/* ===== CSS 변수 ===== */
:root {
    --primary: #1a56db;
    --primary-dark: #1e40af;
    --secondary: #111827;
    --text-primary: #111827;
    --text-secondary: #4b5563;
    --text-muted: #6b7280;
    --bg-white: #ffffff;
    --bg-light: #f9fafb;
    --bg-dark: #111827;
    --border: #e5e7eb;
    --border-dark: #374151;
}

/* ===== 기본 리셋 ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans KR', -apple-system, BlinkMacSystemFont, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-white);
}

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

/* ===== 헤더 ===== */
#header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: var(--bg-white);
    border-bottom: 1px solid var(--border);
}

.navbar {
    padding: 0 24px;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.logo-text {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--primary);
    letter-spacing: -0.5px;
}

.nav-menu {
    display: flex;
    gap: 4px;
}

.menu-link {
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
    padding: 8px 16px;
    border-radius: 4px;
    transition: all 0.15s;
}

.menu-link:hover,
.menu-link.active {
    color: var(--text-primary);
    background: var(--bg-light);
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.mobile-menu-btn span {
    width: 20px;
    height: 2px;
    background: var(--text-primary);
}

.mobile-menu {
    display: none;
    position: fixed;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--bg-white);
    border-bottom: 1px solid var(--border);
    padding: 16px 24px;
    opacity: 0;
    visibility: hidden;
    transition: all 0.2s;
}

.mobile-menu.active {
    opacity: 1;
    visibility: visible;
}

.mobile-nav-menu {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.mobile-menu-link {
    display: block;
    padding: 12px 16px;
    color: var(--text-secondary);
    font-weight: 500;
    border-radius: 4px;
}

.mobile-menu-link:hover,
.mobile-menu-link.active {
    background: var(--bg-light);
    color: var(--text-primary);
}

/* ===== 히어로 섹션 ===== */
.hero-section {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-dark);
    padding: 64px 24px;
    position: relative;
}

.hero-content {
    text-align: center;
    max-width: 800px;
}

.hero-subtitle {
    color: var(--primary);
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 16px;
    letter-spacing: 1px;
}

.hero-content h1 {
    font-size: 3.5rem;
    font-weight: 700;
    color: #fff;
    line-height: 1.2;
    margin-bottom: 24px;
    letter-spacing: -1px;
}

.hero-desc {
    font-size: 1.1rem;
    color: #9ca3af;
    margin-bottom: 40px;
}

.hero-buttons {
    display: flex;
    gap: 12px;
    justify-content: center;
}

.btn-primary {
    display: inline-block;
    background: var(--primary);
    color: #fff;
    padding: 14px 32px;
    font-size: 0.95rem;
    font-weight: 500;
    border-radius: 4px;
    border: none;
    cursor: pointer;
    transition: background 0.15s;
}

.btn-primary:hover {
    background: var(--primary-dark);
}

.hero-scroll {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    text-align: center;
    color: #6b7280;
    font-size: 0.75rem;
    letter-spacing: 2px;
}

.scroll-line {
    width: 1px;
    height: 40px;
    background: linear-gradient(to bottom, #6b7280, transparent);
    margin: 12px auto 0;
}

/* ===== 콘텐츠 섹션 공통 ===== */
.content-section {
    padding: 120px 24px;
}

.section-dark {
    background: var(--bg-dark);
    color: #fff;
}

.section-dark .section-header h2 {
    color: #fff;
}

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

.section-header {
    margin-bottom: 64px;
}

.section-label {
    display: block;
    color: var(--primary);
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 2px;
    margin-bottom: 12px;
}

.section-header h2 {
    font-size: 2.25rem;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -0.5px;
}

/* ===== 회사소개 섹션 ===== */
.company-intro {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
    margin-bottom: 80px;
}

.company-text h3 {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-primary);
    line-height: 1.4;
    margin-bottom: 24px;
}

.company-text p {
    font-size: 1rem;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 16px;
}

.company-image {
    aspect-ratio: 4/3;
    border: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.company-image svg {
    width: 100%;
    height: 100%;
}

.company-features {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.feature-card {
    padding: 32px;
    border: 1px solid var(--border);
    transition: border-color 0.2s;
}

.feature-card:hover {
    border-color: var(--primary);
}

.feature-icon {
    width: 48px;
    height: 48px;
    margin-bottom: 20px;
}

.feature-icon svg {
    width: 100%;
    height: 100%;
    stroke: var(--primary);
}

