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

body {
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    color: #333;
    overflow-x: hidden;
}

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

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    padding: 1rem 0;
    transition: all 0.3s ease;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    display: flex;
    align-items: center;
    font-size: 1.5rem;
    font-weight: 700;
    color: #6366f1;
}

.nav-logo i {
    margin-right: 0.5rem;
    font-size: 1.8rem;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-link {
    text-decoration: none;
    color: #333;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

.nav-link:hover {
    color: #6366f1;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, #6366f1, #8b5cf6);
    transition: width 0.3s ease;
}

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

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.bar {
    width: 25px;
    height: 3px;
    background: #333;
    margin: 3px 0;
    transition: 0.3s;
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    overflow: hidden;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0.1;
}

.floating-code {
    position: absolute;
    width: 100%;
    height: 100%;
}

.code-snippet {
    position: absolute;
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.3);
    animation: float 20s infinite linear;
}

.code-snippet:nth-child(1) { top: 10%; left: 10%; animation-delay: 0s; }
.code-snippet:nth-child(2) { top: 20%; right: 15%; animation-delay: 4s; }
.code-snippet:nth-child(3) { top: 60%; left: 20%; animation-delay: 8s; }
.code-snippet:nth-child(4) { top: 70%; right: 10%; animation-delay: 12s; }
.code-snippet:nth-child(5) { top: 40%; left: 50%; animation-delay: 16s; }

@keyframes float {
    0%, 100% { transform: translateY(0px) rotate(0deg); opacity: 0.3; }
    50% { transform: translateY(-20px) rotate(2deg); opacity: 0.6; }
}

.hero-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    text-align: center;
    z-index: 2;
    position: relative;
}

.hero-title {
    font-size: 4rem;
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.1;
}

.gradient-text {
    background: linear-gradient(45deg, #fff, #a78bfa);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.year {
    display: block;
    font-size: 2rem;
    opacity: 0.8;
    margin-top: 0.5rem;
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    opacity: 0.9;
}

.hero-description {
    font-size: 1.1rem;
    margin-bottom: 2rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
    opacity: 0.8;
}

.hero-details {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.detail-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1rem;
}

.detail-item i {
    color: #a78bfa;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 24px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

.btn-primary {
    background: linear-gradient(45deg, #6366f1, #8b5cf6);
    color: white;
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(99, 102, 241, 0.4);
}

.btn-secondary {
    background: transparent;
    color: white;
    border: 2px solid rgba(255, 255, 255, 0.3);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.5);
}

.btn-large {
    padding: 16px 32px;
    font-size: 1.1rem;
}

/* Sections */
.section-title {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 3rem;
    color: #1f2937;
}

/* About Section */
.about {
    padding: 5rem 0;
    background: #f8fafc;
}

.about-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.about-card {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    text-align: center;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.about-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
}

.card-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(45deg, #6366f1, #8b5cf6);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1rem;
    color: white;
    font-size: 1.5rem;
}

.about-card h3 {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: #1f2937;
}

.about-card p {
    color: #6b7280;
    line-height: 1.6;
}

/* Schedule Section */
.schedule {
    padding: 5rem 0;
    background: white;
}

.schedule-timeline {
    max-width: 800px;
    margin: 0 auto;
}

.timeline-item {
    display: flex;
    margin-bottom: 2rem;
    position: relative;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: 120px;
    top: 0;
    bottom: -2rem;
    width: 2px;
    background: #e5e7eb;
}

.timeline-item:last-child::before {
    display: none;
}

.timeline-time {
    width: 100px;
    font-weight: 600;
    color: #6366f1;
    flex-shrink: 0;
}

.timeline-content {
    background: #f8fafc;
    padding: 1.5rem;
    border-radius: 8px;
    margin-left: 2rem;
    flex: 1;
    position: relative;
}

.timeline-content::before {
    content: '';
    position: absolute;
    left: -8px;
    top: 20px;
    width: 0;
    height: 0;
    border-top: 8px solid transparent;
    border-bottom: 8px solid transparent;
    border-right: 8px solid #f8fafc;
}

.timeline-content h3 {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: #1f2937;
}

.timeline-content p {
    color: #6b7280;
    margin: 0;
}

.keynote .timeline-content {
    background: linear-gradient(45deg, #6366f1, #8b5cf6);
    color: white;
}

.keynote .timeline-content::before {
    border-right-color: #6366f1;
}

.keynote .timeline-content h3,
.keynote .timeline-content p {
    color: white;
}

.keynote-badge {
    display: inline-block;
    background: rgba(255, 255, 255, 0.2);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
    margin-top: 0.5rem;
}

/* CTA Section */
.cta {
    padding: 4rem 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
}

.cta h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.cta p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

