/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Plus Jakarta Sans', sans-serif;
    line-height: 1.7;
    color: #666;
    background-color: #fff;
    font-weight: 300;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 40px 20px;
}

/* Header styles */
header {
    text-align: center;
    margin-bottom: 80px;
    position: relative;
}

.header-visual {
    margin-bottom: 30px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.counterfactual-clock {
    filter: drop-shadow(0 2px 8px rgba(66, 149, 100, 0.15));
    transition: transform 0.3s ease;
}

.counterfactual-clock:hover {
    transform: scale(1.1);
}

header h1 {
    font-size: 2.2em;
    font-weight: 300;
    color: #111;
    margin-bottom: 8px;
    letter-spacing: -0.01em;
}

header h2 {
    font-size: 1.4em;
    font-weight: 400;
    color: #429564;
    text-transform: uppercase;
    letter-spacing: 0.15em;
}

.uai-link {
    text-decoration: none;
    color: inherit;
    border-bottom: 1px solid transparent;
    transition: border-bottom-color 0.3s ease;
}

.uai-link:hover {
    border-bottom-color: #429564;
}

/* Section styles */
section {
    margin-bottom: 80px;
}

h3 {
    font-size: 1.4em;
    font-weight: 500;
    color: #111;
    margin-bottom: 30px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    position: relative;
}

h3:after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 0;
    width: 30px;
    height: 2px;
    background: #429564;
}

h4 {
    font-size: 1.1em;
    font-weight: 500;
    color: #222;
    margin-bottom: 20px;
}

/* Basic details section */
.details-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
    margin-bottom: 50px;
}

.detail-item {
    font-size: 0.95em;
    line-height: 1.6;
    color: #666;
}

.detail-item strong {
    color: #222;
    font-weight: 500;
}

.description {
    margin-bottom: 40px;
}

.description p {
    margin-bottom: 25px;
    font-size: 1em;
    line-height: 1.8;
    color: #666;
    font-weight: 400;
}

.description p:last-child {
    margin-bottom: 0;
}

/* Tutorial info subsection */
.tutorial-info {
    margin-top: 40px;
    padding-top: 30px;
    border-top: 1px solid #f0f0f0;
}

.tutorial-info h4 {
    font-size: 1em;
    font-weight: 500;
    color: #222;
    margin-bottom: 20px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.info-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
}

.info-item {
    font-size: 0.95em;
    line-height: 1.6;
    color: #666;
}

.info-item strong {
    color: #222;
    font-weight: 500;
}

/* Timeline section */
.timeline-grid {
    display: grid;
    gap: 0;
}

.time-slot {
    display: grid;
    grid-template-columns: 140px 1fr;
    gap: 30px;
    padding: 20px 0;
    border-bottom: 1px solid #f0f0f0;
}

.time-slot:last-child {
    border-bottom: none;
}

.time {
    font-weight: 400;
    color: #666;
    font-size: 0.95em;
}

.topic {
    font-weight: 400;
    color: #222;
    font-size: 1em;
}

/* Resources section */
.resource-category {
    margin-bottom: 50px;
}

.resource-list,
.reference-list {
    list-style: none;
}

.resource-list li,
.reference-list li {
    padding: 15px 0;
    border-bottom: 1px solid #f5f5f5;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.resource-list li:last-child,
.reference-list li:last-child {
    border-bottom: none;
}

.resource-link,
.paper-link {
    color: #222;
    text-decoration: none;
    font-weight: 400;
    transition: color 0.2s ease;
}

.resource-link:hover,
.paper-link:hover {
    color: #429564;
}

.format-links {
    font-size: 0.9em;
    color: #999;
}

.format-links a {
    color: #999;
    text-decoration: none;
    margin: 0 5px;
    transition: color 0.2s ease;
}

.format-links a:hover {
    color: #429564;
}

.paper-venue {
    color: #999;
    font-size: 0.9em;
    font-weight: 300;
}

/* Presenters section */
.presenter-grid {
    display: grid;
    gap: 50px;
}

.presenter {
    display: grid;
    grid-template-columns: 100px 1fr;
    gap: 30px;
}

.presenter-photo img {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    object-fit: cover;
    filter: grayscale(20%) brightness(1.1) contrast(0.9);
    opacity: 0.9;
}

