/* ==========================================================================
   Design System Variables
   ========================================================================== */
   :root {
    /* Colors */
    --clr-bg: #0a0a0f;
    --clr-bg-surface: #13131a;
    --clr-bg-surface-hover: #1c1c26;
    
    --clr-text-primary: #f8f9fa;
    --clr-text-secondary: #adb5bd;
    --clr-text-muted: #6c757d;
    
    --clr-accent: #3b82f6; /* Modern Blue */
    --clr-accent-hover: #60a5fa;
    --clr-accent-glow: rgba(59, 130, 246, 0.15);
    
    --clr-border: #27272a;
    
    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    
    /* Animations */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: 300ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 500ms cubic-bezier(0.4, 0, 0.2, 1);
    
    /* Layout */
    --container-width: 1100px;
    --nav-height: 80px;
}

/* ==========================================================================
   Reset & Base Styles
   ========================================================================== */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: var(--font-primary);
    background-color: var(--clr-bg);
    color: var(--clr-text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

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

ul {
    list-style: none;
}

/* ==========================================================================
   Typography
   ========================================================================== */
h1, h2, h3, h4, h5, h6 {
    line-height: 1.2;
    font-weight: 600;
    letter-spacing: -0.02em;
}

/* ==========================================================================
   Navigation
   ========================================================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-height);
    background: rgba(10, 10, 15, 0.8);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--clr-border);
    z-index: 1000;
    transition: transform var(--transition-normal);
}

.navbar.hidden {
    transform: translateY(-100%);
}

.nav-container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 2rem;
    height: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    font-size: 1.25rem;
    font-weight: 600;
    letter-spacing: -0.01em;
    position: relative;
    z-index: 1001; /* Keep above mobile menu */
}

.nav-links {
    display: flex;
    gap: 2.5rem;
}

.nav-link {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--clr-text-secondary);
    position: relative;
    padding: 0.5rem 0;
}

.nav-link:hover {
    color: var(--clr-text-primary);
}

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

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0%;
    height: 2px;
    background-color: var(--clr-accent);
    transition: width var(--transition-normal);
    border-radius: 2px;
}

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

.mobile-menu-btn {
    display: none;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
    z-index: 1001;
}

.hamburger {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--clr-text-primary);
    position: relative;
    transition: background var(--transition-fast);
}

.hamburger::before,
.hamburger::after {
    content: '';
    position: absolute;
    left: 0;
    width: 100%;
    height: 2px;
    background: var(--clr-text-primary);
    transition: transform var(--transition-normal), top var(--transition-normal);
}

.hamburger::before { top: -6px; }
.hamburger::after { top: 6px; }

/* Mobile Menu Active State */
.mobile-menu-btn.active .hamburger { background: transparent; }
.mobile-menu-btn.active .hamburger::before {
    top: 0;
    transform: rotate(45deg);
}
.mobile-menu-btn.active .hamburger::after {
    top: 0;
    transform: rotate(-45deg);
}

/* ==========================================================================
   Hero Section
   ========================================================================== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    padding: calc(var(--nav-height) + 4rem) 2rem 4rem;
    overflow: hidden;
}

.hero-content {
    max-width: var(--container-width);
    margin: 0 auto;
    position: relative;
    z-index: 10;
}

.hero-title {
    font-size: clamp(3rem, 8vw, 5.5rem);
    font-weight: 700;
    margin-bottom: 0.5rem;
    background: linear-gradient(135deg, #fff 0%, #a1a1aa 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: clamp(1.5rem, 4vw, 2.5rem);
    font-weight: 400;
    color: var(--clr-text-secondary);
    margin-bottom: 1.5rem;
}

.hero-affiliation {
    font-size: clamp(1rem, 2vw, 1.25rem);
    font-weight: 500;
    color: var(--clr-text-secondary);
    margin-bottom: 2.5rem;
    padding-left: 1rem;
    border-left: 3px solid var(--clr-accent);
}

.highlight-link {
    color: var(--clr-text-primary);
    text-decoration: underline;
    text-decoration-color: var(--clr-accent);
    text-decoration-thickness: 2px;
    text-underline-offset: 4px;
    transition: color var(--transition-fast);
}

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

.hero-description {
    max-width: 700px;
    font-size: 1.125rem;
    color: var(--clr-text-secondary);
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
    margin-bottom: 3rem;
}

.hero-actions {
    display: flex;
    gap: 1rem;
    margin-bottom: 4rem;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.875rem 1.75rem;
    border-radius: 9999px; /* Pill shape */
    font-weight: 500;
    font-size: 1rem;
    cursor: pointer;
    transition: all var(--transition-normal);
}

.btn-primary {
    background-color: var(--clr-accent);
    color: white;
    box-shadow: 0 0 20px var(--clr-accent-glow);
}

.btn-primary:hover {
    background-color: var(--clr-accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 5px 25px var(--clr-accent-glow);
}

.btn-secondary {
    background-color: var(--clr-bg-surface);
    color: var(--clr-text-primary);
    border: 1px solid var(--clr-border);
}

.btn-secondary:hover {
    background-color: var(--clr-bg-surface-hover);
    border-color: var(--clr-text-muted);
    transform: translateY(-2px);
}

.social-links {
    display: flex;
    gap: 1.5rem;
}

.social-link {
    color: var(--clr-text-muted);
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--clr-bg-surface);
    border: 1px solid var(--clr-border);
}

.social-link:hover {
    color: var(--clr-accent);
    background: var(--clr-bg-surface-hover);
    border-color: var(--clr-accent);
    transform: translateY(-3px);
    box-shadow: 0 10px 20px var(--clr-accent-glow);
}

/* Background Effect */
.hero-background {
    position: absolute;
    top: 50%;
    right: -10%;
    width: 800px;
    height: 800px;
    background: radial-gradient(circle, var(--clr-accent-glow) 0%, transparent 70%);
    transform: translateY(-50%);
    border-radius: 50%;
    z-index: 0;
    pointer-events: none;
    filter: blur(60px);
}

/* ==========================================================================
   Animations
   ========================================================================== */
.reveal-text {
    opacity: 0;
    transform: translateY(30px);
    animation: revealUp 0.8s cubic-bezier(0.2, 0.8, 0.2, 1) forwards;
}

.delay-1 { animation-delay: 0.1s; }
.delay-2 { animation-delay: 0.2s; }
.delay-3 { animation-delay: 0.3s; }
.delay-4 { animation-delay: 0.4s; }
.delay-5 { animation-delay: 0.5s; }

@keyframes revealUp {
    0% {
        opacity: 0;
        transform: translateY(30px);
    }
    100% {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ==========================================================================
   Responsive Design
   ========================================================================== */
@media (max-width: 768px) {
    .mobile-menu-btn {
        display: block;
    }
    
    .nav-links {
        position: fixed;
        top: 0;
        right: -100%;
        width: 100vw;
        height: 100vh;
        background: var(--clr-bg);
        flex-direction: column;
        justify-content: center;
        align-items: center;
        transition: right var(--transition-normal);
        z-index: 1000;
        padding: 2rem;
    }
    
    .nav-links.active {
        right: 0;
    }
    
    .nav-link {
        font-size: 1.5rem;
    }
    
    .hero-background {
        right: 50%;
        transform: translate(50%, -50%);
        width: 100%;
        height: 100vw;
    }
}