/* ===== Academia Research Blog Style ===== */
/* Inspired by pi.website minimal design */

:root {
    --color-bg: #ffffff;
    --color-text: #1a1a1a;
    --color-text-secondary: #666666;
    --color-text-muted: #999999;
    --color-link: #0066cc;
    --color-link-hover: #004499;
    --color-border: #e5e5e5;
    --color-code-bg: #f5f5f5;
    --color-accent: #2563eb;

    --font-serif: 'Source Serif 4', Georgia, 'Times New Roman', serif;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', Consolas, monospace;

    --max-width: 720px;
    --spacing-unit: 1.5rem;
}

/* Reset */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 18px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-serif);
    font-size: 1rem;
    line-height: 1.7;
    color: var(--color-text);
    background: var(--color-bg);
    -webkit-font-smoothing: antialiased;
}

/* ===== Navigation ===== */
.navbar {
    position: sticky;
    top: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(8px);
    border-bottom: 1px solid var(--color-border);
    z-index: 100;
}

.nav-container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-family: var(--font-sans);
    font-weight: 600;
    font-size: 1.1rem;
    color: var(--color-text);
    text-decoration: none;
}

.nav-logo-img {
    width: 32px;
    height: 32px;
    border-radius: 6px;
    object-fit: cover;
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-links a {
    font-family: var(--font-sans);
    font-size: 0.9rem;
    color: var(--color-text-secondary);
    text-decoration: none;
    transition: color 0.2s;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--color-text);
}

/* ===== Main Content ===== */
.main {
    padding: 3rem 2rem 5rem;
}

.article {
    max-width: var(--max-width);
    margin: 0 auto;
}

/* ===== Article Header ===== */
.article-header {
    margin-bottom: 2.5rem;
}

.article-header h1 {
    font-family: var(--font-serif);
    font-size: 2.4rem;
    font-weight: 700;
    line-height: 1.2;
    color: var(--color-text);
    margin-bottom: 1.5rem;
    letter-spacing: -0.02em;
}

.article-meta {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.pdf-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-family: var(--font-sans);
    font-size: 0.9rem;
    color: var(--color-link);
    text-decoration: none;
    padding: 0.5rem 1rem;
    background: #f0f7ff;
    border-radius: 6px;
    transition: background 0.2s;
}

.pdf-link:hover {
    background: #e0efff;
}

/* ===== Badges Section ===== */
.badges-container {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin-top: 1.5rem;
    justify-content: center;
}

.badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-family: var(--font-sans);
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--color-text);
    text-decoration: none;
    padding: 0.55rem 1.1rem;
    background: var(--color-code-bg);
    border: 1px solid var(--color-border);
    border-radius: 6px;
    transition: all 0.2s;
}

.badge:hover {
    background: #ffffff;
    border-color: var(--color-accent);
    color: var(--color-accent);
    box-shadow: 0 2px 8px rgba(37, 99, 235, 0.1);
    transform: translateY(-1px);
}

.badge-disabled {
    opacity: 0.5;
    cursor: not-allowed;
    pointer-events: none;
}

.badge svg {
    flex-shrink: 0;
}

/* ===== Hero Figure ===== */
.hero-figure {
    margin: 2rem 0 3rem;
}

.hero-image {
    width: 100%;
    border-radius: 8px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

/* ===== Content Sections ===== */
.content-section {
    margin-bottom: 3rem;
}

.content-section h2 {
    font-family: var(--font-serif);
    font-size: 1.6rem;
    font-weight: 600;
    margin-bottom: 1.25rem;
    padding-top: 1rem;
    color: var(--color-text);
}

.content-section p {
    margin-bottom: 1.25rem;
}

.content-section p.lead {
    font-size: 1.15rem;
    line-height: 1.8;
    color: var(--color-text);
}

.content-section a {
    color: var(--color-link);
    text-decoration: underline;
    text-underline-offset: 2px;
}

