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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: #ffffff;
    background: linear-gradient(135deg, #0a0a0a 0%, #1a1a1a 100%);
    overflow-x: hidden;
}

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

/* =========================================
   2. Header (Updated for New Structure)
   ========================================= */
header {
    position: fixed;
    top: 0;
    width: 100%;
    padding: 20px 40px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    z-index: 1000;
    background: rgba(10, 10, 10, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    transition: transform 0.3s ease-in-out;
}

header .logo {
    font-size: 24px;
    font-weight: 800;
    letter-spacing: -1px;
    color: #FF6B35; /* 로고 색상 주황색으로 통일 */
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
}

header nav {
    display: flex;
    gap: 30px;
    align-items: center;
    
    /* ▼▼▼ 이 줄을 추가하세요 ▼▼▼ */
    margin-left: auto;  /* 왼쪽 공간을 모두 밀어내서 오른쪽(버튼 옆)으로 붙음 */
    margin-right: 30px; /* 버튼과 메뉴 사이의 간격을 좀 더 띄움 (취향에 따라 조절) */
}

header nav a {
    color: #ffffff;
    text-decoration: none;
    font-size: 14px;
    font-weight: 500;
    transition: color 0.3s ease, opacity 0.3s;
}

header nav a:hover {
    color: #FF6B35;
    opacity: 1;
}

/* Header 내 CTA 버튼 ("Get Started") */
header .cta-button {
    background: linear-gradient(135deg, #FF6B35, #FF8A65);
    color: #fff !important; /* 링크 색상 덮어쓰기 */
    padding: 10px 24px;
    border-radius: 25px;
    font-weight: 600;
    transition: transform 0.3s, box-shadow 0.3s;
}

header .cta-button:hover {
    transform: translateY(-2px) scale(1.05);
    box-shadow: 0 5px 15px rgba(255, 107, 53, 0.4);
    color: #fff;
}

/* =========================================
   3. Hero Section
   ========================================= */
.hero {
    padding: 160px 0 80px; /* 헤더 고정으로 인한 상단 패딩 증가 */
    text-align: center;
    background: radial-gradient(ellipse at center, rgba(255, 107, 53, 0.1) 0%, transparent 70%);
}

.hero-content {
    max-width: 900px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
}

.hero-title {
    font-size: 4rem;
    font-weight: 900;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, #ffffff, #FF6B35);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.5rem;
    color: #FF6B35;
    font-weight: 600;
    margin-bottom: 2rem;
}

.hero-description {
    font-size: 1.2rem;
    color: #cccccc;
    line-height: 1.8;
    max-width: 800px;
    margin: 0 auto 2rem;

    max-width: 1000px;    /* 너비 제한을 넉넉하게 늘림 (기존 100%나 작은 값에서 변경) */
    width: 100%;          /* 부모 컨테이너 내에서 꽉 차게 */
    margin: 0 auto 2rem;
}
@media (min-width: 1024px) {
    .hero-description {
        white-space: nowrap; /* 줄바꿈을 금지함 */
    }
}

/* =========================================
   4. LPU Overview Section
   ========================================= */
.lpu-overview {
    padding: 100px 0;
    background: linear-gradient(180deg, transparent, rgba(255, 107, 53, 0.05));
}

.overview-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 1.5rem;
    color: #ffffff;
}

.section-description {
    font-size: 1.2rem;
    color: #cccccc;
    line-height: 1.7;
    margin-bottom: 2rem;
}

.feature-list {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.feature-item {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    padding: 1.5rem;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.1);
    transition: all 0.3s ease;
}

.feature-item:hover {
    transform: translateY(-5px);
    border-color: rgba(255, 107, 53, 0.3);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

.feature-icon {
    font-size: 2rem;
    min-width: 60px;
    text-align: center;
}

.feature-content h3 {
    font-size: 1.3rem;
    font-weight: 700;
    color: #FF6B35;
    margin-bottom: 0.5rem;
}

