:root {
    --primary-color: #2563eb;
    --secondary-color: #0f172a;
    --accent-color: #f59e0b;
    --text-color: #1f2937;
    --bg-light: #f8fafc;
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-secondary: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --gradient-accent: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
}

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

body {
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
}

.navbar {
    background: rgba(255, 255, 255, 0.95) !important;
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
}

.navbar.scrolled {
    background: rgba(255, 255, 255, 0.98) !important;
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
}

.navbar-brand {
    font-weight: 700;
    font-size: 1.5rem;
    color: var(--primary-color) !important;
}

.nav-link {
    font-weight: 700;
    color: var(--text-color) !important;
    transition: all 0.3s ease;
    position: relative;
}

.nav-link:hover {
    color: var(--primary-color) !important;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: width 0.3s ease;
}

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

.hero-section {
    background: linear-gradient(rgba(37, 99, 235, 0.8), rgba(37, 99, 235, 0.8)), url('assets/images/icebe2025-cover.jpg');
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
    min-height: auto;
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
    padding: 2rem 0;
    padding-top: 80px;
    /* Leave space for fixed navigation bar */
}

.hero-section::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 1000 1000"><defs><radialGradient id="a" cx="50%" cy="50%" r="50%"><stop offset="0%" style="stop-color:rgba(255,255,255,0.1)"/><stop offset="100%" style="stop-color:rgba(255,255,255,0)"/></radialGradient></defs><circle cx="200" cy="200" r="100" fill="url(%23a)"/><circle cx="800" cy="300" r="150" fill="url(%23a)"/><circle cx="400" cy="700" r="120" fill="url(%23a)"/></svg>');
    opacity: 0.6;
}

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    color: white;
    padding: 2rem 0;
}

.hero-title {
    font-family: 'Playfair Display', serif;
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.conference-name {
    white-space: nowrap;
    display: inline-block;
}

.hero-subtitle {
    font-size: 1.5rem;
    font-weight: 300;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.hero-theme {
    font-size: 1.25rem;
    font-weight: 500;
    margin-bottom: 2rem;
    padding: 1rem 2rem;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 50px;
    display: inline-block;
    backdrop-filter: blur(10px);
}

.hero-details {
    display: flex;
    justify-content: center;
    gap: 3rem;
    margin-bottom: 3rem;
    flex-wrap: wrap;
}

.hero-detail {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.1rem;
    font-weight: 500;
}

.hero-detail i {
    font-size: 1.5rem;
    color: var(--accent-color);
}

.btn-primary {
    background: var(--gradient-accent);
    border: none;
    padding: 1rem 2rem;
    font-weight: 600;
    border-radius: 50px;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-block;
    color: white;
    margin-bottom: 0;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
    color: white;
}

/* IEEE Templates button styling */
.btn-ieee-templates {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border: none;
    color: white;
    padding: 12px 24px;
    font-weight: 600;
    border-radius: 25px;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.3);
    position: relative;
    overflow: hidden;
}

.btn-ieee-templates::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s ease;
}

.btn-ieee-templates:hover::before {
    left: 100%;
}

.btn-ieee-templates:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(102, 126, 234, 0.4);
    color: white;
}

.btn-ieee-templates i {
    font-size: 1.1em;
}

/* Easychair Portal button optimization */
.btn-easychair {
    background: var(--gradient-accent);
    border: none;
    color: white;
    padding: 12px 24px;
    font-weight: 600;
    border-radius: 25px;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    box-shadow: 0 4px 15px rgba(79, 172, 254, 0.3);
    position: relative;
    overflow: hidden;
}

.btn-easychair::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s ease;
}

.btn-easychair:hover::before {
    left: 100%;
}

.btn-easychair:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(79, 172, 254, 0.4);
    color: white;
}

.btn-easychair i {
    font-size: 1.1em;
}

.timeline-section {
    background: var(--bg-light);
    padding: 3rem 0;
}

.timeline {
    position: relative;
    max-width: 1200px;
    margin: 0 auto;
}

.timeline::after {
    content: '';
    position: absolute;
    width: 3px;
    background: var(--primary-color);
    top: 0;
    bottom: 0;
    left: 50%;
    margin-left: -1.5px;
}

.timeline-item {
    position: relative;
    background: white;
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
    margin-bottom: 2rem;
    width: 45%;
    transition: all 0.3s ease;
}

.timeline-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.15);
}

.timeline-item.left {
    left: 0;
}

.timeline-item.right {
    left: 55%;
}

.timeline-item::after {
    content: '';
    position: absolute;
    width: 20px;
    height: 20px;
    background: var(--primary-color);
    border-radius: 50%;
    top: 2rem;
    z-index: 1;
}

.timeline-item.left::after {
    right: -10px;
}

.timeline-item.right::after {
    left: -10px;
}

.timeline-date {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.timeline-title {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-color);
}

