/* ===== CSS RESET & BASE STYLES ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Dark Mode Color Palette with UOG Green */
    --primary-color: #00a651; /* University of Guam Green */
    --primary-dark: #008a44;
    --primary-light: #33b86a;
    --secondary-color: #94a3b8;
    --accent-color: #fbbf24;
    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    --text-light: #94a3b8;
    --background-primary: #0f172a;
    --background-secondary: #1e293b;
    --background-tertiary: #334155;
    --border-color: #475569;
    --shadow-light: 0 1px 3px 0 rgba(0, 0, 0, 0.3), 0 1px 2px 0 rgba(0, 0, 0, 0.2);
    --shadow-medium: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
    --shadow-large: 0 10px 15px -3px rgba(0, 0, 0, 0.3), 0 4px 6px -2px rgba(0, 0, 0, 0.2);
    
    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-heading: 'Playfair Display', Georgia, serif;
    
    /* Spacing */
    --section-padding: 5rem 0;
    --container-padding: 0 1.5rem;
    --border-radius: 0.75rem;
    --border-radius-lg: 1rem;
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-medium: 0.3s ease;
    --transition-slow: 0.5s ease;
}

html {
    scroll-behavior: smooth;
}

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

/* ===== TYPOGRAPHY ===== */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: 1rem;
}

h1 { font-size: 3.5rem; }
h2 { font-size: 2.5rem; }
h3 { font-size: 1.875rem; }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }
h6 { font-size: 1.125rem; }

p {
    margin-bottom: 1rem;
    color: var(--text-secondary);
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

/* ===== UTILITY CLASSES ===== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--container-padding);
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-title {
    color: var(--text-primary);
    margin-bottom: 1rem;
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.875rem 2rem;
    border-radius: var(--border-radius);
    font-weight: 500;
    text-decoration: none;
    transition: all var(--transition-medium);
    cursor: pointer;
    border: 2px solid transparent;
}

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

.btn-primary:hover {
    background-color: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-medium);
}

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

.btn-secondary:hover {
    background-color: var(--primary-color);
    color: white;
    transform: translateY(-2px);
}

/* ===== NAVIGATION ===== */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background-color: rgba(15, 23, 42, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    transition: all var(--transition-medium);
}

.navbar.scrolled {
    background-color: rgba(15, 23, 42, 0.98);
    box-shadow: var(--shadow-medium);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 4rem;
}

.nav-logo a {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-primary);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-link {
    color: var(--text-secondary);
    font-weight: 500;
    position: relative;
    transition: color var(--transition-fast);
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary-color);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -0.5rem;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--primary-color);
    transition: width var(--transition-medium);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.bar {
    width: 25px;
    height: 3px;
    background-color: var(--text-primary);
    margin: 3px 0;
    transition: var(--transition-fast);
}

/* ===== HERO SECTION ===== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, var(--background-secondary) 0%, var(--background-primary) 100%);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    width: 50%;
    height: 100%;
    background: linear-gradient(45deg, transparent 0%, rgba(37, 99, 235, 0.05) 100%);
    z-index: 1;
}

.hero-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--container-padding);
    position: relative;
    z-index: 2;
}

.hero-content {
    max-width: 700px;
}

.hero-greeting {
    display: block;
    font-size: 1.25rem;
    color: var(--text-secondary);
    font-weight: 400;
    margin-bottom: 0.5rem;
}

.hero-name {
    display: block;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.5rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    font-weight: 500;
}

.hero-description {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: 2.5rem;
    line-height: 1.7;
}

.hero-cta {
    display: flex;
    gap: 1rem;
    margin-bottom: 3rem;
}

.hero-contact {
    display: flex;
    flex-wrap: wrap;
    gap: 2rem;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.contact-item i {
    color: var(--primary-color);
    width: 16px;
}

/* ===== ABOUT SECTION ===== */
.about {
    padding: var(--section-padding);
    background-color: var(--background-primary);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: start;
}

.about-summary {
    font-size: 1.125rem;
    line-height: 1.7;
    margin-bottom: 2rem;
}



.competencies h3 {
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.competencies-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
}

.competency-item {
    background-color: var(--background-secondary);
    padding: 1rem;
    border-radius: var(--border-radius);
    border-left: 3px solid var(--primary-color);
    transition: transform var(--transition-fast);
}

.competency-item:hover {
    transform: translateX(5px);
}

/* ===== EXPERTISE SECTION ===== */
.expertise {
    padding: var(--section-padding);
    background-color: var(--background-secondary);
}

