/* ========================================
   기본 설정
======================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    padding-top: 100px; /* 헤더 높이만큼 상단 여백 추가 */
}

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

/* ========================================
   헤더
======================================== */
header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 1rem 0;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    z-index: 1000;
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1.5rem;
}

.logo-container {
    flex-shrink: 0;
}

.header-text {
    text-align: left;
}

header h1 {
    font-size: 2rem;
    margin-bottom: 0.3rem;
}

header p {
    font-size: 0.95rem;
    opacity: 0.95;
}

/* ========================================
   히어로 섹션
======================================== */
.hero {
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    padding: 4rem 0;
}

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

.hero h2 {
    font-size: 2rem;
    color: #2d3748;
    margin-bottom: 1.5rem;
}

/* ========================================
   서비스 카드
======================================== */
.services {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
}

.service-card {
    position: relative;
    background-size: cover;
    background-position: center;
    color: white;
    min-height: 220px;
    padding: 1.5rem;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    overflow: hidden;
}

.service-card::before {
    content: "";
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.45);
    z-index: 1;
}

.service-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 15px rgba(0,0,0,0.2);
}

.service-card h3,
.service-card p,
.service-card .card-link {
    position: relative;
    z-index: 2;
    color: #fff;
}

.service-card h3 {
    margin-bottom: 1rem;
    font-size: 1.3rem;
}

.service-card p {
    line-height: 1.8;
}

.card-link {
    display: inline-block;
    font-weight: 600;
    margin-top: 1rem;
    text-decoration: none;
    transition: color 0.3s ease;
}

.card-link:hover {
    color: #764ba2;
}

/* ========================================
   섹션 공통
======================================== */
section {
    padding: 4rem 0;
}

.section-title {
    text-align: center;
    font-size: 2rem;
    color: #2d3748;
    margin-bottom: 1rem;
    position: relative;
    padding-bottom: 1rem;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 3px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.section-description {
    text-align: center;
    font-size: 1.1rem;
    color: #555;
    margin-bottom: 2rem;
}

.content-section {
    padding: 4rem 0;
}

.alt-bg {
    background: #f8f9fa;
}

/* ========================================
   UWB 섹션
======================================== */
.uwb-section {
    background: #f8f9fa;
}

.uwb-features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    margin: 2rem 0;
}

.feature-box {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    border-left: 4px solid #667eea;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.feature-box h3 {
    color: #2d3748;
    margin-bottom: 0.5rem;
}

/* ========================================
   컨트롤러 섹션
======================================== */
.controller-section {
    background: white;
}

.controller-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.controller-card {
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}

.controller-card h3 {
    color: #667eea;
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.controller-card ul {
    list-style: none;
    padding-left: 0;
}

.controller-card ul li {
    padding: 0.5rem 0;
    padding-left: 1.5rem;
    position: relative;
}

.controller-card ul li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: #667eea;
    font-weight: bold;
}

.controller-card .card-link {
    color: #667eea;
}

/* ========================================
   CTA 버튼
======================================== */
.cta-container {
    text-align: center;
    margin-top: 2rem;
}

.cta-button {
    display: inline-block;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 1rem 2rem;
    border-radius: 50px;
    text-decoration: none;
    margin: 0.5rem;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

.cta-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.6);
}

/* ========================================
   연락처 섹션
======================================== */
.contact-section {
    background: #2d3748;
    color: white;
    padding: 3rem 0;
    text-align: center;
}

.contact-section h2 {
    font-size: 2rem;
    margin-bottom: 1rem;
}

.contact-section p {
    font-size: 1.1rem;
    margin-bottom: 2rem;
}

.contact-info {
    display: flex;
    justify-content: center;
    gap: 3rem;
    flex-wrap: wrap;
    margin-top: 2rem;
}

.contact-item {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.contact-item h4 {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
    color: #667eea;
}

.contact-item a {
    color: white;
    text-decoration: none;
    transition: color 0.3s ease;
}

.contact-item a:hover {
    color: #667eea;
}

/* ========================================
   푸터
======================================== */
footer {
    background: #1a202c;
    color: white;
    text-align: center;
    padding: 2rem 0;
}

/* ========================================
   반응형 디자인
======================================== */
@media (max-width: 768px) {
    body {
        padding-top: 0; /* 모바일에서는 헤더 고정 안 함 */
    }

    header {
        position: relative; /* 모바일에서는 일반 위치 */
    }

    header h1 {
        font-size: 1.5rem;
    }

    .header-content {
        flex-direction: column;
        text-align: center;
    }

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

    .hero h2 {
        font-size: 1.5rem;
    }

    .section-title {
        font-size: 1.5rem;
    }

    .contact-info {
        gap: 1.5rem;
    }

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

    .uwb-features {
        grid-template-columns: 1fr;
    }

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