/* CSS Variables - Chattermill Brand Colors */
:root {
    /* Primary Colors */
    --primary-blue: #04AAD6;
    --accent-green: #BBF247;
    --dark-blue: #291C45;

    /* Neutrals */
    --white: #FFFFFF;
    --light-gray: #FAFAFA;
    --soft-gray: #E6E6E6;
    --medium-gray: #9CA3AF;
    --dark-gray: #4B5563;

    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #04AAD6 0%, #BBF247 100%);
    --gradient-dark: linear-gradient(135deg, #291C45 0%, #04AAD6 100%);

    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-display: 'IBM Plex Sans', 'Inter', sans-serif;

    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;

    /* Borders */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;

    /* 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);
}

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

html {
    scroll-behavior: smooth;
}

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

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

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-display);
    font-weight: 700;
    line-height: 1.2;
    color: var(--dark-blue);
}

h1 {
    font-size: clamp(2.5rem, 5vw, 4rem);
    margin-bottom: var(--spacing-lg);
}

h2 {
    font-size: clamp(2rem, 4vw, 3rem);
    margin-bottom: var(--spacing-md);
}

h3 {
    font-size: clamp(1.5rem, 3vw, 2rem);
    margin-bottom: var(--spacing-sm);
}

p {
    margin-bottom: var(--spacing-md);
    color: var(--dark-gray);
}

a {
    color: var(--primary-blue);
    text-decoration: none;
    transition: all 0.3s ease;
}

a:hover {
    opacity: 0.8;
}

/* Navigation */
.navbar {
    background: var(--white);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 1000;
    backdrop-filter: blur(10px);
    background: rgba(255, 255, 255, 0.95);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md) var(--spacing-lg);
}

.nav-brand {
    display: flex;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.logo-text {
    color: var(--dark-blue);
}

.logo-accent {
    color: var(--primary-blue);
    font-weight: 500;
}

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

.nav-link {
    color: var(--dark-gray);
    font-weight: 500;
    font-size: 0.95rem;
    transition: all 0.3s ease;
    position: relative;
}

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

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--gradient-primary);
    border-radius: 2px;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
    background: none;
    border: none;
}

.bar {
    width: 25px;
    height: 3px;
    background-color: var(--dark-blue);
    margin: 3px 0;
    transition: 0.3s;
    border-radius: 2px;
}

/* Hero Section */
.hero {
    padding: var(--spacing-3xl) 0 calc(var(--spacing-3xl) - 19px) 0; /* Reduced bottom by 0.5cm */
    background: linear-gradient(135deg, #E8EAED 0%, #F5F6F8 100%);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -10%;
    width: 60%;
    height: 200%;
    background: var(--gradient-primary);
    opacity: 0.05;
    border-radius: 50%;
    filter: blur(100px);
}

.hero-wrapper {
    display: flex;
    align-items: center;
    gap: var(--spacing-3xl);
    position: relative;
    z-index: 1;
}

.hero-content {
    flex: 1;
    max-width: 700px;
}

.hero-visual {
    flex-shrink: 0;
}

.network-viz {
    width: 302px;  /* 8cm ≈ 302px (2x larger) */
    height: 302px; /* 8cm ≈ 302px (2x larger) */
    display: block;
    position: relative;
    top: -19px;    /* 0.5cm up */
    left: 19px;    /* 0.5cm to the right */
}

.hero-title {
    margin-bottom: var(--spacing-xl);
    font-size: clamp(2.25rem, 4.5vw, 3.5rem);
}

.gradient-text {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--dark-gray);
    margin-bottom: var(--spacing-2xl);
    line-height: 1.8;
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-md);
}

/* Buttons */
.btn {
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-block;
    border: none;
    text-align: center;
}

.btn-primary {
    background: var(--primary-blue);
    color: var(--white);
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    opacity: 1;
}

.btn-secondary {
    background: var(--white);
    color: var(--primary-blue);
    border: 2px solid var(--primary-blue);
}

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

.btn-outline {
    background: transparent;
    color: var(--primary-blue);
    border: 2px solid var(--soft-gray);
    margin-top: var(--spacing-xl);
}

