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

body {
    font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    line-height: 1.6;
    color: #e6e6e6;
    background-color: #000000;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

html {
    scroll-behavior: smooth;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* Variables */
:root {
    --primary-color: #ffffff;
    --secondary-color: #e6e6e6;
    --accent-color: #b3c2cb;
    --background-color: #000000;
    --card-background: #121212;
    --border-color: rgba(255, 255, 255, 0.15);
    --gradient-primary: radial-gradient(61% 200% at 39.7% 21.9%, rgb(255, 255, 255) 0%, rgba(0, 0, 0, 0.35) 100%);
}

/* Navigation */
.nav {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    z-index: 1000;
    transition: all 0.3s ease;
}

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

.nav-logo a {
    color: var(--primary-color);
    text-decoration: none;
    font-size: 1.5rem;
    font-weight: 600;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-link {
    color: var(--secondary-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
    font-size: 0.9rem;
    letter-spacing: -0.02em;
}

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

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 4px;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--secondary-color);
    transition: all 0.3s ease;
    border-radius: 2px;
}

/* Hero Section */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
}

.gradient-blur {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at 50% 50%, rgba(20, 20, 20, 0.8) 0%, rgba(0, 0, 0, 0.9) 100%);
}

.noise-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" width="100" height="100" viewBox="0 0 100 100"><defs><filter id="noiseFilter"><feTurbulence type="fractalNoise" baseFrequency="0.9" numOctaves="4" stitchTiles="stitch"/></filter></defs><rect width="100%" height="100%" filter="url(%23noiseFilter)" opacity="0.05"/></svg>');
    background-size: 128px;
    background-repeat: repeat;
    opacity: 0.075;
}

.hero-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    text-align: center;
}

.hero-content {
    animation: fadeInUp 1s ease 0.2s both;
}

.hero-image {
    margin-bottom: 2rem;
}

.hero-image img {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    object-fit: cover;
    border: 3px solid var(--border-color);
}

.hero-title {
    font-size: clamp(3rem, 6vw, 5rem);
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--primary-color);
    line-height: 1.2;
    letter-spacing: -0.02em;
}

.hero-subtitle {
    font-size: 1.2rem;
    color: var(--accent-color);
    margin-bottom: 3rem;
    font-weight: 300;
    letter-spacing: -0.01em;
}

/* Social Links */
.social-links {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-top: 2rem;
}

.social-link {
    position: relative;
    width: 60px;
    height: 60px;
    background: var(--card-background);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    transition: all 0.3s ease;
    border: 1px solid var(--border-color);
}

.social-link:hover {
    transform: translateY(-5px);
    background: rgba(255, 255, 255, 0.1);
}

.social-link img {
    width: 24px;
    height: 24px;
    filter: invert(1);
}

.tooltip {
    position: absolute;
    bottom: -80px;
    left: 50%;
    transform: translateX(-50%);
    background: rgba(0, 0, 0, 0.9);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    padding: 0.75rem 1rem;
    border-radius: 8px;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    white-space: nowrap;
    border: 1px solid var(--border-color);
}

.social-link:hover .tooltip {
    opacity: 1;
    visibility: visible;
}

.tooltip-title {
    font-weight: 500;
    color: var(--primary-color);
    display: block;
    font-size: 0.9rem;
}

.tooltip-desc {
    font-size: 0.8rem;
    color: var(--accent-color);
    font-weight: 300;
}

/* Section Styles */
section {
    padding: 5rem 0;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 600;
    text-align: center;
    margin-bottom: 3rem;
    color: var(--primary-color);
    letter-spacing: -0.02em;
}

/* About Section */
.about {
    background: rgba(10, 10, 10, 0.5);
}

.about-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 4rem;
    align-items: center;
}

.about-text p {
    font-size: 1.1rem;
    color: var(--accent-color);
    margin-bottom: 1.5rem;
    font-weight: 300;
    line-height: 1.7;
}

.about-stats {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.stat {
    text-align: center;
    padding: 1.5rem;
    background: var(--card-background);
    border-radius: 12px;
    border: 1px solid var(--border-color);
}

.stat-number {
    display: block;
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.stat-label {
    font-size: 0.9rem;
    color: var(--accent-color);
    font-weight: 300;
}

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

.skill-category {
    background: var(--card-background);
    padding: 2rem;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    transition: transform 0.3s ease;
}

