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

body {
    font-family: 'Segoe UI', 'Tahoma', 'Geneva', 'Verdana', sans-serif;
    line-height: 1.6;
    color: #333;
    background: linear-gradient(135deg, #3b82f6, #f97316, #ec4899, #eab308);
    background-size: 400% 400%;
    animation: gradient-shift 8s ease-in-out infinite;
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Background Animations */
@keyframes gradient-shift {
    0%, 100% {
        background-position: 0% 50%;
    }
    25% {
        background-position: 100% 50%;
    }
    50% {
        background-position: 100% 100%;
    }
    75% {
        background-position: 0% 100%;
    }
}

@keyframes float {
    0%, 100% {
        transform: translateY(0px) rotate(0deg);
    }
    33% {
        transform: translateY(-30px) rotate(120deg);
    }
    66% {
        transform: translateY(15px) rotate(240deg);
    }
}

.floating-shapes {
    position: absolute;
    width: 100%;
    height: 100%;
    overflow: hidden;
    z-index: 0;
    pointer-events: none;
}

.floating-shapes::before,
.floating-shapes::after {
    content: '';
    position: absolute;
    border-radius: 50%;
    animation: float 6s ease-in-out infinite;
}

.floating-shapes::before {
    width: 200px;
    height: 200px;
    background: radial-gradient(circle, rgba(236, 72, 153, 0.3), transparent);
    top: 20%;
    right: 20%;
    animation-delay: -2s;
}

.floating-shapes::after {
    width: 150px;
    height: 150px;
    background: radial-gradient(circle, rgba(234, 179, 8, 0.3), transparent);
    bottom: 20%;
    left: 10%;
    animation-delay: -4s;
}

/* Header Styles */
.header {
    background: linear-gradient(135deg, #003366, #1e40af, #7c3aed);
    color: white;
    text-align: center;
    padding: 4rem 0;
    position: relative;
    overflow: hidden;
}

.welcome-section {
    margin: 2rem 0;
}

.welcome-text {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: white;
}

.organization-text {
    font-size: 1.2rem;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 1rem;
}

.highlight {
    font-weight: bold;
    color: #eab308;
}

.bis-description {
    font-size: 1.1rem;
    opacity: 0.9;
    margin-bottom: 1.5rem;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.event-highlight {
    display: flex;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
    margin-top: 1.5rem;
}

.highlight-badge {
    background: rgba(234, 179, 8, 0.2);
    border: 1px solid rgba(234, 179, 8, 0.5);
    color: #eab308;
    padding: 0.5rem 1rem;
    border-radius: 50px;
    font-weight: 600;
    font-size: 0.9rem;
}

.header-title {
    font-size: 3rem;
    font-weight: bold;
    margin-bottom: 0.5rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.5);
}

.header-subtitle {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.bis-logo {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 1rem;
    padding: 2rem;
    margin: 2rem auto;
    max-width: 600px;
}

.bis-title {
    font-size: 2.5rem;
    font-weight: bold;
    margin-bottom: 0.5rem;
    background: linear-gradient(135deg, #3b82f6, #f97316, #ec4899, #eab308);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.bis-subtitle {
    font-size: 1.1rem;
    opacity: 0.8;
}

/* Main Content */
.main {
    position: relative;
    min-height: 100vh;
    padding: 4rem 0;
}

/* Events Section */
.events-section {
    margin-bottom: 4rem;
}

.section-title {
    text-align: center;
    font-size: 3rem;
    font-weight: bold;
    color: white;
    text-shadow: 2px 2px 8px rgba(0, 0, 0, 0.3);
    margin-bottom: 3rem;
}

.events-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(500px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

/* Event Card Styles */
.event-card {
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 1rem;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    overflow: hidden;
}

.event-card:hover {
    background: rgba(255, 255, 255, 0.95);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
    transform: translateY(-8px) scale(1.02);
}

