:root {
    --primary-color: #003366;
    --secondary-color: #0056b3;
    --accent-color: #FF6B35; 
    --text-dark: #222;
    --text-light: #666;
    --bg-light: #f9f9f9;
    --white: #ffffff;
}

/* 기본 설정 */
* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: 'Noto Sans KR', sans-serif; line-height: 1.6; color: var(--text-dark); word-break: keep-all; scroll-behavior: smooth; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }

/* Header & Layout */
header { background: #fff; padding: 10px 0; position: fixed; width: 100%; top: 0; z-index: 1000; box-shadow: 0 2px 10px rgba(0,0,0,0.1); }
.nav-container { display: flex; justify-content: space-between; align-items: center; height: 60px; }

/* Logo 영역 */
.logo a { text-decoration: none; display: flex; align-items: center; color: var(--primary-color); }
.logo-img { height: 40px; width: auto; flex-shrink: 0; border-radius: 4px; }
.logo-text { font-size: 1.2rem; font-weight: 700; margin-left: 10px; white-space: nowrap; }
.logo-text span { font-weight: 300; }

.header-right { display: flex; align-items: center; gap: 30px; }
.nav-links { display: flex; list-style: none; }
.nav-links li { margin: 0 15px; }
.nav-links a { text-decoration: none; color: var(--text-dark); font-weight: 500; transition: 0.3s; }
.nav-links a:hover { color: var(--secondary-color); }

.lang-switch { font-size: 0.85rem; font-weight: bold; white-space: nowrap; color: #ccc; }
.lang-switch a { text-decoration: none; color: #999; transition: 0.3s; padding: 0 5px; }
.lang-switch a.active { color: var(--primary-color); }

/* home Section */
/* home Section Layout */
.home {
    height: 80vh;
    position: relative; /* 슬라이드 배치를 위해 필수 */
    overflow: hidden;
    display: flex;
    align-items: center;
    color: #fff;
    text-align: center;
    padding-top: 60px;
}

/* 개별 슬라이드 스타일 */
.home-slide {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    opacity: 0;
    transition: opacity 1.5s ease-in-out;
    z-index: 1;
}

/* 현재 활성화된 슬라이드 */
.home-slide.active {
    opacity: 1;
    z-index: 2;
}

/* 텍스트 콘텐츠 */
.home-content {
    position: relative;
    z-index: 10;
    width: 100%;
	padding-top: 100px;
}
.home h1 { font-size: 3.5rem; margin-bottom: 20px; font-weight: 700; }
.home h2 { color: var(--accent-color); font-size: 1.2rem; letter-spacing: 2px; margin-bottom: 10px; }
.home p { font-size: 1.1rem; margin-bottom: 30px; opacity: 0.9; }

/* Buttons */
.btn { padding: 15px 30px; border-radius: 4px; text-decoration: none; display: inline-block; transition: 0.3s; font-weight: bold; cursor: pointer; border: none; }
.btn-primary { background: var(--secondary-color); color: #fff; }
.btn-outline { border: 2px solid #fff; color: #fff; margin-left: 10px; }
.btn:hover { transform: translateY(-3px); opacity: 0.9; }

/* Sections Common */
section {
    padding: 100px 0;
    scroll-margin-top: 130px;
}
.section-title { text-align: center; margin-bottom: 60px; }
.section-title h2 { font-size: 2.5rem; color: var(--primary-color); position: relative; padding-bottom: 15px; }
.section-title h2::after { content: ''; position: absolute; bottom: 0; left: 50%; transform: translateX(-50%); width: 50px; height: 3px; background: var(--accent-color); }
.top-space-50 { margin-top: 50px; }

