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

:root {
    --primary-color:  #e87722;
    --secondary-color: #1d5c9e;
    --accent-color: #dc2626;
    --text-dark: #1f2937;
    --text-light: #6b7280;
    --bg-light: #f9fafb;
    --bg-white: #ffffff;
    --border-color: #e5e7eb;
    --success-color: #059669;
    --spacing-unit: 8px;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--bg-white);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 calc(var(--spacing-unit) * 3);
}

.main-header {
    background: var(--bg-white);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.navbar {
    padding: calc(var(--spacing-unit) * 2) 0;
}

.nav-wrapper {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo-img {
    height: 48px;
    width: auto;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: calc(var(--spacing-unit) * 4);
    align-items: center;
}

.nav-menu a {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    font-size: 15px;
    transition: color 0.3s ease;
    position: relative;
}

.nav-menu a:hover,
.nav-menu a.active {
    color: var(--primary-color);
}

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

.mobile-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
}

.mobile-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text-dark);
    transition: all 0.3s ease;
    border-radius: 2px;
}

.hero-section {
    background: linear-gradient(120deg, var(--secondary-color) 0%,  var(--primary-color) 100%);
    color: white;
    padding: calc(var(--spacing-unit) * 15) 0 calc(var(--spacing-unit) * 12);
    text-align: center;
}

.hero-content h1 {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: calc(var(--spacing-unit) * 3);
    line-height: 1.2;
}

.hero-content .subtitle {
    font-size: 1.5rem;
    margin-bottom: calc(var(--spacing-unit) * 5);
    font-weight: 400;
    opacity: 0.95;
}

.hero-buttons {
    display: flex;
    gap: calc(var(--spacing-unit) * 3);
    justify-content: center;
    flex-wrap: wrap;
}

.btn {
    display: inline-block;
    padding: 12px 30px;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    border: 2px solid transparent;
    cursor: pointer;
    font-size: 1rem;
}

.btn-primary {
    background: #1d5c9e;
    color: white;
    border-color: #2563eb;
}

.btn-primary:hover {
    background: #1d4ed8;
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(37, 99, 235, 0.3);
}

.btn-secondary {
    background: transparent;
    color: white;
    border-color: white;
}

.btn-secondary:hover {
    background: white;
    color: #2563eb;
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(255, 255, 255, 0.3);
}

.btn-large {
    padding: 15px 40px;
    font-size: 1.1rem;
}

/* scroll-indicator*/

.scroll-indicator {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    animation: bounce 2s infinite;
}

.scroll-indicator i {
    font-size: 1.5rem;
    opacity: 0.7;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% { transform: translateX(-50%) translateY(0); }
    40% { transform: translateX(-50%) translateY(-10px); }
    60% { transform: translateX(-50%) translateY(-5px); }
}

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


/* section */

.section {
    padding: calc(var(--spacing-unit) * 10) 0;
}

.section-alt {
    background: var(--bg-light);
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: calc(var(--spacing-unit) * 2);
    color: var(--text-dark);
}

.section-subtitle {
    text-align: center;
    font-size: 1.125rem;
    color: var(--text-light);
    margin-bottom: calc(var(--spacing-unit) * 8);
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

/* Dates Section */
.dates {
    background: white;
}

.dates-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
}

.date-card {
    background: #1d5c9e;
    color: white;
    padding: 1rem;
    border-radius: 15px;
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    position: relative;
    overflow: hidden;
}

.date-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(255, 255, 255, 0.1);
    opacity: 0;
    transition: opacity 0.3s ease;
}

.date-card:hover::before {
    opacity: 1;
}

.date-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 35px rgba(102, 126, 234, 0.3);
}

.date-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.date-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.date {
    font-size: 1.1rem;
    font-weight: 700;
    opacity: 0.9;
}
/* tracks section*/
.tracks-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: calc(var(--spacing-unit) * 4);
}

.tracks {
    background: #f8fafc;
}

.tracks-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 80px;
}

.track-card {
    background: white;
    border-radius: 15px;
    padding: 2rem;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.06);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border-top: 4px solid #2563eb;
}

.track-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.1);
}

.track-header {
    text-align: center;
    margin-bottom: 1.5rem;
}

.track-header i {
    font-size: 2.5rem;
    color: #2563eb;
    margin-bottom: 1rem;
}

.track-header h3 {
    font-size: 1.5rem;
    font-weight: 700;
    color: #e87722;
    margin-bottom: 0.5rem;
}

.track-header h4 {
    font-size: 1.1rem;
    font-weight: 500;
    color: #6b7280;
}

.track-topics {
    list-style: none;
}

.track-topics li {
    padding: 0.5rem 0;
    color: #4b5563;
    position: relative;
    padding-left: 1.5rem;
}

.track-topics li::before {
    content: '•';
    color: #2563eb;
    font-weight: bold;
    position: absolute;
    left: 0;
}

.speakers-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: calc(var(--spacing-unit) * 4);
}

.speaker-card {
    background: var(--bg-white);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.speaker-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 12px 28px rgba(0, 0, 0, 0.15);
}

.speaker-image {
    display: block;
    width: 100%;
    height: 350px;
    object-fit: cover;
    object-position: top; 

}



.speaker-info {
    padding: calc(var(--spacing-unit) * 3);
}

.speaker-info h3 {
    font-size: 1.375rem;
    margin-bottom: calc(var(--spacing-unit) * 1);
    color: var(--text-dark);
}

.speaker-info .affiliation {
    color: var(--primary-color);
    font-weight: 500;
    margin-bottom: calc(var(--spacing-unit) * 2);
}

.speaker-info .title {
    font-style: italic;
    color: var(--text-light);
    margin-bottom: calc(var(--spacing-unit) * 2);
}