.expertise-areas {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
    max-width: 800px;
    margin: 0 auto;
}

.expertise-area {
    background-color: var(--background-primary);
    padding: 2.5rem;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-light);
    transition: all var(--transition-medium);
    border-top: 4px solid var(--primary-color);
    position: relative;
    overflow: hidden;
}

.expertise-area::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-light) 100%);
}

.expertise-area:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-medium);
}

.expertise-area:hover::before {
    height: 6px;
}

.expertise-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    border-radius: 12px;
    margin-bottom: 1.5rem;
    transition: all var(--transition-medium);
}

.expertise-area:hover .expertise-icon {
    transform: scale(1.1);
    box-shadow: var(--shadow-medium);
}

.expertise-icon i {
    font-size: 1.5rem;
    color: white;
}

.expertise-title {
    color: var(--text-primary);
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
    line-height: 1.3;
}

.expertise-description {
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 1.5rem;
}

.expertise-achievements {
    list-style: none;
    padding: 0;
    margin: 0;
}

.expertise-achievements li {
    position: relative;
    padding-left: 1.5rem;
    margin-bottom: 0.75rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

.expertise-achievements li::before {
    content: '✓';
    position: absolute;
    left: 0;
    top: 0;
    color: var(--primary-color);
    font-weight: 600;
    font-size: 0.9rem;
}

/* ===== EDUCATION SECTION ===== */
.education {
    padding: var(--section-padding);
    background-color: var(--background-primary);
}

.education-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 4rem;
}

.education-degrees {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.degree-item {
    background-color: var(--background-secondary);
    padding: 2rem;
    border-radius: var(--border-radius-lg);
    border-left: 4px solid var(--primary-color);
    transition: transform var(--transition-medium);
}

.degree-item:hover {
    transform: translateX(10px);
}

.degree-title {
    color: var(--primary-color);
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.degree-school {
    color: var(--text-secondary);
    font-weight: 500;
    margin-bottom: 0.5rem;
}

.degree-year {
    color: var(--text-light);
    font-size: 0.95rem;
}

.certifications h3 {
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.cert-grid {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.cert-item {
    background-color: var(--background-tertiary);
    padding: 1rem;
    border-radius: var(--border-radius);
    border-left: 3px solid var(--accent-color);
    font-size: 0.95rem;
    transition: background-color var(--transition-fast);
}

.cert-item:hover {
    background-color: var(--background-secondary);
}

/* ===== KOREAN LANGUAGE EXPERTISE SECTION ===== */
.korean-expertise {
    padding: var(--section-padding);
    background-color: var(--background-secondary);
}

.expertise-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.expertise-item {
    background-color: var(--background-secondary);
    padding: 2rem;
    border-radius: var(--border-radius-lg);
    text-align: center;
    transition: transform var(--transition-medium);
    border-top: 4px solid var(--primary-color);
    box-shadow: var(--shadow-light);
}

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

.expertise-icon {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.korean-english-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--background-tertiary) 0%, var(--background-secondary) 100%);
    border-radius: 12px;
    border: 2px solid var(--primary-color);
    box-shadow: 0 4px 12px rgba(0, 166, 81, 0.2);
    margin: 0 auto;
    position: relative;
    overflow: hidden;
}

.korean-english-icon::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    width: 1px;
    height: 100%;
    background: linear-gradient(to bottom, transparent 20%, var(--border-color) 50%, transparent 80%);
    transform: translateX(-50%);
}

.english-char {
    color: var(--primary-color);
    font-family: var(--font-primary);
    font-size: 1.8rem;
    font-weight: 700;
    position: absolute;
    left: 25%;
    transform: translateX(-50%);
}

.korean-char {
    color: var(--accent-color);
    font-family: 'Noto Sans KR', 'Malgun Gothic', '맑은 고딕', sans-serif;
    font-size: 1.8rem;
    font-weight: 700;
    position: absolute;
    right: 25%;
    transform: translateX(50%);
}

.expertise-title {
    color: var(--text-primary);
    font-weight: 600;
    margin-bottom: 1rem;
    font-size: 1.25rem;
}

.expertise-description {
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 0;
}

/* ===== PRESENTATIONS SECTION ===== */
.presentations {
    padding: var(--section-padding);
    background-color: var(--background-primary);
}

.presentations-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.presentation-item {
    background-color: var(--background-primary);
    padding: 2rem;
    border-radius: var(--border-radius-lg);
    transition: transform var(--transition-medium);
    border-left: 4px solid var(--accent-color);
    box-shadow: var(--shadow-light);
    position: relative;
}