.feature-content p {
    color: #cccccc;
    line-height: 1.6;
}

/* =========================================
   5. LPU Visual (Chip Animation)
   ========================================= */
.overview-visual {
    display: flex;
    justify-content: center;
    align-items: center;
}

.lpu-chip {
    position: relative;
    width: 300px;
    height: 300px;
    background: linear-gradient(135deg, rgba(255, 107, 53, 0.2), rgba(255, 138, 101, 0.1));
    border: 2px solid #FF6B35;
    border-radius: 20px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    /* JS에서 애니메이션 제어하므로 기본값 설정 */
    box-shadow: 0 0 20px rgba(255, 107, 53, 0.3);
}

.chip-core {
    text-align: center;
    z-index: 2;
}

.core-label {
    font-size: 3rem;
    font-weight: 900;
    color: #FF6B35;
    margin-bottom: 1rem;
}

.core-details {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.detail-item {
    background: rgba(255, 107, 53, 0.2);
    color: #ffffff;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 600;
}

.chip-connections {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

.connection {
    position: absolute;
    width: 4px;
    height: 40px;
    background: linear-gradient(180deg, #FF6B35, transparent);
    border-radius: 2px;
}

.connection:nth-child(1) { top: -20px; left: 50%; transform: translateX(-50%); }
.connection:nth-child(2) { right: -20px; top: 50%; transform: translateY(-50%) rotate(90deg); }
.connection:nth-child(3) { bottom: -20px; left: 50%; transform: translateX(-50%) rotate(180deg); }
.connection:nth-child(4) { left: -20px; top: 50%; transform: translateY(-50%) rotate(270deg); }

@keyframes pulse {
    0%, 100% { box-shadow: 0 0 20px rgba(255, 107, 53, 0.3); }
    50% { box-shadow: 0 0 40px rgba(255, 107, 53, 0.6); }
}

/* =========================================
   6. Architecture Comparison
   ========================================= */
.architecture-comparison {
    padding: 100px 0;
    background: linear-gradient(180deg, rgba(255, 107, 53, 0.05), transparent);
}

.comparison-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    margin-top: 3rem;
}

.comparison-card {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 16px;
    padding: 2rem;
    transition: all 0.3s ease;
}

.comparison-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
}

.lpu-card {
    border-color: rgba(255, 107, 53, 0.3);
    background: linear-gradient(135deg, rgba(255, 107, 53, 0.1), rgba(255, 138, 101, 0.05));
    /* 요청사항: 카드 전체 너비 확장 */
    grid-column: 1 / -1;
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
}

.card-header h3 {
    font-size: 1.5rem;
    font-weight: 700;
    color: #ffffff;
}

.lpu-card .card-header h3 { color: #FF6B35; }
.card-icon { font-size: 2rem; }

.card-content {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.comparison-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.comparison-item:last-child { border-bottom: none; }

.item-label { font-weight: 600; color: #cccccc; }
.item-value { color: #ffffff; font-weight: 500; }
.lpu-card .item-value { color: #FF6B35; font-weight: 600; }

.grid-layout {
    display: grid;
    grid-template-columns: 200px 1fr; /* 왼쪽: 200px 고정, 오른쪽: 나머지 전부 */
    gap: 30px;                        /* 좌우 간격 */
    align-items: center;              /* 세로 중앙 정렬 (내용이 많으면 start로 변경 가능) */
    width: 100%;
}

/* 카드 헤더 스타일 재정의 */
.comparison-card .card-header {
    display: grid; /* flex 덮어쓰기 */
    margin-bottom: 1.5rem;
    padding-bottom: 1rem;
    border-bottom: 2px solid rgba(255, 107, 53, 0.3); /* 헤더 구분선 추가 */
}

/* 오른쪽 헤더 텍스트 색상 및 정렬 */
.comparison-card .card-header h3:last-child {
    color: #FF6B35;
    text-align: left; /* 왼쪽 정렬 */
    margin: 0;
}

