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

body {
    font-family: 'Georgia', serif;
    line-height: 1.8;
    color: #2c3e50;
    background: #f8f9fa;
}

.header {
    background: linear-gradient(135deg, #1e3c72 0%, #2a5298 100%);
    color: white;
    padding: 3rem 2rem 2rem 2rem;
    text-align: center;
}

.header h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    font-weight: 300;
}

.header .subtitle {
    font-size: 1.1rem;
    opacity: 0.95;
    font-style: italic;
}

.nav {
    background: white;
    padding: 1rem;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav .container {
    max-width: 900px;
    margin: 0 auto;
}

.nav-title {
    font-size: 1.3rem;
    font-weight: 700;
    color: #1e3c72;
    margin-bottom: 0.5rem;
    display: inline-block;
    text-decoration: none;
}

.nav-links {
    display: flex;
    gap: 2rem;
    flex-wrap: wrap;
    justify-content: center;
}

.nav-links a {
    color: #2c3e50;
    text-decoration: none;
    font-weight: 600;
    transition: color 0.2s;
}

.nav-links a:hover,
.nav-links a.active {
    color: #2a5298;
}

.nav-inner {
    max-width: 900px;
    margin: 0 auto;
    display: flex;
    gap: 2rem;
    flex-wrap: wrap;
    justify-content: center;
}

.nav a {
    color: #2c3e50;
    text-decoration: none;
    font-weight: 600;
    transition: color 0.2s;
}

.nav a:hover {
    color: #2a5298;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 3rem 2rem;
}

.paper-header {
    background: white;
    padding: 3rem 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    margin-bottom: 2rem;
    text-align: center;
}

.paper-header h1 {
    color: #1e3c72;
    font-size: 2.2rem;
    margin-bottom: 1rem;
}

.paper-header .lead {
    font-size: 1.2rem;
    color: #6c757d;
    font-style: italic;
}

.paper-meta {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    margin-bottom: 2rem;
}

.paper-meta p {
    margin: 0.5rem 0;
}

.paper-section {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    margin-bottom: 2rem;
}

.paper-section h2 {
    margin: 0 0 2rem 0;
    color: #1e3c72;
    font-size: 1.8rem;
    border-bottom: 2px solid #e9ecef;
    padding-bottom: 0.5rem;
}

.paper-section h3 {
    margin: 2rem 0 1rem 0;
    color: #2a5298;
    font-size: 1.4rem;
}

.paper-section p {
    margin: 1.2rem 0;
}

.paper-section ul {
    margin: 1rem 0 1rem 2rem;
}

.paper-section li {
    margin: 0.5rem 0;
}

.faq-item {
    margin-bottom: 2.5rem;
}

.faq-item h3 {
    color: #2563eb;
    margin-bottom: 1rem;
    font-size: 1.3rem;
}

.faq-item p {
    margin-bottom: 1rem;
}

.faq-item ul {
    margin-left: 2rem;
    margin-bottom: 1rem;
}

.faq-item li {
    margin-bottom: 0.5rem;
}

.faq-item a {
    color: #2563eb;
    text-decoration: none;
}

.faq-item a:hover {
    text-decoration: underline;
}

.versions {
    background: #fff3cd;
    padding: 1.5rem;
    border-radius: 8px;
    border-left: 4px solid #ffc107;
    margin: 2rem 0;
}

.versions h3 {
    margin-bottom: 1rem;
    color: #856404;
}

.versions a {
    color: #856404;
    text-decoration: underline;
    margin-right: 1rem;
}

.related {
    background: #d1ecf1;
    padding: 1.5rem;
    border-radius: 8px;
    border-left: 4px solid #17a2b8;
    margin: 2rem 0;
}

.related h3 {
    margin-bottom: 1rem;
    color: #0c5460;
}

.related a {
    color: #0c5460;
    display: block;
    margin: 0.5rem 0;
}

.paper-content {
    background: white;
    padding: 3rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.paper-content h2 {
    margin: 2.5rem 0 1rem 0;
    color: #1e3c72;
    font-size: 1.8rem;
    border-bottom: 2px solid #e9ecef;
    padding-bottom: 0.5rem;
}

.paper-content h3 {
    margin: 2rem 0 1rem 0;
    color: #2a5298;
    font-size: 1.4rem;
}

.paper-content p {
    margin: 1.2rem 0;
    text-align: justify;
}

.paper-content strong {
    color: #1e3c72;
}

.paper-content em {
    color: #495057;
}

.paper-content hr {
    margin: 2rem 0;
    border: none;
    border-top: 1px solid #dee2e6;
}

.footer {
    text-align: center;
    padding: 2rem;
    color: #6c757d;
    font-size: 0.9rem;
    background: white;
    margin-top: 3rem;
}

footer {
    text-align: center;
    padding: 2rem;
    color: #6c757d;
    font-size: 0.9rem;
}

@media (max-width: 768px) {
    .header h1 {
        font-size: 1.8rem;
    }

    .paper-content {
        padding: 1.5rem;
    }

    .container {
        padding: 1.5rem 1rem;
    }

    .nav-links {
        gap: 1rem;
    }

    .paper-header h1 {
        font-size: 1.6rem;
    }
}