/* ===== DataSens Inc. — Corporate Site ===== */
/* Palette derived from the DataSens logo: slate-gray nodes + blue accent node */
:root {
    --primary: #2f80ed;
    /* Accent node blue */
    --primary-dark: #1c6cd6;
    --secondary: #2d3748;
    /* Slate (logo wordmark) */
    --slate: #4a5568;
    --accent: #7fb1f2;
    --navy: #1f2d57;
    /* 세련된 군청 (Mission & Values 대비용) */
    --text-main: #334155;
    --text-muted: #64748b;
    --bg-light: #f3f7fd;
    --bg-white: #ffffff;
    --border: #e6edf6;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-family: 'Inter', 'Pretendard', sans-serif;
    scroll-padding-top: 80px;
}

body {
    color: var(--text-main);
    line-height: 1.6;
    background-color: var(--bg-white);
    overflow-x: hidden;
}

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

ul {
    list-style: none;
}

.text-center {
    text-align: center;
}

.mt-3 {
    margin-top: 1.5rem;
}

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

.highlight {
    color: var(--primary);
}

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

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

/* ===== Typography ===== */
h1,
h2,
h3,
h4 {
    color: var(--secondary);
    font-weight: 700;
    line-height: 1.25;
}

.section {
    padding: 2rem 0;
}

.section-header {
    text-align: center;
    margin-bottom: 1.4rem;
}

.section-header h2 {
    font-size: 1.8rem;
    margin-bottom: 0.2rem;
}

.section-header .text-ko {
    color: var(--text-muted);
    font-size: 0.95rem;
    margin-top: 0.2rem;
    margin-bottom: 0.8rem;
}

.divider {
    height: 4px;
    width: 60px;
    background: var(--primary);
    margin: 0 auto;
    border-radius: 2px;
}

/* ===== Buttons ===== */
.btn {
    display: inline-block;
    padding: 0.8rem 2rem;
    border-radius: 50px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    border: 2px solid transparent;
}

.btn-primary {
    background: var(--primary);
    color: #fff;
    box-shadow: 0 2px 6px rgba(47, 128, 237, 0.18);
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(47, 128, 237, 0.22);
}

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

.btn-secondary:hover {
    background: var(--primary);
    color: #fff;
    transform: translateY(-2px);
}

.btn-light {
    background: #fff;
    color: var(--primary);
}

.btn-light:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.15);
}

/* ===== Navbar ===== */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    transition: var(--transition);
    padding: 0.6rem 0;
    background: rgba(255, 255, 255, 0.97);
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.05);
    border-bottom: 1px solid var(--border);
}

.navbar.scrolled {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
}

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

.logo {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--secondary);
    letter-spacing: -0.5px;
}

.logo img {
    height: 38px;
    width: auto;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 1.6rem;
}

.nav-links a {
    color: var(--secondary);
    font-weight: 500;
    font-size: 0.85rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    line-height: 1.2;
    text-align: center;
}

.nav-links a .nav-ko {
    font-size: 0.7rem;
    font-weight: 300;
    color: var(--text-muted);
    margin-top: 1px;
}

.nav-links a:hover,
.nav-links a:hover .nav-ko {
    color: var(--primary);
}

.btn-contact {
    background: var(--primary);
    color: #fff !important;
    padding: 0.5rem 1.3rem;
    border-radius: 50px;
}

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

.btn-contact .nav-ko {
    color: rgba(255, 255, 255, 0.85) !important;
}

.hamburger {
    display: none;
    color: var(--secondary);
    font-size: 1.5rem;
    cursor: pointer;
}

/* ===== Hero ===== */
.hero {
    padding: 5.5rem 1rem 2.2rem;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    background-color: var(--bg-light);
    color: var(--secondary);
    text-align: center;
    overflow: hidden;
}

.hero-content {
    max-width: 820px;
    z-index: 2;
}

.hero-logo {
    height: 56px;
    width: auto;
    margin-bottom: 0.7rem;
}

.hero h1 {
    font-size: 2.1rem;
    margin-bottom: 0.3rem;
}

.hero .tagline-ko {
    font-size: 0.98rem;
    color: var(--text-muted);
    margin-bottom: 0.9rem;
    font-weight: 400;
}

.hero p.lead {
    font-size: 0.92rem;
    color: var(--text-main);
    max-width: 600px;
    margin: 0 auto 1.1rem;
}

.hero-buttons {
    display: flex;
    gap: 0.9rem;
    justify-content: center;
    flex-wrap: wrap;
}

