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

:root {
    /* Black & White Color Palette */
    --color-black: #000000;
    --color-white: #FFFFFF;
    --color-gray-50: #FAFAFA;
    --color-gray-100: #F5F5F5;
    --color-gray-200: #E5E5E5;
    --color-gray-300: #D4D4D4;
    --color-gray-400: #A3A3A3;
    --color-gray-500: #737373;
    --color-gray-600: #525252;
    --color-gray-700: #404040;
    --color-gray-800: #262626;
    --color-gray-900: #171717;
    
    /* Typography */
    --font-primary: 'Space Grotesk', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-secondary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    --spacing-3xl: 6rem;
    
    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
    
    /* 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);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-secondary);
    background-color: var(--color-white);
    color: var(--color-gray-900);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-primary);
    font-weight: 600;
    line-height: 1.2;
    color: var(--color-black);
}

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

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

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

/* ===================================
   UTILITY CLASSES
   =================================== */
.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

.gradient-text {
    background: linear-gradient(135deg, var(--color-black) 0%, var(--color-gray-600) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ===================================
   NAVIGATION
   =================================== */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--color-gray-200);
    z-index: 1000;
    transition: all var(--transition-base);
}

.nav-container {
    max-width: 1280px;
    margin: 0 auto;
    padding: var(--spacing-md) var(--spacing-lg);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    font-family: var(--font-primary);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-black);
}

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

.nav-link {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--color-gray-700);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--color-black);
    transition: width var(--transition-base);
}

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

.nav-link:hover::after {
    width: 100%;
}

.nav-cta {
    padding: 0.625rem 1.5rem;
    background-color: var(--color-black);
    color: var(--color-white);
    border-radius: 6px;
    font-weight: 500;
    font-size: 0.95rem;
    transition: all var(--transition-base);
}

.nav-cta:hover {
    background-color: var(--color-gray-800);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.mobile-menu-toggle {
    display: none;
    padding: 0.5rem;
    color: var(--color-black);
}

/* ===================================
   HERO SECTION
   =================================== */
.hero {
    padding: 10rem var(--spacing-lg) 6rem;
    background: linear-gradient(180deg, var(--color-gray-50) 0%, var(--color-white) 100%);
    position: relative;
    overflow: hidden;
}

.hero-container {
    max-width: 1280px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-3xl);
    align-items: center;
}

.hero-content {
    animation: fadeInUp 0.8s ease;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: 0.5rem 1rem;
    background-color: var(--color-white);
    border: 1px solid var(--color-gray-200);
    border-radius: 50px;
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: var(--spacing-lg);
    box-shadow: var(--shadow-sm);
}

.hero-badge i {
    width: 16px;
    height: 16px;
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 700;
    margin-bottom: var(--spacing-lg);
    line-height: 1.1;
}

.hero-description {
    font-size: 1.125rem;
    color: var(--color-gray-600);
    margin-bottom: var(--spacing-xl);
    max-width: 600px;
    line-height: 1.7;
}

.hero-cta {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-2xl);
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: 0.875rem 1.75rem;
    border-radius: 8px;
    font-weight: 600;
    font-size: 1rem;
    transition: all var(--transition-base);
    cursor: pointer;
}

.btn i {
    width: 18px;
    height: 18px;
}

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

.btn-primary:hover {
    background-color: var(--color-gray-800);
    transform: translateY(-2px);
    box-shadow: var(--shadow-xl);
}

.btn-secondary {
    background-color: var(--color-white);
    color: var(--color-black);
    border: 2px solid var(--color-gray-200);
}

.btn-secondary:hover {
    border-color: var(--color-black);
    transform: translateY(-2px);
}

.hero-stats {
    display: flex;
    gap: var(--spacing-xl);
}

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

.stat i {
    width: 24px;
    height: 24px;
    color: var(--color-black);
}

.stat-value {
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--color-black);
}

.stat-label {
    font-size: 0.875rem;
    color: var(--color-gray-600);
}

.hero-visual {
    display: flex;
    justify-content: center;
    align-items: center;
    animation: fadeIn 1s ease;
}

.visual-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-md);
    padding: var(--spacing-xl);
}

.grid-item {
    width: 100px;
    height: 100px;
    background-color: var(--color-white);
    border: 2px solid var(--color-gray-200);
    border-radius: 12px;
    transition: all var(--transition-base);
    animation: float 3s ease-in-out infinite;
}

.grid-item:nth-child(1) { animation-delay: 0s; }
.grid-item:nth-child(2) { animation-delay: 0.2s; }
.grid-item:nth-child(3) { animation-delay: 0.4s; }
.grid-item:nth-child(4) { animation-delay: 0.6s; }
.grid-item:nth-child(5) { animation-delay: 0.8s; }
.grid-item:nth-child(6) { animation-delay: 1s; }
.grid-item:nth-child(7) { animation-delay: 1.2s; }
.grid-item:nth-child(8) { animation-delay: 1.4s; }
.grid-item:nth-child(9) { animation-delay: 1.6s; }

