body, html {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: Arial, sans-serif;
    background-color: #f8f9fa; /* 연한 회색 배경 */
    color: #333; /* 기본 텍스트 색상 */
    line-height: 1.6; /* 줄 간격 */
    scroll-behavior: smooth; /* 부드러운 스크롤 */
}

/* 공통 헤딩 및 텍스트 설정 */
h1, h2, h3, p, ul, blockquote {
    margin: 0;
    padding: 0;
}

/* 헤더 스타일 */
.header {
    background-color: #00264d; /* 남색 배경 */
    color: white; /* 흰색 텍스트 */
    text-align: center;
    padding: 20px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1); /* 헤더 그림자 */
    position: relative;
    border-bottom: 5px solid #004080;
    animation: fadeInDown 1s ease-in-out;
}

@keyframes fadeInDown {
    0% {
        opacity: 0;
        transform: translateY(-20px);
    }
    100% {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 홈 버튼 스타일 */
.home-logo {
    position: absolute;
    top: 15px;
    left: 15px;
    width: 60px;
    height: 60px;
    background-color: white;
    border: 2px solid #ddd;
    border-radius: 50%; /* 완벽한 원형 */
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.2); /* 그림자 효과 */
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.home-logo img {
    width: 40px;
    height: 40px;
    border-radius: 50%; /* 이미지도 원형으로 */
}

.home-logo:hover {
    transform: scale(1.1);
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.3);
}

/* 헤더 제목 */
.header h1 {
    font-size: 2.5em;
    font-weight: bold;
    margin-bottom: 10px;
    text-transform: uppercase;
    letter-spacing: 2px;
}

/* 내비게이션 스타일 */
.header nav {
    margin-top: 10px;
    display: flex;
    justify-content: center;
    gap: 15px;
}

.nav-link {
    text-decoration: none;
    color: white;
    font-size: 1.2em;
    font-weight: 600;
    padding: 5px 10px;
    border-radius: 5px;
    transition: color 0.3s ease, background-color 0.3s ease;
}

.nav-link:hover {
    color: #b3cce6;
    background-color: rgba(255, 255, 255, 0.2);
}

/* 메인 콘텐츠 */
main {
    padding: 20px;
    max-width: 1200px;
    margin: 0 auto;
    background-color: white;
    border-radius: 10px;
    animation: fadeIn 1s ease-in-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

/* 섹션 스타일 */
section {
    margin-bottom: 40px;
    padding: 30px;
    background-color: #f9f9f9;
    border-radius: 10px;
    border: 1px solid #ddd;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

section:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.1);
}

section h2, section h3 {
    margin-bottom: 20px;
    color: #00264d;
}

/* 카드 스타일 */
.card {
    background-color: #ffffff;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    padding: 20px;
    margin: 20px auto;
    max-width: 300px;
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: scale(1.05);
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.2);
}

.card img {
    width: 100%;
    height: auto;
    border-radius: 10px;
    margin-bottom: 15px;
}

/* 버튼 스타일 */
.button {
    display: inline-block;
    padding: 10px 20px;
    background-color: #004080;
    color: white;
    font-size: 1em;
    font-weight: bold;
    text-transform: uppercase;
    text-decoration: none;
    border-radius: 5px;
    transition: background-color 0.3s ease, transform 0.2s ease;
}

.button:hover {
    background-color: #00264d;
    transform: translateY(-3px);
}

/* 테이블 스타일 */
table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
    background-color: white;
}

th, td {
    border: 1px solid #ddd;
    padding: 10px;
    text-align: center;
}

th {
    background-color: #004080;
    color: white;
}

tr:nth-child(even) {
    background-color: #f9f9f9;
}

/* 툴팁 */
.tooltip {
    position: relative;
    display: inline-block;
    cursor: pointer;
}

.tooltip .tooltip-text {
    visibility: hidden;
    background-color: #333;
    color: #fff;
    text-align: center;
    padding: 5px;
    border-radius: 5px;
    position: absolute;
    bottom: 125%;
    left: 50%;
    transform: translateX(-50%);
    opacity: 0;
    transition: opacity 0.3s ease;
    width: 200px;
}

.tooltip:hover .tooltip-text {
    visibility: visible;
    opacity: 1;
}

/* 프로그래스바 */
.progress-bar-container {
    background-color: #ddd;
    border-radius: 10px;
    padding: 5px;
    margin: 20px 0;
}

.progress-bar {
    background-color: #004080;
    height: 20px;
    border-radius: 10px;
    width: 70%;
    transition: width 0.5s ease;
}

/* 로딩 애니메이션 */
.loader {
    border: 5px solid #f3f3f3;
    border-top: 5px solid #004080;
    border-radius: 50%;
    width: 50px;
    height: 50px;
    animation: spin 1s linear infinite;
    margin: 20px auto;
}

@keyframes spin {
    0% {
        transform: rotate(0deg);
    }
    100% {
        transform: rotate(360deg);
    }
}

/* 반응형 디자인 */
@media (max-width: 768px) {
    .card {
        max-width: 90%;
    }

    .nav-link {
        font-size: 1em;
    }

    .progress-bar {
        width: 50%;
    }
}

@media (max-width: 480px) {
    section h2, section h3 {
        font-size: 1.5em;
    }

    .progress-bar {
        width: 40%;
    }

    .button {
        font-size: 0.9em;
    }
}