/* 개별 아이템 스타일 재정의 */
.comparison-item {
    display: grid; /* flex 덮어쓰기 */
    padding: 1.5rem 0; /* 위아래 여백을 넉넉하게 */
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.comparison-item:last-child {
    border-bottom: none;
}

/* 왼쪽 텍스트 (대상) */
.user-type {
    font-weight: 700;
    color: #ffffff;
    font-size: 1.1rem;
}

/* 오른쪽 텍스트 (설명) */
.item-desc {
    color: #cccccc;
    font-size: 1rem;
    line-height: 1.6;
    text-align: left;
}

.item-desc strong {
    color: #FF6B35; /* 강조 텍스트 오렌지색 */
    font-weight: 700;
}

/* 모바일 반응형 (768px 이하) */
@media (max-width: 768px) {
    .grid-layout {
        grid-template-columns: 1fr; /* 1열로 변경 */
        gap: 10px;
    }
    
    .comparison-item {
        padding: 1rem 0;
    }
    
    .user-type {
        color: #FF6B35; /* 모바일에서는 제목을 오렌지색으로 구분 */
        margin-bottom: 5px;
    }
}

/* =========================================
   7. Common Grid Sections (Tech, Metrics, Use Cases)
   ========================================= */
/* Technical Deep Dive */
.tech-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.tech-card {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 16px;
    padding: 2rem;
    text-align: center;
    transition: all 0.3s ease;
}

.tech-card:hover {
    transform: translateY(-10px);
    border-color: rgba(255, 107, 53, 0.3);
}

.tech-icon { font-size: 3rem; margin-bottom: 1rem; }
.tech-card h3 { font-size: 1.3rem; font-weight: 700; color: #FF6B35; margin-bottom: 1rem; }
.tech-card p { color: #cccccc; line-height: 1.6; }

/* Performance Metrics */
.metrics-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.metric-card {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 16px;
    padding: 2rem;
    text-align: center;
    transition: all 0.3s ease;
}

.metric-card:hover { transform: translateY(-10px); border-color: rgba(255, 107, 53, 0.3); }
.metric-number { font-size: 3rem; font-weight: 900; color: #FF6B35; margin-bottom: 0.5rem; }
.metric-label { font-size: 1.2rem; font-weight: 700; color: #ffffff; margin-bottom: 0.5rem; }
.metric-description { color: #cccccc; font-size: 0.9rem; }

/* Use Cases */
.use-case-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.use-case-card {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 16px;
    padding: 2rem;
    text-align: center;
    transition: all 0.3s ease;
}

.use-case-card:hover { transform: translateY(-10px); border-color: rgba(255, 107, 53, 0.3); }
.use-case-icon { font-size: 3rem; margin-bottom: 1rem; }
.use-case-card h3 { font-size: 1.3rem; font-weight: 700; color: #FF6B35; margin-bottom: 1rem; }
.use-case-card p { color: #cccccc; line-height: 1.6; }

/* =========================================
   8. CTA Section
   ========================================= */
.cta-section {
    padding: 100px 0;
    background: linear-gradient(135deg, rgba(255, 107, 53, 0.1), rgba(255, 138, 101, 0.05));
    text-align: center;
}

.cta-content {
    /* 요청사항: 최대 너비 100%로 확장 */
    max-width: 100%;
    margin: 0 auto;
    padding: 0 20px;
}

.cta-title {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 1rem;
    color: #ffffff;
}

.cta-description {
    font-size: 1.2rem;
    color: #cccccc;
    margin-bottom: 3rem;
    line-height: 1.6;
    max-width: 800px; /* 텍스트 가독성을 위해 텍스트 영역만 제한 */
    margin-left: auto;
    margin-right: auto;
}

.cta-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.btn-primary {
    background: linear-gradient(135deg, #FF6B35, #FF8A65);
    color: white;
    border: none;
    padding: 1rem 2rem;
    border-radius: 12px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 15px 35px rgba(255, 107, 53, 0.4);
}

