/* Global Styles */
:root {
    --primary-color: #1a2a44; /* Deep Navy */
    --accent-color: #c5a059; /* Gold */
    --text-dark: #333;
    --text-light: #666;
    --bg-light: #f9f9f9;
    --white: #ffffff;
}

body {
    font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: var(--bg-light);
    color: var(--text-dark);
    line-height: 1.6;
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
}

a {
    text-decoration: none;
    color: inherit;
    transition: color 0.3s;
}

/* Navbar */
.navbar {
    background-color: var(--primary-color);
    color: var(--white);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--accent-color);
}

.nav-links {
    list-style: none;
    display: flex;
    gap: 20px;
}

.nav-links a {
    color: var(--white);
    font-weight: 500;
}

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

/* Hero Section */
.proceedings-hero {
    background: linear-gradient(rgba(26, 42, 68, 0.9), rgba(26, 42, 68, 0.9)), url('conference-bg.jpg') center/cover;
    color: var(--white);
    text-align: center;
    padding: 4rem 0;
}

.proceedings-hero h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.isbn {
    font-family: monospace;
    margin-top: 10px;
    color: #ddd;
}

.btn-download {
    display: inline-block;
    background-color: var(--accent-color);
    color: var(--primary-color);
    padding: 12px 25px;
    border-radius: 5px;
    font-weight: bold;
    margin-top: 20px;
    border: 2px solid var(--accent-color);
}

.btn-download:hover {
    background-color: transparent;
    color: var(--accent-color);
}

/* Search Section */
.search-section {
    padding: 2rem 0;
    background-color: #fff;
    border-bottom: 1px solid #eee;
}

#searchInput {
    width: 100%;
    padding: 15px;
    font-size: 1rem;
    border: 1px solid #ddd;
    border-radius: 5px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
}

/* Papers Grid */
.papers-list {
    padding: 3rem 0;
}

.papers-list h2 {
    text-align: center;
    margin-bottom: 2rem;
    color: var(--primary-color);
}

.paper-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
}

.paper-card {
    background: var(--white);
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    border: 1px solid #eee;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.page-number {
    font-size: 0.8rem;
    color: var(--accent-color);
    font-weight: bold;
    text-transform: uppercase;
    margin-bottom: 5px;
}

.paper-card h3 {
    font-size: 1.1rem;
    margin: 10px 0;
    line-height: 1.4;
}

.paper-card h3 a:hover {
    color: var(--primary-color);
    text-decoration: underline;
}

.authors {
    color: var(--text-light);
    font-size: 0.9rem;
    margin-bottom: 15px;
    font-style: italic;
}

.card-actions {
    display: flex;
    gap: 10px;
    margin-top: auto;
}

.btn-view, .btn-pdf-link {
    font-size: 0.85rem;
    padding: 8px 12px;
    border-radius: 4px;
    text-align: center;
    flex: 1;
}

.btn-view {
    background-color: #f0f0f0;
    color: var(--text-dark);
}

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

.btn-pdf-link:hover {
    background-color: var(--accent-color);
    color: var(--primary-color);
}

/* Paper Detail Styling */
.paper-detail-container {
    padding: 4rem 0;
    background: var(--white);
    margin-top: 2rem;
    margin-bottom: 2rem;
    box-shadow: 0 0 20px rgba(0,0,0,0.05);
    border-radius: 8px;
}

.paper-header {
    padding: 0 2rem;
    border-bottom: 1px solid #eee;
    margin-bottom: 2rem;
}

.paper-abstract {
    padding: 0 2rem;
    margin-bottom: 2rem;
}

.paper-actions {
    padding: 0 2rem;
    text-align: center;
}

footer {
    background-color: var(--primary-color);
    color: #ccc;
    text-align: center;
    padding: 2rem 0;
    margin-top: 3rem;
}