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

:root {
    --color-text-primary: #111111;
    --color-text-secondary: #555555;
    --color-text-tertiary: #999999;
    --color-bg-primary: #ffffff;
    --color-bg-secondary: #f5f5f5;
    --color-border: #e0e0e0;
    --color-accent: #2563eb;
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Noto Sans KR', sans-serif;
    --transition: all 0.2s ease;
}

body {
    font-family: var(--font-sans);
    color: var(--color-text-primary);
    background-color: var(--color-bg-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--color-border);
    z-index: 1000;
}

.nav-container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 20px 40px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    font-size: 16px;
    font-weight: 700;
    color: var(--color-text-primary);
    text-decoration: none;
    letter-spacing: -0.02em;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 36px;
}

.nav-menu a {
    text-decoration: none;
    color: var(--color-text-secondary);
    font-size: 14px;
    font-weight: 500;
    transition: var(--transition);
}

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

/* Hero Section */
.hero {
    padding: 180px 40px 120px;
    text-align: center;
    background-color: #0f172a;
}

.hero-container {
    max-width: 800px;
    margin: 0 auto;
}

.hero-label {
    font-size: 13px;
    font-weight: 500;
    color: #94a3b8;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    margin-bottom: 20px;
}

.hero-heading {
    font-size: 72px;
    font-weight: 800;
    color: #ffffff;
    letter-spacing: -0.04em;
    margin-bottom: 28px;
    line-height: 1.05;
}

.hero-description {
    font-size: 19px;
    color: #94a3b8;
    line-height: 1.7;
    max-width: 560px;
    margin: 0 auto;
}

/* Section Styles */
.section {
    padding: 80px 40px;
}

.section-gray {
    background-color: var(--color-bg-secondary);
}

.content-container {
    max-width: 1100px;
    margin: 0 auto;
}

.section-heading {
    font-size: 26px;
    font-weight: 700;
    color: var(--color-text-primary);
    letter-spacing: -0.02em;
    margin-bottom: 40px;
}

/* About Section */
.about-content {
    max-width: 680px;
    margin-bottom: 56px;
}

.about-content p {
    font-size: 17px;
    line-height: 1.8;
    color: var(--color-text-secondary);
    margin-bottom: 20px;
}

.about-content p:first-child {
    font-size: 20px;
    color: var(--color-text-primary);
    font-weight: 600;
    line-height: 1.5;
}

/* Contact Section */
.contact-section {
    max-width: 680px;
}

.contact-heading {
    font-size: 18px;
    font-weight: 700;
    color: var(--color-text-primary);
    margin-bottom: 20px;
}

.contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 12px;
}

.contact-card {
    display: flex;
    flex-direction: column;
    gap: 4px;
    padding: 18px 20px;
    border: 1px solid var(--color-border);
    border-radius: 8px;
    text-decoration: none;
    transition: var(--transition);
    background-color: var(--color-bg-primary);
}

.contact-card:hover {
    border-color: #aaaaaa;
    background-color: var(--color-bg-secondary);
}

.contact-label {
    font-size: 12px;
    color: var(--color-text-tertiary);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

.contact-value {
    font-size: 15px;
    color: var(--color-text-primary);
    font-weight: 500;
}

/* Experience Section */
.experience-card {
    max-width: 680px;
}

.experience-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 20px;
    gap: 20px;
}

.experience-company {
    font-size: 24px;
    font-weight: 700;
    color: var(--color-text-primary);
    margin-bottom: 4px;
    letter-spacing: -0.02em;
}

.experience-role {
    font-size: 16px;
    color: var(--color-text-secondary);
    font-weight: 500;
}

.experience-period-wrap {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: 5px;
    flex-shrink: 0;
}

.experience-period {
    font-size: 14px;
    color: var(--color-text-secondary);
    white-space: nowrap;
    font-weight: 500;
}

.experience-duration {
    font-size: 12px;
    color: var(--color-accent);
    font-weight: 600;
    background-color: #eff6ff;
    padding: 2px 8px;
    border-radius: 4px;
    white-space: nowrap;
}

.experience-description {
    margin-bottom: 24px;
}

.experience-description p {
    font-size: 16px;
    line-height: 1.7;
    color: var(--color-text-secondary);
    margin-bottom: 12px;
}

.experience-responsibilities h4 {
    font-size: 14px;
    font-weight: 700;
    color: var(--color-text-primary);
    margin-bottom: 16px;
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

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

.experience-responsibilities li {
    font-size: 15px;
    color: var(--color-text-secondary);
    padding: 8px 0;
    padding-left: 20px;
    position: relative;
    line-height: 1.6;
    border-bottom: 1px solid #f0f0f0;
}

.experience-responsibilities li:last-child {
    border-bottom: none;
}

.experience-responsibilities li:before {
    content: "–";
    position: absolute;
    left: 0;
    color: var(--color-text-tertiary);
}

/* Projects Grid */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
    gap: 20px;
}

.project-card {
    display: flex;
    flex-direction: column;
    padding: 32px;
    border: 1px solid var(--color-border);
    border-radius: 10px;
    text-decoration: none;
    transition: var(--transition);
    background-color: var(--color-bg-primary);
}

.project-card:hover {
    border-color: #aaaaaa;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.07);
    transform: translateY(-2px);
}

