:root {
    --sidebar-bg: #f8f9fa;
    --sidebar-width: 280px;
    --accent-blue: #007AFF;
    --text-main: #1d1d1f;
    --text-dark-gray: #4a4a4c;
    --text-sub: #6e6e73;
    --border-light: #e5e5e7;
    --neon-cyan: #00f0ff;
}

/* --- 초기화 및 공통 변수 --- */
* { margin: 0; padding: 0; box-sizing: border-box; }
body, html { 
    font-family: 'Noto Sans KR', sans-serif; 
    overflow: hidden; 
    height: 100%; 
    background: #fff; 
    line-height: 1.6;
}

/* 유틸리티 클래스 */
.white { color: #fff !important; }
.blue-text { color: var(--accent-blue); }

/* --- SIDEBAR (구조 변경) --- */
.sidebar {
    width: var(--sidebar-width); height: 100vh; position: fixed; left: 0; top: 0;
    border-right: 1px solid var(--border-light); background: var(--sidebar-bg);
    display: flex; flex-direction: column; 
    /* justify-content: flex-start;  <-- 삭제 */
    padding: 40px 30px; 
    z-index: 1000;
    transition: transform 0.3s ease;
}
.logo { font-size: 1.6rem; font-weight: 900; letter-spacing: -1px; text-transform: uppercase; color: var(--text-main); }

/* 수정: 메뉴 영역이 남은 공간을 모두 차지하고, 그 안에서 중앙 정렬 */
.side-nav {
    width: 100%;
    flex: 1; /* 로고와 푸터 사이의 모든 여백을 차지함 */
    display: flex;
    flex-direction: column;
    justify-content: center; /* 메뉴 리스트를 수직 중앙에 배치 */
}

.side-nav ul { list-style: none; display: flex; flex-direction: column; gap: 24px; }
.nav-link { text-decoration: none; color: var(--text-sub); font-size: 14px; text-transform: uppercase; position: relative; transition: 0.3s; }
.nav-link.active { color: var(--text-main); font-weight: 700; padding-left: 15px; }
.nav-link.active::before { content: ""; position: absolute; left: 0; top: 50%; transform: translateY(-50%); width: 2px; height: 16px; background: var(--accent-blue); }
.demo-btn { border: 1px solid var(--accent-blue); color: var(--accent-blue) !important; padding: 12px; text-align: center; text-decoration: none; margin-top: 15px; font-weight: 600; font-size: 13px; border-radius: 4px; transition: 0.3s; display: block; }
.demo-btn:hover { background: var(--accent-blue); color: #fff !important; }

/* Sidebar Footer (수정: margin-top: auto 삭제) */
.sidebar-footer { 
    font-size: 0.7rem; 
    color: #999; 
    /* margin-top: auto; <-- 삭제 (side-nav가 밀어주므로 불필요) */
    padding-top: 20px; 
    border-top: 1px solid #eee; 
}
.biz-info p { margin-bottom: 4px; line-height: 1.4; word-break: keep-all; }
.biz-name { font-weight: 700; color: #333; margin-bottom: 6px; font-size: 0.75rem; }
.copyright { margin-top: 15px; color: #ccc; }

/* --- CONTAINERS --- */
.page-container { margin-left: var(--sidebar-width); width: calc(100% - var(--sidebar-width)); height: 100vh; position: relative; transition: width 0.3s ease, margin-left 0.3s ease; }
.sub-page { position: absolute; left: 0; top: 100%; width: 100%; height: 100vh; background: #fff; transition: 0.8s cubic-bezier(0.65, 0, 0.35, 1); z-index: 10; overflow: hidden; }
.sub-page.active { top: 0; }

/* --- HOME PAGE & ANIMATION --- */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}
.animate-element { opacity: 0; animation: fadeInUp 0.8s cubic-bezier(0.2, 0.8, 0.2, 1) forwards; }
.delay-1 { animation-delay: 0.1s; }
.delay-2 { animation-delay: 0.3s; }
.delay-3 { animation-delay: 0.5s; }
.delay-4 { animation-delay: 0.7s; }

