/* 기본 스타일 및 다크 모드 테마 */
:root {
    --primary-color: #4a90e2; /* 메인 컬러 (블루 계열) */
    --bg-color: #0d1117;      /* 배경색 (매우 어두운 네이비) */
    --card-color: #161b22;     /* 카드 배경색 */
    --text-color: #c9d1d9;    /* 기본 텍스트 색상 */
    --title-color: #ffffff;   /* 제목 텍스트 색상 */
}

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

/* 스크롤을 부드럽게 (네비게이션 클릭 시) */
html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 1. WebGL 캔버스 컨테이너 (배경에 고정) */
#webgl-canvas-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1; 
    opacity: 0.7;
}

/* 헤더 & 네비게이션 */
header {
    padding: 20px 0;
    position: fixed;
    width: 100%;
    z-index: 10;
    background: linear-gradient(to bottom, rgba(13, 17, 23, 0.7), rgba(13, 17, 23, 0));
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.8rem;
    font-weight: bold;
    color: var(--title-color);
    letter-spacing: -1px;
    text-decoration: none; /* 링크 밑줄 제거 */
}

nav ul {
    list-style: none;
    display: flex;
}

nav ul li {
    margin-left: 25px;
}

nav ul li a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: color 0.3s ease;
}

nav ul li a:hover {
    color: var(--primary-color);
}

/* 2. 히어로 섹션 */
.hero {
    height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: 0 20px;
    position: relative; 
}

.hero-title {
    font-size: 4.2rem; /* 약간 줄임 */
    font-weight: 800;
    color: var(--title-color);
    line-height: 1.2;
    margin-bottom: 20px;
    letter-spacing: -2px;
}

.hero-subtitle {
    font-size: 1.25rem;
    max-width: 600px;
    margin-bottom: 30px;
    color: var(--text-color);
}

.cta-button {
    text-decoration: none;
    background-color: var(--primary-color);
    color: var(--title-color);
    padding: 15px 30px;
    border-radius: 50px;
    font-size: 1.1rem;
    font-weight: bold;
    transition: transform 0.3s ease, background-color 0.3s ease;
    border: none;
    cursor: pointer;
}

.cta-button:hover {
    transform: scale(1.05);
    background-color: #5aa1f2;
}

/* 공통 섹션 제목 */
section {
    padding: 100px 20px;
    background-color: var(--bg-color); 
    position: relative; 
}

section h2 {
    text-align: center;
    font-size: 2.8rem;
    color: var(--title-color);
    margin-bottom: 60px;
}

/* 3. 피처 섹션 (솔루션) */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.feature-card {
    background-color: var(--card-color);
    border: 1px solid #30363d;
    padding: 30px;
    border-radius: 10px;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    
    /* GSAP 스크롤 애니메이션을 위한 초기 상태 */
    opacity: 0;
    transform: translateY(50px);
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

.card-icon {
    font-size: 2.5rem;
    margin-bottom: 15px;
}

.feature-card h3 {
    font-size: 1.5rem;
    color: var(--title-color);
    margin-bottom: 10px;
}

/* 4. About Us 섹션 (신규 추가) */
.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
    align-items: center;
}

.about-text h3 {
    font-size: 2rem;
    color: var(--title-color);
    margin-bottom: 20px;
}
.about-text p {
    margin-bottom: 20px;
    font-size: 1.1rem;
}
.about-text p strong {
    color: var(--primary-color);
}

/* 5. Contact Form 섹션 (신규 추가) */
.contact-form form {
    max-width: 700px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 20px;
}
.contact-form input,
.contact-form textarea {
    padding: 15px;
    border-radius: 8px;
    border: 1px solid #30363d;
    background-color: var(--card-color);
    color: var(--text-color);
    font-size: 1rem;
    font-family: inherit;
}
.contact-form textarea {
    resize: vertical;
}
.contact-form .cta-button {
    align-self: center;
}

/* 푸터 */
footer {
    text-align: center;
    padding: 40px 20px;
    border-top: 1px solid #30363d;
    position: relative;
    background-color: var(--bg-color);
    font-size: 0.9rem;
    color: #8b949e;
}
footer p {
    margin-bottom: 5px;
}


/* 반응형 */
@media (max-width: 768px) {
    .hero-title {
        font-size: 3rem;
    }
    .hero-subtitle {
        font-size: 1.1rem;
    }
    nav {
        flex-direction: column;
    }
    nav ul {
        margin-top: 15px;
    }
    .about-content {
        grid-template-columns: 1fr; /* 모바일에서 1줄로 */
    }
}