:root {
    --primary-color: #006847;
    /* KFUPM Green-ish */
    --secondary-color: #0B2447;
    /* Deep Navy */
    --accent-color: #E8B931;
    /* Gold accent */
    --text-dark: #1f2937;
    --text-light: #4b5563;
    --bg-light: #f3f4f6;
    --white: #ffffff;
    --border-radius: 8px;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --transition: all 0.3s ease;
}

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

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

h1,
h2,
h3,
h4,
h5,
h6 {
    font-family: 'Outfit', sans-serif;
    color: var(--secondary-color);
    font-weight: 700;
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

ul {
    list-style: none;
}

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

.btn {
    display: inline-block;
    padding: 12px 24px;
    border-radius: 50px;
    font-weight: 600;
    text-transform: uppercase;
    font-size: 0.9rem;
    letter-spacing: 0.5px;
    cursor: pointer;
    transition: var(--transition);
}

.btn-primary {
    background-color: var(--primary-color);
    color: var(--white);
    border: 2px solid var(--primary-color);
}

.btn-primary:hover {
    background-color: #005036;
    border-color: #005036;
}

.btn-secondary {
    background-color: transparent;
    color: var(--white);
    border: 2px solid var(--white);
    margin-left: 10px;
}

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

/* Navbar */
.navbar {
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    box-shadow: var(--shadow-sm);
    padding: 15px 0;
}

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

.logo {
    display: flex;
    align-items: center;
}

.logo img {
    height: 60px;
    width: auto;
    object-fit: contain;
}

.nav-links {
    display: flex;
    gap: 30px;
}

.nav-links li a {
    font-weight: 500;
    color: var(--text-dark);
    font-size: 0.95rem;
}

.nav-links li a:hover {
    color: var(--primary-color);
}

.menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--text-dark);
    cursor: pointer;
}

/* Hero Section */
.hero {
    height: 100vh;
    min-height: 600px;
    background: linear-gradient(135deg, var(--secondary-color) 0%, var(--primary-color) 100%);
    position: relative;
    display: flex;
    align-items: center;
    color: var(--white);
    overflow: hidden;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('assets/hero-bg.png') center/cover no-repeat;
    opacity: 0.3;
    z-index: 1;
}

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    width: 100%;
}

.hero-logos {
    display: none;
    /* Hidden in favor of the full logos section */
}

.divider {
    margin: 0 10px;
    opacity: 0.6;
}

.hero-subtitle {
    font-size: 1.2rem;
    font-weight: 400;
    color: var(--accent-color);
    margin-bottom: 10px;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    font-family: 'Inter', sans-serif;
}

.hero-title {
    font-size: 3.5rem;
    line-height: 1.2;
    margin-bottom: 30px;
    color: var(--white);
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.hero-dates,
.hero-department,
.hero-location {
    font-size: 1.2rem;
    margin-bottom: 10px;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 10px;
}

.hero-cta {
    margin-top: 40px;
    margin-bottom: 15px;
}

.hero-event-info {
    margin-top: 15px;
}

.hero-event-info p {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--white);
    opacity: 0.95;
    letter-spacing: 0.3px;
    margin-bottom: 5px;
}

/* Sections */
.section {
    padding: 80px 0;
    background-color: var(--white);
}

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

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-header h2 {
    font-size: 2.5rem;
    color: var(--secondary-color);
    margin-bottom: 10px;
}

.underline {
    width: 60px;
    height: 4px;
    background-color: var(--primary-color);
    margin: 0 auto;
    border-radius: 2px;
}

/* About Section */
.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
    align-items: center;
}

.about-content p {
    font-size: 1.1rem;
    color: var(--text-light);
    margin-bottom: 20px;
    text-align: justify;
}

.organizers-box {
    margin-top: 30px;
    padding: 20px;
    background-color: var(--bg-light);
    border-left: 4px solid var(--accent-color);
    border-radius: 0 var(--border-radius) var(--border-radius) 0;
}

.organizers-box h3 {
    font-size: 1.2rem;
    margin-bottom: 10px;
    color: var(--secondary-color);
}

.organizers-box ul li {
    margin-bottom: 5px;
}

.about-highlights {
    display: grid;
    grid-template-columns: 1fr;
    gap: 20px;
}

.highlight-card {
    background: var(--white);
    padding: 25px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    transition: var(--transition);
}

.highlight-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.highlight-card i {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 15px;
}

.highlight-card h4 {
    margin-bottom: 5px;
    font-size: 1.1rem;
}

/* Sponsors Section */
.sponsors-grid {
    display: flex;
    justify-content: center;
    align-items: center;
    flex-wrap: wrap;
    gap: 80px;
    /* Increased gap for better separation */
    padding: 40px 0;
}

.sponsor-item {
    flex: 0 1 auto;
    display: flex;
    justify-content: center;
    align-items: center;
    transition: var(--transition);
    /* Removed grayscale filter to keep logos clear and professional */
    opacity: 1;
}