.presenter-info h4 {
    margin-bottom: 5px;
    font-weight: 500;
}

.presenter-info h4 a {
    color: #222;
    text-decoration: none;
}

.presenter-info h4 a:hover {
    color: #429564;
}

.affiliation {
    color: #666;
    font-weight: 300;
    margin-bottom: 15px;
    font-size: 0.95em;
}

.bio {
    color: #666;
    line-height: 1.7;
    font-size: 0.95em;
    font-weight: 300;
}

/* Footer */
footer {
    margin-top: 100px;
    padding-top: 40px;
    border-top: 1px solid #f0f0f0;
    text-align: center;
}

.footer-content {
    display: flex;
    justify-content: center;
    align-items: center;
    flex-wrap: wrap;
    gap: 20px;
}

.footer-links {
    font-size: 0.85em;
    color: #999;
    font-weight: 300;
}

.footer-links a {
    color: #999;
    text-decoration: none;
    margin: 0 8px;
}

.footer-links a:hover {
    color: #429564;
}

/* Responsive design */
@media (max-width: 768px) {
    .container {
        padding: 30px 20px;
    }
    
    header h1 {
        font-size: 1.8em;
    }
    
    .details-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .time-slot {
        grid-template-columns: 1fr;
        gap: 10px;
    }
    
    .presenter {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 20px;
    }
    
    .presenter-photo {
        justify-self: center;
    }
    
    .footer-content {
        flex-direction: column;
        text-align: center;
    }
}

@media (max-width: 480px) {
    header h1 {
        font-size: 1.6em;
    }
    
    header h2 {
        font-size: 1em;
    }
    
    h3 {
        font-size: 1.2em;
    }
}

/* Link styles */
a {
    color: #222;
    transition: color 0.2s ease;
}

a:hover {
    color: #429564;
}

/* Reference tabs */
.reference-tabs {
    display: flex;
    margin-bottom: 20px;
    border-bottom: 1px solid #f0f0f0;
}

.reference-tab {
    background: none;
    border: none;
    padding: 8px 20px;
    font-size: 1.8em;
    color: #666;
    cursor: pointer;
    border-bottom: 2px solid transparent;
    transition: all 0.3s ease;
    font-family: inherit;
    border-radius: 8px 8px 0 0;
}

.reference-tab:hover {
    color: #429564;
    background-color: rgba(66, 149, 100, 0.08);
    transform: scale(1.1);
}

.reference-tab.active {
    color: #429564;
    border-bottom-color: #429564;
    background-color: rgba(66, 149, 100, 0.05);
}

.reference-content {
    display: none;
}

.reference-content.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

/* Reference category collapsible sections */
.reference-category {
    margin-bottom: 15px;
    border: 1px solid #f0f0f0;
    border-radius: 8px;
    overflow: hidden;
    transition: all 0.3s ease;
}

.reference-category:hover {
    border-color: rgba(66, 149, 100, 0.3);
    box-shadow: 0 2px 8px rgba(66, 149, 100, 0.1);
}

.category-toggle {
    width: 100%;
    padding: 12px 16px;
    background: #fafafa;
    border: none;
    text-align: left;
    cursor: pointer;
    display: flex;
    align-items: center;
    font-family: inherit;
    font-size: 0.95em;
    font-weight: 500;
    color: #666;
    transition: background-color 0.3s ease;
}

.category-toggle:hover {
    background: rgba(66, 149, 100, 0.08);
}

.reference-category.expanded .category-toggle {
    background: rgba(66, 149, 100, 0.12);
    color: #429564;
}

.toggle-icon {
    margin-right: 10px;
    font-size: 0.8em;
    transition: transform 0.3s ease;
    width: 12px;
    display: inline-block;
}

.category-title {
    font-weight: 500;
}

.reference-category .reference-list {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease;
    margin: 0;
    padding: 0;
    background: white;
}

.reference-category.expanded .reference-list {
    padding: 8px 0;
}

.reference-category .reference-list li {
    padding: 8px 16px;
    margin: 0;
    border-bottom: none;
    line-height: 1.4;
    display: block;
}

.reference-category .reference-list .paper-venue {
    display: block;
    margin-top: 4px;
    margin-left: 0;
}

.reference-category .reference-list li:hover {
    background: rgba(66, 149, 100, 0.05);
}