:root {
    --primary-color: #1e3a5f;
    --secondary-color: #2563eb;
    --accent-color: #dc2626;
    --accent-light: #fee2e2;
    --success-color: #059669;
    --warning-color: #f59e0b;
    --text-color: #1e293b;
    --text-light: #64748b;
    --light-bg: #f8fafc;
    --border-color: #e2e8f0;
    --max-width: 1200px;
    --gradient-1: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-2: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --gradient-3: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    --gradient-hero: linear-gradient(135deg, #1e3a5f 0%, #3b5998 100%);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    line-height: 1.7;
    color: var(--text-color);
    background-color: #fff;
    overflow-x: hidden;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 20px;
}

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

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.02); }
}

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

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #1e3a5f 0%, #2c5282 50%, #3b5998 100%);
    color: white;
    padding: 70px 0 60px;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1440 320"><path fill="rgba(255,255,255,0.03)" d="M0,96L48,112C96,128,192,160,288,160C384,160,480,128,576,112C672,96,768,96,864,112C960,128,1056,160,1152,160C1248,160,1344,128,1392,112L1440,96L1440,320L1392,320C1344,320,1248,320,1152,320C1056,320,960,320,864,320C768,320,672,320,576,320C480,320,384,320,288,320C192,320,96,320,48,320L0,320Z"></path></svg>') no-repeat bottom;
    background-size: cover;
    opacity: 0.5;
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    animation: fadeInUp 0.8s ease-out;
}

.logo-large {
    width: 280px;
    height: auto;
    margin-bottom: 35px;
    filter: drop-shadow(0 8px 16px rgba(0, 0, 0, 0.3));
    animation: float 3s ease-in-out infinite;
}

.hero h2 {
    font-size: 1.9rem;
    font-weight: 500;
    line-height: 1.5;
    max-width: 900px;
    margin: 0 auto 20px;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
    color: #ffffff;
}

.hero .subtitle {
    font-size: 1.15rem;
    font-weight: 400;
    opacity: 0.95;
    margin-bottom: 30px;
    color: #e0e7ff;
}

.hero-badge {
    display: inline-block;
    background: rgba(255, 255, 255, 0.15);
    padding: 10px 24px;
    border-radius: 50px;
    font-size: 1rem;
    margin: 10px;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.25);
    transition: all 0.3s ease;
    color: #ffffff;
}

.hero-badge:hover {
    background: rgba(255, 255, 255, 0.25);
    transform: translateY(-2px);
}

.hero-cta {
    margin-top: 40px;
}

.btn {
    display: inline-block;
    padding: 14px 32px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    font-size: 1rem;
    margin: 8px;
    cursor: pointer;
    border: none;
}

.btn-primary {
    background: white;
    color: var(--primary-color);
    box-shadow: 0 4px 14px rgba(0, 0, 0, 0.2);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3);
}

.btn-outline {
    background: transparent;
    color: white;
    border: 2px solid white;
}

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

/* Navigation */
nav {
    background-color: var(--primary-color);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

nav ul {
    list-style: none;
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    padding: 0;
}

nav ul li {
    margin: 0;
}

nav ul li a {
    display: block;
    padding: 16px 24px;
    color: white;
    text-decoration: none;
    transition: all 0.3s ease;
    font-weight: 500;
    position: relative;
}

nav ul li a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 3px;
    background: var(--warning-color);
    transition: all 0.3s ease;
    transform: translateX(-50%);
}

nav ul li a:hover {
    background-color: var(--secondary-color);
}

nav ul li a:hover::after {
    width: 80%;
}

/* Sections */
section {
    padding: 70px 0;
}

section:nth-child(even) {
    background-color: var(--light-bg);
}

section h2 {
    font-family: 'Playfair Display', serif;
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 20px;
    text-align: center;
    position: relative;
    padding-bottom: 20px;
}

section h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background: var(--gradient-2);
    border-radius: 2px;
}

section h3 {
    font-size: 1.8rem;
    color: var(--secondary-color);
    margin: 40px 0 20px;
}

section p {
    font-size: 1.1rem;
    line-height: 1.8;
    margin-bottom: 20px;
    color: var(--text-color);
}

/* Stats Section */
.stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin: 60px 0;
}

.stat-card {
    background: white;
    padding: 40px 30px;
    border-radius: 16px;
    text-align: center;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    transition: all 0.3s ease;
    border: 1px solid var(--border-color);
}

.stat-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.1);
}

.stat-number {
    font-size: 3.5rem;
    font-weight: 800;
    color: var(--secondary-color);
    margin-bottom: 10px;
    font-family: 'Playfair Display', serif;
}

.stat-label {
    font-size: 1.1rem;
    color: var(--text-light);
    font-weight: 500;
}

/* Featured Conferences */
.featured-conferences {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
    margin-top: 50px;
}

.conference-card {
    background: white;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.07);
    transition: all 0.3s ease;
    border: 1px solid var(--border-color);
    position: relative;
}

.conference-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.12);
}

.conference-card-header {
    padding: 30px;
    background: var(--gradient-hero);
    color: white;
    position: relative;
    overflow: hidden;
}

.conference-card-header::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, transparent 70%);
}

.conference-year {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 10px;
    font-family: 'Playfair Display', serif;
}

.conference-location {
    font-size: 1.1rem;
    opacity: 0.95;
    font-weight: 500;
}

.conference-card-body {
    padding: 30px;
}

.conference-card-body h4 {
    color: var(--primary-color);
    margin-bottom: 15px;
    font-size: 1.2rem;
}

