/* 기본 설정 */
:root {
    --primary-color: #0056b3; /* 진한 파랑 */
    --secondary-color: #6c757d; /* 회색 */
    --accent-color: #28a745; /* 녹색 계열 (버튼, 강조) */
    --light-bg: #f8f9fa; /* 밝은 배경 */
    --dark-bg: #343a40; /* 어두운 배경 (푸터 등) */
    --text-color-dark: #333;
    --text-color-light: #fff;
    --border-color: #dee2e6;
    --font-family-base: 'Noto Sans KR', sans-serif;
    --max-width: 1200px;
    --section-padding: 80px 0;
}

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

body {
    font-family: var(--font-family-base);
    line-height: 1.6;
    color: var(--text-color-dark);
    background-color: #fff;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 20px;
}

a {
    color: var(--primary-color);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

ul {
    list-style: none;
}

/* 섹션 공통 스타일 */
.section-padding {
    padding: var(--section-padding);
}

.section-title {
    font-size: 2.5em;
    font-weight: 700;
    text-align: center;
    margin-bottom: 20px;
    color: var(--primary-color);
}

.section-subtitle {
    font-size: 1.1em;
    text-align: center;
    margin-bottom: 60px;
    color: var(--secondary-color);
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.section-alt-bg {
    background-color: var(--light-bg);
}

/* 버튼 스타일 */
.btn {
    display: inline-block;
    padding: 12px 25px;
    border-radius: 5px;
    text-decoration: none;
    font-weight: 500;
    transition: background-color 0.3s ease;
}

.btn-primary {
    background-color: var(--primary-color);
    color: var(--text-color-light);
    border: 1px solid var(--primary-color);
}

.btn-primary:hover {
    background-color: darken(var(--primary-color), 10%); /* CSS 변수에는 darken 사용 불가, 직접 색상 지정 */
    background-color: #004499;
}

.btn-large {
    padding: 15px 35px;
    font-size: 1.1em;
}

/* 아이콘 (예시 - 실제 아이콘 라이브러리 사용 권장) */
.icon-autowrite, .icon-efficiency, .icon-collaboration,
.icon-autowrite-large, .icon-efficiency-large, .icon-collaboration-large,
.icon-simple, .icon-speed, .icon-accuracy, .icon-efficiency-small {
    /* 실제 아이콘 이미지 또는 Font Awesome/Material Icons 사용 */
    display: inline-block;
    width: 40px;
    height: 40px;
    background-color: var(--accent-color); /* 예시 색상 */
    border-radius: 50%;
    margin-bottom: 10px;
    /* 추상적인 아이콘 모양을 위한 예시 */
    position: relative;
}

.icon-autowrite::after, .icon-efficiency::after, .icon-collaboration::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 20px;
    height: 20px;
    border: 2px solid var(--text-color-light);
    border-radius: 3px;
}
.icon-autowrite-large::after, .icon-efficiency-large::after, .icon-collaboration-large::after,
.icon-simple::after, .icon-speed::after, .icon-accuracy::after, .icon-efficiency-small::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 25px;
    height: 25px;
    background-color: var(--text-color-light);
    border-radius: 50%;
}


/* 1. 상단 내비게이션 바 */
#main-header {
    background-color: #fff;
    padding: 15px 0;
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
}

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

.logo {
    font-size: 1.8em;
    font-weight: 700;
}

.logo a {
    color: var(--primary-color);
    text-decoration: none;
}

#main-nav .nav-links {
    display: flex;
    gap: 30px;
}

#main-nav .nav-links li a {
    color: var(--text-color-dark);
    font-weight: 500;
    transition: color 0.3s ease;
}

#main-nav .nav-links li a:hover {
    color: var(--primary-color);
    text-decoration: none;
}

#main-nav .nav-links li:last-child a {
    padding: 10px 20px;
}

.hamburger-menu {
    display: none; /* 기본적으로 숨김 */
    flex-direction: column;
    cursor: pointer;
}

.hamburger-menu span {
    height: 3px;
    width: 25px;
    background-color: var(--text-color-dark);
    margin-bottom: 5px;
    border-radius: 2px;
    transition: all 0.3s ease;
}

/* 2. 히어로 섹션 */
#hero-section {
    background-color: #eaf3f8; /* 밝은 푸른 계열 배경 */
    color: var(--text-color-dark);
    padding: 100px 0;
    text-align: center;
    position: relative;
    overflow: hidden; /* 배경 이미지/영상 오버플로우 숨김 */
}

