:root {
    --primary-color: #4f46e5;
    --primary-color-hover: #4338ca;
    --background-color: #f3f4f6;
    --container-bg: #ffffff;
    --card-bg: #f9fafb;
    --text-primary: #111827;
    --text-secondary: #6b7280;
    --border-color: #e5e7eb;
    --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --border-radius: 0.75rem;
}

body {
    font-family: 'Noto Sans SC', 'system-ui', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--background-color);
    color: var(--text-primary);
    margin: 0;
    padding: 2rem;
}

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

.header {
    text-align: center;
    margin-bottom: 2.5rem;
}

.header__title {
    font-size: 2.25rem;
    font-weight: 700;
    margin: 0 0 0.5rem 0;
}

.header__subtitle {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin: 0;
}

.controls {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    align-items: center;
    gap: 1.5rem;
    background-color: var(--container-bg);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    margin-bottom: 2.5rem;
}

.controls__group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.controls__group label {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
}

.controls input[type="datetime-local"] {
    font-family: inherit;
    font-size: 1rem;
    padding: 0.5rem 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    background-color: #fff;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.controls input[type="datetime-local"]:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.2);
}

.button--primary {
    font-family: inherit;
    font-size: 1rem;
    font-weight: 500;
    color: #fff;
    background-color: var(--primary-color);
    border: none;
    padding: 0.6rem 1.5rem;
    border-radius: 0.5rem;
    cursor: pointer;
    transition: background-color 0.2s;
    align-self: flex-end;
}

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

.hidden { 
    display: none !important; 
}

.loader {
    text-align: center;
    padding: 40px 0;
    color: var(--text-secondary);
}

.loader__spinner {
    width: 40px;
    height: 40px;
    border: 4px solid #e5e7eb;
    border-top: 4px solid var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 1rem;
}

@keyframes spin { 
    0% { transform: rotate(0deg); } 
    100% { transform: rotate(360deg); } 
}

.error-box {
    text-align: center;
    font-weight: 500;
    color: #991b1b;
    background-color: #fee2e2;
    border: 1px solid #fecaca;
    border-radius: var(--border-radius);
    padding: 1rem;
    margin: 1.5rem 0;
}

.results {
    display: flex;
    flex-direction: column;
    gap: 2.5rem;
}

.summary-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.card {
    background-color: var(--container-bg);
    padding: 1.5rem 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    text-align: center;
}

.card__title {
    margin: 0 0 0.5rem 0;
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-secondary);
}

.card__value {
    margin: 0;
    font-size: 2.25rem;
    font-weight: 700;
    color: var(--text-primary);
    line-height: 1.2;
}

.charts-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2rem;
}

.chart-container {
    background-color: var(--container-bg);
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
}

.chart-container__title {
    text-align: center;
    margin-top: 0;
    margin-bottom: 1.5rem;
    font-size: 1.125rem;
    font-weight: 500;
    color: var(--text-primary);
    line-height: 1.4;
}

.chart-wrapper {
    position: relative;
    height: 400px;
    width: 100%;
}

.chart-wrapper--bar {
    height: 500px;
}

.chart-wrapper canvas {
    max-width: 100%;
    max-height: 100%;
}

@media (max-width: 768px) {
    body {
        padding: 1rem;
    }
    .charts-grid {
        grid-template-columns: 1fr;
    }
    .chart-wrapper {
        height: 350px;
    }
    .chart-wrapper--bar {
        height: 450px;
    }
    .chart-container__title {
        font-size: 1rem;
    }
}