.sponsor-item:hover {
    transform: scale(1.05);
    /* Subtle scale effect remains */
}

.sponsor-item img {
    max-height: 180px;
    max-width: 280px;
    width: auto;
    object-fit: contain;
}

/* Speaker Section */
.speaker-profile {
    display: flex;
    flex-direction: row;
    gap: 50px;
    background: var(--white);
    padding: 40px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-lg);
    align-items: center;
}

.speaker-image-container {
    flex: 0 0 300px;
    display: flex;
    justify-content: center;
}

.speaker-img {
    width: 100%;
    max-width: 300px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
    object-fit: cover;
}

.speaker-info h3 {
    font-size: 2rem;
    margin-bottom: 5px;
    color: var(--primary-color);
}

.speaker-title {
    color: var(--accent-color);
    font-weight: 600;
    font-size: 1.1rem;
    margin-bottom: 20px;
}

.speaker-bio {
    color: var(--text-light);
    line-height: 1.7;
    margin-bottom: 20px;
    text-align: justify;
}

.speaker-bio a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
}

.speaker-bio a:hover {
    color: var(--secondary-color);
}

/* Organizers Section */
.organizers-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
    max-width: 1000px;
    margin: 0 auto;
}

.organizer-card {
    background: var(--white);
    padding: 30px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
    text-align: center;
    transition: var(--transition);
    display: flex;
    flex-direction: column;
    align-items: center;
}

.organizer-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.organizer-img-container {
    width: 150px;
    height: 150px;
    margin-bottom: 20px;
    border-radius: 50%;
    overflow: hidden;
    border: 4px solid var(--bg-light);
    box-shadow: var(--shadow-sm);
}

.organizer-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.organizer-info h3 {
    font-size: 1.3rem;
    color: var(--primary-color);
    margin-bottom: 5px;
}

.organizer-title {
    color: var(--accent-color);
    font-weight: 600;
    font-size: 0.95rem;
    margin-bottom: 15px;
}

.organizer-email {
    font-size: 0.9rem;
    color: var(--text-light);
}

.organizer-email a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
}

.organizer-email a:hover {
    color: var(--secondary-color);
}

/* Schedule Section */
.schedule-tabs {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-bottom: 40px;
}

.tab-btn {
    padding: 10px 30px;
    border: 2px solid var(--secondary-color);
    background: transparent;
    color: var(--secondary-color);
    border-radius: 30px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.tab-btn.active,
.tab-btn:hover {
    background-color: var(--secondary-color);
    color: var(--white);
}

.day-schedule {
    display: none;
    max-width: 900px;
    margin: 0 auto;
}

.day-schedule.active {
    display: block;
    animation: fadeIn 0.5s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.timeline-item {
    display: flex;
    gap: 30px;
    border-left: 3px solid #e5e7eb;
    padding-left: 30px;
    padding-bottom: 40px;
    position: relative;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -9px;
    top: 5px;
    width: 15px;
    height: 15px;
    border-radius: 50%;
    background-color: #e5e7eb;
    border: 3px solid var(--white);
}

.timeline-item.lecture::before {
    background-color: var(--primary-color);
}

.timeline-item.event::before {
    background-color: var(--accent-color);
}

.timeline-item:last-child {
    border-left: none;
    padding-bottom: 0;
}

.timeline-item .time {
    flex: 0 0 120px;
    font-weight: 700;
    color: var(--text-dark);
}

.timeline-item .content {
    flex: 1;
}

.tag {
    display: inline-block;
    padding: 3px 12px;
    border-radius: 12px;
    background-color: #dbeafe;
    color: #1e40af;
    font-size: 0.8rem;
    font-weight: 600;
    margin-bottom: 8px;
}

.hero-logos {
    margin-bottom: 20px;
    font-size: 1.1rem;
    font-weight: 600;
    letter-spacing: 1px;
    opacity: 0.9;
}

.hero-brand-logo {
    max-width: 250px;
    width: 100%;
    height: auto;
    margin-top: 50px;
    margin-bottom: 25px;
    filter: drop-shadow(0 4px 6px rgba(0, 0, 0, 0.3));
    animation: fadeInDown 1s ease-out;
}

.hero-subtitle {
    margin-bottom: 10px;
}

.event-tag {
    background-color: #fce7f3;
    color: #9d174d;
}

.timeline-item h4 {
    font-size: 1.2rem;
    margin-bottom: 5px;
}

/* Abstracts Section */
.abstracts-list {
    max-width: 900px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.abstract-item {
    background: var(--white);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    overflow: hidden;
    transition: var(--transition);
}

.abstract-item:hover {
    box-shadow: var(--shadow-md);
}

.abstract-item summary {
    padding: 20px;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    list-style: none;
    /* Hide default arrow */
    font-weight: 600;
}

.abstract-item summary::-webkit-details-marker {
    display: none;
}

.abstract-item[open] summary {
    background-color: #f9fafb;
    border-bottom: 1px solid #e5e7eb;
}