#hero-section::before { /* 추상적인 배경 효과 */
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, rgba(0,86,179,0.1) 0%, rgba(255,255,255,0.1) 100%);
    z-index: 1;
}

#hero-section .container {
    position: relative;
    z-index: 2;
}

#hero-section h2 {
    font-size: 3.5em;
    font-weight: 700;
    margin-bottom: 20px;
    line-height: 1.2;
    color: var(--primary-color);
}

#hero-section p {
    font-size: 1.5em;
    margin-bottom: 40px;
    color: var(--secondary-color);
}

.hero-bullets {
    display: flex;
    justify-content: center;
    gap: 40px;
    margin-top: 50px;
    margin-bottom: 60px;
    flex-wrap: wrap; /* 반응형을 위해 추가 */
}

.hero-bullets .bullet-item {
    flex: 1;
    min-width: 280px; /* 너무 좁아지지 않도록 최소 너비 설정 */
    max-width: 350px;
    background-color: #fff;
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.08);
    text-align: left;
    transition: transform 0.3s ease;
}

.hero-bullets .bullet-item:hover {
    transform: translateY(-5px);
}

.hero-bullets .bullet-item h3 {
    font-size: 1.3em;
    margin-bottom: 10px;
    color: var(--primary-color);
}

.hero-bullets .bullet-item p {
    font-size: 1em;
    color: var(--text-color-dark);
    margin-bottom: 0;
}

/* 3. Combay AI란? */
#solution-intro .intro-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 40px;
    margin-bottom: 60px;
    text-align: center;
}

#solution-intro .intro-item {
    background-color: #fff;
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
}

#solution-intro .intro-item h3 {
    font-size: 1.4em;
    margin-bottom: 15px;
    color: var(--primary-color);
}

#solution-intro .intro-item p {
    font-size: 1em;
    color: var(--secondary-color);
}

.intro-image-placeholder {
    margin-top: 60px;
    text-align: center;
    background-color: var(--light-bg);
    padding: 40px;
    border-radius: 10px;
    box-shadow: inset 0 0 10px rgba(0,0,0,0.05);
}

.intro-image-placeholder img {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    box-shadow: 0 8px 20px rgba(0,0,0,0.1);
}

.intro-image-placeholder p {
    margin-top: 20px;
    font-style: italic;
    color: var(--secondary-color);
}

/* 4. 왜 Combay AI인가? */
#why-combayai .value-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    text-align: center;
}

#why-combayai .value-item {
    background-color: #fff;
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.08);
    transition: transform 0.3s ease;
}

#why-combayai .value-item:hover {
    transform: translateY(-8px);
}

#why-combayai .value-item .value-icon {
    margin-bottom: 20px;
}

#why-combayai .value-item h3 {
    font-size: 1.5em;
    margin-bottom: 15px;
    color: var(--primary-color);
}

#why-combayai .value-item p {
    font-size: 1em;
    color: var(--secondary-color);
}

/* 5. 주요 기능 */
#key-features .feature-item {
    display: flex;
    align-items: center;
    gap: 50px;
    margin-bottom: 80px;
    flex-wrap: wrap; /* 반응형을 위해 추가 */
}

#key-features .feature-item:last-child {
    margin-bottom: 0;
}

#key-features .feature-item.reverse {
    flex-direction: row-reverse;
}

#key-features .feature-content {
    flex: 1;
    min-width: 300px;
}

#key-features .feature-content h3 {
    font-size: 2em;
    margin-bottom: 20px;
    color: var(--primary-color);
}

#key-features .feature-content p {
    font-size: 1.1em;
    line-height: 1.8;
    color: var(--text-color-dark);
}

#key-features .feature-image {
    flex: 1;
    min-width: 300px;
    text-align: center;
}

#key-features .feature-image img {
    max-width: 100%;
    height: auto;
    border-radius: 10px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.15);
}

/* 6. 도입 안내 */
#how-to-start .cost-efficiency-grid {
    display: flex;
    gap: 40px;
    margin-bottom: 80px;
    flex-wrap: wrap; /* 반응형을 위해 추가 */
}

#how-to-start .efficiency-item {
    flex: 1;
    min-width: 450px; /* 너무 좁아지지 않도록 최소 너비 설정 */
    background-color: #fff;
    padding: 40px;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.08);
}