.speaker-info .bio {
    display: none; 
    color: black;
    line-height: 1.6;
    font-size: 0.9375rem;
    background-color: white;

}

.speaker-card:hover .bio {
  display: block;
}

.submission-guidelines {
    max-width: 900px;
    margin: 0 auto;
}

.guideline-card {
    background: var(--bg-white);
    padding: calc(var(--spacing-unit) * 4);
    border-radius: 12px;
    margin-bottom: calc(var(--spacing-unit) * 3);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}

.guideline-card h3 {
    color: var(--primary-color);
    font-size: 1.375rem;
    margin-bottom: calc(var(--spacing-unit) * 2);
}

.guideline-card p {
    color: var(--text-light);
    line-height: 1.8;
}
.guideline-card .content {
  display: flex;
  align-items: center;
  gap: 20px;
}

.guideline-card .text {
  flex: 2;
}

.guideline-card .image {
  flex: 1; 
}

.guideline-card .image img {
  max-width: 100%;
  height: auto;
  border-radius: 8px; 
 
}


.cta-box {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    padding: calc(var(--spacing-unit) * 5);
    border-radius: 12px;
    text-align: center;
    margin-top: calc(var(--spacing-unit) * 6);
}

.cta-box h3 {
    font-size: 1.875rem;
    margin-bottom: calc(var(--spacing-unit) * 2);
}

.cta-box p {
    margin-bottom: calc(var(--spacing-unit) * 3);
    font-size: 1.125rem;
}

/*commitees*/
.committees {
    padding: 2rem 0;
}

.committee-section {
    margin-bottom: 2rem;
}

.committee-section h2 {
    color: var(--primary-color);
    margin-bottom: 2rem;
    padding-bottom: 0.5rem;
  
}

.committee-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
}

.committee-member {
    background-color: #f8f9fa;
    padding: 1.5rem;
    border-radius: 9px;
    border-left: 4px solid var(--secondary-color);
    border-bottom: 1px solid var(--secondary-color);
}

.committee-member h3 {
    color: var(--dark-color);
    margin-bottom: 0.5rem;
}

.committee-member .title {
    color: var(--secondary-color);
    font-weight: 600;
    margin-bottom: 0.3rem;
}

.committee-member .affiliation {
    color: var(--gray-color);
    font-size: 0.95rem;
}

/*partners*/
.partners-grid {
    display: grid;
    background: white;
    padding: 2rem;
    border-radius: 10px;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: calc(var(--spacing-unit) * 4);
    align-items: center;
    justify-items: center;
}

.partner-logo {
    max-width: 180px;
    height: auto;
    transition: all 0.3s ease;
}

.partner-logo:hover {
    filter: grayscale(1%);
    opacity: 1;
}

/* Contact Section */

.contact {
    background: white;
    margin-top: 50px;
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 5rem;

}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 3rem;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem;
    background: #d6dede31;
    border-radius: 10px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.contact-item i {
    color: #e87722;
    font-size: 1.5rem;
}

.contact-item h4 {
    font-weight: 600;
    color: #1d5c9e;;
    margin-bottom: 0.25rem;
}

.contact-item p {
    color: #e87722;
    margin: 2px;
}

.contact-form {
    background: #e87722;
    padding: 1rem;
    border-radius: 8px;
    box-shadow: 0 2px 2px rgba(0, 0, 0, 0.05);
    margin-bottom: 70px;
}

.form-group {
    margin-bottom: 1rem;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 9px 10px;
    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 {
    outline: none;
    border-color: #2563eb;
}

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

.main-footer {
    background: var(--text-dark);
    color: white;
    padding: calc(var(--spacing-unit) * 8) 0 calc(var(--spacing-unit) * 4);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: calc(var(--spacing-unit) * 5);
    margin-bottom: calc(var(--spacing-unit) * 5);
}

.footer-section h3 {
    margin-bottom: calc(var(--spacing-unit) * 2);
    font-size: 1.25rem;
}

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

.footer-section ul li {
    margin-bottom: calc(var(--spacing-unit) * 1);
}

.footer-section a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section a:hover {
    color: white;
}

.footer-section p {
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: calc(var(--spacing-unit) * 1);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: calc(var(--spacing-unit) * 3);
    text-align: center;
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.9375rem;
}

.cmt-acknowledgment {
    margin-top: calc(var(--spacing-unit) * 2);
    font-size: 0.875rem;
}

@media (max-width: 768px) {
    .mobile-toggle {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        left: -100%;
        top: 92px;
        flex-direction: column;
        background-color: var(--bg-white);
        width: 100%;
        text-align: center;
        transition: left 0.3s ease;
        box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
        padding: calc(var(--spacing-unit) * 3) 0;
    }

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

    .nav-menu a.active::after {
        bottom: -4px;
    }

    .hero-content h1 {
        font-size: 2rem;
    }

    .hero-content .subtitle {
        font-size: 1.125rem;
    }

    .section-title {
        font-size: 1.875rem;
    }

    .dates-grid,
    .tracks-container,
    .speakers-grid {
        grid-template-columns: 1fr;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: stretch;
        padding: 0 calc(var(--spacing-unit) * 3);
    }
}

@media (min-width: 769px) and (max-width: 1024px) {
    .hero-content h1 {
        font-size: 2.5rem;
    }

    .tracks-container {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* Correction pour supprimer l'espace/tiret entre les logos */
.logo {
    display: flex;
    align-items: center;
    gap: 0; /* Pas d'espace entre les logos */
}

.logo a {
    display: inline-block;
    margin: 0;
    padding: 0;
    line-height: 0;
    font-size: 0; /* Supprime l'espace entre les éléments inline */
}

.logo img {
    vertical-align: middle; /* Alignement vertical correct */
}