.btn-secondary {
    background: transparent;
    color: white;
    border: 2px solid rgba(255, 255, 255, 0.3);
    padding: 1rem 2rem;
    border-radius: 12px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-secondary:hover {
    border-color: #FF6B35;
    background: rgba(255, 107, 53, 0.1);
}

/* =========================================
   9. Footer
   ========================================= */
.footer {
    padding: 60px 0 30px;
    background: linear-gradient(180deg, transparent, #0a0a0a);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

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

.footer-section {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 1rem;
}

.footer-description {
    color: #888888;
    max-width: 300px;
}

/* Footer Links - Mobile Default */
.footer-links {
    display: grid;
    grid-template-columns: repeat(2, 1fr); /* 모바일에서는 2열 */
    gap: 1rem;
}

.footer-column {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.footer-column h4 {
    color: #FF6B35;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.footer-column a {
    color: #cccccc;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-column a:hover { color: #FF6B35; }

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: #888888;
}

/* =========================================
   10. Responsive & Footer Desktop Fix
   ========================================= */

/* 데스크탑 푸터 정렬 (769px 이상) */
@media (min-width: 769px) {
    .footer-content {
        display: flex;
        flex-direction: column;
        align-items: center;
        text-align: center;
    }

    .footer-section {
        align-items: center;
    }
    
    .footer-links {
        display: flex;           /* Grid 대신 Flex 사용 */
        justify-content: center; /* 중앙 정렬 */
        gap: 60px;               /* 요청사항: 간격 60px 고정 */
        width: 100%;
        margin-top: 20px;
    }

    .footer-column {
        text-align: center;
        width: auto;
        white-space: nowrap;
    }
}

/* 모바일/태블릿 반응형 (768px 이하) */
@media (max-width: 768px) {
    header {
        padding: 15px 20px;
    }

    /* 모바일에서 네비게이션 숨기기 (또는 햄버거 메뉴 필요시 추가 구현) */
    header nav {
        display: none; 
    }
    
    .hero-title { font-size: 2.5rem; }
    .section-title { font-size: 2rem; }
    
    .overview-grid, 
    .comparison-grid, 
    .footer-content,
    .cta-buttons {
        grid-template-columns: 1fr;
        flex-direction: column;
    }
    
    .metrics-grid { grid-template-columns: repeat(2, 1fr); }
    
    .lpu-chip { width: 250px; height: 250px; }
    .core-label { font-size: 2rem; }
    
    /* 모바일에서 푸터 링크 */
    .footer-links {
        grid-template-columns: 1fr 1fr;
    }
}

/* =========================================
   11. Animations
   ========================================= */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}

.animate-in { animation: fadeInUp 0.8s ease-out forwards; }

.scroll-animate {
    opacity: 0;
    transform: translateY(50px);
    transition: all 0.8s ease-out;
}

.scroll-animate.visible {
    opacity: 1;
    transform: translateY(0);
}

.sub-header {
    position: fixed;
    /* 메인 헤더의 높이(약 75~80px)만큼 아래에 배치 */
    top: 76px; 
    width: 100%;
    z-index: 999;
    background: rgba(20, 20, 20, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    transition: transform 0.3s ease-in-out;
}

/* 내부 컨테이너 */
.sub-header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 12px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

/* 서브 로고 스타일 */
.sub-logo {
    font-size: 18px;
    font-weight: 700;
    color: #cccccc;
    white-space: nowrap;
}

/* 서브 네비게이션 */
.sub-nav ul {
    display: flex;
    list-style: none;
    gap: 30px;
    margin: 0 30px;
}

.sub-nav a {
    text-decoration: none;
    color: #cccccc;
    font-size: 14px;
    font-weight: 500;
    transition: color 0.3s;
}

.sub-nav a:hover {
    color: #FF6B35;
}

/* 서브 CTA 버튼 (문의하기) */
.cta-button.sub-cta {
    background: transparent;
    border: 1px solid #FF6B35;
    color: #FF6B35 !important;
    padding: 8px 20px;
    font-size: 13px;
}