.btn-outline:hover {
    border-color: var(--primary-blue);
    background: var(--light-gray);
}


/* Section Styles */
.section-header {
    text-align: center;
    margin-bottom: var(--spacing-3xl);
}

.section-title {
    margin-bottom: var(--spacing-md);
    font-size: clamp(1.75rem, 3.5vw, 2.25rem);
}

.section-subtitle {
    font-size: 1.25rem;
    color: var(--medium-gray);
}

.research-description {
    margin: var(--spacing-2xl) 0 var(--spacing-xl);
    text-align: left;
}

.research-description p {
    font-size: 1.05rem;
    line-height: 1.8;
    color: var(--dark-gray);
    margin-bottom: var(--spacing-lg);
}

/* Research Section */
.research-section {
    padding: var(--spacing-3xl) 0;
    background: var(--white);
}

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

.research-card {
    background: var(--light-gray);
    padding: var(--spacing-2xl);
    border-radius: var(--radius-lg);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.research-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: var(--gradient-primary);
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

.research-card:hover::before {
    transform: scaleX(1);
}

.research-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.research-card-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.research-number {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-blue);
    opacity: 0.3;
}

.research-card h3 {
    font-size: 1.5rem;
    flex: 1;
}

.member-role {
    color: var(--primary-blue);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    font-size: 1rem;
}

.member-links {
    margin-top: var(--spacing-lg);
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--soft-gray);
}

.linkedin-link {
    display: inline-block;
    color: var(--primary-blue);
    font-weight: 500;
    padding: var(--spacing-sm) var(--spacing-md);
    background: linear-gradient(135deg, rgba(4, 170, 214, 0.1), rgba(187, 242, 71, 0.1));
    border-radius: var(--radius-sm);
    transition: all 0.3s ease;
    text-decoration: none;
}

.linkedin-link:hover {
    background: var(--gradient-primary);
    color: var(--white);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.research-card p {
    margin-bottom: var(--spacing-md);
    line-height: 1.6;
    font-size: 0.95rem;
}

.research-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.tag {
    background: var(--white);
    color: var(--primary-blue);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 500;
}

/* Publications Section */
.publications-section {
    padding: var(--spacing-3xl) 0;
    background: var(--light-gray);
}

.publications-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
}

.publication-item {
    background: var(--white);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    display: flex;
    gap: var(--spacing-xl);
    transition: all 0.3s ease;
    box-shadow: var(--shadow-sm);
}

.publication-item:hover {
    box-shadow: var(--shadow-md);
    transform: translateX(5px);
}

.publication-date {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-width: 80px;
    padding: var(--spacing-md);
    background: var(--gradient-primary);
    border-radius: var(--radius-md);
    color: var(--white);
}

.publication-date .month {
    font-size: 0.875rem;
    text-transform: uppercase;
    font-weight: 600;
}

.publication-date .year {
    font-size: 1.25rem;
    font-weight: 700;
}

.publication-content {
    flex: 1;
}

.publication-content h3 {
    margin-bottom: var(--spacing-sm);
    color: var(--dark-blue);
    font-size: 1.35rem;
}

.publication-authors {
    color: var(--medium-gray);
    margin-bottom: var(--spacing-xs);
}

.publication-venue {
    color: var(--primary-blue);
    font-weight: 600;
    margin-bottom: var(--spacing-md);
}

.publication-links {
    display: flex;
    gap: var(--spacing-md);
}

.publication-links a {
    color: var(--primary-blue);
    font-weight: 500;
    padding: var(--spacing-xs) var(--spacing-sm);
    border: 1px solid var(--soft-gray);
    border-radius: var(--radius-sm);
    transition: all 0.3s ease;
}

.publication-links a:hover {
    background: var(--primary-blue);
    color: var(--white);
    border-color: var(--primary-blue);
}

/* Team Section */
.team-section {
    padding: var(--spacing-3xl) 0;
    background: var(--white);
}

.team-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-2xl);
}

.team-member {
    text-align: center;
    padding: var(--spacing-xl);
    background: var(--light-gray);
    border-radius: var(--radius-lg);
    transition: all 0.3s ease;
}