.hero-layout { display: flex; align-items: center; justify-content: space-between; width: 100%; height: 100%; padding: 0 10%; gap: 40px; }
.hero-content { flex: 1.2; max-width: 520px; }
.badge-tech { display: inline-block; color: var(--accent-blue); font-size: 0.8rem; font-weight: 700; letter-spacing: 2px; margin-bottom: 1.5rem; }
.hero-content .main-title { font-size: 3.2rem; font-weight: 900; line-height: 1.35; margin-bottom: 1.5rem; word-break: keep-all; color: var(--text-main); }
.hero-content .description { font-size: 1.15rem; color: var(--text-sub); line-height: 1.8; margin-bottom: 3rem; }
.hero-image-box { flex: 1; display: flex; justify-content: flex-end; }
.home-robot-img { width: 100%; max-width: 620px; filter: drop-shadow(0 30px 70px rgba(0,0,0,0.06)); border-radius: 8px; }

/* Buttons */
.hero-btns { display: flex; gap: 15px; }
.btn-primary { padding: 1.1rem 2.5rem; background: #1d1d1f; color: #fff; text-decoration: none; font-weight: 700; border-radius: 4px; display: inline-block; transition: 0.3s; font-size: 0.95rem; text-align: center; }
.btn-primary:hover { opacity: 0.8; transform: translateY(-2px); }
.btn-secondary { padding: 1.1rem 2.5rem; background: transparent; color: #1d1d1f; border: 1px solid #1d1d1f; text-decoration: none; font-weight: 700; border-radius: 4px; display: inline-block; transition: 0.3s; font-size: 0.95rem; text-align: center; }
.btn-secondary:hover { background: rgba(29, 29, 31, 0.05); transform: translateY(-2px); }

/* --- ABOUT US PAGE --- */
.full-scroll-container { width: 100%; height: 100%; overflow-y: auto; scroll-behavior: smooth; }
.full-scroll-container::-webkit-scrollbar { display: none; }

.about-hero { width: 100%; height: 70vh; position: relative; overflow: hidden; }
.about-full-img { width: 100%; height: 100%; object-fit: cover; filter: brightness(0.65); }
.about-hero-overlay { position: absolute; left: 8%; top: 55%; transform: translateY(-50%); }

.about-sub-label.white { color: #fff; opacity: 0.9; font-weight: 400; font-size: 0.95rem; letter-spacing: 4px; display: block; margin-bottom: 25px; }
.about-main-title { font-size: 3.4rem; font-weight: 900; line-height: 1.35; color: #fff; word-break: keep-all; letter-spacing: -1px; }

.about-info-section, .about-impact-bridge, .about-footer { padding: 140px 8%; }
.inner-wrap { max-width: 1200px; margin: 0 auto; width: 100%; }
.section-label { font-size: 1rem; color: var(--accent-blue); font-weight: 700; letter-spacing: 2px; margin-bottom: 20px; border-left: 3px solid var(--accent-blue); padding-left: 15px; display: block; }

/* Identity Grid */
.identity-grid-layout { display: grid; grid-template-columns: 0.8fr 1.2fr; gap: 80px; margin-bottom: 120px; align-items: flex-start; border-bottom: 1px solid #e5e5e7; padding-bottom: 80px; }
.identity-title { font-size: 2.2rem; line-height: 1.3; margin-top: 10px; word-break: keep-all; color: var(--text-main); }
.identity-desc { color: #555; font-size: 1.15rem; line-height: 1.8; margin-top: 45px; word-break: keep-all; }
.identity-desc strong { color: #1d1d1f; font-weight: 700; }

