:root {
    --color-white: #ffffff;
    --color-black: #000000;
    --color-gray-100: #f8f9fa;
    --color-gray-200: #e9ecef;
    --color-gray-300: #dee2e6;
    --color-gray-400: #ced4da;
    --color-gray-500: #6c757d;
    --color-gray-600: #5a6268;
    --color-gray-700: #495057;
    --color-gray-800: #343a40;
    --color-gray-900: #212529;
    --color-primary: #2c3e50;
    --color-primary-light: #34495e;
    --color-primary-hover: #1a252f;
    --font-primary: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica Neue', Arial, sans-serif;
    --container-max-width: 1200px;
    --spacing-unit: 8px;
    --border-radius: 4px;
    --transition-fast: 0.15s ease;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 2rem;
    --font-size-4xl: 2.5rem;
    --font-size-5xl: 3rem;
    --spacing-xs: 8px;
    --spacing-sm: 12px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-2xl: 48px;
    --spacing-3xl: 64px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-primary);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--color-gray-800);
    background-color: var(--color-white);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    text-decoration: none;
    color: inherit;
    transition: color var(--transition-fast);
}

ul {
    list-style: none;
}

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

.row {
    display: grid;
    grid-template-columns: repeat(12, 1fr);
    gap: var(--spacing-lg);
    align-items: start;
}

.col-1 { grid-column: span 1; }
.col-2 { grid-column: span 2; }
.col-3 { grid-column: span 3; }
.col-4 { grid-column: span 4; }
.col-5 { grid-column: span 5; }
.col-6 { grid-column: span 6; }
.col-7 { grid-column: span 7; }
.col-8 { grid-column: span 8; }
.col-9 { grid-column: span 9; }
.col-10 { grid-column: span 10; }
.col-11 { grid-column: span 11; }
.col-12 { grid-column: span 12; }

@media (max-width: 992px) {
    .row {
        grid-template-columns: repeat(8, 1fr);
        gap: var(--spacing-md);
    }
}

@media (max-width: 768px) {
    .row {
        grid-template-columns: repeat(4, 1fr);
        gap: var(--spacing-sm);
    }
    
    .col-1, .col-2, .col-3, .col-4, 
    .col-5, .col-6, .col-7, .col-8, 
    .col-9, .col-10, .col-11 {
        grid-column: span 4;
    }
}

@media (max-width: 576px) {
    .row {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }
    
    .col-1, .col-2, .col-3, .col-4, 
    .col-5, .col-6, .col-7, .col-8, 
    .col-9, .col-10, .col-11, .col-12 {
        grid-column: span 1;
    }
}

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

.section-title {
    font-size: var(--font-size-4xl);
    font-weight: 600;
    color: var(--color-gray-900);
    margin-bottom: var(--spacing-sm);
    letter-spacing: -0.5px;
    line-height: 1.2;
}

.section-subtitle {
    font-size: var(--font-size-sm);
    color: var(--color-primary);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 2px;
    margin-bottom: var(--spacing-sm);
}

.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 72px;
    background: var(--color-white);
    border-bottom: 1px solid var(--color-gray-200);
    z-index: 1000;
    display: flex;
    align-items: center;
}

.header-inner {
    display: flex;
    justify-content: flex-start;
    align-items: center;
    padding-left: 0;
}

.logo {
    display: flex;
    align-items: center;
    margin-right: auto;
}

.logo img {
    height: 50px;
    width: auto;
}

.logo-text {
    font-size: var(--font-size-2xl);
    font-weight: 600;
    color: var(--color-gray-900);
    margin-left: var(--spacing-sm);
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: var(--spacing-xl);
}

.nav-link {
    font-size: var(--font-size-sm);
    font-weight: 500;
    color: var(--color-gray-700);
    padding: var(--spacing-xs) var(--spacing-sm);
    position: relative;
    transition: color var(--transition-fast);
    letter-spacing: 0.5px;
}

.nav-link:hover,
.nav-link.active {
    color: var(--color-primary);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: var(--spacing-sm);
    right: var(--spacing-sm);
    height: 2px;
    background: var(--color-primary);
    transform: scaleX(0);
    transition: transform var(--transition-fast);
}

.nav-link:hover::after,
.nav-link.active::after {
    transform: scaleX(1);
}

.hero {
    padding-top: 72px;
    min-height: 520px;
    display: flex;
    align-items: center;
    background: var(--color-gray-100);
}