.presentation-item:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-medium);
}

.presentation-year {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background-color: var(--accent-color);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: var(--border-radius);
    font-size: 0.85rem;
    font-weight: 600;
}

.presentation-title {
    color: var(--text-primary);
    font-weight: 600;
    margin-bottom: 0.75rem;
    font-size: 1.125rem;
    padding-right: 4rem;
}

.presentation-organization {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 0;
}

/* ===== RESEARCH SECTION ===== */
.research {
    padding: var(--section-padding);
    background-color: var(--background-secondary);
}

.research-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
}

.publications h3,
.research-projects h3 {
    margin-bottom: 2rem;
    color: var(--text-primary);
}

.publication-item {
    background-color: var(--background-primary);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow-light);
    transition: transform var(--transition-medium);
}

.publication-item:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-medium);
}

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

.publication-details {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.projects-grid {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.project-item {
    background-color: var(--background-primary);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-light);
    border-left: 4px solid var(--accent-color);
    transition: transform var(--transition-medium);
}

.project-item:hover {
    transform: translateX(5px);
}

.project-title {
    color: var(--text-primary);
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.project-period {
    color: var(--text-light);
    font-size: 0.9rem;
}

/* ===== SKILLS SECTION ===== */
.skills {
    padding: var(--section-padding);
    background-color: var(--background-primary);
}

.skills-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 4rem;
}

.technical-skills h3,
.languages h3 {
    margin-bottom: 2rem;
    color: var(--text-primary);
}

.skills-categories {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.skill-category {
    background-color: var(--background-secondary);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    border-left: 4px solid var(--primary-color);
}

.skill-category h4 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.125rem;
}

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.skill-tag {
    background-color: var(--background-tertiary);
    color: var(--text-secondary);
    padding: 0.5rem 1rem;
    border-radius: var(--border-radius);
    font-size: 0.9rem;
    transition: all var(--transition-fast);
}

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

.language-grid {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.language-item {
    background-color: var(--background-secondary);
    padding: 1rem;
    border-radius: var(--border-radius);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.language-name {
    font-weight: 500;
    color: var(--text-primary);
}

.language-level {
    background-color: var(--accent-color);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: var(--border-radius);
    font-size: 0.85rem;
    font-weight: 500;
}

/* ===== AWARDS SECTION ===== */
.awards {
    padding: var(--section-padding);
    background-color: var(--background-secondary);
}

.awards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    max-width: 1000px;
    margin: 0 auto;
}

.award-item {
    background-color: var(--background-primary);
    padding: 2rem;
    border-radius: var(--border-radius-lg);
    text-align: center;
    box-shadow: var(--shadow-light);
    transition: transform var(--transition-medium);
    border-top: 4px solid var(--accent-color);
}

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

.award-icon {
    font-size: 2.5rem;
    color: var(--accent-color);
    margin-bottom: 1rem;
}

.award-title {
    color: var(--text-primary);
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.award-year {
    color: var(--text-light);
    font-size: 0.9rem;
}

/* ===== CONTACT SECTION ===== */
.contact {
    padding: var(--section-padding);
    background-color: var(--background-primary);
}

.contact-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 4rem;
    max-width: 1000px;
    margin: 0 auto;
}

.contact-form-section {
    display: flex;
    flex-direction: column;
}

.contact-form-card {
    background-color: var(--background-secondary);
    padding: 2.5rem;
    border-radius: var(--border-radius-lg);
    border-top: 4px solid var(--primary-color);
    box-shadow: var(--shadow-light);
}

.contact-form-card h3 {
    color: var(--text-primary);
    margin-bottom: 1.5rem;
    text-align: center;
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.form-group {
    display: flex;
    flex-direction: column;
}

.form-group label {
    color: var(--text-primary);
    font-weight: 500;
    margin-bottom: 0.5rem;
    font-size: 0.95rem;
}

.form-group input,
.form-group textarea {
    background-color: var(--background-tertiary);
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 0.875rem;
    color: var(--text-primary);
    font-family: var(--font-primary);
    font-size: 1rem;
    transition: all var(--transition-fast);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 166, 81, 0.1);
}

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

.submit-btn {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    border: none;
    padding: 1rem 2rem;
    border-radius: var(--border-radius);
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: all var(--transition-medium);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.submit-btn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: var(--shadow-medium);
}

.submit-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.form-status {
    text-align: center;
    padding: 0.75rem;
    border-radius: var(--border-radius);
    font-weight: 500;
    margin-top: 0.5rem;
    transition: all var(--transition-fast);
}

