

 .chart-header {
     display: flex;
     justify-content: space-between;
     align-items: center;
     margin-bottom: 24px;
     flex-wrap: wrap;
     gap: 16px;
 }

 .chart-title {
     font-size: 1.5rem;
     color: #333;
     font-weight: 600;
 }

 .time-tabs {
     display: flex;
     gap: 8px;
     background: #f1f5f9;
     padding: 4px;
     border-radius: 12px;
 }

 .time-tab {
     padding: 8px 16px;
     border: none;
     background: transparent;
     border-radius: 8px;
     cursor: pointer;
     font-size: 0.9rem;
     font-weight: 500;
     color: #64748b;
     transition: all 0.3s ease;
 }

 .time-tab.active {
     background: #6366f1;
     color: white;
     box-shadow: 0 2px 8px rgba(99, 102, 241, 0.3);
 }

 .time-tab:hover:not(.active) {
     background: #e2e8f0;
     color: #334155;
 }

 .chart-container {
     position: relative;
     height: 400px;
     margin-bottom: 20px;
 }

 .chart-grid {
     display: grid;
     grid-template-columns: 2fr 1fr;
     gap: 20px;
     margin-bottom: 20px;
 }

 .stat-card {
     background: rgba(255, 255, 255, 0.95);
     border-radius: 16px;
     padding: 24px;
     box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
     backdrop-filter: blur(10px);
     border: 1px solid rgba(255, 255, 255, 0.2);
     transition: transform 0.3s ease, box-shadow 0.3s ease;
 }

 .stat-card:hover {
     transform: translateY(-5px);
     box-shadow: 0 12px 48px rgba(0, 0, 0, 0.15);
 }

 .stat-card h3 {
     font-size: 1.2rem;
     color: #333;
     margin-bottom: 16px;
     display: flex;
     align-items: center;
     gap: 8px;
 }

 .api-icon {
     width: 24px;
     height: 24px;
     border-radius: 6px;
     display: flex;
     align-items: center;
     justify-content: center;
     font-size: 12px;
     font-weight: bold;
     color: white;
 }

 .openai-icon {
     background: #10a37f;
 }

 .gemini-icon {
     background: #4285f4;
 }

 .claude-icon {
     background: #d97706;
 }

 .xai-icon {
     background: #000000;
 }

 .total-icon {
     background: #6366f1;
 }

 .stat-row {
     display: flex;
     justify-content: space-between;
     align-items: center;
     padding: 12px 0;
     border-bottom: 1px solid #eee;
 }

 .stat-row:last-child {
     border-bottom: none;
 }

 .stat-label {
     color: #666;
     font-size: 0.9rem;
 }

 .stat-value {
     font-size: 1.1rem;
     font-weight: 600;
     color: #333;
 }

 .usage-guide {
     background: rgba(255, 255, 255, 0.95);
     border-radius: 16px;
     padding: 32px;
     box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
     backdrop-filter: blur(10px);
     border: 1px solid rgba(255, 255, 255, 0.2);
 }

 .usage-guide h2 {
     color: #333;
     margin-bottom: 20px;
     font-size: 1.5rem;
 }

 .endpoint-list {
     display: grid;
     grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
     gap: 12px;
     margin: 20px 0;
 }

 .endpoint-item {
     background: #f8f9fa;
     padding: 16px;
     border-radius: 8px;
     border-left: 4px solid #6366f1;
     transition: all 0.3s ease;
     cursor: pointer;
 }

 .endpoint-item:hover {
     background: #f1f5f9;
     transform: translateY(-2px);
     box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
 }

 .endpoint-path {
     font-weight: bold;
     color: #6366f1;
     margin-bottom: 4px;
     font-family: 'Courier New', monospace;
 }

 .endpoint-url {
     font-size: 0.8rem;
     color: #666;
     word-break: break-all;
     font-family: 'Courier New', monospace;
 }

 .example-section {
     margin-top: 24px;
     padding-top: 24px;
     border-top: 1px solid #eee;
 }

 .example-section h3 {
     color: #333;
     margin-bottom: 12px;
 }

 .code-block {
     background: #1a1a1a;
     color: #f8f8f2;
     padding: 16px;
     border-radius: 8px;
     font-family: 'Courier New', monospace;
     font-size: 0.9rem;
     overflow-x: auto;
     margin: 12px 0;
     white-space: pre-wrap;
     word-wrap: break-word;
     line-height: 1.4;
 }

 .refresh-btn {
     position: fixed;
     bottom: 30px;
     right: 30px;
     background: #6366f1;
     color: white;
     border: none;
     border-radius: 50px;
     padding: 12px 24px;
     font-size: 1rem;
     cursor: pointer;
     box-shadow: 0 4px 16px rgba(99, 102, 241, 0.3);
     transition: all 0.3s ease;
     z-index: 1000;
 }

 .refresh-btn:hover {
     background: #5855eb;
     transform: translateY(-2px);
     box-shadow: 0 6px 20px rgba(99, 102, 241, 0.4);
 }

 .toast {
     position: fixed;
     top: 20px;
     right: 20px;
     background: #10b981;
     color: white;
     padding: 12px 20px;
     border-radius: 8px;
     font-size: 14px;
     z-index: 1001;
     opacity: 0;
     transform: translateX(100%);
     transition: all 0.3s ease;
 }

 .toast.show {
     opacity: 1;
     transform: translateX(0);
 }

 .chart-legend {
     display: flex;
     flex-direction: column;
     gap: 10px;
     margin-top: 16px;
     padding-top: 16px;
     border-top: 1px solid #e2e8f0;
 }

 .legend-item {
     display: flex;
     align-items: center;
     gap: 8px;
     font-size: 0.9rem;
 }

 .legend-color {
     width: 12px;
     height: 12px;
     border-radius: 2px;
 }

 .legend-line {
     width: 16px;
     height: 3px;
     border-radius: 2px;
 }

 .no-data {
     text-align: center;
     color: #64748b;
     font-style: italic;
     padding: 40px 0;
 }

 .chart-info {
     background: #f8fafc;
     padding: 12px 16px;
     border-radius: 8px;
     margin-bottom: 16px;
     border-left: 4px solid #6366f1;
 }

 .chart-info p {
     color: #64748b;
     font-size: 0.9rem;
     margin: 0;
 }

 @media (max-width: 768px) {
     .stats-grid {
         grid-template-columns: 1fr;
     }

     .endpoint-list {
         grid-template-columns: 1fr;
     }

     .header h1 {
         font-size: 2rem;
     }

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

     .chart-header {
         flex-direction: column;
         align-items: stretch;
     }

     .time-tabs {
         justify-self: stretch;
     }
 }