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

:root {
    --primary-color: #2c5530;
    --secondary-color: #4a7c59;
    --accent-color: #8b9a46;
    --text-primary: #2c2c2c;
    --text-secondary: #666666;
    --background: #f8f9fa;
    --surface: #ffffff;
    --border: #e9ecef;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --gradient: linear-gradient(135deg, #2c5530 0%, #4a7c59 50%, #8b9a46 100%);
}

body {
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--background);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header Styles */
.header {
    background: var(--gradient);
    color: white;
    padding: 1rem 0;
    box-shadow: var(--shadow);
}

.header-content {
    display: flex;
    justify-content: center;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo i {
    font-size: 2rem;
    color: var(--accent-color);
}

.logo h1 {
    font-size: 1.5rem;
    font-weight: 600;
}

/* Hero Section */
.hero {
    background: var(--gradient);
    color: white;
    padding: 3rem 0;
    text-align: center;
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.hero-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.hero-subtitle {
    font-size: 1.1rem;
    opacity: 0.9;
}

/* References Section */
.references-section {
    padding: 3rem 0;
    background-color: var(--surface);
}

.section-header {
    text-align: center;
    margin-bottom: 2rem;
}

.section-header h2 {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

/* References List */
.references-list {
    max-width: 900px;
    margin: 0 auto;
}

.reference-item {
    background-color: var(--surface);
    border-radius: 8px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow);
    border-left: 4px solid var(--secondary-color);
    transition: all 0.3s ease;
}

.reference-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
    border-left-color: var(--accent-color);
}

.reference-title {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
    line-height: 1.4;
}

.reference-authors {
    color: var(--secondary-color);
    font-weight: 500;
    margin-bottom: 0.5rem;
}

.reference-journal {
    color: var(--text-secondary);
    font-style: italic;
    margin-bottom: 0.5rem;
}

.reference-year {
    display: inline-block;
    background-color: var(--accent-color);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 15px;
    font-size: 0.8rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.reference-doi {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}

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

.reference-doi a:hover {
    text-decoration: underline;
}

.reference-description {
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.5;
    margin-bottom: 1rem;
    font-style: italic;
}

.reference-link {
    display: flex;
    justify-content: flex-end;
}

.link-btn {
    background-color: var(--secondary-color);
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.link-btn:hover {
    background-color: var(--primary-color);
    transform: translateY(-1px);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.link-btn i {
    font-size: 0.8rem;
}

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

.footer-content p {
    opacity: 0.8;
}

/* Responsive Design */
@media (max-width: 768px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .section-header h2 {
        font-size: 1.8rem;
    }
    
    .reference-item {
        padding: 1rem;
    }
    
    .reference-title {
        font-size: 1rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }
    
    .hero-title {
        font-size: 1.8rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .logo h1 {
        font-size: 1.3rem;
    }
    
    .reference-item {
        padding: 1rem;
        margin-bottom: 1rem;
    }
}