:root {
    --color-bg: #FFF8F0;
    --color-surface: #F5EDE0;
    --color-text: #3D2B1F;
    --color-muted: #7A6E62;
    --color-primary: #2D6A4F;
    --color-primary-hover: #245A42;
    --color-highlight: #D4A03C;
    --color-border: #E8DDD0;
    --color-dark: #2A211A;
    --color-light-text: #F5EDE0;

    --font-heading: 'DM Sans', sans-serif;
    --font-body: 'Source Sans 3', sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
}

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

body {
    font-family: var(--font-body);
    background: var(--color-bg);
    color: var(--color-text);
    font-size: 1.0625rem;
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* Header */
header {
    background: var(--color-dark);
    color: var(--color-light-text);
    padding: 3rem 0 2.5rem;
    text-align: center;
}

header h1 {
    font-family: var(--font-heading);
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

header .subtitle {
    color: var(--color-highlight);
    font-size: 1.15rem;
    font-weight: 500;
}

/* Series Navigation */
.series-nav {
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    padding: 0.75rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

.series-tabs {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.series-tab {
    font-family: var(--font-heading);
    font-size: 0.9rem;
    font-weight: 600;
    padding: 0.5rem 1.25rem;
    border: 1px solid var(--color-border);
    border-radius: 6px;
    background: var(--color-bg);
    color: var(--color-muted);
    cursor: pointer;
    transition: all 0.15s ease;
}

.series-tab:hover { border-color: var(--color-highlight); color: var(--color-text); }
.series-tab.active { background: var(--color-primary); color: white; border-color: var(--color-primary); }

/* Sections */
.section { padding: 2rem 0; }
.section h2 { font-family: var(--font-heading); font-size: 1.75rem; font-weight: 600; margin-bottom: 0.5rem; }
.section h3 { font-family: var(--font-heading); font-size: 1.25rem; font-weight: 600; margin-bottom: 0.5rem; }
.section-desc { color: var(--color-muted); margin-bottom: 1.5rem; }

.series-intro {
    font-size: 1.1rem;
    margin-bottom: 1.25rem;
    line-height: 1.5;
}

.series-intro strong { color: var(--color-primary); }

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

.stat-card {
    background: var(--color-surface);
    border-radius: 8px;
    padding: 1.25rem;
    text-align: center;
    border: 1px solid var(--color-border);
}

.stat-value {
    font-family: var(--font-heading);
    font-size: 2rem;
    font-weight: 700;
    color: var(--color-primary);
    line-height: 1.2;
}

.stat-label {
    font-size: 0.85rem;
    color: var(--color-muted);
    margin-top: 0.25rem;
}

/* Bipartite Graph */
#bipartiteContainer {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
}

.bipartite-svg {
    display: block;
    min-width: 700px;
}

.bipartite-link {
    transition: opacity 0.15s ease;
    pointer-events: none;
}

.bipartite-node rect {
    transition: opacity 0.15s ease;
}

.bipartite-node text {
    transition: opacity 0.15s ease;
    user-select: none;
}

/* Detail View */
.detail-header { margin-bottom: 1.5rem; }

.btn-back {
    font-family: var(--font-heading);
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--color-primary);
    background: none;
    border: 1px solid var(--color-border);
    border-radius: 6px;
    padding: 0.4rem 1rem;
    cursor: pointer;
    margin-bottom: 1rem;
    transition: all 0.15s;
}

.btn-back:hover { border-color: var(--color-highlight); background: var(--color-surface); }

.posting-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 8px;
    padding: 1.25rem;
    margin-bottom: 0.75rem;
    transition: border-color 0.15s;
}

.posting-card:hover { border-color: var(--color-highlight); }

.posting-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 1rem;
    margin-bottom: 0.5rem;
}

.posting-fed-title {
    font-family: var(--font-heading);
    font-size: 1rem;
    font-weight: 600;
}

.posting-plain-title {
    font-family: var(--font-heading);
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--color-primary);
    background: rgba(45, 106, 79, 0.1);
    padding: 0.2rem 0.6rem;
    border-radius: 4px;
    flex-shrink: 0;
}

.posting-meta {
    font-size: 0.85rem;
    color: var(--color-muted);
    margin-bottom: 0.5rem;
}

.posting-link {
    color: var(--color-primary);
    text-decoration: underline;
    text-underline-offset: 2px;
}

.posting-reasoning {
    font-size: 0.9rem;
    color: var(--color-text);
    margin-bottom: 0.5rem;
    font-style: italic;
}

.posting-duties {
    font-size: 0.85rem;
    color: var(--color-muted);
    line-height: 1.5;
}

.posting-duties summary {
    cursor: pointer;
    font-weight: 500;
    color: var(--color-primary);
    font-style: normal;
}

/* Methodology */
.methodology-content { max-width: 800px; }
.method-block { margin-bottom: 2rem; }
.method-block p { margin-bottom: 0.75rem; }
.method-block a { color: var(--color-primary); text-decoration: underline; text-underline-offset: 2px; }
.method-block a:hover { color: var(--color-highlight); }

.pipeline-steps {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin-top: 1rem;
}

.pipeline-step {
    display: flex;
    gap: 1rem;
    align-items: flex-start;
}

.step-number {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: var(--color-primary);
    color: white;
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.step-content h4 { font-family: var(--font-heading); font-weight: 600; font-size: 1rem; margin-bottom: 0.25rem; }
.step-content p { font-size: 0.95rem; color: var(--color-muted); }

/* Footer */
footer {
    background: var(--color-dark);
    color: var(--color-muted);
    padding: 1.5rem 0;
    text-align: center;
    font-size: 0.85rem;
    margin-top: 2rem;
}

footer a { color: var(--color-highlight); }

/* Responsive */
@media (max-width: 768px) {
    header h1 { font-size: 1.75rem; }
    .container { padding: 0 1rem; }
    .posting-header { flex-direction: column; }
    .stats-grid { grid-template-columns: repeat(2, 1fr); }
}