/* ==================== */
/* CSS Reset & Base */
/* ==================== */

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

:root {
    /* Color Palette - Professional Academic */
    --primary-color: #1b5e20;
    --secondary-color: #388e3c;
    --accent-color: #66bb6a;
    --dark-bg: #0f1419;
    --light-bg: #f8f9fa;
    --card-bg: #ffffff;
    --text-primary: #2c3e50;
    --text-secondary: #546e7a;
    --border-color: #e1e8ed;
    --shadow: rgba(0, 0, 0, 0.1);
    
    /* Typography */
    --font-main: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-mono: 'Consolas', 'Monaco', 'Courier New', monospace;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-main);
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: #f8fdf9;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ==================== */
/* Header Section */
/* ==================== */

.header {
    background: linear-gradient(135deg, #e8f5e9 0%, #f1f8f4 100%);
    padding: 60px 0 80px;
    margin-bottom: -20px;
}

.header-content {
    display: flex;
    align-items: center;
    gap: 60px;
}

.header-info {
    flex: 1;
    text-align: left;
}

.portfolio-label {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--secondary-color);
    letter-spacing: 2px;
    margin-bottom: 24px;
}

.name-intro {
    font-size: 3.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 16px;
    letter-spacing: -1px;
    line-height: 1.2;
}

.name-highlight {
    color: var(--secondary-color);
}

.header .title {
    font-size: 1.375rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 24px;
    line-height: 1.4;
}

.description {
    font-size: 1.0625rem;
    line-height: 1.8;
    color: var(--text-secondary);
    margin-bottom: 32px;
    max-width: 600px;
}

.header-buttons {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}

.btn {
    padding: 14px 32px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    font-size: 1rem;
    transition: all 0.3s ease;
    display: inline-block;
    border: 2px solid transparent;
}

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

.btn-primary:hover {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(27, 94, 32, 0.3);
}

.btn-secondary {
    background-color: transparent;
    color: var(--secondary-color);
    border-color: var(--secondary-color);
}

.btn-secondary:hover {
    background-color: var(--secondary-color);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(27, 94, 32, 0.2);
}

.header-photo {
    flex-shrink: 0;
}

.profile-photo {
    width: 400px;
    height: 450px;
    border-radius: 16px;
    object-fit: cover;
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.15);
    border: 8px solid white;
}

/* Research Interests in Header */
.research-interests-header {
    margin-top: 60px;
    padding-top: 40px;
    border-top: 2px solid rgba(255, 255, 255, 0.3);
}

.interests-title {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 32px;
    text-align: center;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
}

.interests-title i {
    color: var(--accent-color);
    font-size: 1.5rem;
}

/* ==================== */
/* Navigation */
/* ==================== */

.nav {
    background-color: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 4px var(--shadow);
}

.nav .container {
    display: flex;
    justify-content: center;
    gap: 8px;
    padding: 0;
}

.nav a {
    padding: 16px 24px;
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 500;
    transition: all 0.3s ease;
    border-bottom: 3px solid transparent;
}

.nav a:hover {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
    background-color: rgba(26, 84, 144, 0.05);
}

/* ==================== */
/* Main Content */
/* ==================== */

.main {
    padding: 60px 0;
    background-color: #f8fdf9;
}

.section {
    background-color: var(--card-bg);
    border-radius: 16px;
    padding: 32px;
    margin-bottom: 40px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    border: 1px solid #e8f5e9;
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 24px;
    padding-bottom: 12px;
    border-bottom: 3px solid var(--accent-color);
}

.content {
    color: var(--text-primary);
}

.content p {
    margin-bottom: 16px;
    line-height: 1.8;
    font-size: 1.0625rem;
}

/* ==================== */
/* Professional Summary */
/* ==================== */

.interests {
    margin-top: 32px;
    padding: 24px;
    background-color: #e8f5e9;
    border-radius: 8px;
    border-left: 4px solid var(--accent-color);
}

.interests h3 {
    font-size: 1.25rem;
    color: var(--primary-color);
    margin-bottom: 16px;
}

.tags {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

.tag {
    display: inline-block;
    padding: 8px 16px;
    background-color: var(--secondary-color);
    color: white;
    border-radius: 20px;
    font-size: 0.9375rem;
    font-weight: 500;
    transition: transform 0.2s ease;
}

