/* 
   ChromeBird AI Labs - Design System 
   Inspiration: Editorial Tech (Anthropic), Warm, Precise.
*/

:root {
    /* Color Palette */
    --bg-paper: #FDFCF8;      /* Warm, paper-like background */
    --surface: #FFFFFF;       /* Clean white for cards */
    --primary-navy: #031829;  /* Deep Navy from Logo */
    --secondary-slate: #53616B; /* Muted Slate from Logo */
    --accent-yellow: #D4C32E;   /* slightly darkened logo yellow for better visibility on white */
    
    --border-subtle: rgba(3, 24, 41, 0.08);
    --border-focus: rgba(3, 24, 41, 0.2);

    /* Typography */
    --font-serif: 'Domine', serif;
    --font-sans: 'Inter', sans-serif;

    /* Spacing */
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 8rem;
}

/* Reset & Base */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    background-color: var(--bg-paper);
    color: var(--primary-navy);
    font-family: var(--font-sans);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

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

a {
    color: inherit;
    text-decoration: none;
}

/* Typography Scale */
h1, h2, h3 {
    font-family: var(--font-serif);
    font-weight: 600;
    line-height: 1.2;
}

.display-text {
    font-size: 3.5rem; /* Large, editorial */
    letter-spacing: -0.02em;
    margin-bottom: var(--spacing-md);
    color: var(--primary-navy);
}

.sub-text {
    font-size: 1.25rem;
    color: var(--secondary-slate);
    max-width: 600px;
    margin: 0 auto;
    font-family: var(--font-serif); /* Serif for subtitle adds elegance */
}

.section-title {
    font-size: 2rem;
    margin-bottom: var(--spacing-lg);
    border-top: 1px solid var(--primary-navy); /* Brutalist/Editorial line */
    padding-top: var(--spacing-sm);
    display: inline-block;
}

/* Layout Utilities */
.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* Header */
header {
    padding: var(--spacing-md) 0;
    border-bottom: 1px solid var(--border-subtle);
    background-color: rgba(253, 252, 248, 0.9); /* Translucent paper */
    backdrop-filter: blur(8px);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    font-family: var(--font-sans);
    font-weight: 600;
    font-size: 1.1rem;
    letter-spacing: -0.01em;
}

.logo img {
    height: 32px;
    margin-right: 12px;
}

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

nav a {
    font-size: 0.95rem;
    color: var(--secondary-slate);
    transition: color 0.2s ease;
}

nav a:hover {
    color: var(--primary-navy);
}

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

.btn-nav {
    font-size: 0.9rem;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    transition: all 0.2s ease;
}

.btn-nav-primary {
    background-color: var(--primary-navy);
    color: white !important;
}

.btn-nav-primary:hover {
    background-color: #052a4a;
    transform: translateY(-1px);
}

.btn-nav-secondary {
    border: 1px solid var(--border-subtle);
}

.btn-nav-secondary:hover {
    background-color: var(--border-subtle);
}

/* Hero Section */
.hero {
    padding: 5rem 0 3rem;
    text-align: center;
    position: relative;
    overflow: hidden;
}

/* Integrating the background.png subtly */
.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 100%;
    background-image: url('background.png');
    background-size: cover;
    background-position: center;
    opacity: 0.08; /* Very subtle texture */
    z-index: -1;
    mix-blend-mode: multiply; /* Blends into the paper background */
}

.hero-visual {
    margin-top: var(--spacing-lg);
    display: flex;
    justify-content: center;
}

.rounded-shadow {
    border-radius: 8px;
    box-shadow: 0 20px 40px -10px rgba(3, 24, 41, 0.12); /* Soft navy shadow */
    border: 1px solid var(--border-subtle);
    max-height: 500px;
    object-fit: cover;
}

/* Yousuf Karsh Portrait Filter */
.karsh-filter {
    filter: grayscale(100%) contrast(1.2) brightness(0.9);
    mix-blend-mode: multiply; /* Optional: adds depth if background is warm */
    background-color: var(--bg-paper);
}

.karsh-container {
    background-color: var(--bg-paper); /* Matches page bg so multiply mode works correctly */
    position: relative;
}

.karsh-container::after {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    box-shadow: inset 0 0 80px rgba(0,0,0,0.4); /* Subtle vignette */
    pointer-events: none;
}


/* Content Blocks */
.content-block {
    padding: var(--spacing-xl) 0;
}

.alt-bg {
    background-color: #F6F5F2; /* Slightly darker paper tone for contrast */
}

