:root {
    --primary: #3b82f6;
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
    --dark: #1f2937;
    --gray: #6b7280;
    --light-gray: #f9fafb;
    --border: #e5e7eb;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 2rem;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    background: white;
    border-radius: 20px;
    padding: 2rem;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
}

header {
    text-align: center;
    margin-bottom: 3rem;
    padding-bottom: 1.5rem;
    border-bottom: 3px solid var(--primary);
}

h1 {
    font-size: 2.5rem;
    color: var(--dark);
    margin-bottom: 0.5rem;
}

.subtitle {
    color: var(--gray);
    font-size: 1.1rem;
}

/* Metrics Cards */
.metrics-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-bottom: 3rem;
}

.metric-card {
    background: linear-gradient(135deg, var(--primary) 0%, #2563eb 100%);
    color: white;
    padding: 2rem;
    border-radius: 15px;
    display: flex;
    align-items: center;
    gap: 1.5rem;
    box-shadow: 0 4px 15px rgba(59, 130, 246, 0.3);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.metric-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(59, 130, 246, 0.4);
}

.metric-card.success {
    background: linear-gradient(135deg, var(--success) 0%, #059669 100%);
    box-shadow: 0 4px 15px rgba(16, 185, 129, 0.3);
}

.metric-card.success:hover {
    box-shadow: 0 8px 25px rgba(16, 185, 129, 0.4);
}

.metric-icon {
    font-size: 3rem;
}

.metric-content h3 {
    font-size: 2.5rem;
    font-weight: bold;
    margin-bottom: 0.25rem;
}

.metric-content p {
    font-size: 1rem;
    opacity: 0.9;
}

/* Charts */
.charts-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(500px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.chart-container {
    background: var(--light-gray);
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

.chart-container.full-width {
    grid-column: 1 / -1;
}

.chart-container h2 {
    color: var(--dark);
    margin-bottom: 1.5rem;
    font-size: 1.5rem;
}

canvas {
    max-height: 300px;
}

/* Footer */
footer {
    text-align: center;
    padding-top: 2rem;
    border-top: 2px solid var(--border);
    color: var(--gray);
}

#refreshBtn {
    margin-top: 1rem;
    background: var(--primary);
    color: white;
    border: none;
    padding: 0.75rem 2rem;
    border-radius: 10px;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
}

#refreshBtn:hover {
    background: #2563eb;
    transform: scale(1.05);
}

@media (max-width: 768px) {
    .charts-grid {
        grid-template-columns: 1fr;
    }
    
    h1 {
        font-size: 2rem;
    }
    
    body {
        padding: 1rem;
    }
}