.form-status.success {
    background-color: rgba(16, 185, 129, 0.1);
    color: #10b981;
    border: 1px solid rgba(16, 185, 129, 0.2);
}

.form-status.error {
    background-color: rgba(239, 68, 68, 0.1);
    color: #ef4444;
    border: 1px solid rgba(239, 68, 68, 0.2);
}

.form-status.sending {
    background-color: rgba(59, 130, 246, 0.1);
    color: #3b82f6;
    border: 1px solid rgba(59, 130, 246, 0.2);
}

.contact-info {
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
}

.contact-card {
    background-color: var(--background-secondary);
    padding: 2rem;
    border-radius: var(--border-radius-lg);
    text-align: center;
    transition: transform var(--transition-medium);
    border-top: 4px solid var(--primary-color);
}

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

.contact-card i {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.contact-card h3 {
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.contact-card p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    text-align: center;
}

.linkedin-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    background: linear-gradient(135deg, #0077b5 0%, #005582 100%);
    color: white;
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    font-weight: 500;
    text-decoration: none;
    transition: all var(--transition-medium);
}

.linkedin-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-medium);
    color: white;
}



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

.footer-content p {
    color: var(--background-secondary);
    margin-bottom: 0.5rem;
}

.footer-content p:last-child {
    color: var(--text-light);
    font-size: 0.9rem;
}

/* ===== RESPONSIVE DESIGN ===== */
@media (max-width: 768px) {
    :root {
        --section-padding: 3rem 0;
    }
    
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 4rem;
        flex-direction: column;
        background-color: var(--background-primary);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: var(--shadow-medium);
        padding: 2rem 0;
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .nav-toggle {
        display: flex;
    }
    
    .nav-toggle.active .bar:nth-child(2) {
        opacity: 0;
    }
    
    .nav-toggle.active .bar:nth-child(1) {
        transform: translateY(8px) rotate(45deg);
    }
    
    .nav-toggle.active .bar:nth-child(3) {
        transform: translateY(-8px) rotate(-45deg);
    }
    
    h1 { font-size: 2.5rem; }
    h2 { font-size: 2rem; }
    
    .hero-cta {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .hero-contact {
        flex-direction: column;
        gap: 1rem;
    }
    
    .about-content,
    .education-content,
    .research-content,
    .skills-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .expertise-areas {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .expertise-area {
        padding: 2rem;
    }
    
    .contact-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .contact-form-card {
        padding: 2rem;
    }
}

@media (max-width: 600px) {
    .expertise-area {
        padding: 1.5rem;
    }
    
    .expertise-icon {
        width: 50px;
        height: 50px;
        margin-bottom: 1rem;
    }
    
    .expertise-icon i {
        font-size: 1.25rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 1rem;
    }
    
    h1 { font-size: 2rem; }
    
    .hero-subtitle {
        font-size: 1.25rem;
    }
    
    .hero-description {
        font-size: 1rem;
    }
    
    .expertise-areas {
        gap: 1rem;
    }
    
    .expertise-area {
        padding: 1.25rem;
    }
    
    .expertise-title {
        font-size: 1.125rem;
    }
    
    .contact-form-card {
        padding: 1.5rem;
    }
    
    .form-group input,
    .form-group textarea {
        padding: 0.75rem;
    }
}

/* ===== ANIMATIONS ===== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in-up {
    animation: fadeInUp 0.6s ease forwards;
}

/* ===== SCROLL ANIMATIONS ===== */
.scroll-reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.6s ease;
}

.scroll-reveal.revealed {
    opacity: 1;
    transform: translateY(0);
}

/* ===== LOADING STATES ===== */
.loading-placeholder {
    background: linear-gradient(90deg, var(--background-secondary) 25%, var(--background-tertiary) 50%, var(--background-secondary) 75%);
    background-size: 200% 100%;
    animation: loading 1.5s infinite;
    border-radius: var(--border-radius);
    height: 60px;
    margin-bottom: 1rem;
}

@keyframes loading {
    0% {
        background-position: 200% 0;
    }
    100% {
        background-position: -200% 0;
    }
}

/* ===== PRINT STYLES ===== */
@media print {
    .navbar,
    .hero-cta,
    .email-reveal-btn,
    .copy-btn {
        display: none !important;
    }
    
    body {
        background: white !important;
        color: black !important;
    }
    
    .hero,
    .about,
    .experience,
    .education,
    .korean-expertise,
    .presentations,
    .research,
    .skills,
    .awards,
    .contact {
        background: white !important;
        color: black !important;
    }
}