/* Core Tech */
.tech-deep-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 60px 100px; margin-top: 60px; }
.tech-item h5 { font-size: 1.6rem; font-weight: 700; margin-bottom: 15px; }
.tech-item p { color: var(--text-sub); line-height: 1.8; font-size: 1.05rem; }
.tech-icon-circle { 
    width: 60px; height: 60px; background: rgba(0, 122, 255, 0.1); 
    border-radius: 50%; display: flex; align-items: center; justify-content: center; 
    margin-bottom: 20px; font-size: 1.8rem; color: var(--accent-blue); 
}

/* Hover Animation (하얀 배경 없음) */
.hover-card { transition: transform 0.3s ease, box-shadow 0.3s ease; border-radius: 12px; padding: 20px; }
.hover-card:hover { transform: translateY(-8px); box-shadow: 0 15px 30px rgba(0,0,0,0.08); } 

/* Light Theme Hover (밝은 섹션 카드에만 하얀 배경 적용) */
.tech-item.hover-card:hover { background: #fff; }

.about-simulation-visual { width: 100%; height: 65vh; background: #000; }
.simulation-img { width: 100%; height: 100%; object-fit: cover; }

.about-impact-bridge { background: #f9f9fb; }
.stat-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 40px; text-align: center; margin-top: 80px; }
.stat-text-box { padding: 20px; }
.stat-num { font-size: 4.5rem; font-weight: 900; color: var(--accent-blue); display: block; }
.stat-desc { color: var(--text-sub); font-weight: 500; }
.stat-source { font-size: 0.85rem; color: #999; margin-top: 40px; text-align: center; }

/* Partnership */
.about-collaboration { background: #0a111a; padding: 120px 8%; }
.collab-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; margin-top: 60px; }
.collab-item { background: rgba(255, 255, 255, 0.05); border: 1px solid rgba(255, 255, 255, 0.1); padding: 35px 25px; display: flex; align-items: flex-start; gap: 20px; border-radius: 4px; transition: 0.3s ease; }
.collab-item:hover { background: rgba(255, 255, 255, 0.08); transform: translateY(-5px); }
.collab-text { display: flex; flex-direction: column; gap: 5px; }
.blue-bar { width: 4px; height: 50px; background-color: var(--accent-blue); flex-shrink: 0; }
.collab-item p { color: #fff; font-size: 1.15rem; font-weight: 700; margin-top: 5px; }
.collab-badge { font-size: 0.75rem; color: rgba(255, 255, 255, 0.6); text-transform: uppercase; letter-spacing: 1px; font-weight: 400; border: 1px solid rgba(255, 255, 255, 0.2); padding: 2px 8px; border-radius: 4px; align-self: flex-start; }

.about-footer { text-align: center; padding: 180px 8%; }
.outro-minimal { font-size: 1.1rem; color: #8e8e93 !important; letter-spacing: 4px; text-transform: uppercase; font-weight: 300; }
.outro-minimal strong { font-weight: 900; color: #8e8e93 !important; margin-left: 10px; }

.main-title { font-size: 3.2rem; font-weight: 900; line-height: 1.25; margin-bottom: 25px; word-break: keep-all; color: var(--text-main); }
.main-title.white { color: #fff; }

/* --- TECHNOLOGY PAGE (DARK THEME) --- */
.dark-tech-bg { background: #050b14; width: 100%; min-height: 100vh; overflow-x: hidden; }
.grey-tech-bg { background: #0a1321; }
.roadmap-tech-bg { background: #040912; }

.tech-section { padding: 120px 0; display: flex; flex-direction: column; align-items: flex-start; }
.tech-content-wrap { width: 100%; text-align: left; margin-top: 20px; }

.section-label.neon-blue {
    color: var(--neon-cyan);
    border-left: 4px solid var(--neon-cyan);
    font-size: 0.9rem;
    font-weight: 800;
    margin-bottom: 50px;
    padding-left: 20px;
    letter-spacing: 3px;
    text-transform: uppercase;
    display: inline-block;
}

