:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --danger: #dc2626;
    --danger-dark: #b91c1c;
    --text-primary: #1f2937;
    --text-secondary: #4b5563;
    --border: #d1d5db;
    --background: #f5f5f5;
}

body {
    font-family: system-ui, -apple-system, sans-serif;
    margin: 0;
    padding: 20px;
    background-color: var(--background);
    color: var(--text-primary);
}

.container { 
    max-width: 1200px; 
    margin: 0 auto; 
}

.card {
    background: white;
    border-radius: 8px;
    padding: 20px;
    margin-bottom: 16px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.button {
    background: var(--primary);
    color: white;
    border: none;
    padding: 8px 16px;
    border-radius: 6px;
    cursor: pointer;
    font-weight: 500;
    transition: background-color 0.2s;
}

.button:hover {
    background: var(--primary-dark);
}

.button.danger {
    background: var(--danger);
}

.button.danger:hover {
    background: var(--danger-dark);
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 16px;
}

.input-group {
    margin-bottom: 16px;
}

.input-group label {
    display: block;
    margin-bottom: 4px;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.input-group input {
    width: 100%;
    padding: 8px;
    border: 1px solid var(--border);
    border-radius: 6px;
    transition: all 0.2s;
}

.input-group input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 2px rgba(37,99,235,0.1);
}

.chart-container {
    height: 400px;
    background: white;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.tabs {
    display: flex;
    gap: 8px;
    margin-bottom: 16px;
    flex-wrap: wrap;
}

.tab {
    padding: 8px 16px;
    border: none;
    background: #e5e7eb;
    cursor: pointer;
    border-radius: 6px;
    font-weight: 500;
    transition: all 0.2s;
}

.tab:hover {
    background: #d1d5db;
}

.tab.active {
    background: var(--primary);
    color: white;
}

.value-display {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
}

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

.error-message {
    color: var(--danger);
    font-size: 0.875rem;
    margin-top: 4px;
}

@media (max-width: 768px) {
    .grid {
        grid-template-columns: 1fr;
    }
    
    .tabs {
        flex-direction: column;
    }
    
    .tab {
        width: 100%;
        text-align: center;
    }
}