/* Strengths Grid */
.strength-grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.strength-item { padding: 40px 20px; background: var(--bg-light); text-align: center; border-bottom: 4px solid var(--primary-color); transition: 0.3s; }
.strength-item:hover { transform: translateY(-10px); background: #fff; box-shadow: 0 10px 30px rgba(0,0,0,0.05); }
.strength-item .icon { font-size: 3rem; margin-bottom: 20px; display: block; }
.strength-item h4 { font-size: 1.2rem; color: var(--primary-color); margin-bottom: 10px; }

/* Solutions Grid & Hover Effect */
.solution-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 20px; }
.solution-item { background: #fff; padding: 30px; border: 1px solid #eee; border-radius: 8px; position: relative; transition: all 0.3s ease; overflow: hidden; }
.sol-num { font-size: 2rem; font-weight: 700; color: #eee; position: absolute; top: 20px; right: 20px; transition: all 0.3s ease; }
.solution-item h3 { margin-bottom: 15px; color: var(--primary-color); position: relative; z-index: 1; transition: 0.3s; }
.solution-item p { position: relative; z-index: 1; transition: 0.3s; }

.solution-item:hover { background: var(--primary-color); transform: translateY(-5px); border-color: var(--primary-color); box-shadow: 0 10px 20px rgba(0, 51, 102, 0.2); }
.solution-item:hover h3, .solution-item:hover p { color: #fff; }
.solution-item:hover .sol-num { color: #D96441; transform: scale(1.1); }

/* Patent & Tech Section */
.tech-grid { display: grid; grid-template-columns: 1.5fr 1fr; gap: 30px; }
.tech-card { background: #fff; padding: 40px; border: 1px solid #eee; border-radius: 12px; box-shadow: 0 5px 15px rgba(0,0,0,0.03); }
.tech-header { margin-bottom: 25px; border-bottom: 2px solid var(--bg-light); padding-bottom: 15px; }
.badge { display: inline-block; padding: 4px 12px; background: var(--accent-color); color: #fff; font-size: 0.8rem; font-weight: bold; border-radius: 20px; margin-bottom: 10px; }
.badge.secondary { background: var(--primary-color); }
.tech-header h3 { color: var(--primary-color); font-size: 1.4rem; }
.patent-list { list-style: none; }
.patent-list li { display: flex; justify-content: space-between; padding: 12px 0; border-bottom: 1px solid #f5f5f5; font-size: 0.95rem; }
.patent-list li span { color: #888; font-size: 0.85rem; }
.patent-list li strong { color: var(--text-dark); }
.tech-info-box { margin-top: 30px; padding: 20px; background: var(--bg-light); border-radius: 8px; font-size: 0.9rem; color: #666; line-height: 1.5; }

/* Equipment Grid */
.equipment-grid { 
    display: grid; 
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); 
    gap: 25px; 
}

.equipment-item { 
    background: var(--white);
    border-radius: 8px; 
    overflow: hidden; 
    border: 1px solid #eee; 
    transition: 0.3s;
}

.equipment-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.1);
}

/* 이미지 영역 스타일 */
.eq-img { 
    height: 220px; /* 이미지 높이 고정 */
    overflow: hidden;
    background: #f4f4f4; /* 이미지 로딩 전 배경색 */
    display: flex;
    align-items: center;
    justify-content: center;
}

.eq-img img {
    width: 100%;
    height: 100%;
    object-fit: cover; /* 이미지가 비율을 유지하며 박스를 꽉 채움 */
    transition: transform 0.3s ease;
}

/* 호버 시 이미지 살짝 확대 효과 */
.equipment-item:hover .eq-img img {
    transform: scale(1.1);
}

.eq-info { 
    padding: 25px; 
}

.eq-info h3 { 
    font-size: 1.15rem; 
    color: var(--primary-color); 
    margin-bottom: 10px;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 8px;
}

.eq-info h3 span { 
    font-size: 0.85rem; 
    font-weight: 400; 
    color: var(--secondary-color); 
}

.eq-info p {
    font-size: 0.9rem;
    color: var(--text-light);
    line-height: 1.5;
}