.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: var(--spacing-md);
}

/* Card Component */
.card {
    background: var(--surface);
    padding: var(--spacing-md);
    border: 1px solid var(--border-subtle);
    border-radius: 4px;
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    min-height: 280px;
    position: relative;
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 24px -8px rgba(3, 24, 41, 0.08);
    border-color: var(--border-focus);
}

.card-tag {
    font-family: var(--font-sans);
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--secondary-slate);
    margin-bottom: var(--spacing-sm);
    display: block;
}

.card h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
    font-family: var(--font-serif);
}

.card p {
    color: var(--secondary-slate);
    font-size: 1rem;
    max-width: 90%;
}

.card-footer {
    margin-top: auto; /* Pushes footer to bottom */
    padding-top: var(--spacing-sm);
}

.linkedin-link {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--secondary-slate);
    border-bottom: 1px solid transparent;
    transition: all 0.2s ease;
    display: inline-flex;
    align-items: center;
    gap: 4px;
}

.linkedin-link:hover {
    color: var(--primary-navy);
    border-bottom-color: var(--primary-navy);
}

.arrow {
    margin-top: var(--spacing-md);
    font-size: 1.25rem;
    color: var(--primary-navy);
    opacity: 0;
    transform: translateX(-10px);
    transition: all 0.3s ease;
}

.card:hover .arrow {
    opacity: 1;
    transform: translateX(0);
}

/* Collaborate Section */
.collaborate-section {
    padding: var(--spacing-xl) 0;
    text-align: center;
    background-color: var(--primary-navy); /* Inverted section */
    color: white;
}

.collaborate-section h2 {
    color: white;
    margin-bottom: var(--spacing-sm);
    border: none;
}

.collaborate-section p {
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: var(--spacing-md);
    font-family: var(--font-serif);
    font-size: 1.25rem;
}

.btn-text {
    color: var(--accent-yellow);
    font-weight: 500;
    font-size: 1.1rem;
    border-bottom: 1px solid transparent;
    transition: border-color 0.2s ease;
}

.btn-text:hover {
    border-bottom-color: var(--accent-yellow);
}

/* Feature Rows (Zig-Zag Layout) */
.feature-row {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.feature-row:nth-child(even) {
    flex-direction: row-reverse;
}

.feature-text {
    flex: 1;
    min-width: 300px;
}

.feature-media {
    flex: 1.5;
    min-width: 300px;
    width: 100%; /* Ensures it takes full width on wrap */
}

.feature-text h3 {
    font-size: 2rem;
    margin-bottom: var(--spacing-sm);
    color: var(--primary-navy);
}

.feature-text p {
    font-size: 1.1rem;
    color: var(--secondary-slate);
    margin-bottom: var(--spacing-md);
}

@media (max-width: 900px) {
    .feature-row, .feature-row:nth-child(even) {
        flex-direction: column;
        text-align: left;
        gap: var(--spacing-md);
        margin-bottom: var(--spacing-lg);
    }
    
    .feature-media {
        width: 100%;
    }
}

/* Footer */
footer {
    padding: var(--spacing-lg) 0;
    border-top: 1px solid var(--border-subtle);
    font-size: 0.875rem;
    color: var(--secondary-slate);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

/* Logo Carousel */
.logo-carousel {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: var(--spacing-lg);
    flex-wrap: wrap;
    margin: var(--spacing-md) 0 var(--spacing-lg);
}

.partner-logo {
    height: 40px; /* Standardized height */
    width: auto;
    filter: grayscale(100%) opacity(0.6);
    transition: all 0.4s ease;
    mix-blend-mode: multiply;
}

.partner-logo:hover {
    filter: grayscale(0%) opacity(1);
    transform: scale(1.05);
}

/* Video Embeds */
.video-container {
    position: relative;
    padding-bottom: 56.25%; /* 16:9 Aspect Ratio */
    height: 0;
    overflow: hidden;
    border-radius: 8px;
    box-shadow: 0 20px 40px -10px rgba(3, 24, 41, 0.12);
    border: 1px solid var(--border-subtle);
    margin-bottom: 2rem;
}

.video-container iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border: 0;
}

/* Mailing List CTA */
.research-cta {
    margin-top: var(--spacing-lg);
    border-top: 1px solid var(--border-subtle);
    padding-top: var(--spacing-md);
    display: inline-block;
}


/* Responsive */
@media (max-width: 768px) {
    .display-text {
        font-size: 2.5rem;
    }
    
    .nav-container {
        flex-direction: column;
        gap: var(--spacing-sm);
    }
    
    .card-grid {
        grid-template-columns: 1fr;
    }

    .hero {
        padding: var(--spacing-lg) 0;
    }
}