/* Base Styles */
:root {
    --primary-color: #3498db;
    --secondary-color: #2c3e50;
    --accent-color: #e74c3c;
    --light-color: #ecf0f1;
    --dark-color: #2c3e50;
    --text-color: #333;
    --text-light: #7f8c8d;
    --font-primary: 'Lato', sans-serif;
    --font-secondary: 'Playfair Display', serif;
    --transition: all 0.3s ease;
    --shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 8px 25px rgba(0, 0, 0, 0.15);
}

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

body {
    font-family: var(--font-primary);
    color: var(--text-color);
    line-height: 1.6;
    overflow-x: hidden;
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

section {
    padding: 80px 0;
}

.section-title {
    font-family: var(--font-secondary);
    font-size: 2.5rem;
    margin-bottom: 50px;
    text-align: center;
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 80px;
    height: 4px;
    background: var(--primary-color);
    margin: 15px auto;
}

.btn {
    display: inline-block;
    padding: 12px 30px;
    border-radius: 30px;
    text-decoration: none;
    font-weight: 700;
    transition: var(--transition);
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

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

.btn-primary:hover {
    background: #2980b9;
    transform: translateY(-3px);
    box-shadow: var(--shadow-hover);
}

.btn-secondary {
    background: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.btn-secondary:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-3px);
    box-shadow: var(--shadow-hover);
}

.highlight {
    color: var(--primary-color);
    font-weight: 700;
}

/* Header Styles */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background: white;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    transition: var(--transition);
}

.header.scrolled {
    padding: 10px 0;
    background: rgba(255, 255, 255, 0.95);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 0;
}

.logo {
    font-family: var(--font-secondary);
    font-size: 1.8rem;
    color: var(--dark-color);
    font-weight: 700;
}

.logo a {
    text-decoration: none;
    font-family: var(--font-secondary);
    font-size: 1.8rem;
    color: var(--dark-color);
    font-weight: 700;
}

.nav ul {
    display: flex;
    list-style: none;
}

.nav ul li {
    margin-left: 30px;
}

.nav ul li a {
    text-decoration: none;
    color: var(--dark-color);
    font-weight: 700;
    transition: var(--transition);
    position: relative;
}

.nav ul li a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: var(--transition);
}

.nav ul li a:hover::after {
    width: 100%;
}

.nav ul li a:hover {
    color: var(--primary-color);
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--dark-color);
    cursor: pointer;
}

/* Hero Section */
.hero {
    padding: 150px 0 100px;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
}

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

.hero-text {
    flex: 1;
    padding-right: 50px;
}

.hero-text h2 {
    font-family: var(--font-secondary);
    font-size: 3rem;
    margin-bottom: 20px;
    line-height: 1.2;
}

.hero-text p {
    font-size: 1.2rem;
    color: var(--text-light);
    margin-bottom: 30px;
}

.hero-btns {
    display: flex;
    gap: 20px;
}

.hero-image {
    position: relative;
    flex: 1;
    display: flex;
    justify-content: center;
}

.profile-img {
    /* width: 350px;
    height: 350px; */
    width: 250px;
    height: auto;
    object-fit: cover;
    border-radius: 50%;
    border: 10px solid white;
    box-shadow: var(--shadow);
    z-index: 2;
    position: relative;
}

.decoration-circle {
    position: absolute;
    width: 400px;
    /* height: 400px; */
    height: auto;
    border-radius: 50%;
    background: var(--primary-color);
    opacity: 0.1;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

/* About Section */
.about-content {
    display: flex;
    gap: 50px;
}

.about-text {
    flex: 1;
}

.about-text p {
    margin-bottom: 20px;
}

.education h3 {
    font-family: var(--font-secondary);
    margin: 30px 0 15px;
    font-size: 1.5rem;
}

.education ul {
    list-style: none;
}

.education ul li {
    margin-bottom: 15px;
    padding-left: 25px;
    position: relative;
}

.education ul li::before {
    content: '▹';
    position: absolute;
    left: 0;
    color: var(--primary-color);
}

