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

body {
    background-color: #e8f4fc;
    font-family: "맑은 고딕", "Malgun Gothic", sans-serif;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

header {
    background-color: #1565c0;
    color: white;
    text-align: center;
    padding: 20px;
}

header h1 {
    font-size: 2em;
    letter-spacing: 4px;
}

header audio {
    margin-top: 10px;
}

/* nav + section 가로 배치 */
.wrapper {
    display: flex;
    flex: 1;
}

nav {
    background-color: #90caf9;
    width: 180px;
    min-width: 160px;
    padding: 20px 15px;
    flex-shrink: 0;
}

nav h3 {
    color: #0d47a1;
    font-size: 1.1em;
    margin-bottom: 12px;
    border-bottom: 2px solid #1565c0;
    padding-bottom: 6px;
}

nav ul {
    list-style: disc;
    padding-left: 18px;
}

nav li {
    margin-bottom: 8px;
}

nav li a {
    color: #1a237e;
    text-decoration: none;
    font-size: 0.95em;
    display: block;
    padding: 4px 6px;
    border-radius: 4px;
    transition: background-color 0.2s;
}

nav li a:hover {
    background-color: #42a5f5;
    color: white;
}

section {
    background-color: #e8f5e9;  /* 연한 초록색 */
    flex: 1;
    padding: 25px 30px;
}

article {
    margin-bottom: 25px;
}

article > p {
    color: #37474f;
    line-height: 1.7;
    font-size: 0.95em;
}

h3 {
    margin-bottom: 8px;
    color: #1565c0;
}

h3 a {
    color: #1565c0;
    text-decoration: none;
    font-size: 1.1em;
}

h3 a:hover {
    color: #7b1fa2;
    text-decoration: underline;
}

img {
    border: 3px solid #90caf9;
    border-radius: 10px;
    margin: 4px;
}

table {
    margin-top: 10px;
}

footer {
    background-color: #e1bee7;  /* 연한 파스텔 보라색 */
    color: #1a237e;
    text-align: center;
    padding: 15px;
    font-size: 0.9em;
}

footer a {
    color: #1a237e;
    font-weight: bold;
    text-decoration: none;
}

footer a:hover {
    text-decoration: underline;
}