.tag:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px var(--shadow);
}

/* ==================== */
/* Experience Section */
/* ==================== */

.experience-item {
    margin-bottom: 20px;
    padding: 16px;
    background-color: #f1f8f4;
    border-radius: 8px;
    border-left: 4px solid var(--secondary-color);
    transition: all 0.3s ease;
}

.experience-item:hover {
    box-shadow: 0 4px 12px var(--shadow);
    transform: translateX(4px);
}

.experience-item:last-child {
    margin-bottom: 0;
}

.experience-item h3 {
    font-size: 1.375rem;
    color: var(--primary-color);
    margin-bottom: 10px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.experience-item h3 i {
    color: var(--accent-color);
    font-size: 1.25rem;
}

.education-meta {
    margin-bottom: 10px;
}

.education-meta p {
    margin-bottom: 2px;
    line-height: 1.5;
}

.education-meta strong {
    color: var(--primary-color);
    font-size: 1.0625rem;
}

.education-meta .date {
    color: var(--text-secondary);
    font-size: 0.9375rem;
    font-style: italic;
}

.experience-item ul {
    list-style: none;
    padding-left: 0;
}

.experience-item li {
    padding: 4px 0 4px 28px;
    position: relative;
    line-height: 1.6;
}

.experience-item li:before {
    content: "▹";
    position: absolute;
    left: 0;
    color: var(--accent-color);
    font-size: 1.25rem;
    font-weight: bold;
}

/* ==================== */
/* Publications Section */
/* ==================== */

.publication-card {
    margin-bottom: 24px;
    padding: 20px;
    background-color: #f1f8f4;
    border-radius: 8px;
    border-left: 4px solid var(--accent-color);
    transition: all 0.3s ease;
}

.publication-card:hover {
    box-shadow: 0 4px 12px var(--shadow);
    transform: translateX(4px);
}

.publication-card:last-child {
    margin-bottom: 0;
}

.publication-card h3 {
    font-size: 1.25rem;
    color: var(--primary-color);
    margin-bottom: 12px;
    line-height: 1.4;
}

.publication-meta {
    margin-bottom: 12px;
}

.publication-meta p {
    margin-bottom: 4px;
    font-size: 0.9375rem;
    line-height: 1.5;
}

.publication-meta .authors {
    color: var(--text-secondary);
}

.publication-meta .venue {
    color: var(--text-primary);
    font-style: italic;
}

.publication-meta .date {
    color: var(--text-secondary);
}

.publication-card .abstract {
    font-size: 0.9375rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 12px;
}

.publication-links {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
}

.pub-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 14px;
    background-color: var(--secondary-color);
    color: white;
    text-decoration: none;
    border-radius: 4px;
    font-size: 0.875rem;
    font-weight: 500;
    transition: all 0.2s ease;
}

.pub-link:hover {
    background-color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(27, 94, 32, 0.3);
}

.pub-link i {
    font-size: 0.875rem;
}

/* ==================== */
/* Research Areas */
/* ==================== */

.research-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}

.research-card {
    padding: 20px 16px;
    background-color: #f1f8f4;
    border-radius: 12px;
    border: 2px solid #e8f5e9;
    text-align: center;
    transition: all 0.3s ease;
}

.research-card:hover {
    border-color: var(--accent-color);
    box-shadow: 0 8px 16px var(--shadow);
    transform: translateY(-4px);
}

.research-card i {
    font-size: 2rem;
    color: var(--secondary-color);
    margin-bottom: 12px;
}

.research-card h3 {
    font-size: 1.25rem;
    color: var(--primary-color);
    margin-bottom: 8px;
}

.research-card p {
    font-size: 0.9375rem;
    color: var(--text-secondary);
    line-height: 1.4;
    margin: 0;
}

/* ==================== */
/* Projects Section */
/* ==================== */

.project-card {
    margin-bottom: 40px;
    padding: 32px;
    background-color: #f1f8f4;
    border-radius: 12px;
    border: 1px solid #e8f5e9;
    border-left: 5px solid var(--accent-color);
    transition: all 0.3s ease;
}