.grid-item.active {
    background-color: var(--color-black);
    border-color: var(--color-black);
}

.grid-item:hover {
    transform: scale(1.05);
    border-color: var(--color-black);
}

/* ===================================
   SECTION STYLES
   =================================== */
.section-header {
    text-align: center;
    max-width: 800px;
    margin: 0 auto var(--spacing-3xl);
}

.section-badge {
    display: inline-block;
    padding: 0.5rem 1rem;
    background-color: var(--color-gray-100);
    border-radius: 50px;
    font-size: 0.875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: var(--spacing-md);
}

.section-title {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 700;
    margin-bottom: var(--spacing-md);
}

.section-description {
    font-size: 1.125rem;
    color: var(--color-gray-600);
    line-height: 1.7;
}

/* ===================================
   ABOUT SECTION
   =================================== */
.about {
    padding: var(--spacing-3xl) var(--spacing-lg);
    background-color: var(--color-white);
}

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

.about-card {
    padding: var(--spacing-xl);
    background-color: var(--color-gray-50);
    border: 1px solid var(--color-gray-200);
    border-radius: 12px;
    transition: all var(--transition-base);
}

.about-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
    border-color: var(--color-black);
}

.card-icon {
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--color-black);
    color: var(--color-white);
    border-radius: 10px;
    margin-bottom: var(--spacing-md);
}

.card-icon i {
    width: 24px;
    height: 24px;
}

.card-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.card-description {
    color: var(--color-gray-600);
    line-height: 1.6;
}

/* ===================================
   HELIUM AI SECTION
   =================================== */
.helium {
    padding: var(--spacing-3xl) var(--spacing-lg);
    background: linear-gradient(180deg, var(--color-gray-50) 0%, var(--color-white) 100%);
}

.helium-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-3xl);
    align-items: center;
}

.helium-description {
    font-size: 1.125rem;
    color: var(--color-gray-600);
    line-height: 1.7;
    margin-bottom: var(--spacing-xl);
}

.helium-features {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
}

.feature-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-weight: 500;
}

.feature-item i {
    width: 20px;
    height: 20px;
    color: var(--color-black);
}

.platform-card {
    background-color: var(--color-white);
    border: 1px solid var(--color-gray-200);
    border-radius: 16px;
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-lg);
}

.platform-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
    font-weight: 600;
    font-size: 1.125rem;
}

.platform-header i {
    width: 24px;
    height: 24px;
}

.platform-metric {
    margin-bottom: var(--spacing-md);
}

.metric-label {
    font-size: 0.875rem;
    color: var(--color-gray-600);
    margin-bottom: var(--spacing-xs);
}

.metric-bar {
    height: 8px;
    background-color: var(--color-gray-200);
    border-radius: 50px;
    overflow: hidden;
}

.metric-fill {
    height: 100%;
    background-color: var(--color-black);
    border-radius: 50px;
    transition: width 1s ease;
}

/* ===================================
   FEATURES SECTION
   =================================== */
.features {
    padding: var(--spacing-3xl) var(--spacing-lg);
    background-color: var(--color-white);
}

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

.feature-card {
    padding: var(--spacing-xl);
    background-color: var(--color-white);
    border: 1px solid var(--color-gray-200);
    border-radius: 12px;
    transition: all var(--transition-base);
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
    border-color: var(--color-black);
}

.feature-icon {
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--color-gray-100);
    border-radius: 10px;
    margin-bottom: var(--spacing-md);
    transition: all var(--transition-base);
}

.feature-card:hover .feature-icon {
    background-color: var(--color-black);
    color: var(--color-white);
}

.feature-icon i {
    width: 24px;
    height: 24px;
}

.feature-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

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

/* ===================================
   TECHNOLOGY SECTION
   =================================== */
.technology {
    padding: var(--spacing-3xl) var(--spacing-lg);
    background: linear-gradient(180deg, var(--color-gray-50) 0%, var(--color-white) 100%);
}

.tech-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-3xl);
    align-items: center;
}

.tech-stack {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-md);
}

.tech-item {
    padding: var(--spacing-lg);
    background-color: var(--color-white);
    border: 1px solid var(--color-gray-200);
    border-radius: 12px;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: var(--spacing-sm);
    transition: all var(--transition-base);
}

.tech-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--color-black);
}

.tech-item i {
    width: 32px;
    height: 32px;
    color: var(--color-black);
}

.tech-item span {
    font-weight: 500;
    font-size: 0.95rem;
}

.tech-description {
    font-size: 1.125rem;
    color: var(--color-gray-600);
    line-height: 1.7;
    margin-bottom: var(--spacing-xl);
}

