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

:root {
    --primary: #3b82f6;
    --primary-light: #60a5fa;
    --accent: #10b981;
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-hover: #f3f4f6;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --text-muted: #9ca3af;
    --border: #e5e7eb;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--bg-primary);
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
header {
    padding: 60px 0 40px;
    border-bottom: 1px solid var(--border);
}

.header-content {
    display: flex;
    align-items: center;
    gap: 40px;
}

.profile-photo {
    flex-shrink: 0;
    width: 150px;
    height: 150px;
    border-radius: 50%;
    overflow: hidden;
    border: 3px solid var(--border);
}

.profile-photo img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.header-text {
    flex: 1;
}

header h1 {
    font-size: 2.5rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
}

header .subtitle {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 20px;
}

/* Navigation */
nav {
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(10px);
    background: rgba(255, 255, 255, 0.95);
}

nav .container {
    display: flex;
    gap: 40px;
    padding: 0 20px;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
}

nav a {
    padding: 16px 0;
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    border-bottom: 2px solid transparent;
    transition: all 0.2s ease;
    font-size: 0.95rem;
    white-space: nowrap;
}

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

nav a.active {
    color: var(--primary);
    border-bottom-color: var(--primary);
}

/* Main Content */
main {
    padding: 50px 0 80px;
}

section {
    margin-top: 10px;
    margin-bottom: 20px;
}

h2 {
    font-size: 1.75rem;
    margin-bottom: 30px;
    color: var(--text-primary);
    font-weight: 600;
}

/* About Section */
.about-content ul {
    color: var(--text-secondary);
    font-size: 1rem;
    line-height: 1.7;
    margin-bottom: 15px;
}

.about-content a {
    color: var(--primary);
    text-decoration: none;
    font-size: 0.95rem;
    transition: color 0.2s ease;
}


.links {
    margin-top: 25px;
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
}

.links a {
    color: var(--primary);
    text-decoration: none;
    font-size: 0.95rem;
    transition: color 0.2s ease;
}

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

/* Research Interests */
.interests {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 20px;
}

.interest-tag {
    padding: 6px 14px;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 4px;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

/* Topic Filter */
.filter-tabs {
    display: flex;
    gap: 8px;
    margin-bottom: 30px;
    flex-wrap: wrap;
}

.filter-tab {
    padding: 8px 16px;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.2s ease;
    font-weight: 500;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.filter-tab:hover {
    background: var(--bg-hover);
    border-color: var(--primary);
    color: var(--primary);
}

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

/* Publications */
.publications-grid {
    display: grid;
    gap: 30px;
}

.paper-card {
    display: flex;
    gap: 20px;
    padding: 24px 0;
    border-bottom: 1px solid var(--border);
    transition: all 0.2s ease;
}

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

.paper-card:hover {
    padding-left: 12px;
}

.paper-thumbnail {
    flex-shrink: 0;
    width: 100px;
    height: 100px;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 4px;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-muted);
    font-size: 0.85rem;
}

.paper-thumbnail img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.paper-content {
    flex: 1;
    min-width: 0;
}

.paper-title {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
    line-height: 1.4;
}

.paper-authors {
    color: var(--text-secondary);
    margin-bottom: 8px;
    font-size: 0.95rem;
}

.paper-authors strong {
    color: var(--text-primary);
}

.paper-venue {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-bottom: 12px;
}

.venue-badge {
    padding: 3px 10px;
    border-radius: 3px;
    font-size: 0.85rem;
    font-weight: 500;
}

.venue-conference {
    background: #dbeafe;
    color: #1e40af;
}

.venue-workshop {
    background: #f3f4f6;
    color: #4b5563;
}

.venue-journal {
    background: #d1fae5;
    color: #065f46;
}

.venue-award {
    background: #fef3c7;
    color: #92400e;
}

.paper-links {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
    margin-top: 10px;
}

.paper-link {
    color: var(--primary);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.2s ease;
}

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

/* Footer */
footer {
    background: var(--bg-secondary);
    padding: 30px 0;
    text-align: center;
    color: var(--text-muted);
    border-top: 1px solid var(--border);
    font-size: 0.9rem;
}

/* Mobile Responsive */
@media (max-width: 768px) {
    header {
        padding: 40px 0 30px;
    }

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

    .profile-photo {
        width: 120px;
        height: 120px;
    }

    header h1 {
        font-size: 2rem;
    }

    header .subtitle {
        font-size: 1rem;
    }

    nav .container {
        gap: 20px;
    }

    h2 {
        font-size: 1.5rem;
    }

    .paper-card {
        flex-direction: column;
        gap: 15px;
    }

    .paper-thumbnail {
        width: 100px;
        height: 100px;
    }

    .links {
        justify-content: center;
    }

    main {
        padding: 30px 0 60px;
    }

    section {
        margin-bottom: 60px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }

    header h1 {
        font-size: 1.75rem;
    }

    .filter-tabs {
        gap: 6px;
    }

    .filter-tab {
        padding: 6px 12px;
        font-size: 0.85rem;
    }

    .interest-tag {
        padding: 5px 12px;
        font-size: 0.85rem;
    }
}