.conference-card-body p {
    color: var(--text-light);
    margin-bottom: 20px;
    font-size: 1rem;
}

.conference-link {
    display: inline-block;
    color: var(--secondary-color);
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    font-size: 1rem;
}

.conference-link:hover {
    color: var(--accent-color);
    transform: translateX(5px);
}

.conference-link::after {
    content: ' →';
    transition: all 0.3s ease;
}

.conference-link:hover::after {
    transform: translateX(5px);
}

/* Special Issue Section */
.special-issue-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(500px, 1fr));
    gap: 40px;
    margin-top: 50px;
}

.special-issue-card {
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
    padding: 40px;
    border-radius: 16px;
    border-left: 5px solid var(--secondary-color);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    transition: all 0.3s ease;
}

.special-issue-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.1);
}

.special-issue-card h3 {
    color: var(--primary-color);
    margin-top: 0;
    font-size: 1.6rem;
}

.journal-name {
    display: inline-block;
    background: var(--secondary-color);
    color: white;
    padding: 6px 16px;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 20px;
}

.papers-list {
    background: white;
    padding: 25px;
    border-radius: 12px;
    margin-top: 25px;
}

.papers-list h4 {
    color: var(--primary-color);
    margin-bottom: 15px;
    font-size: 1.2rem;
}

.papers-list ul {
    list-style: none;
    padding: 0;
}

.papers-list li {
    padding: 12px 0;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-color);
    position: relative;
    padding-left: 25px;
}

.papers-list li:last-child {
    border-bottom: none;
}

.papers-list li::before {
    content: '📄';
    position: absolute;
    left: 0;
    font-size: 1rem;
}

/* Organization Section */
.organization-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin: 50px 0;
}

.organization-card {
    background: white;
    padding: 30px;
    border-radius: 16px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.organization-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 24px rgba(0,0,0,0.1);
}

.organization-card h3 {
    margin-top: 0;
    color: var(--primary-color);
    font-size: 1.4rem;
    margin-bottom: 20px;
    padding-bottom: 15px;
    border-bottom: 3px solid var(--secondary-color);
}

.organization-card ul {
    list-style: none;
    padding: 0;
}

.organization-card ul li {
    padding: 12px 0;
    border-bottom: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.organization-card ul li:last-child {
    border-bottom: none;
}

.organization-card ul li:hover {
    padding-left: 10px;
    color: var(--secondary-color);
}

/* Footer */
footer {
    background: linear-gradient(135deg, #1a365d 0%, #0f172a 100%);
    color: white;
    padding: 60px 0 30px;
    margin-top: 0;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.footer-section h3 {
    color: white;
    margin-bottom: 20px;
    font-size: 1.3rem;
}

.footer-section p, .footer-section a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    display: block;
    margin-bottom: 10px;
    transition: all 0.3s ease;
}

.footer-section a:hover {
    color: white;
    padding-left: 5px;
}

.footer-logos {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 40px;
    flex-wrap: wrap;
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-logo {
    width: 80px;
    height: auto;
    opacity: 0.9;
    transition: all 0.3s ease;
    background: white;
    padding: 10px;
    border-radius: 8px;
}

.footer-logo:hover {
    opacity: 1;
    transform: scale(1.1);
    box-shadow: 0 4px 12px rgba(255, 255, 255, 0.2);
}

.footer-bottom {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    margin-top: 40px;
    color: rgba(255, 255, 255, 0.7);
}

.dblp-link {
    background-color: rgba(255,255,255,0.1);
    padding: 25px;
    border-radius: 12px;
    text-align: center;
    margin-bottom: 40px;
    backdrop-filter: blur(10px);
}

.dblp-link a {
    color: white;
    text-decoration: none;
    font-weight: 600;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
    font-size: 1.1rem;
}

.dblp-link a:hover {
    text-decoration: underline;
}

/* Conference Item Styling */
.conference-item {
    background: white;
    padding: 30px;
    margin-bottom: 30px;
    border-radius: 16px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}

.conference-item h3 {
    color: var(--primary-color);
    margin-top: 0;
    font-size: 1.8rem;
}

.conference-item h4 {
    color: var(--secondary-color);
    margin: 15px 0;
}

.conference-item em {
    display: block;
    margin: 15px 0;
    line-height: 1.8;
    color: var(--text-light);
}

.conference-item a {
    color: var(--secondary-color);
    text-decoration: none;
    font-weight: 600;
}

.conference-item a:hover {
    text-decoration: underline;
}

/* Responsive Design */
@media (max-width: 768px) {
    .hero h2 {
        font-size: 1.4rem;
    }

    .hero .subtitle {
        font-size: 1rem;
    }

    nav ul {
        flex-direction: column;
    }

    nav ul li a {
        text-align: center;
        padding: 12px;
    }

    section h2 {
        font-size: 2rem;
    }

    .featured-conferences,
    .special-issue-grid {
        grid-template-columns: 1fr;
    }

    .organization-grid {
        grid-template-columns: 1fr;
    }

    .footer-content {
        grid-template-columns: 1fr;
    }

    .logo-large {
        width: 140px;
    }

    section {
        padding: 50px 0;
    }
}

/* Utility Classes */
.text-center {
    text-align: center;
}

.mt-4 {
    margin-top: 40px;
}

.mb-4 {
    margin-bottom: 40px;
}

.highlight {
    background: linear-gradient(120deg, #fef3c7 0%, #fde68a 100%);
    padding: 2px 8px;
    border-radius: 4px;
    font-weight: 600;
}