/* Modern Website Styles for P.H. Handel Research Archive */

:root {
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --accent-color: #e74c3c;
    --text-color: #333;
    --light-bg: #ecf0f1;
    --white: #ffffff;
    --shadow: rgba(0, 0, 0, 0.1);
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--light-bg);
}

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

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

h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    font-weight: 300;
}

.subtitle {
    font-size: 1.2rem;
    opacity: 0.9;
    font-weight: 300;
}

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

.nav-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-links a {
    color: var(--primary-color);
    text-decoration: none;
    margin-left: 2rem;
    font-weight: 500;
    transition: color 0.3s;
}

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

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

.intro {
    background-color: var(--white);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 10px var(--shadow);
    margin-bottom: 3rem;
}

.intro h2 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

/* Focus Areas Grid */
.focus-areas {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.focus-card {
    background-color: var(--white);
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 4px 15px var(--shadow);
    transition: transform 0.3s, box-shadow 0.3s;
    cursor: pointer;
    text-decoration: none;
    color: var(--text-color);
    display: block;
}

.focus-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.focus-image {
    width: 100%;
    height: 250px;
    object-fit: cover;
    background: linear-gradient(135deg, var(--secondary-color) 0%, var(--primary-color) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-size: 4rem;
}

.focus-content {
    padding: 1.5rem;
}

.focus-content h3 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
    font-size: 1.5rem;
}

.focus-content p {
    color: #666;
    line-height: 1.6;
}

.paper-count {
    display: inline-block;
    margin-top: 0.5rem;
    padding: 0.3rem 0.8rem;
    background-color: var(--secondary-color);
    color: var(--white);
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 500;
}

/* Paper List Page */
.back-link {
    display: inline-block;
    margin-bottom: 2rem;
    color: var(--secondary-color);
    text-decoration: none;
    font-weight: 500;
}

.back-link:hover {
    text-decoration: underline;
}

.focus-header {
    background-color: var(--white);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 10px var(--shadow);
    margin-bottom: 2rem;
}

.focus-header h2 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.focus-description {
    line-height: 1.8;
    color: #555;
}

.papers-list {
    background-color: var(--white);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 10px var(--shadow);
}

.papers-list h3 {
    color: var(--primary-color);
    margin-bottom: 1.5rem;
    font-size: 1.8rem;
}

.paper-item {
    padding: 1.5rem;
    border-bottom: 1px solid #e0e0e0;
    transition: background-color 0.3s;
}

.paper-item:last-child {
    border-bottom: none;
}

.paper-item:hover {
    background-color: #f8f9fa;
}

.paper-number {
    display: inline-block;
    background-color: var(--secondary-color);
    color: var(--white);
    padding: 0.3rem 0.8rem;
    border-radius: 4px;
    font-weight: 600;
    margin-right: 0.5rem;
    font-size: 0.9rem;
}

.paper-title {
    color: var(--primary-color);
    font-size: 1.1rem;
    font-weight: 600;
    margin: 0.5rem 0;
}

.paper-authors {
    color: #666;
    font-style: italic;
    margin: 0.3rem 0;
}

.paper-venue {
    color: #888;
    font-size: 0.95rem;
    margin: 0.3rem 0;
}

.paper-links {
    margin-top: 0.5rem;
}

.paper-link {
    display: inline-block;
    margin-right: 1rem;
    padding: 0.4rem 1rem;
    background-color: var(--secondary-color);
    color: var(--white);
    text-decoration: none;
    border-radius: 4px;
    font-size: 0.9rem;
    transition: background-color 0.3s;
}

.paper-link:hover {
    background-color: var(--primary-color);
}

.summary-link {
    background-color: #95a5a6;
}

.summary-link:hover {
    background-color: #7f8c8d;
}

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

footer p {
    opacity: 0.9;
}

/* Responsive Design */
@media (max-width: 768px) {
    h1 {
        font-size: 2rem;
    }

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

    .nav-content {
        flex-direction: column;
        gap: 1rem;
    }

    .nav-links {
        display: flex;
        flex-direction: column;
        gap: 0.5rem;
        text-align: center;
    }

    .nav-links a {
        margin-left: 0;
    }
}

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

.focus-card, .paper-item {
    animation: fadeIn 0.5s ease-out;
}