.feature-card h4 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 12px;
}

.feature-card p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ===== 주요기술 섹션 ===== */
.tech-category {
    margin-bottom: 60px;
}

.tech-category:last-of-type {
    margin-bottom: 40px;
}

.tech-category-header {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 24px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--border-dark);
}

.tech-category-number {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--primary);
    background: rgba(26, 86, 219, 0.15);
    padding: 6px 12px;
    border-radius: 4px;
}

.tech-category-header h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: #fff;
}

.tech-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

.tech-grid-wide {
    grid-template-columns: 1fr;
}

.tech-grid-half {
    grid-template-columns: repeat(2, 1fr);
}

.tech-card {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-dark);
    padding: 24px;
    transition: border-color 0.2s;
}

.tech-card:hover {
    border-color: var(--primary);
}

.tech-card-featured {
    background: rgba(26, 86, 219, 0.08);
    border-color: rgba(26, 86, 219, 0.3);
}

.tech-card h4 {
    font-size: 1.05rem;
    font-weight: 600;
    color: #fff;
    margin-bottom: 12px;
}

.tech-card > p {
    font-size: 0.9rem;
    color: #9ca3af;
    line-height: 1.7;
    margin-bottom: 16px;
}

.tech-card strong {
    color: #d1d5db;
}

.tech-card-detail {
    padding: 16px;
    background: rgba(0, 0, 0, 0.2);
    border-left: 3px solid var(--primary);
    margin-bottom: 16px;
}

.tech-card-detail p {
    font-size: 0.85rem;
    color: #9ca3af;
    line-height: 1.7;
    margin: 0;
}

.tech-features {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.tech-features li {
    font-size: 0.8rem;
    color: #6b7280;
    padding-left: 16px;
    position: relative;
}

.tech-features li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 8px;
    width: 6px;
    height: 6px;
    background: var(--primary);
    border-radius: 50%;
}

.tech-summary {
    padding: 32px;
    background: rgba(26, 86, 219, 0.1);
    border: 1px solid rgba(26, 86, 219, 0.2);
    text-align: center;
}

.tech-summary p {
    font-size: 0.95rem;
    color: #d1d5db;
    line-height: 1.8;
}

.tech-summary strong {
    color: #fff;
}

/* ===== 제품소개 섹션 ===== */
.product-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.product-card {
    padding: 32px;
    border: 1px solid var(--border);
    transition: border-color 0.2s;
}

.product-card:hover {
    border-color: var(--primary);
}

.product-header {
    margin-bottom: 16px;
}

.product-tag {
    display: inline-block;
    font-size: 0.7rem;
    font-weight: 600;
    color: var(--primary);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 8px;
}

.product-header h4 {
    font-size: 1.15rem;
    font-weight: 600;
    color: var(--text-primary);
}

.product-card > p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 20px;
}

.product-features {
    list-style: none;
}

.product-features li {
    font-size: 0.85rem;
    color: var(--text-muted);
    padding: 8px 0;
    border-top: 1px solid var(--border);
}

.product-features li:last-child {
    padding-bottom: 0;
}

/* ===== 기술비전 섹션 ===== */
.vision-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: start;
}

.vision-main h3 {
    font-size: 1.75rem;
    font-weight: 700;
    color: #fff;
    margin-bottom: 20px;
    line-height: 1.4;
}

.vision-main p {
    font-size: 1rem;
    color: #9ca3af;
    line-height: 1.8;
}

.vision-goals {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.vision-goal {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 20px;
    border: 1px solid var(--border-dark);
}

.goal-icon {
    width: 24px;
    height: 24px;
    flex-shrink: 0;
}

.goal-icon svg {
    width: 100%;
    height: 100%;
    stroke: var(--primary);
}

.vision-goal span {
    font-size: 0.95rem;
    color: #d1d5db;
}

/* ===== 연구소장 소개 섹션 ===== */
.director-intro {
    display: flex;
    flex-direction: column;
    gap: 40px;
    margin-bottom: 60px;
}

.director-profile-header {
    padding-bottom: 32px;
    border-bottom: 1px solid var(--border);
}

.director-info h3 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.director-info h3 span {
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-secondary);
}

.director-title {
    font-size: 0.9rem;
    color: var(--primary);
    font-weight: 500;
    margin-bottom: 16px;
}

