:root {
    --bg-color: #FAF8F5; /* Elegant book-paper warm off-white */
    --bg-secondary: #F3ECE0; /* Slightly darker warm cream for code/cards */
    --text-primary: #1C1917; /* Charcoal/dark stone for readable text */
    --text-secondary: #57534E; /* Scholarly gray-brown for captions and labels */
    --accent-color: #8C6239; /* Muted academic leather/brown */
    --accent-hover: #5B4029;
    --border-color: #E7E1D3; /* Soft tan/cream borders */
    --card-bg: #F5F0E6; /* Scholarly tan card background */
    --code-bg: #EFECE6; /* Cool/warm grey-cream for code */
    --link-bg: #FFFFFF;
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    line-height: 1.75;
    font-size: 1.05rem;
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: 850px;
    margin: 0 auto;
    padding: 5rem 2rem;
}

/* Typography */
h1, h2, h3, h4, .serif {
    font-family: 'Lora', Georgia, Cambria, "Times New Roman", Times, serif;
    color: #1C1917;
    font-weight: 700;
}

h1 {
    font-size: 2.5rem;
    line-height: 1.2;
    margin-bottom: 1.5rem;
    text-align: center;
}

h2 {
    font-size: 1.6rem;
    margin-top: 3.5rem;
    margin-bottom: 1.2rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.5rem;
    color: var(--accent-color);
}

h3 {
    font-size: 1.25rem;
    margin-top: 2rem;
    margin-bottom: 0.8rem;
}

p {
    margin-bottom: 1.5rem;
    text-align: justify;
}

/* Paper Header (PhD / Academic Portfolio Style) */
.paper-header {
    text-align: center;
    margin-bottom: 4rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid var(--border-color);
}

.paper-preprint {
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 2px;
    font-weight: 600;
    color: var(--accent-color);
    margin-bottom: 1.2rem;
}

.paper-title {
    margin-bottom: 0.5rem;
}

.paper-subtitle {
    font-size: 1.4rem;
    margin-top: 0;
    margin-bottom: 1.5rem;
    border-bottom: none;
    text-align: center;
    color: var(--text-secondary);
    font-weight: 500;
}

.paper-authors {
    margin: 1.5rem 0;
    font-size: 1.1rem;
}

.author-block {
    display: inline-block;
    margin: 0 1rem;
}

.author-name {
    font-weight: 600;
    color: var(--text-primary);
}

.author-affiliation {
    display: block;
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-top: 0.2rem;
}

.paper-links {
    display: flex;
    justify-content: center;
    gap: 0.8rem;
    flex-wrap: wrap;
    margin-top: 2rem;
}

.paper-link-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background-color: var(--link-bg);
    border: 1px solid var(--border-color);
    padding: 0.5rem 1rem;
    border-radius: 4px;
    color: var(--text-primary);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all 0.2s ease;
    box-shadow: 0 1px 2px rgba(0,0,0,0.03);
}

.paper-link-btn:hover {
    background-color: var(--card-bg);
    border-color: var(--accent-color);
    color: var(--accent-color);
    transform: translateY(-1px);
}

.paper-link-btn svg {
    width: 16px;
    height: 16px;
    fill: currentColor;
}

/* Abstract Box */
.abstract-container {
    background-color: var(--card-bg);
    padding: 2.2rem;
    border-radius: 6px;
    border: 1px solid var(--border-color);
    margin-bottom: 3.5rem;
    box-shadow: inset 0 1px 3px rgba(0,0,0,0.02);
}

.abstract-title {
    text-align: center;
    font-size: 1.1rem;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    margin-bottom: 1.2rem;
    font-weight: 700;
    color: var(--text-primary);
}

.abstract-text {
    font-family: 'Lora', Georgia, serif;
    font-size: 1.05rem;
    line-height: 1.8;
    color: #292524;
    margin-bottom: 0;
}

/* Architecture Highlight Section */
.architecture-container {
    margin: 2.5rem 0;
    text-align: center;
}

.architecture-diagram {
    background-color: #FFFFFF;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 1.5rem;
    margin-bottom: 1rem;
    box-shadow: 0 4px 10px rgba(0,0,0,0.02);
}

.architecture-caption {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.5;
    margin-top: 0.5rem;
}

/* Key Features Grid */
.features-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
    margin: 2.5rem 0;
}

@media (max-width: 600px) {
    .features-grid {
        grid-template-columns: 1fr;
    }
}

.feature-card {
    background-color: #FFFFFF;
    border: 1px solid var(--border-color);
    padding: 1.5rem;
    border-radius: 6px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.01);
}

.feature-card h3 {
    margin-top: 0;
    color: var(--accent-color);
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.4rem;
}

.feature-card p {
    font-size: 0.95rem;
    margin-bottom: 0;
    color: var(--text-secondary);
}

/* Academic Tables */
.table-wrapper {
    overflow-x: auto;
    margin: 2rem 0;
}

.academic-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.95rem;
    margin-bottom: 0.5rem;
}

.academic-table th {
    border-top: 2px solid var(--text-primary);
    border-bottom: 1px solid var(--text-primary);
    padding: 10px 12px;
    font-weight: 600;
    text-align: left;
}

.academic-table td {
    border-bottom: 1px solid var(--border-color);
    padding: 10px 12px;
}

.academic-table tr:last-child td {
    border-bottom: 2px solid var(--text-primary);
}

.table-caption {
    font-size: 0.85rem;
    color: var(--text-secondary);
    text-align: center;
    margin-top: 0.5rem;
}

/* Code & BibTeX */
.citation-section {
    margin-top: 4rem;
}

.bibtex-wrapper {
    position: relative;
    background-color: var(--code-bg);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 1.2rem;
    margin-top: 1rem;
}

.bibtex-code {
    font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, Courier, monospace;
    font-size: 0.85rem;
    white-space: pre;
    overflow-x: auto;
    display: block;
    color: #292524;
}

.copy-btn {
    position: absolute;
    top: 10px;
    right: 10px;
    background-color: #FFFFFF;
    border: 1px solid var(--border-color);
    padding: 4px 8px;
    font-size: 0.75rem;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.2s;
    font-family: inherit;
    font-weight: 500;
}

.copy-btn:hover {
    background-color: var(--card-bg);
    border-color: var(--accent-color);
    color: var(--accent-color);
}

/* Footer */
footer {
    text-align: center;
    padding-top: 4rem;
    border-top: 1px solid var(--border-color);
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-top: 5rem;
}

footer p {
    text-align: center;
    margin-bottom: 0.5rem;
}