.education ul li strong {
    display: block;
    margin-bottom: 5px;
}

.education ul li span {
    color: var(--text-light);
    font-size: 0.9rem;
}

.skills {
    flex: 1;
}

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 30px;
}

.skill-tag {
    background: var(--light-color);
    padding: 5px 15px;
    border-radius: 20px;
    font-size: 0.9rem;
    transition: var(--transition);
}

.skill-tag:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-3px);
}

.skill-bars {
    margin-top: 20px;
}

.skill-bar {
    margin-bottom: 20px;
}

.skill-bar label {
    display: block;
    margin-bottom: 5px;
    font-weight: 700;
}

.bar-container {
    width: 100%;
    height: 10px;
    background: var(--light-color);
    border-radius: 5px;
    overflow: hidden;
}

.bar {
    height: 100%;
    background: var(--primary-color);
    border-radius: 5px;
    position: relative;
    transition: width 1.5s ease;
}

.bar::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    animation: shine 2s infinite;
}

@keyframes shine {
    0% {
        transform: translateX(-100%);
    }
    100% {
        transform: translateX(100%);
    }
}

/* Research Section */
.research {
    background: #f9f9f9;
}

.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 30px;
}

.research-card {
    background: white;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.research-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-hover);
}

.research-image {
    position: relative;
    height: 200px;
    overflow: hidden;
}

.research-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
}

.research-card:hover .research-image img {
    transform: scale(1.1);
}

.research-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: var(--transition);
}

.research-card:hover .research-overlay {
    opacity: 1;
}

.research-link {
    color: white;
    text-decoration: none;
    font-weight: 700;
    padding: 10px 20px;
    border: 2px solid white;
    border-radius: 30px;
    transition: var(--transition);
}

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

.research-content {
    padding: 20px;
}

.research-content h3 {
    font-family: var(--font-secondary);
    margin-bottom: 10px;
    font-size: 1.3rem;
}

.research-content p {
    color: var(--text-light);
    margin-bottom: 15px;
    font-size: 0.95rem;
}

.research-meta {
    display: flex;
    justify-content: space-between;
    font-size: 0.85rem;
    color: var(--text-light);
}

.research-year {
    font-weight: 700;
}

.research-funding {
    background: var(--light-color);
    padding: 3px 10px;
    border-radius: 20px;
}

/* Publications Section */
.publication-filters {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-bottom: 30px;
    flex-wrap: wrap;
}

.filter-btn {
    padding: 8px 20px;
    border-radius: 20px;
    background: var(--light-color);
    border: none;
    cursor: pointer;
    transition: var(--transition);
    font-weight: 700;
    font-size: 0.9rem;
}

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

.filter-btn:hover:not(.active) {
    background: #d6dbdf;
}

.publication-list {
    display: grid;
    gap: 20px;
}

.publication-item {
    background: white;
    border-radius: 8px;
    padding: 20px;
    box-shadow: var(--shadow);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
    opacity: 1; /* Fully visible */
    transform: scale(1); /* Normal size */
    transition: opacity 0.3s ease, transform 0.3s ease; /* Smooth transition */
}

.publication-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}


/* Hidden state for filtered items */
.publication-item.hidden {
    opacity: 0; /* Fade out */
    transform: scale(0.95); /* Slightly shrink */
    pointer-events: none; /* Disable interactions */
}


.publication-badge {
    position: absolute;
    top: 0;
    right: 0;
    padding: 5px 15px;
    border-bottom-left-radius: 8px;
    color: white;
    font-size: 0.8rem;
    font-weight: 700;
    display: inline-block; /* Ensure the badge is treated as an inline block */
    margin-bottom: 10px; /* Add spacing below the badge */
}

/* Responsive fix for mobile screens */
@media (max-width: 768px) {
    .publication-badge {
        margin-bottom: 15px; /* Increase spacing for smaller screens */
    }

    .publication-content h3 {
        font-size: 1rem; /* Reduce font size for smaller screens */
    }
}

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

.conference-badge {
    background: #27ae60;
}

.workshop-badge {
    background: #f39c12;
}

.publication-content {
    padding-right: 80px;
}

.publication-content h3 {
    font-family: var(--font-secondary);
    margin-bottom: 10px;
    font-size: 1.2rem;
    margin-top: 15px; 
}

.publication-authors {
    font-style: italic;
    color: var(--text-light);
    margin-bottom: 5px;
    font-size: 0.95rem;
}