#how-to-start .efficiency-item h3 {
    font-size: 1.8em;
    color: var(--primary-color);
    margin-bottom: 30px;
    text-align: center;
}

.time-savings-graphic {
    display: flex;
    justify-content: space-around;
    align-items: flex-start;
    gap: 30px;
    margin-top: 20px;
}

.time-savings-graphic h4 {
    font-size: 1.2em;
    color: var(--secondary-color);
    margin-bottom: 15px;
}

.time-savings-graphic ul {
    list-style-type: disc;
    padding-left: 20px;
    color: var(--text-color-dark);
}

.time-savings-graphic li {
    margin-bottom: 8px;
}

.time-savings-graphic .time-estimate {
    font-weight: 700;
    font-size: 1.1em;
    color: var(--accent-color);
    margin-top: 20px;
}

.cost-savings-details p {
    margin-bottom: 10px;
    color: var(--text-color-dark);
}

.cost-savings-details strong {
    color: var(--primary-color);
}

.cost-summary {
    font-size: 1.3em;
    font-weight: 700;
    text-align: center;
    margin-top: 30px;
    color: var(--accent-color);
}

.cta-block {
    text-align: center;
    background-color: var(--primary-color);
    padding: 50px;
    border-radius: 10px;
    color: var(--text-color-light);
}

.cta-block h3 {
    font-size: 2em;
    margin-bottom: 40px;
}

.steps-grid {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 30px;
    margin-bottom: 50px;
}

.step-item {
    background-color: rgba(255,255,255,0.15);
    border-radius: 8px;
    padding: 25px;
    width: 220px;
    text-align: center;
    transition: background-color 0.3s ease;
}

.step-item:hover {
    background-color: rgba(255,255,255,0.25);
}

.step-number {
    font-size: 2em;
    font-weight: 700;
    color: var(--text-color-light);
    margin-bottom: 15px;
    background-color: var(--accent-color);
    width: 60px;
    height: 60px;
    border-radius: 50%;
    display: inline-flex;
    justify-content: center;
    align-items: center;
}

.step-item p {
    font-size: 1.1em;
    color: var(--text-color-light);
}

/* 7. 고객사 사례 (주석 처리된 섹션) */
/*
#customer-stories {
    text-align: center;
}

#customer-stories .customer-logos {
    display: flex;
    justify-content: center;
    gap: 40px;
    margin-top: 40px;
    margin-bottom: 60px;
    flex-wrap: wrap;
}

#customer-stories .customer-logos img {
    max-height: 80px;
    filter: grayscale(100%);
    opacity: 0.7;
    transition: filter 0.3s ease, opacity 0.3s ease;
}

#customer-stories .customer-logos img:hover {
    filter: grayscale(0%);
    opacity: 1;
}

.testimonials-slider {
    max-width: 800px;
    margin: 0 auto;
    background-color: var(--light-bg);
    padding: 40px;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
}

.testimonial-item p {
    font-size: 1.2em;
    font-style: italic;
    margin-bottom: 20px;
    color: var(--text-color-dark);
}

.testimonial-item span {
    font-weight: 500;
    color: var(--primary-color);
}
*/

/* 8. 푸터 */
#main-footer {
    background-color: var(--dark-bg);
    color: var(--text-color-light);
    padding: 50px 0 20px;
    font-size: 0.9em;
}

#main-footer .footer-content {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    flex-wrap: wrap; /* 반응형을 위해 추가 */
    gap: 30px;
    margin-bottom: 30px;
}

.footer-logo h2 {
    font-size: 2em;
    color: var(--text-color-light);
    margin-bottom: 20px;
}

.footer-info p {
    margin-bottom: 5px;
}

.footer-info a {
    color: var(--text-color-light);
    text-decoration: underline;
}

.footer-links ul {
    display: flex;
    gap: 20px;
    margin-bottom: 15px;
    flex-wrap: wrap;
}

.footer-links a {
    color: var(--text-color-light);
    transition: color 0.3s ease;
}

.footer-links a:hover {
    color: var(--accent-color);
}

.social-links {
    display: flex;
    gap: 15px;
    margin-top: 10px;
}

.social-links img {
    width: 24px;
    height: 24px;
    filter: invert(1); /* 아이콘 색상 반전 */
    opacity: 0.8;
    transition: opacity 0.3s ease;
}

