/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans KR', sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #ffffff;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header Styles */
.header {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
}

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

.nav-brand h1 {
    font-size: 1.8rem;
    font-weight: 700;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

.nav-links a {
    text-decoration: none;
    color: #333;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

.nav-links a:hover {
    color: #667eea;
}

.nav-links a::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -5px;
    left: 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    transition: width 0.3s ease;
}

.nav-links a:hover::after {
    width: 100%;
}

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

.hamburger span {
    width: 25px;
    height: 3px;
    background: #333;
    margin: 3px 0;
    transition: 0.3s;
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: 0 2rem;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grain" width="100" height="100" patternUnits="userSpaceOnUse"><circle cx="50" cy="50" r="1" fill="white" opacity="0.1"/></pattern></defs><rect width="100" height="100" fill="url(%23grain)"/></svg>');
    opacity: 0.3;
}

.hero-content {
    flex: 1;
    max-width: 600px;
    z-index: 2;
    position: relative;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.highlight {
    background: linear-gradient(135deg, #ffd700 0%, #ffed4e 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.3rem;
    margin-bottom: 2rem;
    opacity: 0.9;
    font-weight: 300;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.btn {
    padding: 12px 30px;
    border: none;
    border-radius: 50px;
    font-size: 1rem;
    font-weight: 500;
    text-decoration: none;
    display: inline-block;
    transition: all 0.3s ease;
    cursor: pointer;
}

.btn-primary {
    background: white;
    color: #667eea;
}

.btn-primary:hover {
    background: #f8f9fa;
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

.btn-secondary {
    background: transparent;
    color: white;
    border: 2px solid white;
}

.btn-secondary:hover {
    background: white;
    color: #667eea;
    transform: translateY(-2px);
}

.hero-image {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 2;
    position: relative;
}

.code-animation {
    width: 300px;
    height: 200px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 10px;
    padding: 20px;
    backdrop-filter: blur(10px);
}

.code-line {
    height: 20px;
    background: rgba(255, 255, 255, 0.3);
    margin: 10px 0;
    border-radius: 10px;
    animation: pulse 2s infinite;
}

.code-line:nth-child(2) {
    width: 80%;
    animation-delay: 0.5s;
}

.code-line:nth-child(3) {
    width: 60%;
    animation-delay: 1s;
}

@keyframes pulse {
    0%, 100% { opacity: 0.3; }
    50% { opacity: 0.7; }
}

/* Section Styles */
section {
    padding: 80px 0;
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 3rem;
    color: #333;
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 2px;
}

/* About Section */
.about {
    background: #f8f9fa;
}

.about-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.about-text p {
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
    color: #666;
    line-height: 1.8;
}

.about-stats {
    display: flex;
    justify-content: center;
    gap: 3rem;
    margin-top: 3rem;
}

.stat {
    text-align: center;
}

.stat h3 {
    font-size: 2.5rem;
    font-weight: 700;
    color: #667eea;
    margin-bottom: 0.5rem;
}

.stat p {
    color: #666;
    font-weight: 500;
}

/* Skills Section */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.skill-category {
    background: white;
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease;
}

.skill-category:hover {
    transform: translateY(-5px);
}

.skill-category h3 {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    color: #333;
    text-align: center;
}

.skill-items {
    display: flex;
    flex-wrap: wrap;
    gap: 0.8rem;
    justify-content: center;
}

.skill-item {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 500;
}

/* Projects Section */
.projects {
    background: #f8f9fa;
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

.project-card {
    background: white;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease;
}

.project-card:hover {
    transform: translateY(-10px);
}

.project-image {
    height: 200px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    align-items: center;
    justify-content: center;
}

.project-placeholder {
    color: white;
    font-size: 1.1rem;
    font-weight: 500;
}

.project-content {
    padding: 2rem;
}

.project-content h3 {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: #333;
}

.project-content p {
    color: #666;
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}

.project-tech span {
    background: #e9ecef;
    color: #495057;
    padding: 4px 12px;
    border-radius: 15px;
    font-size: 0.8rem;
    font-weight: 500;
}

.project-links {
    display: flex;
    gap: 1rem;
}

.project-link {
    color: #667eea;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
}

.project-link:hover {
    color: #764ba2;
}

/* Contact Section */
.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: start;
}

.contact-info h3 {
    font-size: 1.8rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: #333;
}

.contact-info p {
    color: #666;
    margin-bottom: 2rem;
    line-height: 1.6;
}

.contact-items {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.contact-item {
    display: flex;
    flex-direction: column;
    gap: 0.3rem;
}

.contact-item strong {
    color: #333;
    font-weight: 600;
}

.contact-item span {
    color: #667eea;
    font-weight: 500;
}

.contact-form {
    background: #f8f9fa;
    padding: 2rem;
    border-radius: 15px;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid #e9ecef;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
    font-family: inherit;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: #667eea;
}

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

/* Footer */
.footer {
    background: #333;
    color: white;
    text-align: center;
    padding: 2rem 0;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    
    .hamburger {
        display: flex;
    }
    
    .hero {
        flex-direction: column;
        text-align: center;
        padding: 2rem;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-subtitle {
        font-size: 1.1rem;
    }
    
    .hero-buttons {
        justify-content: center;
    }
    
    .about-stats {
        flex-direction: column;
        gap: 2rem;
    }
    
    .contact-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .projects-grid {
        grid-template-columns: 1fr;
    }
    
    .skills-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .nav {
        padding: 1rem;
    }
    
    .container {
        padding: 0 15px;
    }
}