.section-title {
    font-family: 'Playfair Display', serif;
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 2rem;
    color: var(--text-color);
}

.section-subtitle {
    text-align: center;
    font-size: 1.2rem;
    color: #6b7280;
    margin-bottom: 4rem;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.card {
    border: none;
    border-radius: 15px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    overflow: hidden;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.15);
}

.card-header {
    background: var(--gradient-primary);
    color: white;
    font-weight: 600;
    border: none;
    padding: 1.5rem;
}

.committee-card {
    background: white;
    border-radius: 15px;
    padding: 2rem;
    text-align: center;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    margin-bottom: 2rem;
}

.committee-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.15);
}

.committee-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.committee-affiliation {
    color: #6b7280;
    font-size: 0.9rem;
}

.news-item {
    background: white;
    border-radius: 15px;
    padding: 1.5rem;
    margin-bottom: 1rem;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    transition: all 0.3s ease;
}

.news-item:hover {
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
}

.news-date {
    color: #4dabf7;
    font-weight: 700;
    font-size: 1.2rem;
}

.venue-card {
    background: white;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
}

.venue-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.15);
}

.venue-image {
    height: 200px;
    background: var(--gradient-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 3rem;
}

.footer {
    background: var(--secondary-color);
    color: white;
    padding: 3rem 0;
}

.footer-title {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--accent-color);
    text-align: center;
}

.footer-link {
    color: #d1d5db;
    text-decoration: none;
    transition: all 0.3s ease;
}

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

@media (max-width: 768px) {
    .hero-title {
        font-size: 2rem;
    }

    .hero-details {
        flex-direction: column;
        gap: 1rem;
    }

    .timeline::after {
        left: 20px;
    }

    .timeline-item {
        width: 100%;
        left: 40px !important;
    }

    .timeline-item::after {
        left: -10px !important;
    }
}

/* Mobile compact layout optimization */
@media (max-width: 768px) {
    .timeline-section {
        padding: 2rem 0;
    }

    .section-title {
        font-size: 2rem;
        margin-bottom: 1.5rem;
    }

    .py-4 {
        padding-top: 2.5rem !important;
        padding-bottom: 2.5rem !important;
    }

    .hero-section {
        padding: 1.5rem 0;
        padding-top: 80px;
        /* Keep navigation bar space */
        min-height: auto;
    }

    .hero-content {
        padding: 1rem 0;
    }

    /* Make Important Dates module more compact */
    .timeline-item {
        padding: 1.2rem;
        margin-bottom: 1.2rem;
    }

    .timeline-date {
        font-size: 1.2rem;
        margin-bottom: 0.3rem;
    }

    .timeline-title {
        font-size: 1rem;
    }

    /* IEEE Templates button optimization for tablet devices */
    .btn-ieee-templates {
        padding: 10px 20px;
        font-size: 0.95rem;
        margin-bottom: 1rem;
        width: 100%;
        justify-content: center;
    }

    /* Easychair Portal button optimization for tablet devices */
    .btn-easychair {
        padding: 10px 20px;
        font-size: 0.95rem;
        margin-bottom: 1rem;
        width: 100%;
        justify-content: center;
    }
}

/* Ensure ICEBE 2025 doesn't wrap on mobile devices */
@media (max-width: 576px) {
    .hero-title {
        font-size: 1.5rem;
    }

    .conference-name {
        font-size: 0.9em;
    }

    .timeline-section {
        padding: 1.5rem 0;
    }

    .section-title {
        font-size: 1.5rem;
        margin-bottom: 1rem;
    }

    .py-4 {
        padding-top: 2rem !important;
        padding-bottom: 2rem !important;
    }

    .hero-section {
        padding: 1rem 0;
        padding-top: 80px;
        /* Keep navigation bar space */
    }

    .hero-content {
        padding: 0.5rem 0;
    }

    /* Further reduce Important Dates module size */
    .timeline-item {
        padding: 1rem;
        margin-bottom: 1rem;
    }

    .timeline-date {
        font-size: 1.1rem;
        margin-bottom: 0.2rem;
    }

    .timeline-title {
        font-size: 0.9rem;
    }

    /* IEEE Templates button optimization for mobile devices */
    .btn-ieee-templates {
        padding: 10px 20px;
        font-size: 0.9rem;
        margin-bottom: 1rem;
        width: 100%;
        justify-content: center;
    }

    /* Easychair Portal button optimization for mobile devices */
    .btn-easychair {
        padding: 10px 20px;
        font-size: 0.9rem;
        margin-bottom: 1rem;
        width: 100%;
        justify-content: center;
    }

    /* Hero background image optimization for mobile devices */
    .hero-section {
        background-attachment: scroll !important;
    }

    /* Ensure venue images display properly on mobile devices */
    .venue-image {
        min-height: 150px;
    }

    /* Special Issues background image optimization for mobile devices */
    #special-issue {
        background-attachment: scroll !important;
    }
}