/* ===== Stats Strip ===== */
.stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1rem;
    max-width: 820px;
    margin: 1.3rem auto 0;
}

.stat-item {
    text-align: center;
}

.stat-num {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
}

.stat-label {
    font-size: 0.82rem;
    color: var(--text-muted);
}

/* R&D 연구실 링크 버튼 */
.stat-link {
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 0.5rem 0.4rem;
    background: #fff;
    transition: var(--transition);
}

.stat-link:hover {
    border-color: var(--primary);
    box-shadow: 0 8px 20px rgba(47, 128, 237, 0.14);
    transform: translateY(-3px);
}

.stat-link .stat-label i {
    font-size: 0.65rem;
    margin-left: 0.15rem;
}

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

/* ===== About ===== */
.about-grid {
    display: grid;
    grid-template-columns: 1.4fr 1fr;
    gap: 2.4rem;
    align-items: center;
}

.about-text .bilingual-group {
    margin-bottom: 0.9rem;
}

.about-text p {
    color: var(--text-main);
    font-size: 0.92rem;
}

.about-card {
    background-color: var(--navy);
    border-radius: 16px;
    padding: 1.8rem;
    color: #fff;
    box-shadow: 0 16px 36px rgba(31, 45, 87, 0.28);
}

.about-card h3 {
    color: #fff;
    margin-bottom: 0.9rem;
    font-size: 1.15rem;
}

.about-card ul li {
    display: flex;
    align-items: flex-start;
    gap: 0.6rem;
    margin-bottom: 0.6rem;
    font-size: 0.88rem;
    color: rgba(255, 255, 255, 0.88);
}

.about-card ul li i {
    margin-top: 0.25rem;
    color: var(--accent);
}

/* ===== Cards grid (services / why) ===== */
.card-grid {
    display: grid;
    gap: 1rem;
}

/* 솔루션: 한 줄에 3개, 강점: 한 줄에 4개 → 세로 행 수 최소화 */
#solutions .card-grid {
    grid-template-columns: repeat(3, 1fr);
}

#why .card-grid {
    grid-template-columns: repeat(4, 1fr);
}

.feature-card {
    background: #fff;
    border: 1px solid var(--border);
    padding: 1.2rem 1.3rem;
    border-radius: 14px;
    transition: var(--transition);
    position: relative;
}

.feature-card:hover {
    box-shadow: 0 14px 32px rgba(47, 128, 237, 0.12);
    transform: translateY(-4px);
}

.card-icon {
    width: 42px;
    height: 42px;
    background: var(--bg-light);
    border-radius: 11px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    color: var(--primary);
    margin-bottom: 0.7rem;
}

.feature-card h3 {
    font-size: 1.02rem;
    margin-bottom: 0.1rem;
}

.feature-card h4.text-ko {
    font-size: 0.8rem;
    color: var(--primary);
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.feature-card p {
    color: var(--text-muted);
    font-size: 0.85rem;
    line-height: 1.5;
}

/* ===== Portfolio ===== */
.project-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.1rem;
}

.project-card {
    background: #fff;
    border: 1px solid var(--border);
    border-left: 4px solid var(--primary);
    border-radius: 14px;
    padding: 1.4rem 1.6rem;
    transition: var(--transition);
}

.project-card:hover {
    box-shadow: 0 14px 32px rgba(31, 45, 87, 0.1);
    transform: translateY(-4px);
}

.project-meta {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: 0.4rem;
    margin-bottom: 0.6rem;
}

.project-tag {
    font-size: 0.72rem;
    font-weight: 600;
    color: var(--primary);
    background: var(--bg-light);
    padding: 0.2rem 0.7rem;
    border-radius: 50px;
}

.project-year {
    font-size: 0.78rem;
    color: var(--text-muted);
    font-weight: 500;
}

.project-card h3 {
    font-size: 1.05rem;
    margin-bottom: 0.4rem;
}

.project-card p {
    font-size: 0.85rem;
    color: var(--text-muted);
    line-height: 1.55;
    margin-bottom: 0.8rem;
}

.project-outcome {
    display: inline-flex;
    align-items: center;
    gap: 0.45rem;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--navy);
    background: #eef3fb;
    padding: 0.4rem 0.8rem;
    border-radius: 8px;
}

.project-outcome i {
    color: var(--primary);
}

/* ===== Education ===== */
.edu-list {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 0.7rem 1.1rem;
}

.edu-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 0.8rem 1.1rem;
    transition: var(--transition);
}

.edu-item:hover {
    border-color: var(--primary);
    transform: translateX(4px);
    box-shadow: 0 8px 20px rgba(31, 45, 87, 0.06);
}