/* Footer */
.footer {
    background: #1f2937;
    color: white;
    padding: 3rem 0 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3,
.footer-section h4 {
    margin-bottom: 1rem;
    color: #f9fafb;
}

.footer-section p,
.footer-section li {
    color: #d1d5db;
    margin-bottom: 0.5rem;
}

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

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

.footer-section a:hover {
    color: #6366f1;
}

.social-links {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
}

.social-links a {
    width: 40px;
    height: 40px;
    background: #374151;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.3s ease;
}

.social-links a:hover {
    background: #6366f1;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid #374151;
    color: #9ca3af;
}

/* Speakers Page Styles */
.speakers-hero {
    padding: 8rem 0 4rem;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
}

.page-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.page-subtitle {
    font-size: 1.2rem;
    opacity: 0.9;
    max-width: 600px;
    margin: 0 auto;
}

.keynote-speaker {
    padding: 4rem 0;
    background: #f8fafc;
}

.keynote-card {
    display: flex;
    align-items: center;
    background: white;
    border-radius: 16px;
    padding: 3rem;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    max-width: 900px;
    margin: 0 auto;
    gap: 3rem;
}

.keynote-avatar {
    width: 150px;
    height: 150px;
    background: linear-gradient(45deg, #6366f1, #8b5cf6);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 3rem;
    flex-shrink: 0;
}

.keynote-content h3 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: #1f2937;
}

.team-speakers {
    padding: 5rem 0;
    background: white;
}

.speakers-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

.speaker-card {
    background: white;
    border-radius: 12px;
    padding: 2rem;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border: 1px solid #e5e7eb;
}

.speaker-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
}

.speaker-avatar {
    width: 80px;
    height: 80px;
    background: linear-gradient(45deg, #6366f1, #8b5cf6);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.8rem;
    margin-bottom: 1.5rem;
}

.speaker-card h3 {
    font-size: 1.4rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: #1f2937;
}

.nickname {
    font-size: 0.9rem;
    font-weight: 400;
    color: #6366f1;
    font-style: italic;
    display: block;
    margin-top: 0.25rem;
}

.speaker-title {
    color: #6366f1;
    font-weight: 600;
    margin-bottom: 1rem;
    font-size: 0.95rem;
}

.speaker-bio {
    color: #6b7280;
    line-height: 1.6;
    margin-bottom: 1.5rem;
}

.speaker-topics {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.topic-tag {
    background: #f3f4f6;
    color: #374151;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 500;
}

.speakers-cta {
    padding: 4rem 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
}

.speakers-cta h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.speakers-cta p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.nav-link.active {
    color: #6366f1;
}

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

/* Responsive Design */
@media (max-width: 768px) {
    .hamburger {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: white;
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: 0 10px 27px rgba(0, 0, 0, 0.05);
        padding: 2rem 0;
    }

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

    .hero-title, .page-title {
        font-size: 2.5rem;
    }

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

    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }

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

    .timeline-item::before {
        display: none;
    }

    .timeline-content {
        margin-left: 0;
        margin-top: 0.5rem;
    }

    .timeline-content::before {
        display: none;
    }

    .keynote-card {
        flex-direction: column;
        text-align: center;
        padding: 2rem;
        gap: 2rem;
    }

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

/* Submit Page Styles */
.submit-hero {
    padding: 8rem 0 4rem;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
}

.guidelines {
    padding: 5rem 0;
    background: #f8fafc;
}

.guidelines-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.guideline-card {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    text-align: center;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    transition: transform 0.3s ease;
}

.guideline-card:hover {
    transform: translateY(-5px);
}

.guideline-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(45deg, #6366f1, #8b5cf6);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1rem;
    color: white;
    font-size: 1.5rem;
}

.guideline-card h3 {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: #1f2937;
}

.topics {
    padding: 5rem 0;
    background: white;
}

.topics-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.topic-category {
    background: #f8fafc;
    padding: 2rem;
    border-radius: 12px;
    border-left: 4px solid #6366f1;
}

.topic-category h3 {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: #1f2937;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.topic-category h3 i {
    color: #6366f1;
}

.topic-category ul {
    list-style: none;
}

.topic-category li {
    padding: 0.5rem 0;
    color: #6b7280;
    position: relative;
    padding-left: 1.5rem;
}

.topic-category li::before {
    content: '→';
    position: absolute;
    left: 0;
    color: #6366f1;
    font-weight: bold;
}

.submission-form {
    padding: 5rem 0;
    background: #f8fafc;
}

.talk-form {
    max-width: 800px;
    margin: 0 auto;
    background: white;
    padding: 3rem;
    border-radius: 16px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.form-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
}