.tech-highlights {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.highlight {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-weight: 500;
}

.highlight i {
    width: 20px;
    height: 20px;
    color: var(--color-black);
}

/* ===================================
   CONTACT SECTION
   =================================== */
.contact {
    padding: var(--spacing-3xl) var(--spacing-lg);
    background-color: var(--color-white);
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-3xl);
    align-items: start;
}

.contact-description {
    font-size: 1.125rem;
    color: var(--color-gray-600);
    line-height: 1.7;
    margin-bottom: var(--spacing-xl);
}

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

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

.contact-item i {
    width: 24px;
    height: 24px;
    color: var(--color-black);
    margin-top: 4px;
}

.contact-label {
    font-size: 0.875rem;
    color: var(--color-gray-600);
    margin-bottom: 4px;
}

.contact-value {
    font-weight: 600;
    color: var(--color-black);
}

.contact-value:hover {
    text-decoration: underline;
}

.contact-cta-box {
    background: linear-gradient(135deg, var(--color-gray-900) 0%, var(--color-black) 100%);
    border-radius: 16px;
    padding: var(--spacing-2xl);
    color: var(--color-white);
    text-align: center;
}

.cta-box-content i {
    width: 48px;
    height: 48px;
    margin: 0 auto var(--spacing-md);
}

.cta-box-content h3 {
    font-size: 1.75rem;
    color: var(--color-white);
    margin-bottom: var(--spacing-sm);
}

.cta-box-content p {
    color: var(--color-gray-300);
    margin-bottom: var(--spacing-lg);
}

.cta-box-content .btn-primary {
    background-color: var(--color-white);
    color: var(--color-black);
}

.cta-box-content .btn-primary:hover {
    background-color: var(--color-gray-100);
}

/* ===================================
   FOOTER
   =================================== */
.footer {
    padding: var(--spacing-2xl) var(--spacing-lg);
    background-color: var(--color-gray-900);
    color: var(--color-white);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-xl);
    border-bottom: 1px solid var(--color-gray-700);
}

.footer-logo {
    font-family: var(--font-primary);
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
}

.footer-tagline {
    color: var(--color-gray-400);
    font-size: 0.875rem;
}

.footer-links {
    display: flex;
    gap: var(--spacing-xl);
}

.footer-links a {
    color: var(--color-gray-400);
    font-weight: 500;
    transition: color var(--transition-base);
}

.footer-links a:hover {
    color: var(--color-white);
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: var(--color-gray-500);
    font-size: 0.875rem;
}

/* ===================================
   ANIMATIONS
   =================================== */
@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes float {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-10px);
    }
}

/* ===================================
   RESPONSIVE DESIGN
   =================================== */
@media (max-width: 1024px) {
    .hero-container,
    .helium-content,
    .tech-content,
    .contact-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-2xl);
    }
    
    .hero-visual,
    .helium-visual {
        order: -1;
    }
    
    .nav-links {
        gap: var(--spacing-lg);
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    
    .mobile-menu-toggle {
        display: block;
    }
    
    .hero {
        padding: 8rem var(--spacing-md) 4rem;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-cta {
        flex-direction: column;
    }
    
    .hero-stats {
        flex-direction: column;
        gap: var(--spacing-md);
    }
    
    .visual-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--spacing-sm);
    }
    
    .grid-item {
        width: 80px;
        height: 80px;
    }
    
    .section-title {
        font-size: 1.75rem;
    }
    
    .about-grid,
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .helium-features {
        grid-template-columns: 1fr;
    }
    
    .tech-stack {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        flex-direction: column;
        gap: var(--spacing-lg);
        text-align: center;
    }
    
    .footer-links {
        flex-direction: column;
        gap: var(--spacing-sm);
    }
    
    .footer-bottom {
        flex-direction: column;
        gap: var(--spacing-sm);
        text-align: center;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 var(--spacing-md);
    }
    
    .hero-title {
        font-size: 1.75rem;
    }
    
    .hero-description {
        font-size: 1rem;
    }
    
    .btn {
        padding: 0.75rem 1.5rem;
        font-size: 0.95rem;
    }
    
    .section-title {
        font-size: 1.5rem;
    }
    
    .section-description {
        font-size: 1rem;
    }
}

/* ===================================
   PRINT STYLES
   =================================== */
@media print {
    @page {
        margin: 0.5in;
        @top-center {
            content: "Neural Arc - Intelligence in Motion";
        }
        @bottom-center {
            content: "Created by Helium AI";
        }
    }
    
    body {
        print-color-adjust: exact;
        -webkit-print-color-adjust: exact;
    }
    
    .nav,
    .mobile-menu-toggle {
        display: none;
    }
    
    .hero {
        padding-top: 2rem;
    }
    
    section {
        page-break-inside: avoid;
    }
}