.project-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 16px;
}

.project-period {
    font-size: 13px;
    color: var(--color-accent);
    font-weight: 600;
    background-color: #eff6ff;
    padding: 3px 8px;
    border-radius: 4px;
}

.project-role {
    font-size: 12px;
    color: var(--color-text-tertiary);
    font-weight: 500;
}

.project-title {
    font-size: 22px;
    font-weight: 700;
    color: var(--color-text-primary);
    margin-bottom: 8px;
    letter-spacing: -0.02em;
}

.project-summary {
    font-size: 15px;
    color: var(--color-text-secondary);
    margin-bottom: 20px;
    line-height: 1.6;
    flex: 1;
}

.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-top: auto;
}

.tag {
    font-size: 12px;
    color: var(--color-text-secondary);
    padding: 4px 10px;
    background-color: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: 4px;
    font-weight: 500;
}

/* Footer */
.footer {
    padding: 48px 40px;
    text-align: center;
    border-top: 1px solid var(--color-border);
}

.footer-container {
    max-width: 1100px;
    margin: 0 auto;
}

.footer p {
    font-size: 13px;
    color: var(--color-text-tertiary);
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-container {
        padding: 18px 24px;
    }

    .nav-menu {
        gap: 24px;
    }

    .hero {
        padding: 160px 24px 80px;
    }

    .hero-heading {
        font-size: 52px;
    }

    .hero-description {
        font-size: 17px;
    }

    .section {
        padding: 60px 24px;
    }

    .section-heading {
        font-size: 22px;
        margin-bottom: 32px;
    }

    .experience-header {
        flex-direction: column;
        gap: 12px;
    }

    .experience-period-wrap {
        align-items: flex-start;
    }

    .projects-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }

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

@media (max-width: 480px) {
    .hero-heading {
        font-size: 42px;
    }

    .project-card {
        padding: 24px;
    }

    .section {
        padding: 48px 20px;
    }
}

/* Project Detail Page Styles */
.detail-hero {
    padding: 140px 40px 60px;
    border-bottom: 1px solid var(--color-border);
    background-color: #0f172a;
}

.detail-hero-container {
    max-width: 800px;
    margin: 0 auto;
}

.back-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-size: 14px;
    color: #94a3b8;
    text-decoration: none;
    margin-bottom: 40px;
    transition: var(--transition);
    font-weight: 500;
}

.back-link:hover {
    color: #ffffff;
}

.detail-meta {
    display: flex;
    gap: 20px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.detail-meta-item {
    font-size: 14px;
    color: #64748b;
}

.detail-meta-item strong {
    color: #94a3b8;
    font-weight: 600;
}

.detail-title {
    font-size: 52px;
    font-weight: 800;
    color: #ffffff;
    letter-spacing: -0.03em;
    margin-bottom: 14px;
    line-height: 1.1;
}

.detail-subtitle {
    font-size: 19px;
    color: #94a3b8;
    line-height: 1.6;
    margin-bottom: 32px;
}

.detail-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.detail-tag {
    font-size: 12px;
    color: #94a3b8;
    padding: 5px 12px;
    background-color: rgba(255, 255, 255, 0.07);
    border: 1px solid rgba(255, 255, 255, 0.12);
    border-radius: 4px;
    font-weight: 500;
}

.detail-content {
    padding: 72px 40px;
}

.detail-content-container {
    max-width: 800px;
    margin: 0 auto;
}

.detail-section {
    margin-bottom: 56px;
}

.detail-section:last-child {
    margin-bottom: 0;
}

.detail-section h3 {
    font-size: 12px;
    font-weight: 700;
    color: var(--color-accent);
    letter-spacing: 0.1em;
    text-transform: uppercase;
    margin-bottom: 20px;
    padding-left: 12px;
    border-left: 3px solid var(--color-accent);
}

.detail-highlights {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
    margin-bottom: 64px;
}

.detail-highlight-card {
    padding: 24px 20px;
    background-color: var(--color-bg-secondary);
    border-radius: 10px;
    border: 1px solid var(--color-border);
}

.detail-highlight-number {
    font-size: 36px;
    font-weight: 800;
    color: var(--color-text-primary);
    letter-spacing: -0.04em;
    line-height: 1;
    margin-bottom: 6px;
}

.detail-highlight-label {
    font-size: 13px;
    color: var(--color-text-secondary);
    line-height: 1.5;
}

@media (max-width: 600px) {
    .detail-highlights {
        grid-template-columns: repeat(3, 1fr);
        gap: 10px;
    }

    .detail-highlight-number {
        font-size: 28px;
    }

    .detail-highlight-label {
        font-size: 11px;
    }
}

.detail-section p {
    font-size: 17px;
    line-height: 1.8;
    color: var(--color-text-secondary);
    margin-bottom: 14px;
}

.detail-section ul {
    list-style: disc;
    padding-left: 20px;
}

.detail-section li {
    font-size: 16px;
    color: var(--color-text-secondary);
    padding: 6px 0;
    line-height: 1.7;
}

@media (max-width: 768px) {
    .detail-hero {
        padding: 130px 24px 48px;
    }

    .detail-title {
        font-size: 38px;
    }

    .detail-subtitle {
        font-size: 17px;
    }

    .detail-content {
        padding: 56px 24px;
    }
}