.social-links img:hover {
    opacity: 1;
}

.copyright {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid rgba(255,255,255,0.1);
}

/* ================================================================= */
/* 반응형 디자인 (Media Queries) */
/* ================================================================= */

/* 태블릿 및 작은 데스크탑 (992px 이하) */
@media (max-width: 992px) {
    .section-title {
        font-size: 2em;
    }

    #hero-section h2 {
        font-size: 2.8em;
    }
    #hero-section p {
        font-size: 1.3em;
    }

    #main-nav .nav-links {
        gap: 20px;
    }

    #key-features .feature-item,
    #key-features .feature-item.reverse {
        flex-direction: column;
        text-align: center;
    }

    #key-features .feature-image {
        margin-top: 30px;
    }

    #how-to-start .cost-efficiency-grid {
        flex-direction: column;
        align-items: center;
    }
    #how-to-start .efficiency-item {
        min-width: unset; /* 너비 제약 해제 */
        width: 100%;
    }
}

/* 모바일 (768px 이하) */
@media (max-width: 768px) {
    .section-padding {
        padding: 60px 0;
    }

    .section-title {
        font-size: 1.8em;
    }

    .section-subtitle {
        font-size: 1em;
        margin-bottom: 40px;
    }

    /* 헤더 */
    #main-header .container {
        flex-wrap: wrap;
        justify-content: center;
    }
    .logo {
        width: 100%;
        text-align: center;
        margin-bottom: 15px;
    }
    #main-nav {
        display: none; /* 햄버거 메뉴로 대체 */
        width: 100%;
        margin-top: 15px;
    }
    #main-nav.active {
        display: block;
    }
    #main-nav .nav-links {
        flex-direction: column;
        align-items: center;
        gap: 15px;
    }
    .hamburger-menu {
        display: flex; /* 햄버거 메뉴 표시 */
        position: absolute;
        right: 20px;
        top: 25px;
    }
    /* 햄버거 메뉴 애니메이션 (active 클래스에 의해 제어) */
    .hamburger-menu.active span:nth-child(1) {
        transform: rotate(-45deg) translate(-5px, 6px);
    }
    .hamburger-menu.active span:nth-child(2) {
        opacity: 0;
    }
    .hamburger-menu.active span:nth-child(3) {
        transform: rotate(45deg) translate(-5px, -6px);
    }


    /* 히어로 섹션 */
    #hero-section {
        padding: 80px 0;
    }
    #hero-section h2 {
        font-size: 2.2em;
    }
    #hero-section p {
        font-size: 1.1em;
    }
    .hero-bullets {
        flex-direction: column;
        gap: 20px;
    }
    .hero-bullets .bullet-item {
        width: 100%;
        min-width: unset;
    }

    /* Combay AI란? */
    #solution-intro .intro-grid {
        grid-template-columns: 1fr;
    }

    /* 왜 Combay AI인가? */
    #why-combayai .value-grid {
        grid-template-columns: 1fr;
    }

    /* 주요 기능 */
    #key-features .feature-content h3 {
        font-size: 1.8em;
    }
    #key-features .feature-item {
        margin-bottom: 60px;
    }

    /* 도입 안내 */
    .time-savings-graphic {
        flex-direction: column;
        align-items: center;
        gap: 40px;
    }
    .time-savings-graphic > div {
        width: 100%;
    }
    .cta-block {
        padding: 40px 20px;
    }
    .cta-block h3 {
        font-size: 1.6em;
    }
    .steps-grid {
        flex-direction: column;
        align-items: center;
    }
    .step-item {
        width: 100%;
        max-width: 300px; /* 너무 넓어지지 않게 */
    }

    /* 푸터 */
    #main-footer .footer-content {
        flex-direction: column;
        align-items: center;
        text-align: center;
        gap: 20px;
    }
    .footer-links ul {
        flex-direction: column;
        gap: 10px;
    }
    .social-links {
        justify-content: center;
    }
}

/* 추가적인 작은 화면 (480px 이하) */
@media (max-width: 480px) {
    .btn-large {
        padding: 12px 25px;
        font-size: 1em;
    }

    #hero-section h2 {
        font-size: 1.8em;
    }
    #hero-section p {
        font-size: 1em;
    }

    #main-header .nav-links li a.btn-primary {
        width: 100%;
        text-align: center;
    }

    #how-to-start .efficiency-item {
        padding: 30px 20px;
    }
}