.lecture-id {
    color: var(--primary-color);
    font-weight: 700;
    width: 100px;
}

.lecture-title {
    flex: 1;
    margin-right: 20px;
}

.abstract-content {
    padding: 25px;
    background-color: var(--white);
    color: var(--text-light);
    line-height: 1.6;
    text-align: justify;
}

.abstract-img {
    float: left;
    margin-right: 25px;
    margin-bottom: 15px;
    max-width: 350px;
    width: 100%;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
    transition: var(--transition);
}

.abstract-img:hover {
    transform: scale(1.02);
}

/* Venue Section */
.venue-content {
    display: flex;
    gap: 40px;
    align-items: center;
}

.venue-info {
    flex: 1;
}

.venue-building-img {
    width: 100%;
    max-height: 250px;
    object-fit: cover;
    border-radius: var(--border-radius);
    margin-bottom: 20px;
    box-shadow: var(--shadow-md);
}

.venue-info h3 {
    font-size: 1.8rem;
    margin-bottom: 15px;
    color: var(--secondary-color);
}

.venue-info p {
    font-size: 1.2rem;
    color: var(--text-light);
    margin-bottom: 10px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.venue-map {
    flex: 1.2;
    min-height: 400px;
}

.venue-map iframe {
    width: 100%;
    height: 100%;
    border-radius: var(--border-radius);
}

/* Footer */
.footer {
    background-color: var(--secondary-color);
    color: var(--white);
    padding: 40px 0;
    text-align: center;
}

.footer-logo h3 {
    color: var(--white);
    margin-bottom: 15px;
}

/* Venue Details */
.venue-detail {
    font-size: 1.15rem;
    font-weight: 500;
}

.venue-note {
    margin-top: 15px;
    font-weight: 700;
    color: var(--primary-color) !important;
}

.tbd-text {
    margin-top: 10px;
    font-style: italic;
    color: var(--accent-color);
    font-weight: 500;
}

/* Social Share in Footer */
.social-share {
    margin: 20px 0;
}

.social-share p {
    margin-bottom: 10px;
    font-size: 0.9rem;
    opacity: 0.8;
}

.social-icons {
    display: flex;
    justify-content: center;
    gap: 15px;
}

.social-btn {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background-color: rgba(255, 255, 255, 0.1);
    color: var(--white);
    transition: var(--transition);
    font-size: 1.2rem;
}

.social-btn:hover {
    background-color: var(--white);
    transform: translateY(-3px);
}

.social-btn.linkedin:hover {
    color: #0077b5;
}

.social-btn.facebook:hover {
    color: #1877f2;
}

.social-btn.twitter:hover {
    color: #1da1f2;
}

/* Responsive */
@media (max-width: 768px) {
    .section {
        padding: 60px 0;
    }

    .section-header {
        margin-bottom: 40px;
    }

    .section-header h2 {
        font-size: 2rem;
    }

    .hero {
        height: auto;
        padding: 120px 0 60px 0;
    }

    .hero-title {
        font-size: 2.2rem;
    }

    .hero-brand-logo {
        max-width: 180px;
        margin-top: 0;
    }

    .hero-department,
    .hero-location,
    .hero-dates {
        font-size: 1rem;
        padding: 0 20px;
    }

    .menu-toggle {
        display: block;
    }

    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background-color: var(--white);
        flex-direction: column;
        padding: 20px;
        box-shadow: var(--shadow-md);
        text-align: center;
        z-index: 1000;
    }

    .nav-links li {
        margin: 15px 0;
    }

    .nav-links.active {
        display: flex;
    }

    .about-grid,
    .speaker-profile,
    .venue-content {
        grid-template-columns: 1fr;
        flex-direction: column;
        gap: 30px;
    }

    .speaker-image-container {
        flex: 0 0 auto;
        width: 100%;
        max-width: 250px;
        margin: 0 auto;
    }

    .timeline-item {
        flex-direction: column;
        gap: 5px;
        padding-bottom: 30px;
    }

    .timeline-item .time {
        flex: 0 0 auto;
        font-size: 0.95rem;
        color: var(--primary-color);
    }

    .abstract-item summary {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
        padding: 15px;
    }

    .lecture-id {
        width: auto;
        margin-bottom: 5px;
    }

    .abstract-item summary i {
        display: none;
    }

    .abstract-img {
        float: none;
        display: block;
        margin: 0 auto 20px auto;
        max-width: 100%;
    }

    .organizers-grid {
        grid-template-columns: 1fr;
        padding: 0 10px;
    }

    .venue-map {
        min-height: 300px;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 1.8rem;
    }

    .hero-brand-logo {
        max-width: 150px;
    }

    .logo img {
        height: 45px;
    }

    .btn {
        width: 100%;
        margin-bottom: 10px;
        margin-right: 0 !important;
    }

    .hero-cta {
        padding: 0 20px;
    }
}