/* ==============================================
   SEO 최적화 수익형 사이트 스타일시트
   모바일 우선 반응형 디자인
   ============================================== */

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

/* 기본 타이포그래피 */
body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Malgun Gothic', '맑은 고딕', sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f8f9fa;
    font-size: 16px;
}

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

/* 헤더 & 네비게이션 */
header {
    background: #fff;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 100;
}

.main-nav {
    padding: 1rem 0;
}

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

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: #007bff;
    text-decoration: none;
    transition: color 0.3s ease;
}

.logo:hover {
    color: #0056b3;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-menu a {
    color: #333;
    text-decoration: none;
    transition: color 0.3s ease;
    font-weight: 500;
}

.nav-menu a:hover {
    color: #007bff;
}

/* 메인 콘텐츠 */
main {
    background: #fff;
    min-height: 60vh;
    padding: 2rem 0;
}

article {
    padding: 2rem 0;
}

h1 {
    font-size: 2.5rem;
    color: #222;
    margin-bottom: 1.5rem;
    line-height: 1.2;
}

h2 {
    font-size: 2rem;
    color: #333;
    margin: 2rem 0 1rem;
    line-height: 1.3;
}

h3 {
    font-size: 1.5rem;
    color: #444;
    margin: 1.5rem 0 1rem;
}

p {
    margin-bottom: 1rem;
    line-height: 1.8;
}

/* 콘텐츠 섹션 */
.content-section {
    margin: 2rem 0;
}

/* 광고 영역 */
.ad-section {
    margin: 3rem 0;
    padding: 2rem;
    background: #f8f9fa;
    border-radius: 8px;
    text-align: center;
    min-height: 250px;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* 홈페이지 소개 섹션 */
.intro {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 3rem 2rem;
    border-radius: 12px;
    margin: 2rem 0;
    text-align: center;
}

.intro p {
    font-size: 1.2rem;
    line-height: 1.8;
}

/* 서비스 그리드 */
.services {
    margin: 3rem 0;
}

.service-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.service-card {
    background: #fff;
    border: 1px solid #e0e0e0;
    border-radius: 12px;
    padding: 2rem;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    text-decoration: none;
    display: flex;
    flex-direction: column;
}

.service-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.1);
}

.service-card h3 {
    color: #007bff;
    margin-top: 0;
    margin-bottom: 1rem;
    font-size: 1.4rem;
}

.service-card p {
    color: #666;
    flex-grow: 1;
    margin-bottom: 1.5rem;
}

.btn {
    display: inline-block;
    background: #007bff;
    color: white;
    padding: 0.75rem 1.5rem;
    border-radius: 6px;
    text-decoration: none;
    transition: background 0.3s ease;
    text-align: center;
    font-weight: 500;
}

.btn:hover {
    background: #0056b3;
}

/* 특징 섹션 */
.why-us {
    background: #f8f9fa;
    padding: 3rem 2rem;
    border-radius: 12px;
    margin: 3rem 0;
}

.features {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.feature {
    text-align: center;
}

.feature h3 {
    color: #28a745;
    margin-bottom: 0.5rem;
}

/* 이용 방법 */
.how-to-use {
    margin: 3rem 0;
}

.how-to-use ol {
    margin-left: 2rem;
    margin-top: 1rem;
}

.how-to-use li {
    margin-bottom: 1rem;
    line-height: 1.8;
    font-size: 1.1rem;
}

/* 사이트 소개 */
.about-site {
    background: #fff;
    padding: 2rem;
    border-left: 4px solid #007bff;
    margin: 3rem 0;
}

/* 푸터 */
footer {
    background: #333;
    color: #fff;
    padding: 2rem 0;
    margin-top: 4rem;
}

footer .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-nav {
    display: flex;
    gap: 2rem;
}

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

.footer-nav a:hover {
    color: #007bff;
}

/* 반응형 - 모바일 (768px 이하) */
@media (max-width: 768px) {
    h1 {
        font-size: 2rem;
    }

    h2 {
        font-size: 1.5rem;
    }

    .nav-menu {
        flex-direction: column;
        gap: 1rem;
    }

    .main-nav .container {
        flex-direction: column;
        gap: 1rem;
    }

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

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

    footer .container {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }

    .footer-nav {
        flex-direction: column;
        gap: 0.5rem;
    }

    .intro {
        padding: 2rem 1rem;
    }

    .intro p {
        font-size: 1rem;
    }
}

/* 반응형 - 태블릿 (769px ~ 1024px) */
@media (min-width: 769px) and (max-width: 1024px) {
    .container {
        max-width: 960px;
    }

    .service-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* 반응형 - 데스크톱 (1025px 이상) */
@media (min-width: 1025px) {
    .container {
        max-width: 1200px;
    }

    .service-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

/* 접근성 */
a:focus,
button:focus {
    outline: 2px solid #007bff;
    outline-offset: 2px;
}

/* 프린트 스타일 */
@media print {
    header,
    footer,
    .ad-section {
        display: none;
    }
}