:root {
    --bg-primary: #1a1a2e;
    --bg-secondary: #16213e;
    --bg-card: #0f3460;
    --text-primary: #e8e8e8;
    --text-secondary: #a8a8a8;
    --accent-blue: #4d9de0;
    --accent-green: #3bb78f;
    --accent-red: #e15554;
    --accent-yellow: #e1bc29;
    --accent-purple: #9b5de5;
    --supporting: #3bb78f;
    --contrasting: #e1bc29;
    --refuting: #e15554;
    --contextual: #4d9de0;
    --methodological: #9b5de5;
    --neutral: #a8a8a8;
}

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

body {
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 2rem;
}

header {
    background: var(--bg-secondary);
    padding: 1.5rem 0;
    border-bottom: 2px solid var(--accent-blue);
    position: sticky;
    top: 0;
    z-index: 100;
}

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

.logo {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--accent-blue);
    text-decoration: none;
}

.logo span {
    color: var(--text-secondary);
    font-weight: 400;
}

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

nav a {
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}

nav a:hover, nav a.active {
    color: var(--accent-blue);
}

main {
    padding: 2rem 0;
    min-height: calc(100vh - 200px);
}

h1, h2, h3 {
    color: var(--text-primary);
    margin-bottom: 1rem;
}

h1 {
    font-size: 2.5rem;
    border-bottom: 3px solid var(--accent-blue);
    padding-bottom: 0.5rem;
    margin-bottom: 2rem;
}

h2 {
    font-size: 1.8rem;
    margin-top: 2rem;
}

/* Stats cards */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-bottom: 3rem;
}

.stat-card {
    background: var(--bg-card);
    border-radius: 12px;
    padding: 1.5rem;
    text-align: center;
    border: 1px solid rgba(77, 157, 224, 0.3);
}

.stat-card .number {
    font-size: 3rem;
    font-weight: 700;
    color: var(--accent-blue);
}

.stat-card .label {
    color: var(--text-secondary);
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* Paper cards */
.paper-grid {
    display: grid;
    gap: 1.5rem;
}

.paper-card {
    background: var(--bg-card);
    border-radius: 12px;
    padding: 1.5rem;
    border-left: 4px solid var(--accent-blue);
    transition: transform 0.2s, box-shadow 0.2s;
}

.paper-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.3);
}

.paper-card h3 {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
}

.paper-card h3 a {
    color: var(--text-primary);
    text-decoration: none;
}

.paper-card h3 a:hover {
    color: var(--accent-blue);
}

.paper-meta {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 0.75rem;
}

.paper-abstract {
    font-size: 0.95rem;
    color: var(--text-secondary);
    margin-top: 0.75rem;
}

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

.paper-links a {
    color: var(--accent-blue);
    font-size: 0.85rem;
    text-decoration: none;
}

.paper-links a:hover {
    text-decoration: underline;
}

/* Citation badges */
.citation-badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.citation-badge.supporting { background: var(--supporting); color: #000; }
.citation-badge.contrasting { background: var(--contrasting); color: #000; }
.citation-badge.refuting { background: var(--refuting); color: #fff; }
.citation-badge.contextual { background: var(--contextual); color: #000; }
.citation-badge.methodological { background: var(--methodological); color: #fff; }
.citation-badge.neutral { background: var(--neutral); color: #000; }

/* Citations list */
.citations-section {
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.citation-item {
    background: rgba(0, 0, 0, 0.2);
    border-radius: 8px;
    padding: 1rem;
    margin-bottom: 0.75rem;
}

.citation-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 0.5rem;
}

.citation-papers {
    font-size: 0.9rem;
}

.citation-arrow {
    color: var(--accent-blue);
    margin: 0 0.5rem;
}

.citation-reasoning {
    font-size: 0.85rem;
    color: var(--text-secondary);
    font-style: italic;
    margin-top: 0.5rem;
}

/* Hypothesis cards */
.hypothesis-grid {
    display: grid;
    gap: 1.5rem;
}

.hypothesis-card {
    background: var(--bg-card);
    border-radius: 12px;
    padding: 1.5rem;
    transition: transform 0.2s;
}

