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

:root {
    --primary-color: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary-color: #64748b;
    --accent-color: #0ea5e9;
    --text-color: #1e293b;
    --text-light: #64748b;
    --bg-color: #ffffff;
    --bg-light: #f8fafc;
    --bg-dark: #0f172a;
    --border-color: #e2e8f0;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --radius: 8px;
    --transition: all 0.3s ease;
}

html {
    scroll-behavior: smooth;
}

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

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

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

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

img {
    max-width: 100%;
    height: auto;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 24px;
    border-radius: var(--radius);
    font-weight: 600;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    font-size: 1rem;
}

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

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

.btn-secondary {
    background-color: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

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

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow);
    z-index: 1000;
}

.header-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--text-color);
}

.logo img {
    height: 40px;
    width: auto;
}

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

.nav-list {
    display: flex;
    list-style: none;
    gap: 30px;
}

.nav-list a {
    color: var(--text-color);
    font-weight: 500;
    padding: 8px 0;
    position: relative;
}

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

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

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

.mobile-menu-btn span {
    display: block;
    width: 25px;
    height: 3px;
    background-color: var(--text-color);
    border-radius: 2px;
    transition: var(--transition);
}

/* Hero Section */
.hero {
    padding: 180px 0 100px;
    background: linear-gradient(135deg, var(--bg-light) 0%, #dbeafe 100%);
    text-align: center;
}

.hero-content h1 {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 20px;
    color: var(--text-color);
    line-height: 1.2;
}

.hero-content p {
    font-size: 1.25rem;
    color: var(--text-light);
    margin-bottom: 30px;
}

/* Sections */
.section {
    padding: 80px 0;
}

.section-title {
    font-size: 2.25rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 50px;
    color: var(--text-color);
}

/* About Section */
.about {
    background-color: var(--bg-color);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
    align-items: start;
}

.about-text h3 {
    font-size: 1.5rem;
    margin-bottom: 20px;
    color: var(--text-color);
}

.about-text p {
    color: var(--text-light);
    margin-bottom: 15px;
}

.about-features {
    list-style: none;
    margin-top: 20px;
}

.about-features li {
    padding: 8px 0 8px 30px;
    position: relative;
    color: var(--text-color);
}

.about-features li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

.info-card {
    background-color: var(--bg-light);
    padding: 30px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.info-card h4 {
    font-size: 1.25rem;
    margin-bottom: 20px;
    color: var(--text-color);
}

.info-card dl {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 10px 15px;
}

.info-card dt {
    font-weight: 600;
    color: var(--text-color);
}

.info-card dd {
    color: var(--text-light);
}

/* Products Section */
.products {
    background-color: var(--bg-light);
}

.products-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}

.products-grid-3 {
    grid-template-columns: repeat(3, 1fr);
}

.product-card {
    background-color: var(--bg-color);
    padding: 40px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.product-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.product-icon {
    width: 60px;
    height: 60px;
    background-color: var(--primary-color);
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
}

.product-icon svg {
    width: 30px;
    height: 30px;
    stroke: white;
}

.product-icon.sensor-icon {
    background-color: #0d9488;
}

.product-icon.center-icon {
    background-color: #7c3aed;
}

.product-icon.tbm-icon {
    background-color: #10b981;
}

.product-card h3 {
    font-size: 1.5rem;
    margin-bottom: 10px;
    color: var(--text-color);
}

.product-version {
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 15px;
}

.product-desc {
    color: var(--text-light);
    margin-bottom: 20px;
}

.product-features {
    list-style: none;
    margin-bottom: 25px;
}

.product-features li {
    padding: 6px 0 6px 25px;
    position: relative;
    color: var(--text-color);
    font-size: 0.95rem;
}

.product-features li::before {
    content: '•';
    position: absolute;
    left: 8px;
    color: var(--primary-color);
}

/* Contact Section */
.contact {
    background-color: var(--bg-color);
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: 50px;
}

.contact-info h3 {
    font-size: 1.5rem;
    margin-bottom: 25px;
    color: var(--text-color);
}

.contact-item {
    display: flex;
    gap: 15px;
    margin-bottom: 20px;
}

.contact-item svg {
    width: 24px;
    height: 24px;
    stroke: var(--primary-color);
    flex-shrink: 0;
    margin-top: 3px;
}

.contact-item strong {
    display: block;
    color: var(--text-color);
    margin-bottom: 5px;
}

