/* Import Space Grotesk font */
@import url('https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@300;400;500;600;700&display=swap');

/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --color-bg: #1a1a1a;
    --color-text: #e8e8e8;
    --color-text-secondary: #a0a0a0;
    --color-border: #333333;
    --color-accent: #ffffff;
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 6rem;
}

body {
    font-family: 'Space Grotesk', -apple-system, BlinkMacSystemFont, sans-serif;
    line-height: 1.6;
    color: var(--color-text);
    background-color: var(--color-bg);
    font-size: 16px;
}

/* Typography */
h1, h2, h3, h4 {
    font-weight: 600;
    line-height: 1.2;
    letter-spacing: -0.02em;
}

h1 {
    font-size: clamp(2rem, 5vw, 3.5rem);
    margin-bottom: var(--spacing-md);
}

h2 {
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    margin-bottom: var(--spacing-md);
}

h3 {
    font-size: clamp(1.25rem, 3vw, 1.75rem);
    margin-bottom: var(--spacing-sm);
}

h4 {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-xs);
}

p {
    margin-bottom: var(--spacing-sm);
}

a {
    color: var(--color-accent);
    text-decoration: none;
    border-bottom: 1px solid var(--color-accent);
    transition: opacity 0.2s;
}

a:hover {
    opacity: 0.6;
}

/* Header and Navigation */
header {
    border-bottom: 1px solid var(--color-border);
    padding: var(--spacing-md) 0;
    position: sticky;
    top: 0;
    background-color: var(--color-bg);
    z-index: 100;
}

nav {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.25rem;
    font-weight: 600;
    letter-spacing: -0.02em;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: var(--spacing-md);
}

.nav-links a {
    border-bottom: none;
    font-weight: 400;
}

/* Main content */
main {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

section {
    padding: var(--spacing-xl) 0;
    border-bottom: 1px solid var(--color-border);
}

section:last-of-type {
    border-bottom: none;
}

/* Hero section */
.hero {
    min-height: 60vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.subtitle {
    font-size: clamp(1.125rem, 2.5vw, 1.5rem);
    color: var(--color-text-secondary);
    max-width: 800px;
    line-height: 1.5;
}

/* Systems section */
.system-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-lg);
}

.system-card {
    padding: var(--spacing-md);
    border: 1px solid var(--color-border);
}

.system-card h3 {
    font-weight: 600;
}

.system-card p {
    color: var(--color-text-secondary);
    margin-bottom: 0;
}

/* Technology section */
.tech-content {
    margin-top: var(--spacing-lg);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.tech-section h3 {
    font-weight: 600;
}

.tech-section p {
    color: var(--color-text-secondary);
    max-width: 800px;
    margin-bottom: 0;
}

/* Research section */
.research-content {
    margin-top: var(--spacing-lg);
}

.research-content > p {
    color: var(--color-text-secondary);
    max-width: 800px;
    margin-bottom: var(--spacing-lg);
}

.research-areas {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-md);
}

.research-item {
    padding: var(--spacing-md);
    border: 1px solid var(--color-border);
}

.research-item h4 {
    font-weight: 600;
}

.research-item p {
    color: var(--color-text-secondary);
    font-size: 0.9375rem;
    margin-bottom: 0;
}

/* Contact section */
.contact {
    text-align: center;
}

.contact p {
    color: var(--color-text-secondary);
    max-width: 600px;
    margin: 0 auto var(--spacing-md);
}

.contact-info {
    margin-top: var(--spacing-md);
}

.contact-info a {
    font-size: 1.125rem;
}

/* Footer */
footer {
    border-top: 1px solid var(--color-border);
    padding: var(--spacing-md);
    text-align: center;
    color: var(--color-text-secondary);
    font-size: 0.875rem;
}

/* Responsive adjustments */
@media (max-width: 768px) {
    :root {
        --spacing-lg: 3rem;
        --spacing-xl: 4rem;
    }

    .nav-links {
        gap: var(--spacing-sm);
    }

    .system-grid,
    .research-areas {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }

    nav {
        flex-direction: column;
        gap: var(--spacing-sm);
        text-align: center;
    }

    .hero {
        min-height: 50vh;
    }
}

@media (max-width: 480px) {
    body {
        font-size: 15px;
    }

    .nav-links {
        flex-wrap: wrap;
        justify-content: center;
    }
}