/* --- [1. 기본 스타일 및 초기화] --- */
:root {
    --primary-color: #2563EB; /* 신뢰감을 주는 테크 블루 */
    --accent-color: #10B981; /* 클릭을 유도하는 그린 */
    --dark-bg: #1F2937;
    --light-bg: #F3F4F6;
    --text-color: #374151;
}
* { margin: 0; padding: 0; box-sizing: border-box; font-family: 'Inter', sans-serif; }
body { 
    color: var(--text-color); 
    line-height: 1.6;
    background-color: #ffffff;
    background-image: radial-gradient(#e5e7eb 1px, transparent 1px);
    background-size: 24px 24px;
}
a { text-decoration: none; color: inherit; }
ul { list-style: none; }

/* --- [2. 레이아웃 유틸리티] --- */
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
.section-padding { padding: 80px 0; }
.btn { display: inline-block; padding: 12px 24px; border-radius: 8px; font-weight: 600; transition: 0.3s; }
.btn-primary { background-color: var(--primary-color); color: white; }
.btn-primary:hover { background-color: #1d4ed8; }

/* --- [3. 헤더 (Navigation)] --- */
header { background: rgba(255, 255, 255, 0.95); backdrop-filter: blur(10px); box-shadow: 0 2px 10px rgba(0,0,0,0.05); position: sticky; top: 0; z-index: 100; }
nav { display: flex; justify-content: space-between; align-items: center; height: 70px; }
.logo { font-size: 1.5rem; font-weight: 800; color: var(--dark-bg); text-decoration: none; }
.nav-links { display: flex; gap: 30px; }
.nav-links a { font-weight: 500; font-size: 0.95rem; }
.nav-links a:hover { color: var(--primary-color); }

/* --- [4. 히어로 섹션 (첫인상)] --- */
.hero { background: linear-gradient(135deg, #1e3a8a 0%, #3b82f6 100%); color: white; text-align: center; padding: 100px 20px; }
.hero h1 { font-size: 3rem; margin-bottom: 20px; font-weight: 800; }
.hero p { font-size: 1.2rem; margin-bottom: 40px; opacity: 0.9; }

/* --- [5. 섹션 A: AI Tools (수익화: 제휴마케팅)] --- */
.ai-section { /* background-color removed to show body pattern */ }
.section-title { text-align: center; margin-bottom: 50px; }
.section-title h2 { font-size: 2rem; margin-bottom: 10px; }
.section-title span { color: var(--primary-color); text-transform: uppercase; font-size: 0.8rem; letter-spacing: 2px; font-weight: 700; }

.grid-3 { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 30px; }
.card { border: 1px solid #e5e7eb; border-radius: 12px; padding: 30px; transition: 0.3s; background: white; }
.card:hover { transform: translateY(-5px); box-shadow: 0 10px 20px rgba(0,0,0,0.1); }
.tag { background: #dbeafe; color: var(--primary-color); padding: 5px 10px; border-radius: 20px; font-size: 0.8rem; font-weight: 600; }

/* --- [6. 섹션 B: How-To (수익화: 구글 애드센스)] --- */
.howto-section { /* background-color removed */ }
.howto-list { display: flex; flex-direction: column; gap: 20px; }
.howto-item { background: white; padding: 20px; border-radius: 10px; display: flex; justify-content: space-between; align-items: center; cursor: pointer; }
.howto-item:hover { border-left: 5px solid var(--accent-color); }

/* 광고 영역 플레이스홀더 */
.ad-banner { background: #e5e7eb; height: 120px; margin: 40px 0; display: flex; justify-content: center; align-items: center; color: #9ca3af; font-weight: 600; border: 2px dashed #d1d5db; }

/* --- [7. 섹션 C: Wellness (브랜딩 & 전자책 판매)] --- */
.wellness-section { /* background-color removed */ text-align: center; }
.wellness-box { background: url('https://images.unsplash.com/photo-1506126613408-eca07ce68773?ixlib=rb-1.2.1&auto=format&fit=crop&w=1000&q=80') no-repeat center/cover; padding: 100px 20px; border-radius: 20px; color: white; position: relative; }
.wellness-box::before { content: ''; position: absolute; top:0; left:0; width:100%; height:100%; background: rgba(0,0,0,0.5); border-radius: 20px; }
.wellness-content { position: relative; z-index: 1; }

/* --- [8. 푸터] --- */
footer { background: var(--dark-bg); color: #9ca3af; padding: 50px 0; text-align: center; font-size: 0.9rem; }
.footer-links { margin-bottom: 20px; }
.footer-links a { margin: 0 15px; }

/* 모바일 대응 */
@media (max-width: 768px) {
    .hero h1 { font-size: 2rem; }
    .nav-links { display: none; } /* 모바일 메뉴 구현 필요 */
}