/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --accent-color: #e74c3c;
    --bg-color: #ecf0f1;
    --text-color: #333;
    --code-bg: #f4f4f4;
    --border-color: #ddd;
}

body {
    font-family: 'Noto Sans KR', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: #fff;
}

/* Header */
header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    padding: 2rem 0;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

header .container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

header h1 {
    font-size: 2rem;
    margin-bottom: 0.5rem;
    font-weight: 700;
}

header p {
    font-size: 1.1rem;
    opacity: 0.9;
}

/* Navigation */
nav {
    background-color: var(--primary-color);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

nav ul {
    list-style: none;
    display: flex;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

nav ul li {
    margin-right: 2rem;
}

nav ul li a {
    display: block;
    color: white;
    text-decoration: none;
    padding: 1rem 0;
    transition: color 0.3s;
    font-weight: 500;
}

nav ul li a:hover,
nav ul li a.active {
    color: var(--secondary-color);
    border-bottom: 3px solid var(--secondary-color);
}

/* Main Content */
main {
    max-width: 1200px;
    margin: 2rem auto;
    padding: 0 2rem;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* Paper Content */
.paper-content {
    background: white;
    padding: 3rem;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    margin-bottom: 2rem;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    color: var(--primary-color);
    margin-top: 2rem;
    margin-bottom: 1rem;
    font-weight: 700;
}

h1 {
    font-size: 2.5rem;
    border-bottom: 3px solid var(--secondary-color);
    padding-bottom: 0.5rem;
}

h2 {
    font-size: 2rem;
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 0.3rem;
}

h3 {
    font-size: 1.5rem;
    color: var(--secondary-color);
}

h4 {
    font-size: 1.2rem;
}

p {
    margin-bottom: 1rem;
    text-align: justify;
}

/* Links */
a {
    color: var(--secondary-color);
    text-decoration: none;
    transition: color 0.3s;
}

a:hover {
    color: var(--accent-color);
    text-decoration: underline;
}

/* Code Blocks */
pre {
    background-color: var(--code-bg);
    border: 1px solid var(--border-color);
    border-left: 4px solid var(--secondary-color);
    padding: 1rem;
    overflow-x: auto;
    border-radius: 4px;
    margin: 1rem 0;
    font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
    font-size: 0.9rem;
    line-height: 1.4;
}

code {
    background-color: var(--code-bg);
    padding: 0.2rem 0.4rem;
    border-radius: 3px;
    font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
    font-size: 0.9em;
}

pre code {
    background: none;
    padding: 0;
}

/* Tables */
table {
    width: 100%;
    border-collapse: collapse;
    margin: 1.5rem 0;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
}

table th,
table td {
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    text-align: left;
}

table th {
    background-color: var(--primary-color);
    color: white;
    font-weight: 600;
}

table tr:nth-child(even) {
    background-color: #f8f9fa;
}

table tr:hover {
    background-color: #e9ecef;
}

/* Lists */
ul, ol {
    margin-left: 2rem;
    margin-bottom: 1rem;
}

li {
    margin-bottom: 0.5rem;
}

/* Blockquotes */
blockquote {
    border-left: 4px solid var(--secondary-color);
    padding-left: 1rem;
    margin: 1rem 0;
    color: #555;
    font-style: italic;
    background-color: #f8f9fa;
    padding: 1rem 1rem 1rem 2rem;
    border-radius: 0 4px 4px 0;
}

/* Cards */
.card {
    background: white;
    border-radius: 8px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    transition: transform 0.3s, box-shadow 0.3s;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 20px rgba(0,0,0,0.1);
}

.card h3 {
    margin-top: 0;
    color: var(--secondary-color);
}

/* Badges */
.badge {
    display: inline-block;
    padding: 0.25rem 0.6rem;
    border-radius: 12px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-right: 0.5rem;
}

.badge-primary {
    background-color: var(--secondary-color);
    color: white;
}

.badge-success {
    background-color: #27ae60;
    color: white;
}

.badge-warning {
    background-color: #f39c12;
    color: white;
}

.badge-danger {
    background-color: var(--accent-color);
    color: white;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: 4px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s;
    cursor: pointer;
    border: none;
}

.btn-primary {
    background-color: var(--secondary-color);
    color: white;
}

.btn-primary:hover {
    background-color: #2980b9;
    transform: translateY(-2px);
    box-shadow: 0 4px 10px rgba(0,0,0,0.2);
}

/* Grid Layout */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin: 2rem 0;
}

/* Abstract Box */
.abstract {
    background-color: #f8f9fa;
    border-left: 5px solid var(--secondary-color);
    padding: 1.5rem;
    margin: 2rem 0;
    border-radius: 0 8px 8px 0;
}

.abstract h2 {
    margin-top: 0;
    color: var(--secondary-color);
}

/* Metadata */
.metadata {
    background-color: #ecf0f1;
    padding: 1rem;
    border-radius: 4px;
    margin: 1rem 0;
}

.metadata p {
    margin: 0.5rem 0;
}

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

/* Table of Contents */
.toc {
    background-color: #f8f9fa;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem;
    margin: 2rem 0;
}

.toc h2 {
    margin-top: 0;
    font-size: 1.3rem;
}

.toc ul {
    list-style: none;
    margin-left: 0;
}

.toc ul li {
    margin: 0.5rem 0;
}

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

.toc a:hover {
    color: var(--secondary-color);
}

/* Footer */
footer {
    background-color: var(--primary-color);
    color: white;
    text-align: center;
    padding: 2rem 0;
    margin-top: 4rem;
}

footer p {
    margin: 0.5rem 0;
}

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

/* Math Display */
.math {
    overflow-x: auto;
    margin: 1rem 0;
}

/* Responsive */
@media (max-width: 768px) {
    header h1 {
        font-size: 1.5rem;
    }

    nav ul {
        flex-direction: column;
        padding: 0;
    }

    nav ul li {
        margin: 0;
        border-bottom: 1px solid rgba(255,255,255,0.1);
    }

    nav ul li a {
        padding: 1rem 2rem;
    }

    .paper-content {
        padding: 1.5rem;
    }

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

    main {
        padding: 0 1rem;
    }
}

/* Syntax Highlighting (for code blocks) */
.keyword { color: #0077aa; font-weight: bold; }
.string { color: #669900; }
.comment { color: #999; font-style: italic; }
.number { color: #ff6600; }
.function { color: #9900cc; }

/* Print Styles */
@media print {
    nav, footer {
        display: none;
    }

    header {
        background: none;
        color: black;
    }

    .paper-content {
        box-shadow: none;
    }

    a {
        color: black;
        text-decoration: underline;
    }
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    animation: fadeIn 0.5s ease-in;
}

/* Highlight boxes */
.highlight-box {
    background-color: #fff3cd;
    border-left: 4px solid #ffc107;
    padding: 1rem;
    margin: 1rem 0;
    border-radius: 0 4px 4px 0;
}

.info-box {
    background-color: #d1ecf1;
    border-left: 4px solid #17a2b8;
    padding: 1rem;
    margin: 1rem 0;
    border-radius: 0 4px 4px 0;
}

.success-box {
    background-color: #d4edda;
    border-left: 4px solid #28a745;
    padding: 1rem;
    margin: 1rem 0;
    border-radius: 0 4px 4px 0;
}

.warning-box {
    background-color: #f8d7da;
    border-left: 4px solid #dc3545;
    padding: 1rem;
    margin: 1rem 0;
    border-radius: 0 4px 4px 0;
}