/* ==================== RESET & BASE STYLES ==================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Color Palette */
    --primary-50: #eff6ff;
    --primary-100: #dbeafe;
    --primary-500: #3b82f6;
    --primary-600: #2563eb;
    --primary-700: #1d4ed8;
    --primary-900: #1e3a8a;

    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;

    --success-500: #10b981;
    --success-600: #059669;
    --error-500: #ef4444;
    --error-600: #dc2626;
    --warning-500: #f59e0b;

    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;

    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);

    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 300ms cubic-bezier(0.4, 0, 0.2, 1);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background-color: var(--gray-50);
    color: var(--gray-900);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

/* ==================== HEADER ==================== */
.header {
    background: white;
    border-bottom: 1px solid var(--gray-200);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-sm);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md) 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.logo h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--gray-900);
}

.nav {
    display: flex;
    gap: var(--spacing-lg);
}

.nav-link {
    color: var(--gray-600);
    text-decoration: none;
    font-weight: 500;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.nav-link:hover {
    color: var(--primary-600);
    background-color: var(--primary-50);
}

.nav-link.active {
    color: var(--primary-600);
    background-color: var(--primary-50);
}

/* ==================== MAIN CONTENT ==================== */
.main {
    flex: 1;
    padding: var(--spacing-2xl) 0;
}

/* Hero Section */
.hero {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
}

.hero-title {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: var(--spacing-md);
}

.hero-subtitle {
    font-size: 1.125rem;
    color: var(--gray-600);
    max-width: 600px;
    margin: 0 auto;
}

/* Controls Section */
.controls-section {
    margin-bottom: var(--spacing-2xl);
}

.controls-card {
    background: white;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    padding: var(--spacing-xl);
}

.controls-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-lg);
    border-bottom: 2px solid var(--gray-100);
}

.controls-header h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--gray-900);
}

.status-indicator {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.status-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background-color: var(--success-500);
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

.status-text {
    font-size: 0.875rem;
    color: var(--gray-600);
    font-weight: 500;
}

.controls-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: var(--spacing-lg);
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.control-label {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--gray-700);
    text-transform: uppercase;
    letter-spacing: 0.025em;
}

.control-label .icon {
    width: 18px;
    height: 18px;
    color: var(--primary-600);
}

.select-input {
    width: 100%;
    padding: var(--spacing-md);
    font-size: 1rem;
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-md);
    background-color: white;
    color: var(--gray-900);
    cursor: pointer;
    transition: all var(--transition-fast);
    font-family: inherit;
}

.select-input:hover {
    border-color: var(--gray-300);
}

.select-input:focus {
    outline: none;
    border-color: var(--primary-500);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.select-input:disabled {
    background-color: var(--gray-100);
    cursor: not-allowed;
    opacity: 0.6;
}

/* Chart Section */
.chart-section {
    margin-bottom: var(--spacing-2xl);
}

.chart-card {
    background: white;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    padding: var(--spacing-xl);
    position: relative;
    min-height: 600px;
}

.chart-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: var(--spacing-xl);
}

.chart-title {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--gray-900);
    margin-bottom: var(--spacing-xs);
}

.chart-subtitle {
    font-size: 0.875rem;
    color: var(--gray-500);
}

.chart-actions {
    display: flex;
    gap: var(--spacing-sm);
}

.btn-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-md);
    background: white;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.btn-icon:hover {
    border-color: var(--primary-500);
    background-color: var(--primary-50);
}

.btn-icon svg {
    width: 20px;
    height: 20px;
    color: var(--gray-600);
}

.btn-icon:hover svg {
    color: var(--primary-600);
}

.chart-container {
    width: 100%;
    height: 500px;
    min-height: 500px;
}

/* Loading Overlay */
.loading-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(255, 255, 255, 0.95);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-lg);
    border-radius: var(--radius-xl);
    z-index: 10;
}

.loading-overlay.hidden {
    display: none;
}

.spinner {
    width: 48px;
    height: 48px;
    border: 4px solid var(--gray-200);
    border-top-color: var(--primary-600);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

.loading-overlay p {
    color: var(--gray-600);
    font-weight: 500;
}

/* Error Message */
.error-message {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-lg);
    background-color: rgba(239, 68, 68, 0.1);
    border: 2px solid var(--error-500);
    border-radius: var(--radius-md);
    color: var(--error-600);
    margin-bottom: var(--spacing-lg);
}

.error-message svg {
    width: 24px;
    height: 24px;
    flex-shrink: 0;
}

.error-message strong {
    display: block;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.error-message p {
    font-size: 0.875rem;
    margin: 0;
}

/* Info Section */
.info-section {
    margin-bottom: var(--spacing-2xl);
}

.info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.info-card {
    background: white;
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
}

.info-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.info-icon {
    width: 48px;
    height: 48px;
    background: var(--primary-100);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-md);
}

.info-icon svg {
    width: 24px;
    height: 24px;
    color: var(--primary-600);
}

.info-card h4 {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--gray-900);
    margin-bottom: var(--spacing-sm);
}

.info-card p {
    color: var(--gray-600);
    font-size: 0.875rem;
    line-height: 1.6;
}

/* ==================== FOOTER ==================== */
.footer {
    background: white;
    border-top: 1px solid var(--gray-200);
    padding: var(--spacing-xl) 0;
    margin-top: auto;
}

.footer p {
    text-align: center;
    color: var(--gray-600);
    font-size: 0.875rem;
}

/* ==================== RESPONSIVE DESIGN ==================== */
@media (max-width: 1024px) {
    .hero-title {
        font-size: 2rem;
    }

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

@media (max-width: 768px) {
    .container {
        padding: 0 var(--spacing-md);
    }

    .header-content {
        flex-direction: column;
        gap: var(--spacing-md);
    }

    .nav {
        width: 100%;
        justify-content: center;
        flex-wrap: wrap;
    }

    .hero-title {
        font-size: 1.75rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

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

    .chart-container {
        height: 350px;
        min-height: 350px;
    }

    .chart-card {
        padding: var(--spacing-md);
        min-height: 450px;
    }

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

@media (max-width: 480px) {
    .hero-title {
        font-size: 1.5rem;
    }

    .controls-card {
        padding: var(--spacing-md);
    }

    .chart-container {
        height: 300px;
        min-height: 300px;
    }
}

/* ==================== ACCESSIBILITY ==================== */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus Visible for Keyboard Navigation */
:focus-visible {
    outline: 2px solid var(--primary-500);
    outline-offset: 2px;
}