.hypothesis-card.active {
    border-left: 4px solid var(--accent-green);
}

.hypothesis-card.uncertain {
    border-left: 4px solid var(--accent-yellow);
}

.hypothesis-card.ruled_out {
    border-left: 4px solid var(--accent-red);
}

.hypothesis-card.superseded {
    border-left: 4px solid var(--accent-purple);
}

.hypothesis-status {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    margin-bottom: 0.75rem;
}

.hypothesis-status.active { background: var(--accent-green); color: #000; }
.hypothesis-status.uncertain { background: var(--accent-yellow); color: #000; }
.hypothesis-status.ruled_out { background: var(--accent-red); color: #fff; }
.hypothesis-status.superseded { background: var(--accent-purple); color: #fff; }

.hypothesis-card h3 {
    font-size: 1.2rem;
    margin-bottom: 0.75rem;
}

.hypothesis-description {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 1rem;
}

.hypothesis-reason {
    background: rgba(0, 0, 0, 0.2);
    border-radius: 8px;
    padding: 1rem;
    margin-top: 1rem;
}

.hypothesis-reason strong {
    color: var(--accent-red);
}

.evidence-list {
    margin-top: 1rem;
}

.evidence-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.evidence-item:last-child {
    border-bottom: none;
}

.stance-badge {
    font-size: 0.7rem;
    padding: 0.2rem 0.5rem;
    border-radius: 10px;
    font-weight: 600;
}

.stance-badge.supports { background: var(--accent-green); color: #000; }
.stance-badge.refutes { background: var(--accent-red); color: #fff; }
.stance-badge.discusses { background: var(--accent-blue); color: #000; }
.stance-badge.proposes { background: var(--accent-purple); color: #fff; }

/* D3 Visualization */
#citation-network {
    width: 100%;
    height: 600px;
    background: var(--bg-secondary);
    border-radius: 12px;
    margin: 2rem 0;
    border: 1px solid rgba(77, 157, 224, 0.3);
}

.node-label {
    font-size: 10px;
    fill: var(--text-primary);
    pointer-events: none;
}

.link {
    fill: none;
    stroke-opacity: 0.6;
}

.link.supporting { stroke: var(--supporting); }
.link.contrasting { stroke: var(--contrasting); }
.link.refuting { stroke: var(--refuting); }
.link.contextual { stroke: var(--contextual); }
.link.methodological { stroke: var(--methodological); }
.link.neutral { stroke: var(--neutral); }

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

.legend-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.85rem;
}

.legend-color {
    width: 20px;
    height: 4px;
    border-radius: 2px;
}

/* Footer */
footer {
    background: var(--bg-secondary);
    padding: 2rem 0;
    margin-top: 3rem;
    border-top: 1px solid rgba(77, 157, 224, 0.3);
    text-align: center;
    color: var(--text-secondary);
}

footer a {
    color: var(--accent-blue);
}

/* Responsive */
@media (max-width: 768px) {
    .container {
        padding: 0 1rem;
    }

    header .container {
        flex-direction: column;
        gap: 1rem;
    }

    nav ul {
        gap: 1rem;
    }

    h1 {
        font-size: 1.8rem;
    }

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

/* Tooltip */
.tooltip {
    position: absolute;
    background: var(--bg-card);
    border: 1px solid var(--accent-blue);
    border-radius: 8px;
    padding: 1rem;
    max-width: 350px;
    font-size: 0.85rem;
    pointer-events: none;
    z-index: 1000;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.5);
}

.tooltip h4 {
    color: var(--accent-blue);
    margin-bottom: 0.5rem;
}

/* Classification summary */
.classification-summary {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
    margin: 2rem 0;
}

.classification-item {
    background: var(--bg-card);
    border-radius: 8px;
    padding: 1rem;
    text-align: center;
}

.classification-item .count {
    font-size: 2rem;
    font-weight: 700;
}

.classification-item.supporting .count { color: var(--supporting); }
.classification-item.contrasting .count { color: var(--contrasting); }
.classification-item.refuting .count { color: var(--refuting); }
.classification-item.contextual .count { color: var(--contextual); }