.director-career p {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 6px;
    padding-left: 12px;
    border-left: 2px solid var(--border);
}

.director-career-list {
    list-style: none;
    margin-top: 8px;
}

.director-career-list li {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 6px;
    padding-left: 16px;
    position: relative;
}

.director-career-list li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 8px;
    width: 6px;
    height: 6px;
    background: var(--primary);
    border-radius: 50%;
}

.director-content {
    display: flex;
    flex-direction: column;
    gap: 40px;
}

.director-philosophy h4,
.director-achievements h4 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 16px;
}

.director-philosophy blockquote {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--primary);
    padding: 20px 24px;
    background: var(--bg-light);
    border-left: 4px solid var(--primary);
    margin-bottom: 20px;
}

.director-philosophy p {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 12px;
}

.director-philosophy strong {
    color: var(--text-primary);
}

.director-achievements ul {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.director-achievements li {
    padding: 20px;
    border: 1px solid var(--border);
    transition: border-color 0.2s;
}

.director-achievements li:hover {
    border-color: var(--primary);
}

.director-achievements li strong {
    display: block;
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.director-achievements li p {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* 저작권/특허/인증 섹션 */
.credentials-section {
    margin-bottom: 60px;
    padding-top: 40px;
    border-top: 1px solid var(--border);
}

.credentials-section > h4 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 24px;
}

.credentials-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.credential-category {
    border: 1px solid var(--border);
    padding: 24px;
}

.credential-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border);
}

.credential-type {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
}

.credential-count {
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--primary);
    background: rgba(26, 86, 219, 0.1);
    padding: 4px 10px;
    border-radius: 12px;
}

.credential-items {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(100px, 1fr));
    gap: 12px;
}

.credential-item {
    aspect-ratio: 3/4;
    overflow: hidden;
    border: 1px solid var(--border);
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
}

.credential-item:hover {
    transform: scale(1.02);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.credential-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

/* 약속 섹션 */
.director-promise {
    text-align: center;
    padding: 40px;
    background: var(--bg-dark);
}

.director-promise p {
    font-size: 1.1rem;
    font-weight: 500;
    color: #d1d5db;
    font-style: italic;
}

/* section-alt 스타일 */
.section-alt {
    background: var(--bg-light);
}

/* ===== 오시는길 섹션 ===== */
.contact-info-box {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.contact-info-box .info-item {
    padding: 40px;
    background: var(--bg-light);
    text-align: center;
}

.contact-info-box .info-item h4 {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 12px;
}

.contact-info-box .info-item p {
    font-size: 1.1rem;
    color: var(--text-primary);
    font-weight: 500;
}

/* ===== 푸터 ===== */
#footer {
    background: var(--bg-dark);
    color: #9ca3af;
    padding: 64px 24px 32px;
}

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

.footer-main {
    display: flex;
    justify-content: space-between;
    padding-bottom: 40px;
    border-bottom: 1px solid var(--border-dark);
}

.footer-logo {
    font-size: 1.25rem;
    font-weight: 800;
    color: #fff;
    margin-bottom: 12px;
}

.footer-brand p {
    font-size: 0.9rem;
    line-height: 1.6;
}

.footer-contact p {
    font-size: 0.9rem;
    margin-bottom: 4px;
}

.footer-contact strong {
    color: #fff;
}

.footer-bottom {
    padding-top: 24px;
    text-align: center;
    font-size: 0.8rem;
}

/* ===== 반응형 ===== */
@media (max-width: 1024px) {
    .tech-grid,
    .tech-grid-half {
        grid-template-columns: 1fr;
    }

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

    .company-intro {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .company-image {
        order: -1;
    }

    .company-features {
        grid-template-columns: 1fr;
    }

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

    .vision-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }

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

@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }

    .mobile-menu-btn {
        display: flex;
    }

    .mobile-menu {
        display: block;
    }

    .hero-content h1 {
        font-size: 2.25rem;
    }

    .content-section {
        padding: 80px 24px;
    }

    .section-header {
        margin-bottom: 48px;
    }

    .section-header h2 {
        font-size: 1.75rem;
    }

    .director-philosophy blockquote {
        font-size: 1.1rem;
    }

    .tech-category-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 8px;
    }

    .footer-main {
        flex-direction: column;
        gap: 32px;
    }
}