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

.publication-actions {
    display: flex;
    gap: 15px;
}

.publication-link {
    color: var(--primary-color);
    text-decoration: none;
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 5px;
    transition: var(--transition);
}

.publication-link:hover {
    color: var(--dark-color);
}

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

.publication-more {
    text-align: center;
    margin-top: 40px;
}

/* Contact Section */
.contact {
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
}

.contact-content {
    display: flex;
    gap: 50px;
}

.contact-info {
    flex: 1;
}

.contact-card {
    background: white;
    padding: 30px;
    border-radius: 10px;
    margin-bottom: 20px;
    box-shadow: var(--shadow);
    text-align: center;
    transition: var(--transition);
}

.contact-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.contact-card i {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 15px;
}

.contact-card h3 {
    font-family: var(--font-secondary);
    margin-bottom: 10px;
}

.contact-card p {
    color: var(--text-light);
}

.social-links {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-top: 30px;
}

.social-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: white;
    color: var(--primary-color);
    font-size: 1.2rem;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.social-link:hover {
    /* background: var(--primary-color); */
    color: white;
    transform: translateY(-5px);
}

.contact-form {
    flex: 1;
    background: white;
    padding: 30px;
    border-radius: 10px;
    box-shadow: var(--shadow);
}

.form-group {
    margin-bottom: 20px;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-family: var(--font-primary);
    transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.2);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

/* Footer */
.footer {
    background: var(--dark-color);
    color: white;
    padding: 30px 0;
}

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

.footer-links {
    display: flex;
    gap: 20px;
}

.footer-links a {
    color: white;
    text-decoration: none;
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--primary-color);
}

/* Responsive Styles */
@media (max-width: 992px) {
    .hero-content {
        flex-direction: column;
    }

    .hero-text {
        padding-right: 0;
        margin-bottom: 50px;
        text-align: center;
    }

    .hero-btns {
        justify-content: center;
    }

    .about-content {
        flex-direction: column;
    }

    .contact-content {
        flex-direction: column;
    }
}

@media (max-width: 768px) {
    .nav {
        position: fixed;
        top: 80px;
        left: 0;
        width: 100%;
        background: white;
        box-shadow: 0 5px 10px rgba(0, 0, 0, 0.1);
        padding: 20px;
        transform: translateY(-150%);
        transition: var(--transition);
        opacity: 0;
    }

    .nav.active {
        transform: translateY(0);
        opacity: 1;
    }

    .nav ul {
        flex-direction: column;
    }

    .nav ul li {
        margin: 10px 0;
    }

    .mobile-menu-btn {
        display: block;
    }

    .section-title {
        font-size: 2rem;
    }

    .hero-text h2 {
        font-size: 2.2rem;
    }

    .profile-img {
        width: 250px;
        height: 250px;
    }

    .decoration-circle {
        width: 300px;
        height: 300px;
    }
}

@media (max-width: 576px) {
    .hero-btns {
        flex-direction: column;
        gap: 15px;
    }

    .btn {
        width: 100%;
        text-align: center;
    }

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

    .publication-filters {
        gap: 10px;
    }

    .publication-content {
        padding-right: 0;
    }

    .publication-actions {
        flex-wrap: wrap;
    }

    .footer-content {
        flex-direction: column;
        gap: 20px;
        text-align: center;
    }

}

.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgba(0, 0, 0, 0.5);
}

.modal-content {
    background-color: #fff;
    margin: 15% auto;
    padding: 20px;
    border: 1px solid #888;
    width: 80%;
    max-width: 500px;
    border-radius: 8px;
    text-align: center;
}

.close-btn {
    color: #aaa;
    float: right;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
}

.close-btn:hover,
.close-btn:focus {
    color: #000;
    text-decoration: none;
}
.citation-text {
    background: #f4f4f4;
    padding: 10px;
    border-radius: 5px;
    font-family: monospace;
    margin-top: 10px;
    white-space: pre-wrap;
    word-wrap: break-word;
}

.fa-cv::before {
  content: "CV";
  font-weight: bold;
  font-family: Arial, sans-serif; /* 원하는 폰트 */
  font-size: 0.8em;
}