.event-header {
    cursor: pointer;
}

.event-image {
    position: relative;
    margin-bottom: 1rem;
    overflow: hidden;
    border-radius: 0.5rem;
}

.event-image img {
    width: 100%;
    height: 16rem;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.event-image:hover img {
    transform: scale(1.1);
}

.image-overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(to top, rgba(0, 0, 0, 0.5), transparent);
}

.image-content {
    position: absolute;
    bottom: 1rem;
    left: 1rem;
    right: 1rem;
}

.event-title {
    font-size: 1.5rem;
    font-weight: bold;
    color: white;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.8);
    margin-bottom: 0.5rem;
}

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

.toggle-text {
    font-size: 1.1rem;
    font-weight: 600;
    color: #3b82f6;
}

.toggle-icon {
    transition: transform 0.3s ease;
}

.toggle-icon svg {
    width: 1.5rem;
    height: 1.5rem;
    color: #3b82f6;
}

.event-card.active .toggle-icon {
    transform: rotate(180deg);
}

/* Event Details */
.event-details {
    max-height: 0;
    overflow: hidden;
    transition: all 0.5s ease-in-out;
    opacity: 0;
}

.event-details.active {
    max-height: 24rem;
    opacity: 1;
    margin-top: 1.5rem;
}

.event-content {
    border-top: 2px solid rgba(59, 130, 246, 0.2);
    padding-top: 1.5rem;
    max-height: 20rem;
    overflow-y: auto;
    padding-right: 0.5rem;
}

/* Custom Scrollbar */
.event-content {
    scrollbar-width: thin;
    scrollbar-color: #3b82f6 #f1f5f9;
}

.event-content::-webkit-scrollbar {
    width: 6px;
}

.event-content::-webkit-scrollbar-track {
    background: #f1f5f9;
    border-radius: 3px;
}

.event-content::-webkit-scrollbar-thumb {
    background: linear-gradient(135deg, #3b82f6, #f97316);
    border-radius: 3px;
}

.event-content::-webkit-scrollbar-thumb:hover {
    background: linear-gradient(135deg, #f97316, #ec4899);
}

.event-description {
    color: #374151;
    line-height: 1.6;
    margin-bottom: 1rem;
}

.event-section {
    margin-bottom: 1.5rem;
}

.section-header {
    display: flex;
    align-items: center;
    font-size: 1.1rem;
    font-weight: 600;
    color: #3b82f6;
    margin-bottom: 0.75rem;
}

.section-header.themes {
    color: #ec4899;
}

.section-header.submission {
    color: #f97316;
}

.section-header.guidelines {
    color: #ec4899;
}

.event-list {
    list-style: none;
    margin-left: 1rem;
}

.event-list li {
    display: flex;
    align-items: flex-start;
    margin-bottom: 0.5rem;
    color: #374151;
}

.event-list li::before {
    content: '•';
    color: #3b82f6;
    margin-right: 0.5rem;
    flex-shrink: 0;
}

.themes-container {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.theme-tag {
    padding: 0.25rem 0.75rem;
    background: rgba(236, 72, 153, 0.1);
    color: #ec4899;
    border-radius: 9999px;
    font-size: 0.875rem;
    font-weight: 500;
}

.submission-box {
    background: rgba(249, 115, 22, 0.1);
    padding: 1rem;
    border-radius: 0.5rem;
    color: #374151;
}

/* Participation Section */
.participation-section {
    margin: 4rem 0;
}

.participation-container {
    background: linear-gradient(135deg, #ff6b9d, #f97316);
    border-radius: 2rem;
    padding: 3rem 2rem;
    text-align: center;
    max-width: 64rem;
    margin: 0 auto;
    box-shadow: 0 20px 40px rgba(255, 107, 157, 0.3);
}

.participation-title {
    font-size: 2.5rem;
    font-weight: bold;
    color: white;
    margin-bottom: 1.5rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.participation-text {
    font-size: 1.2rem;
    color: white;
    margin-bottom: 2rem;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
    line-height: 1.6;
}