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

.skill-category h3 {
    font-size: 1.3rem;
    color: var(--primary-color);
    margin-bottom: 1.5rem;
    font-weight: 600;
}

.skill-items {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.skill-item {
    background: rgba(255, 255, 255, 0.1);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.9rem;
    color: var(--secondary-color);
    font-weight: 400;
    border: 1px solid var(--border-color);
}

/* Projects Section */
.projects {
    background: rgba(10, 10, 10, 0.5);
}

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

.project-card {
    background: var(--card-background);
    border-radius: 12px;
    overflow: hidden;
    border: 1px solid var(--border-color);
    transition: transform 0.3s ease;
}

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

.project-image img {
    width: 100%;
    height: 200px;
    object-fit: cover;
}

.project-content {
    padding: 1.5rem;
}

.project-content h3 {
    font-size: 1.3rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-weight: 600;
}

.project-content p {
    color: var(--accent-color);
    margin-bottom: 1.5rem;
    line-height: 1.6;
    font-weight: 300;
}

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

.tech-tag {
    background: rgba(255, 255, 255, 0.1);
    padding: 0.25rem 0.75rem;
    border-radius: 12px;
    font-size: 0.8rem;
    color: var(--secondary-color);
    border: 1px solid var(--border-color);
}

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

.project-link {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.9rem;
    border: 1px solid var(--border-color);
    padding: 0.5rem 1rem;
    border-radius: 6px;
    transition: all 0.3s ease;
}

.project-link:hover {
    background: rgba(255, 255, 255, 0.1);
}

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

.contact-info h3 {
    font-size: 1.5rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-weight: 600;
}

.contact-info p {
    color: var(--accent-color);
    margin-bottom: 2rem;
    line-height: 1.6;
    font-weight: 300;
}

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

.contact-method {
    display: flex;
    align-items: center;
    gap: 1rem;
    color: var(--accent-color);
    font-weight: 300;
}

.contact-icon {
    font-size: 1.2rem;
}

.contact-form {
    background: var(--card-background);
    padding: 2rem;
    border-radius: 12px;
    border: 1px solid var(--border-color);
}

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

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.75rem 1rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    color: var(--primary-color);
    font-family: inherit;
    font-size: 0.9rem;
    transition: border-color 0.3s ease;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: var(--accent-color);
}

.submit-btn {
    width: 100%;
    padding: 0.75rem 1rem;
    background: var(--primary-color);
    color: var(--background-color);
    border: none;
    border-radius: 6px;
    font-family: inherit;
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
}

.submit-btn:hover {
    background: var(--secondary-color);
}

/* Footer */
.footer {
    background: var(--card-background);
    padding: 2rem 0;
    border-top: 1px solid var(--border-color);
}

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

.footer-content p {
    color: var(--accent-color);
    font-weight: 300;
}

.footer-links {
    display: flex;
    gap: 2rem;
}

.footer-links a {
    color: var(--accent-color);
    text-decoration: none;
    font-weight: 300;
    transition: color 0.3s ease;
}

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

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

/* Responsive Design */
@media (max-width: 1024px) {
    .nav-links {
        display: none;
    }

    .hamburger {
        display: flex;
    }

    .about-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .about-stats {
        flex-direction: row;
        justify-content: space-around;
    }

    .contact-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
}

@media (max-width: 768px) {
    .container {
        padding: 0 1rem;
    }

    .nav-container {
        padding: 1rem;
    }

    section {
        padding: 3rem 0;
    }

    .hero-title {
        font-size: 2.5rem;
    }

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

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

    .social-links {
        gap: 1rem;
    }

    .social-link {
        width: 50px;
        height: 50px;
    }

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

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

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

    .footer-content {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }

    .footer-links {
        gap: 1rem;
    }
}

@media (max-width: 480px) {
    .hero-image img {
        width: 150px;
        height: 150px;
    }

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

    .social-link {
        width: 45px;
        height: 45px;
    }

    .social-link img {
        width: 20px;
        height: 20px;
    }
}

/* Mobile Navigation */
@media (max-width: 1024px) {
    .nav-links.active {
        display: flex;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background: rgba(0, 0, 0, 0.95);
        backdrop-filter: blur(10px);
        -webkit-backdrop-filter: blur(10px);
        flex-direction: column;
        padding: 2rem;
        gap: 1rem;
        border-top: 1px solid var(--border-color);
    }

    .hamburger.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }

    .hamburger.active span:nth-child(2) {
        opacity: 0;
    }

    .hamburger.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }
}