.content-section a:hover {
    color: var(--color-link-hover);
}

.content-section strong {
    font-weight: 600;
}

.content-section em {
    font-style: italic;
}

/* ===== Stats Section ===== */
.stats-section {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1rem;
    margin: 2.5rem 0;
    padding: 1.5rem 0;
    border-top: 1px solid var(--color-border);
    border-bottom: 1px solid var(--color-border);
}

.stat-item {
    text-align: center;
}

.stat-number {
    display: block;
    font-family: var(--font-sans);
    font-size: 2.2rem;
    font-weight: 700;
    color: var(--color-accent);
    line-height: 1;
}

.stat-label {
    display: block;
    font-family: var(--font-sans);
    font-size: 0.8rem;
    color: var(--color-text-secondary);
    margin-top: 0.5rem;
}

/* ===== Info Cards ===== */
.info-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
    margin: 2rem 0;
}

.info-card {
    background: var(--color-code-bg);
    border-radius: 8px;
    padding: 1.5rem;
}

.info-card-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
}

.info-icon {
    width: 40px;
    height: 40px;
    border-radius: 6px;
}

.info-card h3 {
    font-family: var(--font-sans);
    font-size: 1rem;
    font-weight: 600;
}

.info-card ul {
    list-style: none;
    font-family: var(--font-sans);
    font-size: 0.9rem;
    line-height: 1.8;
}

.info-card li {
    color: var(--color-text-secondary);
}

/* ===== Feature List ===== */
.feature-list {
    list-style: none;
    margin: 1.5rem 0;
}

.feature-list li {
    position: relative;
    padding-left: 1.5rem;
    margin-bottom: 0.75rem;
}

.feature-list li::before {
    content: "•";
    position: absolute;
    left: 0;
    color: var(--color-accent);
    font-weight: bold;
}

/* ===== Content Figures ===== */
.content-figure {
    margin: 2rem 0;
}

.content-figure img {
    width: 100%;
    border-radius: 6px;
    border: 1px solid var(--color-border);
}

.content-figure figcaption {
    font-family: var(--font-sans);
    font-size: 0.85rem;
    color: var(--color-text-muted);
    text-align: center;
    margin-top: 0.75rem;
}

/* ===== Code Blocks ===== */
.code-block {
    background: #1e1e1e;
    color: #d4d4d4;
    border-radius: 8px;
    padding: 1.5rem;
    overflow-x: auto;
    font-family: var(--font-mono);
    font-size: 0.85rem;
    line-height: 1.6;
    margin: 1.5rem 0;
}

.code-block .comment {
    color: #6a9955;
}

.code-block.bibtex {
    background: var(--color-code-bg);
    color: var(--color-text);
}

/* ===== Citation Section ===== */
.citation-section {
    padding-top: 2rem;
    border-top: 1px solid var(--color-border);
}

/* ===== Footer ===== */
.footer {
    border-top: 1px solid var(--color-border);
    padding: 2rem;
}

.footer-container {
    max-width: var(--max-width);
    margin: 0 auto;
    text-align: center;
}

.footer p {
    font-family: var(--font-sans);
    font-size: 0.85rem;
    color: var(--color-text-muted);
}

.footer a {
    color: var(--color-text-secondary);
    text-decoration: none;
}

.footer a:hover {
    color: var(--color-text);
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
    html {
        font-size: 16px;
    }

    .nav-container {
        padding: 0.75rem 1.5rem;
    }

    .nav-links {
        gap: 1.25rem;
    }

    .main {
        padding: 2rem 1.5rem 4rem;
    }

    .article-header h1 {
        font-size: 1.8rem;
    }

    .stats-section {
        grid-template-columns: repeat(2, 1fr);
        gap: 1.5rem;
    }

    .info-grid {
        grid-template-columns: 1fr;
    }

    .stat-number {
        font-size: 1.8rem;
    }
}

@media (max-width: 480px) {
    .nav-links {
        gap: 1rem;
        font-size: 0.8rem;
    }

    .article-header h1 {
        font-size: 1.5rem;
    }

    .content-section h2 {
        font-size: 1.3rem;
    }

    .code-block {
        padding: 1rem;
        font-size: 0.75rem;
    }
}