:root {
    --color-primary: #1a1a1a;
    --color-secondary: #6b7280;
    --color-accent: #3b82f6;
    --color-success: #10b981;
    --color-warning: #f59e0b;
    --color-danger: #ef4444;
    --color-background: #ffffff;
    --color-surface: #fafafa;
    --color-border: #e5e7eb;
    --color-text: #1a1a1a;
    --color-text-muted: #6b7280;
    
    --font-family: ui-sans-serif, system-ui, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji";
    --font-size-base: 16px;
    --line-height-base: 1.5;
    
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;
    
    --border-radius: 0.5rem;
    --border-radius-lg: 0.75rem;
    --border-radius-xl: 1rem;
    
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
}

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

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: var(--line-height-base);
    color: var(--color-text);
    background-color: var(--color-background);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.header {
    background-color: var(--color-background);
    border-bottom: 1px solid var(--color-border);
    position: sticky;
    top: 0;
    z-index: 100;
}

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

.nav-brand {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-primary);
}

.logo {
    color: var(--color-accent);
}

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

.nav-link {
    text-decoration: none;
    color: var(--color-text);
    font-weight: 500;
    transition: color 0.2s ease;
}

.nav-link:hover {
    color: var(--color-accent);
}

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

.theme-toggle {
    background: none;
    border: none;
    font-size: 1.25rem;
    cursor: pointer;
    padding: var(--spacing-sm);
    border-radius: var(--border-radius);
    transition: background-color 0.2s ease;
}

.theme-toggle:hover {
    background-color: var(--color-surface);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: 500;
    transition: all 0.2s ease;
    border: none;
    cursor: pointer;
    font-size: var(--font-size-base);
}

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

.btn-primary:hover {
    background-color: #333333;
    transform: translateY(-1px);
}

.btn-secondary {
    background-color: transparent;
    color: var(--color-text);
    border: 1px solid var(--color-border);
}

.btn-secondary:hover {
    background-color: var(--color-surface);
}

.hero {
    padding: var(--spacing-3xl) 0;
    text-align: center;
    background-color: var(--color-background);
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: var(--spacing-lg);
    letter-spacing: -0.02em;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--color-text-muted);
    max-width: 600px;
    margin: 0 auto var(--spacing-xl);
    line-height: 1.6;
}

.hero-actions {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
}

.dashboard-preview {
    padding: var(--spacing-3xl) 0;
    background-color: var(--color-surface);
}

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

.dashboard-card {
    background-color: var(--color-background);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--color-border);
}

.card-header {
    margin-bottom: var(--spacing-lg);
}

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

.avatar {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background-color: var(--color-accent);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
}

.profile-details h4 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.badge {
    background-color: var(--color-danger);
    color: white;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--border-radius);
    font-size: 0.75rem;
    font-weight: 600;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
}

.stat-item {
    text-align: center;
}

.stat-label {
    display: block;
    font-size: 0.875rem;
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-xs);
}

.stat-value {
    display: block;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-primary);
}

.chart-container {
    display: flex;
    justify-content: center;
    margin: var(--spacing-xl) 0;
}

.chart-circle {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    background: conic-gradient(var(--color-accent) 0deg 312deg, var(--color-border) 312deg 360deg);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
}

.chart-inner {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background-color: var(--color-background);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.chart-value {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-primary);
}

.chart-label {
    font-size: 0.75rem;
    color: var(--color-text-muted);
}

.chart-legend {
    display: flex;
    justify-content: center;
    gap: var(--spacing-lg);
}

.legend-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 0.875rem;
}

.legend-color {
    width: 12px;
    height: 12px;
    border-radius: 50%;
}

.performance-grid {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

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

.performance-label {
    flex: 0 0 120px;
    font-size: 0.875rem;
    color: var(--color-text-muted);
}

.performance-bar {
    flex: 1;
    height: 8px;
    background-color: var(--color-border);
    border-radius: var(--border-radius);
    overflow: hidden;
}

.performance-fill {
    height: 100%;
    background-color: var(--color-accent);
    transition: width 0.3s ease;
}

.performance-value {
    flex: 0 0 40px;
    text-align: right;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--color-primary);
}