.team-member:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.member-avatar {
    width: 100px;
    height: 100px;
    margin: 0 auto var(--spacing-lg);
    position: relative;
    border-radius: 50%;
    overflow: hidden;
}

.member-avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.avatar-placeholder {
    width: 100%;
    height: 100%;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    font-weight: 700;
    color: var(--white);
}

.team-member h3 {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-xs);
}

.member-role {
    color: var(--primary-blue);
    font-weight: 600;
    margin-bottom: var(--spacing-md);
}

.member-bio {
    font-size: 0.95rem;
    color: var(--medium-gray);
    line-height: 1.6;
    margin-bottom: var(--spacing-md);
}

.team-member .linkedin-link {
    display: inline-block;
    color: var(--primary-blue);
    font-weight: 500;
    font-size: 0.9rem;
    padding: var(--spacing-xs) var(--spacing-sm);
    background: linear-gradient(135deg, rgba(4, 170, 214, 0.1), rgba(187, 242, 71, 0.1));
    border-radius: var(--radius-sm);
    transition: all 0.3s ease;
    text-decoration: none;
}

.team-member .linkedin-link:hover {
    background: var(--gradient-primary);
    color: var(--white);
    transform: translateY(-2px);
}

/* News Section */
.news-section {
    padding: var(--spacing-3xl) 0;
    background: var(--light-gray);
}

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

.news-card {
    background: var(--white);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    transition: all 0.3s ease;
    position: relative;
}

.news-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.news-badge {
    display: inline-block;
    padding: var(--spacing-xs) var(--spacing-sm);
    background: var(--soft-gray);
    color: var(--dark-gray);
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    margin-bottom: var(--spacing-md);
}

.news-badge.new {
    background: var(--accent-green);
    color: var(--dark-blue);
}

.news-card h3 {
    margin-bottom: var(--spacing-md);
    font-size: 1.25rem;
}

.news-card h3 a:hover {
    color: var(--primary-blue) !important;
    text-decoration: underline !important;
}

.news-card p {
    margin-bottom: var(--spacing-md);
}

.news-card .author-tag {
    font-size: 0.9rem;
    font-style: italic;
    color: var(--medium-gray);
    margin-top: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
}

.news-card time {
    color: var(--medium-gray);
    font-size: 0.875rem;
}

/* Footer */
.footer {
    background: var(--dark-blue);
    color: var(--white);
    padding: var(--spacing-3xl) 0 var(--spacing-xl);
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: var(--spacing-2xl);
    margin-bottom: var(--spacing-2xl);
}

.footer-section h4 {
    color: var(--white);
    margin-bottom: var(--spacing-md);
}

.footer-section p {
    color: var(--soft-gray);
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: var(--spacing-sm);
}

.footer-section a {
    color: var(--soft-gray);
    transition: color 0.3s ease;
}

.footer-section a:hover {
    color: var(--accent-green);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: var(--spacing-lg);
    text-align: center;
    color: var(--medium-gray);
}

/* Responsive Design */
@media (max-width: 1024px) {
    .network-viz {
        width: 220px;
        height: 220px;
        top: -15px;    /* Proportionally smaller offset */
        left: 15px;
    }
}

@media (max-width: 768px) {
    .footer-content {
        grid-template-columns: 1fr;
    }

    .nav-menu {
        position: fixed;
        right: -100%;
        top: 70px;
        flex-direction: column;
        background-color: var(--white);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: var(--shadow-lg);
        padding: var(--spacing-xl) 0;
    }

    .nav-menu.active {
        right: 0;
    }

    .nav-toggle {
        display: flex;
    }

    .hero-buttons {
        flex-direction: column;
    }

    .hero-wrapper {
        flex-direction: column;
        text-align: center;
    }

    .hero-content {
        max-width: 100%;
    }

    .network-viz {
        width: 180px;
        height: 180px;
        top: 0;      /* Reset positioning on mobile */
        left: 0;
    }

    .publication-item {
        flex-direction: column;
    }

    .publication-date {
        flex-direction: row;
        width: 100%;
    }
}