.tech-main-title { font-size: 2.8rem; font-weight: 800; line-height: 1.4; margin-bottom: 25px; letter-spacing: -1px; word-break: keep-all; color: #ffffff; }
.tech-sub-copy { color: rgba(255, 255, 255, 0.7); font-size: 1.15rem; line-height: 1.8; margin-bottom: 60px; }

/* Technology - Problems Grid */
.problem-grid-new { display: grid; grid-template-columns: repeat(3, 1fr); gap: 25px; width: 100%; }
.problem-card-new { background: #121d2e; padding: 50px 40px; border-radius: 12px; border: 1px solid rgba(255, 255, 255, 0.05); transition: 0.3s ease; }
.problem-card-new:hover { transform: translateY(-5px); border-color: rgba(0, 240, 255, 0.3); }
.problem-icon { font-size: 2.5rem; margin-bottom: 30px; color: var(--neon-cyan); }
.problem-card-new h4 { color: #fff; font-size: 1.4rem; font-weight: 700; margin-bottom: 25px; }
.problem-card-new ul { list-style: none; }
.problem-card-new li { color: rgba(255, 255, 255, 0.7); font-size: 0.95rem; line-height: 1.8; }

/* Technology - Metrics */
.metrics-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; margin-top: 50px; margin-bottom: 40px; }
.metric-card { background: rgba(18, 29, 46, 0.8); border: 1px solid rgba(0, 240, 255, 0.1); padding: 50px 20px; border-radius: 12px; text-align: center; }
.metric-value { display: block; font-size: 3.5rem; font-weight: 900; color: var(--neon-cyan); margin-bottom: 15px; text-shadow: 0 0 20px rgba(0, 240, 255, 0.3); }
.metric-label { color: rgba(255, 255, 255, 0.8); font-size: 1rem; }

.verification-info-bar { background: rgba(255, 255, 255, 0.03); padding: 30px 40px; border-radius: 8px; display: flex; gap: 50px; margin-top: 40px; }
.info-tag { color: var(--neon-cyan); font-weight: 700; display: block; margin-bottom: 8px; }
.info-item p { color: rgba(255, 255, 255, 0.7); font-size: 0.95rem; line-height: 1.6; }

/* Technology - Benefits */
.benefit-container-new { display: grid; grid-template-columns: 1fr 1fr; gap: 30px; width: 100%; margin-top: 50px; }
.benefit-card-new { background: #121d2e; padding: 50px; border-radius: 12px; border: 1px solid rgba(255, 255, 255, 0.05); }
.benefit-card-new h4 { color: #ffffff !important; font-size: 1.5rem; margin-bottom: 30px; font-weight: 800; }
.benefit-card-new li { color: #fff; opacity: 0.8; font-size: 1.1rem; line-height: 1.7; margin-bottom: 15px; list-style: none; position: relative; padding-left: 20px; }
.benefit-card-new li::before { content: "•"; color: var(--neon-cyan); position: absolute; left: 0; }

.tech-img-main, .tech-img-roadmap { width: 100%; border-radius: 8px; box-shadow: 0 20px 50px rgba(0,0,0,0.2); }
.tech-footer { text-align: center; padding: 120px 0; }

/* --- SOLUTION PAGE --- */
.solution-page { background: radial-gradient(circle at 50% 50%, #0a192f 0%, #050b14 100%); color: #ffffff; overflow: hidden; }
.sol-section { padding: 60px 0; }
.sol-section.hero { padding-top: 100px; padding-bottom: 40px; }
.sol-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; align-items: center; }
.sol-img { width: 100%; border-radius: 15px; box-shadow: 0 15px 40px rgba(0, 240, 255, 0.15); border: 1px solid rgba(255, 255, 255, 0.05); transition: transform 0.4s ease; }
.sol-img:hover { transform: translateY(-8px); }
.sol-feature-item { padding-left: 25px; border-left: 2px solid var(--neon-cyan); }
.feature-num { color: var(--neon-cyan); font-weight: 800; font-size: 1.1rem; display: block; margin-bottom: 10px; }
.feature-num i { font-size: 1.3rem; margin-right: 5px; vertical-align: middle; }
.sol-feature-item h4 { font-size: 1.8rem; margin-bottom: 15px; font-weight: 700; color: #fff; }
.sol-feature-item p { color: #ccc; line-height: 1.6; font-size: 1.05rem; }
.sol-list { list-style: none; padding: 0; margin-top: 15px; }
.sol-list li { color: var(--neon-cyan); font-size: 0.9rem; margin-bottom: 8px; padding-left: 20px; position: relative; }
.sol-list li::before { content: "→"; position: absolute; left: 0; }