.form-group {
    margin-bottom: 2rem;
}

.form-group label {
    display: block;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: #1f2937;
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid #e5e7eb;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
    font-family: inherit;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: #6366f1;
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

.checkbox-group {
    display: flex;
    align-items: flex-start;
    margin-bottom: 2rem;
}

.checkbox-label {
    display: flex;
    align-items: flex-start;
    cursor: pointer;
    font-weight: 500;
    color: #374151;
    padding: 8px;
    border-radius: 4px;
    transition: background-color 0.2s ease;
    width: 100%;
}

.checkbox-label:hover {
    background-color: #f9fafb;
}

.checkbox-label input[type="checkbox"] {
    display: none;
}

.checkmark {
    width: 24px;
    height: 24px;
    border: 2px solid #d1d5db;
    border-radius: 4px;
    margin-right: 12px;
    margin-top: 2px;
    position: relative;
    transition: all 0.3s ease;
    flex-shrink: 0;
}

.checkbox-label input[type="checkbox"]:checked + .checkmark {
    background: #6366f1;
    border-color: #6366f1;
}

.checkbox-label input[type="checkbox"]:checked + .checkmark::after {
    content: '✓';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: white;
    font-size: 14px;
    font-weight: bold;
}

.form-actions {
    text-align: center;
    margin-top: 2rem;
}

.success-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
}

.success-content {
    background: white;
    padding: 3rem;
    border-radius: 16px;
    text-align: center;
    max-width: 400px;
    margin: 0 20px;
}

.success-icon {
    width: 80px;
    height: 80px;
    background: #10b981;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    color: white;
    font-size: 2rem;
}

.success-content h2 {
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: #1f2937;
}

.success-content p {
    color: #6b7280;
    margin-bottom: 2rem;
    line-height: 1.6;
}

/* Google Form Styles */
.google-form-container {
    max-width: 800px;
    margin: 0 auto;
    background: white;
    border-radius: 16px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    overflow: hidden;
}

.form-instructions {
    padding: 2rem 2rem 1rem;
    text-align: center;
    background: #f8fafc;
    border-bottom: 1px solid #e5e7eb;
}

.form-instructions p {
    color: #6b7280;
    font-size: 1.1rem;
    margin: 0;
}

.google-form {
    border: none;
    width: 100%;
    min-height: 800px;
    background: white;
}

.form-fallback {
    padding: 1rem 2rem 2rem;
    text-align: center;
    background: #f8fafc;
    border-top: 1px solid #e5e7eb;
}

.form-fallback p {
    color: #6b7280;
    margin: 0;
}

.form-fallback a {
    color: #6366f1;
    text-decoration: none;
    font-weight: 500;
}

.form-fallback a:hover {
    text-decoration: underline;
}

/* Additional responsive styles for submit page */
@media (max-width: 768px) {
    .form-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .talk-form {
        padding: 2rem 1.5rem;
    }

    .guidelines-grid,
    .topics-grid {
        grid-template-columns: 1fr;
    }

    .submit-hero {
        padding: 6rem 0 3rem;
    }
}

/* Animation classes */
.timeline-item.active .timeline-content {
    background: linear-gradient(45deg, #6366f1, #8b5cf6);
    color: white;
    transform: scale(1.02);
}

.timeline-item.active .timeline-content::before {
    border-right-color: #6366f1;
}

.timeline-item.active .timeline-content h3,
.timeline-item.active .timeline-content p {
    color: white;
}

/* Particle animation */
@keyframes particleFloat {
    0% {
        transform: translateY(100vh) rotate(0deg);
        opacity: 0;
    }
    10% {
        opacity: 1;
    }
    90% {
        opacity: 1;
    }
    100% {
        transform: translateY(-100vh) rotate(360deg);
        opacity: 0;
    }
}

.particle {
    animation: particleFloat 15s infinite linear;
}

/* Loading animation */
@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.fa-spin {
    animation: spin 1s linear infinite;
}

/* Hover effects */
.about-card,
.speaker-card,
.guideline-card {
    transition: all 0.3s ease;
}

/* Focus styles for accessibility */
.btn:focus,
.nav-link:focus,
input:focus,
textarea:focus,
select:focus {
    outline: 2px solid #6366f1;
    outline-offset: 2px;
}

/* Print styles */
@media print {
    .navbar,
    .footer,
    .floating-code,
    .hero-buttons,
    .cta,
    .speakers-cta,
    .form-actions {
        display: none;
    }

    .hero {
        background: none;
        color: #333;
        min-height: auto;
        padding: 2rem 0;
    }

    .section-title {
        color: #333;
        page-break-after: avoid;
    }

    .speaker-card,
    .about-card {
        break-inside: avoid;
        box-shadow: none;
        border: 1px solid #ddd;
    }
}