.project-card:hover {
    box-shadow: 0 8px 20px var(--shadow);
}

.project-card:last-child {
    margin-bottom: 0;
}

.project-card h3 {
    font-size: 1.625rem;
    color: var(--primary-color);
    margin-bottom: 12px;
}

.project-meta {
    margin-bottom: 16px;
}

.project-meta .date {
    display: inline-block;
    padding: 4px 12px;
    background-color: var(--secondary-color);
    color: white;
    border-radius: 4px;
    font-size: 0.875rem;
    font-weight: 500;
}

.project-details {
    list-style: none;
    padding-left: 0;
    margin-bottom: 24px;
}

.project-details li {
    padding: 8px 0 8px 28px;
    position: relative;
    line-height: 1.7;
}

.project-details li:before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--accent-color);
    font-size: 1.125rem;
    font-weight: bold;
}

.project-tech {
    margin-bottom: 16px;
}

.project-tech strong {
    display: block;
    margin-bottom: 12px;
    color: var(--primary-color);
    font-size: 1rem;
}

.project-tech .tags {
    gap: 8px;
}

.project-tech .tag {
    padding: 6px 14px;
    font-size: 0.875rem;
    background-color: var(--primary-color);
}

.project-outcome {
    padding: 16px;
    background-color: rgba(65, 182, 196, 0.1);
    border-left: 3px solid var(--accent-color);
    border-radius: 4px;
    margin-top: 16px;
}

.project-outcome strong {
    color: var(--primary-color);
    font-weight: 600;
}

/* ==================== */
/* Skills Section */
/* ==================== */

.skills-category {
    margin-bottom: 36px;
}

.skills-category:last-child {
    margin-bottom: 0;
}

.skills-category h3 {
    font-size: 1.375rem;
    color: var(--primary-color);
    margin-bottom: 16px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.skills-category h3 i {
    color: var(--accent-color);
}

.skills-list {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

.skill {
    display: inline-block;
    padding: 10px 20px;
    background-color: #f1f8f4;
    border: 2px solid #e8f5e9;
    border-radius: 6px;
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--text-primary);
    transition: all 0.2s ease;
}

.skill:hover {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px var(--shadow);
}

/* ==================== */
/* Contact Section */
/* ==================== */

.contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 16px;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 20px;
    background-color: #f1f8f4;
    border: 2px solid #e8f5e9;
    border-radius: 8px;
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 500;
    transition: all 0.3s ease;
}

.contact-item:hover {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px var(--shadow);
}

.contact-item i {
    font-size: 1.75rem;
    color: var(--accent-color);
}

.contact-item:hover i {
    color: white;
}

/* ==================== */
/* Footer */
/* ==================== */

.footer {
    background-color: var(--dark-bg);
    color: white;
    text-align: center;
    padding: 32px 0;
    margin-top: 48px;
}

.footer p {
    opacity: 0.8;
    font-size: 0.9375rem;
}

/* ==================== */
/* Responsive Design */
/* ==================== */

@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        gap: 40px;
    }
    
    .header-info {
        text-align: center;
    }
    
    .profile-photo {
        width: 280px;
        height: 320px;
    }
    
    .name-intro {
        font-size: 2.5rem;
    }
    
    .header .title {
        font-size: 1.125rem;
    }
    
    .description {
        max-width: 100%;
    }
    
    .header-buttons {
        justify-content: center;
    }
    
    .research-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 12px;
    }
    
    .nav .container {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .nav a {
        padding: 12px 16px;
        font-size: 0.9375rem;
    }
    
    .section {
        padding: 32px 24px;
    }
    
    .section-title {
        font-size: 1.625rem;
    }
    
    .research-grid {
        grid-template-columns: 1fr;
    }
    
    .contact-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }
    
    .header {
        padding: 40px 0 50px;
    }
    
    .profile-photo {
        width: 240px;
        height: 280px;
    }
    
    .name-intro {
        font-size: 2rem;
    }
    
    .header .title {
        font-size: 1rem;
    }
    
    .btn {
        padding: 12px 24px;
        font-size: 0.9375rem;
    }
    
    .section {
        padding: 24px 16px;
    }
    
    .nav a {
        padding: 12px;
        font-size: 0.875rem;
    }
}