/* --- PHM & ENERGY TECH --- */
.phm-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 30px; margin-top: 40px; }
.phm-card { background: linear-gradient(145deg, #121d2e 0%, #0a111a 100%); border: 1px solid rgba(255, 255, 255, 0.08); border-radius: 16px; padding: 40px; transition: transform 0.3s ease, border-color 0.3s ease; }
.phm-card:hover { transform: translateY(-5px); border-color: rgba(0, 240, 255, 0.4); box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3); }
.phm-header { display: flex; align-items: center; gap: 15px; margin-bottom: 25px; border-bottom: 1px solid rgba(255, 255, 255, 0.1); padding-bottom: 20px; }
.phm-icon { font-size: 2rem; background: rgba(0, 240, 255, 0.1); width: 60px; height: 60px; display: flex; align-items: center; justify-content: center; border-radius: 50%; }
.phm-header h4 { color: #fff; font-size: 1.5rem; font-weight: 700; }
.phm-body p.phm-desc { color: rgba(255, 255, 255, 0.75); font-size: 1.05rem; line-height: 1.7; margin-bottom: 25px; }
.phm-body p.phm-desc strong { color: var(--neon-cyan); font-weight: 600; }
.tech-tag-box { display: flex; flex-wrap: wrap; gap: 10px; }
.tech-tag-box span { background: rgba(255, 255, 255, 0.05); color: #aaa; padding: 6px 12px; border-radius: 20px; font-size: 0.85rem; border: 1px solid rgba(255, 255, 255, 0.1); }

/* --- MOBILE RESPONSIVENESS --- */
@media screen and (max-width: 768px) {
    .sidebar { width: 100%; height: auto; position: relative; border-right: none; border-bottom: 1px solid #e5e5e7; padding: 20px; }
    .side-nav ul { flex-direction: row; gap: 15px; margin-top: 20px; flex-wrap: wrap; justify-content: center; }
    .page-container { margin-left: 0; width: 100%; height: auto; overflow-y: auto; }
    .sub-page { position: relative; height: auto; overflow: visible; }
    
    .hero-layout { flex-direction: column; padding: 60px 20px; text-align: center; }
    .hero-content { margin-bottom: 40px; }
    .hero-btns { justify-content: center; }
    .home-robot-img { width: 80%; }
    
    .tech-deep-grid, .collab-grid, .stat-grid, .problem-grid-new, 
    .metrics-grid, .benefit-container-new, .phm-grid, .sol-grid,
    .identity-grid-layout { grid-template-columns: 1fr; gap: 30px; }
    
    .main-title, .tech-main-title, .about-main-title { font-size: 2rem !important; }
    .stat-num { font-size: 3rem; }
    
    .identity-grid-layout { padding-bottom: 40px; margin-bottom: 60px; }
    .identity-desc { margin-top: 10px; }
    
    .sol-grid { display: flex; flex-direction: column; }
    .sol-visual { order: -1; }
    .sol-desc { order: 1; }
    
    .sol-feature-item { border-left: none; border-top: 2px solid var(--neon-cyan); padding-left: 0; padding-top: 20px; }
    .about-info-section, .about-impact-bridge, .about-footer, .tech-section, .about-collaboration { padding: 60px 5%; }
    .verification-info-bar { flex-direction: column; gap: 20px; }
}