.contact-item p {
    color: var(--text-light);
}

.contact-form {
    background-color: var(--bg-light);
    padding: 30px;
    border-radius: var(--radius);
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--text-color);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    font-size: 1rem;
    font-family: inherit;
    transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

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

/* Technology Section */
.technology {
    background-color: var(--bg-color);
}

.technology-content {
    max-width: 1000px;
    margin: 0 auto;
}

.technology-intro {
    text-align: center;
    margin-bottom: 50px;
}

.technology-intro h3 {
    font-size: 1.5rem;
    margin-bottom: 15px;
    color: var(--text-color);
}

.technology-intro p {
    color: var(--text-light);
    font-size: 1.1rem;
    max-width: 700px;
    margin: 0 auto;
}

.patents-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}

.patent-card {
    background-color: var(--bg-light);
    padding: 30px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    transition: var(--transition);
    border-left: 4px solid var(--primary-color);
}

.patent-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.patent-icon {
    width: 50px;
    height: 50px;
    background-color: var(--primary-color);
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 15px;
}

.patent-icon svg {
    width: 24px;
    height: 24px;
    stroke: white;
}

.patent-status {
    display: inline-block;
    background-color: #dbeafe;
    color: var(--primary-color);
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 15px;
}

.patent-card h4 {
    font-size: 1.15rem;
    margin-bottom: 10px;
    color: var(--text-color);
    line-height: 1.4;
}

.patent-meta {
    font-size: 0.9rem;
    color: var(--primary-color);
    margin-bottom: 10px;
    font-weight: 500;
}

.patent-desc {
    color: var(--text-light);
    margin-bottom: 15px;
    font-size: 0.95rem;
}

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

.patent-features li {
    padding: 5px 0 5px 20px;
    position: relative;
    color: var(--text-color);
    font-size: 0.9rem;
}

.patent-features li::before {
    content: '•';
    position: absolute;
    left: 5px;
    color: var(--primary-color);
}

@media (max-width: 768px) {
    .patents-grid {
        grid-template-columns: 1fr;
    }
}

/* Notices Section */
.notices {
    background-color: var(--bg-light);
}

.notices-list {
    max-width: 800px;
    margin: 0 auto;
}

.notice-item {
    background-color: var(--bg-color);
    border-radius: var(--radius);
    margin-bottom: 15px;
    box-shadow: var(--shadow);
    overflow: hidden;
}

.notice-header {
    display: flex;
    align-items: center;
    padding: 20px 25px;
    cursor: pointer;
    transition: var(--transition);
    position: relative;
}

.notice-header:hover {
    background-color: var(--bg-light);
}

.notice-header h4 {
    font-size: 1.1rem;
    color: var(--text-color);
    flex: 1;
    margin-right: 15px;
}

.notice-header .notice-date {
    font-size: 0.9rem;
    color: var(--text-light);
    margin-right: 15px;
}

.notice-toggle {
    font-size: 0.8rem;
    color: var(--text-light);
    transition: transform 0.3s ease;
}

.notice-item.active .notice-toggle {
    transform: rotate(180deg);
}

.notice-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease, padding 0.3s ease;
    padding: 0 25px;
    border-top: 0 solid var(--border-color);
}

.notice-item.active .notice-content {
    max-height: 500px;
    padding: 20px 25px;
    border-top: 1px solid var(--border-color);
}

.notice-content p {
    color: var(--text-color);
    line-height: 1.7;
    white-space: pre-wrap;
}

.no-notices {
    text-align: center;
    color: var(--text-light);
    padding: 40px;
}

/* 공지사항 더보기 버튼 */
.notices-more {
    text-align: center;
    margin-top: 30px;
}

/* 첨부파일 스타일 */
.notice-attachments {
    margin-top: 20px;
    padding-top: 15px;
    border-top: 1px dashed var(--border-color);
}

.notice-attachments h5 {
    font-size: 0.95rem;
    color: var(--text-color);
    margin-bottom: 12px;
}

.notice-attachments ul {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
}

.notice-attachments .attachment-image {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
}

.notice-attachments .attachment-image img {
    max-width: 200px;
    max-height: 150px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    object-fit: cover;
}

.notice-attachments .attachment-image span {
    font-size: 0.85rem;
    color: var(--text-light);
}

.notice-attachments .attachment-file a {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 15px;
    background-color: var(--bg-light);
    border-radius: var(--radius);
    color: var(--primary-color);
    font-size: 0.9rem;
    transition: var(--transition);
}