/* References */
.ref-category h3 { 
    font-size: 1.3rem; 
    color: var(--primary-color); 
    margin-bottom: 20px; 
    border-left: 4px solid var(--accent-color); 
    padding-left: 15px; 
    font-weight: 700;
}
.ref-category h3 span { 
    font-size: 0.9rem; 
    font-weight: 400; 
    color: #888;
    margin-left: 10px; 
    letter-spacing: 0;
}
.logo-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(180px, 1fr)); gap: 15px; }
.logo-box { height: 100px; padding: 20px; border: 1px solid #eee; background: #fff; display: flex; align-items: center; justify-content: center; transition: 0.3s; overflow: hidden; }
.logo-box img { max-width: 100%; max-height: 100%; object-fit: contain; filter: none; opacity: 1; transition: 0.3s; }
.logo-box:hover { border-color: var(--secondary-color); background: #fcfcfc; box-shadow: 0 5px 15px rgba(0,0,0,0.05); }
.logo-box:hover img { transform: scale(1.05); }

/* Contact Form */
.contact-box { max-width: 800px; margin: 0 auto; background: var(--bg-light); padding: 50px; border-radius: 15px; }
.form-group { display: flex; gap: 15px; margin-top: 15px; }
input, textarea { width: 100%; padding: 15px; border: 1px solid #ddd; border-radius: 4px; font-family: inherit; margin-top: 5px; margin-bottom: 5px; }
input:focus, textarea:focus { outline: 2px solid var(--secondary-color); border-color: transparent; }
.form-btn-wrap { display: flex; justify-content: flex-end; margin-top: 20px; }

/* Footer & TopBtn */
footer { background: #111; color: #888; padding: 60px 0; text-align: center; font-size: 0.9rem; }
footer strong { color: #fff; display: block; margin-bottom: 10px; font-size: 1.1rem; }
footer p { margin-bottom: 5px; }
#topBtn { position: fixed; bottom: 30px; right: 30px; width: 50px; height: 50px; background: var(--primary-color); color: #fff; border: none; border-radius: 50%; cursor: pointer; display: none; z-index: 999; box-shadow: 0 4px 10px rgba(0,0,0,0.2); }

/* Mobile Menu Toggle */
.menu-toggle { display: none; flex-direction: column; justify-content: space-between; width: 25px; height: 18px; cursor: pointer; }
.menu-toggle .bar { height: 3px; width: 100%; background: var(--primary-color); border-radius: 2px; transition: 0.3s; }

/* --- Mobile Responsive --- */
@media (max-width: 768px) {
    .mobile-hide { display: none; }
    .header-right { gap: 15px; }
    .menu-toggle { display: flex; z-index: 1001; }
    .menu-toggle.is-active .bar:nth-child(2) { opacity: 0; }
    .menu-toggle.is-active .bar:nth-child(1) { transform: translateY(7.5px) rotate(45deg); }
    .menu-toggle.is-active .bar:nth-child(3) { transform: translateY(-7.5px) rotate(-45deg); }

    nav {
        position: fixed; top: 0; right: -100%; width: 60%; height: 100vh;
        background: #fff; display: flex; flex-direction: column;
        justify-content: center; align-items: center; transition: 0.4s;
        box-shadow: -5px 0 15px rgba(0,0,0,0.1); z-index: 1000;
    }
    nav.active { right: 0; }
    .nav-links { flex-direction: column; text-align: center; }
    .nav-links li { margin: 20px 0; }
    .nav-links a { font-size: 1.2rem; }

    .home h1 { font-size: 2rem; }
    .strength-grid-4, .logo-grid, .form-group, .tech-grid { grid-template-columns: 1fr; }
    .section-title h2 { font-size: 2rem; }
    .contact-box { padding: 30px 20px; }
    .form-btn-wrap { justify-content: center; }
    .form-btn-wrap .btn { width: 100%; }
}