.heatmap-container {
    text-align: center;
}

.heatmap-grid {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-md);
}

.heatmap-cell {
    aspect-ratio: 1;
    background-color: var(--color-border);
    border-radius: var(--spacing-xs);
    transition: background-color 0.2s ease;
}

.heatmap-cell.active {
    background-color: var(--color-success);
}

.heatmap-caption {
    font-size: 0.875rem;
    color: var(--color-text-muted);
}

.features-overview {
    padding: var(--spacing-3xl) 0;
    background-color: var(--color-background);
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-3xl);
}

.section-header h2 {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: var(--spacing-lg);
}

.section-header p {
    font-size: 1.125rem;
    color: var(--color-text-muted);
    max-width: 600px;
    margin: 0 auto;
    line-height: 1.6;
}

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

.feature-card {
    text-align: center;
    padding: var(--spacing-xl);
    background-color: var(--color-background);
    border-radius: var(--border-radius-lg);
    border: 1px solid var(--color-border);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

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

.feature-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-lg);
}

.feature-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
}

.feature-card p {
    color: var(--color-text-muted);
    line-height: 1.6;
}

.footer {
    background-color: var(--color-primary);
    color: var(--color-background);
    padding: var(--spacing-3xl) 0 var(--spacing-xl);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.footer-section h4 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
}

.footer-section p {
    color: #d1d5db;
    margin-bottom: var(--spacing-sm);
}

.footer-link {
    display: block;
    color: #d1d5db;
    text-decoration: none;
    margin-bottom: var(--spacing-sm);
    transition: color 0.2s ease;
}

.footer-link:hover {
    color: var(--color-background);
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-xl);
    border-top: 1px solid #374151;
    color: #9ca3af;
}

@media (max-width: 768px) {
    .header .container {
        flex-direction: column;
        gap: var(--spacing-md);
    }
    
    .nav {
        order: 3;
        width: 100%;
        justify-content: center;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-actions {
        flex-direction: column;
        align-items: center;
    }
    
    .dashboard-grid {
        grid-template-columns: 1fr;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .performance-item {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--spacing-sm);
    }
    
    .performance-label {
        flex: none;
    }
    
    .performance-bar {
        width: 100%;
    }
}

.page-header {
    padding: var(--spacing-2xl) 0;
    background-color: var(--color-surface);
    text-align: center;
}

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

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

.content-section {
    padding: var(--spacing-3xl) 0;
}

.form-group {
    margin-bottom: var(--spacing-lg);
}

.form-label {
    display: block;
    font-weight: 500;
    color: var(--color-text);
    margin-bottom: var(--spacing-sm);
}

.form-input,
.form-textarea,
.form-select {
    width: 100%;
    padding: var(--spacing-md);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    font-size: var(--font-size-base);
    font-family: var(--font-family);
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

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

.form-textarea {
    resize: vertical;
    min-height: 120px;
}

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

.pricing-card {
    background-color: var(--color-background);
    border: 2px solid var(--color-border);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-xl);
    text-align: center;
    position: relative;
    transition: transform 0.2s ease, border-color 0.2s ease;
}

.pricing-card:hover {
    transform: translateY(-4px);
    border-color: var(--color-accent);
}

.pricing-card.featured {
    border-color: var(--color-accent);
    transform: scale(1.05);
}

.pricing-badge {
    position: absolute;
    top: -12px;
    left: 50%;
    transform: translateX(-50%);
    background-color: var(--color-accent);
    color: white;
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--border-radius);
    font-size: 0.875rem;
    font-weight: 600;
}

.pricing-title {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
}

.pricing-price {
    font-size: 3rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: var(--spacing-xs);
}

.pricing-period {
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-xl);
}

.pricing-features {
    list-style: none;
    margin-bottom: var(--spacing-xl);
}

.pricing-features li {
    padding: var(--spacing-sm) 0;
    color: var(--color-text);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.pricing-features li::before {
    content: "✓";
    color: var(--color-success);
    font-weight: 600;
}

.success-message {
    background-color: #d1fae5;
    border: 1px solid #10b981;
    color: #065f46;
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    margin-bottom: var(--spacing-lg);
    text-align: center;
}

.error-message {
    background-color: #fee2e2;
    border: 1px solid #ef4444;
    color: #991b1b;
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    margin-bottom: var(--spacing-lg);
    text-align: center;
}

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

@media (max-width: 768px) {
    .contact-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
}