.notice-attachments .attachment-file a:hover {
    background-color: var(--primary-color);
    color: white;
}

.notice-attachments .attachment-file a::before {
    content: '📎';
}

/* Footer */
.footer {
    background-color: var(--bg-dark);
    color: #94a3b8;
    padding: 50px 0 20px;
}

.footer-content {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr;
    gap: 40px;
    padding-bottom: 30px;
    border-bottom: 1px solid #334155;
}

.footer-brand {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.footer-logo span {
    color: white;
    font-weight: 700;
    font-size: 1.3rem;
}

.footer-tagline {
    color: #64748b;
    font-size: 0.95rem;
}

.footer-contact h4,
.footer-address h4 {
    color: white;
    font-size: 1rem;
    margin-bottom: 15px;
    font-weight: 600;
}

.footer-contact ul,
.footer-address ul {
    list-style: none;
}

.footer-contact li,
.footer-address li {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 12px;
    font-size: 0.9rem;
}

.footer-contact svg,
.footer-address svg {
    width: 16px;
    height: 16px;
    stroke: var(--primary-color);
    flex-shrink: 0;
}

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    font-size: 0.9rem;
}

/* Responsive */
@media (max-width: 992px) {
    .about-content,
    .contact-content {
        grid-template-columns: 1fr;
    }

    .products-grid,
    .products-grid-3 {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .hero-content h1 {
        font-size: 2rem;
    }

    .hero-content p {
        font-size: 1rem;
    }

    .section {
        padding: 60px 0;
    }

    .section-title {
        font-size: 1.75rem;
    }

    .nav-list {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background-color: white;
        flex-direction: column;
        padding: 20px;
        gap: 15px;
        box-shadow: var(--shadow);
    }

    .nav-list.active {
        display: flex;
    }

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

    .footer-content {
        grid-template-columns: 1fr;
        gap: 30px;
        text-align: center;
    }

    .footer-brand {
        align-items: center;
    }

    .footer-contact li,
    .footer-address li {
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .hero {
        padding: 140px 0 60px;
    }

    .hero-content h1 {
        font-size: 1.5rem;
    }

    .product-card {
        padding: 25px;
    }

    .info-card dl {
        grid-template-columns: 1fr;
    }
}

/* Admin specific styles */
.admin-header {
    background-color: var(--bg-dark);
    color: white;
    padding: 15px 0;
}

.admin-header .logo {
    color: white;
}

.admin-header .logo img {
    display: none;
}

.admin-nav {
    background-color: #1e293b;
    padding: 10px 0;
}

.admin-nav ul {
    display: flex;
    list-style: none;
    gap: 20px;
}

.admin-nav a {
    color: #94a3b8;
    padding: 8px 15px;
    border-radius: var(--radius);
}

.admin-nav a:hover,
.admin-nav a.active {
    background-color: var(--primary-color);
    color: white;
}

.admin-content {
    padding: 30px 0;
    min-height: calc(100vh - 200px);
}

.admin-card {
    background-color: var(--bg-color);
    padding: 25px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    margin-bottom: 20px;
}

.admin-card h3 {
    margin-bottom: 20px;
    padding-bottom: 15px;
    border-bottom: 1px solid var(--border-color);
}

.admin-table {
    width: 100%;
    border-collapse: collapse;
}

.admin-table th,
.admin-table td {
    padding: 12px 15px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.admin-table th {
    background-color: var(--bg-light);
    font-weight: 600;
}

.admin-table tr:hover {
    background-color: var(--bg-light);
}

.btn-small {
    padding: 6px 12px;
    font-size: 0.875rem;
}

.btn-danger {
    background-color: #ef4444;
    color: white;
}

.btn-danger:hover {
    background-color: #dc2626;
    color: white;
}

.alert {
    padding: 15px 20px;
    border-radius: var(--radius);
    margin-bottom: 20px;
}

.alert-success {
    background-color: #d1fae5;
    color: #065f46;
    border: 1px solid #a7f3d0;
}

.alert-error {
    background-color: #fee2e2;
    color: #991b1b;
    border: 1px solid #fecaca;
}

/* Login page */
.login-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--bg-light) 0%, #dbeafe 100%);
}

.login-box {
    background-color: var(--bg-color);
    padding: 40px;
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    width: 100%;
    max-width: 400px;
}

.login-box h2 {
    text-align: center;
    margin-bottom: 30px;
}

.login-box .form-group {
    margin-bottom: 20px;
}

.login-box .btn {
    width: 100%;
}