.cta-button.sub-cta:hover {
    background: #FF6B35;
    color: #fff !important;
    transform: translateY(-2px);
    box-shadow: none;
}

/* 본문 패딩 조정 (헤더가 2개가 되었으므로 상단 여백 추가) */
.hero {
    padding-top: 200px; /* 기존 160px에서 증가 */
}

/* 반응형: 모바일/태블릿 */
@media (max-width: 960px) {
    .sub-header {
        top: 70px; /* 모바일 헤더 높이에 맞춤 */
    }
    
    .sub-header-container {
        flex-direction: column;
        gap: 15px;
        padding: 15px 20px;
    }

    .sub-nav ul {
        gap: 15px;
        margin: 0;
        flex-wrap: wrap; /* 줄바꿈 허용 */
        justify-content: center;
    }
    
    .sub-nav a {
        font-size: 12px;
    }

    /* 모바일에서 문의 버튼 숨기기 (공간 부족 시) 또는 스타일 조정 */
    .cta-button.sub-cta {
        width: 100%;
        text-align: center;
    }
}

.footer-address {
    text-align: left; /* PC에서는 왼쪽 정렬 */
    margin-top: 1rem;
}

.footer-address h3 {
    font-size: 1.1rem;
    color: #ffffff;
    margin-bottom: 0.5rem;
    font-weight: 700;
}

.footer-address p {
    color: #888888;
    font-size: 0.95rem;
    line-height: 1.6;
}

/* 기존 CSS 덮어쓰기 및 보완 */
.footer-links {
    /* 링크가 하나로 줄었으므로 오른쪽 끝이나 중앙에 배치 */
    justify-content: flex-end; 
    gap: 0; /* 단일 컬럼이므로 갭 제거 */
}

/* 데스크탑(PC)에서의 레이아웃 조정 */
@media (min-width: 769px) {
    .footer-content {
        flex-direction: row; /* 가로 배치 */
        justify-content: space-between; /* 양 끝으로 벌림 */
        align-items: flex-start; /* 위쪽 라인 맞춤 */
        text-align: left;
    }

    .footer-section {
        align-items: flex-start; /* 로고와 주소 왼쪽 정렬 */
    }

    .footer-links {
        margin-top: 0;
        width: auto; /* 너비 자동 */
    }
    
    .footer-column {
        text-align: left; /* 링크 텍스트 왼쪽 정렬 */
        align-items: flex-start; /* 링크 아이템 왼쪽 정렬 */
    }
}

/* 모바일 대응 */
@media (max-width: 768px) {
    .footer-content {
        gap: 2rem;
    }
    
    .footer-address {
        text-align: center; /* 모바일에서는 주소 가운데 정렬 */
    }

    .footer-section {
        align-items: center; /* 모바일에서는 로고/주소 가운데 정렬 */
    }
    
    .footer-links {
        grid-template-columns: 1fr; /* 1열로 변경 */
        text-align: center;
    }
    
    .footer-column {
        align-items: center; /* 링크들 가운데 정렬 */
    }
}

/* =========================================
   12. Back to Top Button
   ========================================= */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: #FF6B35;
    color: #ffffff;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    z-index: 9999; /* 다른 요소보다 위에 오도록 */
    
    /* 기본적으로 숨김 상태 */
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    
    /* 부드러운 전환 효과 */
    transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    
    /* 그림자 및 정렬 */
    box-shadow: 0 4px 15px rgba(255, 107, 53, 0.4);
    display: flex;
    align-items: center;
    justify-content: center;
}

/* 버튼이 활성화되었을 때 (JS로 클래스 추가) */
.back-to-top.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

/* 호버 효과 */
.back-to-top:hover {
    background: #ff8f6b;
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(255, 107, 53, 0.6);
}

/* 모바일에서는 버튼 크기와 위치 약간 조정 */
@media (max-width: 768px) {
    .back-to-top {
        width: 45px;
        height: 45px;
        bottom: 20px;
        right: 20px;
    }
}