.participation-highlights {
    display: flex;
    justify-content: center;
    gap: 2rem;
    flex-wrap: wrap;
}

.highlight-item {
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: 50px;
    padding: 1rem 2rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    transition: all 0.3s ease;
}

.highlight-item:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.highlight-icon {
    font-size: 1.5rem;
}

.highlight-text {
    color: white;
    font-weight: 600;
    font-size: 1.1rem;
}

/* Contact Section */
.contact-section {
    text-align: center;
    margin-top: 4rem;
}

.contact-container {
    background: rgba(255, 255, 255, 0.15);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: 2rem;
    padding: 2rem;
    max-width: 64rem;
    margin: 0 auto;
}

.contact-title {
    font-size: 2rem;
    font-weight: bold;
    color: white;
    margin-bottom: 1.5rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.contact-card {
    padding: 1rem;
    border-radius: 0.75rem;
    transition: all 0.3s ease;
}

.contact-card.blue {
    background: rgba(59, 130, 246, 0.2);
    border: 1px solid rgba(59, 130, 246, 0.3);
}

.contact-card.blue:hover {
    background: rgba(59, 130, 246, 0.3);
}

.contact-card.orange {
    background: rgba(249, 115, 22, 0.2);
    border: 1px solid rgba(249, 115, 22, 0.3);
}

.contact-card.orange:hover {
    background: rgba(249, 115, 22, 0.3);
}

.contact-card.pink {
    background: rgba(236, 72, 153, 0.2);
    border: 1px solid rgba(236, 72, 153, 0.3);
}

.contact-card.pink:hover {
    background: rgba(236, 72, 153, 0.3);
}

.contact-card.yellow {
    background: rgba(234, 179, 8, 0.2);
    border: 1px solid rgba(234, 179, 8, 0.3);
}

.contact-card.yellow:hover {
    background: rgba(234, 179, 8, 0.3);
}

.contact-card.gradient {
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.2), rgba(236, 72, 153, 0.2));
    border: 1px solid rgba(255, 255, 255, 0.2);
    grid-column: span 2;
}

.contact-card.gradient:hover {
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.3), rgba(236, 72, 153, 0.3));
}

.contact-name {
    color: white;
    font-weight: 600;
    font-size: 1.1rem;
    margin-bottom: 0.25rem;
}

.contact-number {
    color: rgba(255, 255, 255, 0.9);
    font-size: 1.25rem;
    font-family: 'Courier New', monospace;
    font-weight: 500;
}

.contact-footer {
    margin-top: 1.5rem;
}

.contact-footer p {
    color: rgba(255, 255, 255, 0.8);
    font-size: 0.875rem;
}

/* Footer */
.footer {
    background: #003366;
    color: white;
    text-align: center;
    padding: 2rem 0;
    margin-top: 4rem;
}

.footer p {
    opacity: 0.9;
}

/* Responsive Design */
@media (max-width: 768px) {
    .header-title {
        font-size: 2rem;
    }
    
    .bis-title {
        font-size: 1.8rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .events-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .event-card {
        margin-bottom: 1rem;
    }
    
    .contact-grid {
        grid-template-columns: 1fr;
    }
    
    .contact-card.gradient {
        grid-column: span 1;
    }
    
    .contact-title {
        font-size: 1.5rem;
    }
    
    .participation-title {
        font-size: 1.8rem;
    }
    
    .participation-highlights {
        flex-direction: column;
        align-items: center;
    }
    
    .highlight-item {
        width: 100%;
        max-width: 300px;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }
    
    .header-title {
        font-size: 1.5rem;
    }
    
    .bis-title {
        font-size: 1.5rem;
    }
    
    .event-image img {
        height: 12rem;
    }
    
    .event-title {
        font-size: 1.25rem;
    }
    
    .participation-title {
        font-size: 1.5rem;
    }
    
    .participation-text {
        font-size: 1rem;
    }
    
    .highlight-text {
        font-size: 1rem;
    }
}