.hero-content {
    max-width: 720px;
    margin: 0 auto;
    text-align: center;
}

.hero-title {
    font-size: var(--font-size-5xl);
    font-weight: 700;
    color: var(--color-gray-900);
    margin-bottom: var(--spacing-md);
    letter-spacing: -1px;
    line-height: 1.1;
}

.hero-subtitle {
    font-size: var(--font-size-xl);
    color: var(--color-gray-600);
    margin-bottom: var(--spacing-xl);
    line-height: 1.5;
    font-weight: 500;
}

.hero-description {
    font-size: var(--font-size-base);
    color: var(--color-gray-700);
    margin-bottom: var(--spacing-xl);
    line-height: 1.8;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: var(--font-size-base);
    font-weight: 600;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: background-color var(--transition-fast), transform var(--transition-fast);
    border: none;
    letter-spacing: 0.5px;
}

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

.btn-primary:hover {
    background: var(--color-primary-light);
    transform: translateY(-2px);
}

.btn-outline {
    background: transparent;
    color: var(--color-primary);
    border: 2px solid var(--color-primary);
}

.btn-outline:hover {
    background: var(--color-primary);
    color: var(--color-white);
    transform: translateY(-2px);
}

.card {
    background: var(--color-white);
    border: 1px solid var(--color-gray-200);
    border-radius: var(--border-radius);
    padding: var(--spacing-xl);
    transition: border-color var(--transition-fast), transform var(--transition-fast), box-shadow var(--transition-fast);
    height: 480px;
    display: flex;
    flex-direction: column;
}

.card:hover {
    border-color: var(--color-primary);
    transform: translateY(-4px);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

.card-title {
    font-size: var(--font-size-2xl);
    font-weight: 600;
    color: var(--color-gray-900);
    margin-bottom: var(--spacing-md);
    line-height: 1.3;
}

.card-content {
    color: var(--color-gray-600);
    line-height: 1.7;
    font-size: var(--font-size-sm);
    flex-grow: 1;
}

.card-image {
    width: 100%;
    height: 180px;
    object-fit: cover;
    border-radius: var(--border-radius);
    margin-bottom: var(--spacing-lg);
}

.features {
    background: var(--color-gray-100);
}

.feature-item {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.feature-icon {
    width: 48px;
    height: 48px;
    background: var(--color-primary);
    border-radius: var(--border-radius);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.feature-icon svg {
    width: 24px;
    height: 24px;
    fill: var(--color-white);
}

.feature-content {
    flex: 1;
}

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

.feature-description {
    color: var(--color-gray-600);
    line-height: 1.6;
    font-size: var(--font-size-sm);
}

.footer {
    background: var(--color-white);
    border-top: 1px solid var(--color-gray-200);
    color: var(--color-gray-700);
    padding: var(--spacing-3xl) 0;
}

.footer-title {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--color-gray-900);
    margin-bottom: var(--spacing-md);
}

.footer-links {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.footer-link {
    color: var(--color-gray-600);
    transition: color var(--transition-fast);
    font-size: var(--font-size-sm);
}

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

.footer-bottom {
    margin-top: var(--spacing-2xl);
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--color-gray-300);
    text-align: center;
    font-size: var(--font-size-sm);
    color: var(--color-gray-500);
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 6px;
    cursor: pointer;
    padding: var(--spacing-xs);
}

.mobile-menu-btn span {
    width: 24px;
    height: 2px;
    background: var(--color-gray-900);
    transition: all var(--transition-fast);
}

@media (max-width: 768px) {
    .mobile-menu-btn {
        display: flex;
    }
    
    .nav-menu {
        display: none;
    }
    
    .hero-title {
        font-size: var(--font-size-3xl);
    }
    
    .section-title {
        font-size: var(--font-size-3xl);
    }
    
    .section {
        padding: var(--spacing-2xl) 0;
    }
    
    .card-title {
        font-size: var(--font-size-xl);
    }
    
    .card-image {
        height: 160px;
    }
}

@media (max-width: 576px) {
    .hero {
        min-height: 480px;
    }
    
    .hero-title {
        font-size: var(--font-size-2xl);
    }
    
    .hero-subtitle {
        font-size: var(--font-size-base);
    }
    
    .card {
        padding: var(--spacing-lg);
    }
}