.edu-date {
    flex: 0 0 auto;
    font-size: 0.78rem;
    font-weight: 700;
    color: var(--primary);
    min-width: 80px;
    text-align: center;
}

.edu-body h4 {
    font-size: 0.92rem;
    margin-bottom: 0.1rem;
}

.edu-client {
    font-size: 0.78rem;
    color: var(--text-muted);
}

/* ===== CTA banner ===== */
.cta-banner {
    padding: 3rem 0;
    text-align: center;
}

.cta-banner h2 {
    color: #fff;
    font-size: 1.5rem;
    margin-bottom: 0.4rem;
}

.cta-banner .text-ko {
    color: rgba(255, 255, 255, 0.9);
    font-size: 0.95rem;
    margin-bottom: 1.2rem;
}

/* ===== Contact ===== */
.contact-bar {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: 1.5rem 2rem;
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 1.6rem 2.2rem;
    box-shadow: 0 8px 24px rgba(31, 45, 87, 0.05);
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 0.8rem;
    flex: 1 1 auto;
}

.contact-item i {
    color: var(--primary);
    font-size: 1.3rem;
    width: 26px;
    text-align: center;
}

.contact-item div {
    display: flex;
    flex-direction: column;
    line-height: 1.35;
}

.contact-item strong {
    font-size: 0.95rem;
    color: var(--secondary);
}

.contact-item span,
.contact-item a {
    font-size: 0.88rem;
    color: var(--text-muted);
}

.contact-item a {
    color: var(--primary);
    font-weight: 600;
}

.contact-bar .btn {
    flex: 0 0 auto;
    white-space: nowrap;
}

/* ===== Footer ===== */
.footer {
    background: var(--secondary);
    color: #fff;
    padding: 2.6rem 0 1.4rem;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1.4fr;
    gap: 3rem;
    margin-bottom: 2.5rem;
}

.footer-brand img {
    height: 42px;
    margin-bottom: 1rem;
    filter: brightness(0) invert(1);
    opacity: 0.95;
}

.footer-brand p {
    color: rgba(255, 255, 255, 0.6);
    max-width: 320px;
    font-size: 0.95rem;
}

.footer-links h3,
.footer-contact h3 {
    color: #fff;
    font-size: 1.05rem;
    margin-bottom: 1.2rem;
}

.footer-links ul li {
    margin-bottom: 0.7rem;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.95rem;
}

.footer-links a:hover {
    color: var(--accent);
    padding-left: 4px;
}

.footer-contact p {
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: 0.8rem;
    font-size: 0.92rem;
    display: flex;
    gap: 0.7rem;
}

.footer-contact i {
    color: var(--accent);
    margin-top: 0.25rem;
}

.footer-bottom {
    text-align: center;
    padding-top: 1.8rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.5);
    font-size: 0.88rem;
}

/* ===== Bilingual utilities ===== */
.bilingual-group {
    margin-bottom: 1rem;
}

.text-en {
    font-weight: 600;
    line-height: 1.4;
}

.text-ko {
    font-size: 0.95em;
    margin-top: 0.2rem;
    line-height: 1.4;
    font-weight: 400;
}

/* ===== Animations ===== */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ===== Responsive ===== */
@media (max-width: 992px) {

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

    .contact-bar {
        flex-direction: column;
        align-items: flex-start;
        gap: 1.1rem;
    }

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

    .stats {
        grid-template-columns: repeat(4, 1fr);
        gap: 1rem;
    }

    /* 좁아지면 솔루션·강점 모두 2열로 */
    #solutions .card-grid,
    #why .card-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 700px) {
    .project-grid,
    .edu-list {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 560px) {

    #solutions .card-grid,
    #why .card-grid {
        grid-template-columns: 1fr;
    }

    .stats {
        grid-template-columns: repeat(2, 1fr);
        gap: 1rem;
    }
}

@media (max-width: 768px) {
    .nav-links {
        position: fixed;
        background: var(--bg-white);
        top: 0;
        right: -100%;
        width: 250px;
        height: 100vh;
        flex-direction: column;
        justify-content: center;
        box-shadow: -5px 0 20px rgba(0, 0, 0, 0.1);
        transition: right 0.4s ease;
        gap: 1.8rem;
    }

    .nav-links.active {
        right: 0;
    }

    .nav-links a {
        font-size: 1.1rem;
    }

    .hamburger {
        display: block;
        z-index: 1001;
    }

    .hero h1 {
        font-size: 2.1rem;
    }

    .section-header h2 {
        font-size: 1.9rem;
    }
}