body {
    font-family: 'Segoe UI', Arial, sans-serif;
    background: #f4f6fb;
    color: #222;
    margin: 0;
    padding: 0 0 40px 0;
}

header {
    background: #2a4d69;
    color: #fff;
    padding: 24px 0 16px 0;
    text-align: center;
    box-shadow: 0 2px 8px rgba(44,62,80,0.07);
}

header nav {
    text-align: left;
    margin-left: 24px;
}

header .voltar {
    color: #fff;
    text-decoration: none;
    font-size: 1em;
    margin-bottom: 8px;
    display: inline-block;
    transition: color 0.2s;
}

header .voltar:hover {
    color: #b3c6e0;
    text-decoration: underline;
}

header h1 {
    margin: 0;
    font-size: 2.2em;
    letter-spacing: 1px;
}

header .descricao {
    margin-top: 8px;
    color: #dbe9f6;
    font-size: 1.1em;
}

main {
    max-width: 820px;
    margin: 0 auto;
    padding: 24px 12px 0 12px;
}

section {
    margin-bottom: 36px;
}

h2 {
    color: #173f5f;
    margin-top: 32px;
    margin-bottom: 10px;
    font-size: 1.5em;
    border-bottom: 2px solid #e3eaf2;
    padding-bottom: 4px;
}

h3, h4 {
    color: #4b86b4;
    margin-top: 18px;
    margin-bottom: 8px;
}

ol, ul {
    background: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(44,62,80,0.07);
    padding: 18px 32px 18px 40px;
    margin: 18px auto 24px auto;
    max-width: 700px;
}

li {
    margin-bottom: 10px;
    line-height: 1.6;
}

a {
    color: #20639b;
    text-decoration: none;
    transition: color 0.2s;
}

a:hover {
    color: #173f5f;
    text-decoration: underline;
}

strong {
    color: #173f5f;
}

/* Nested lists */
ol > ol, ul > ul {
    background: #f0f4fa;
    margin: 10px 0 10px 20px;
    padding: 10px 20px;
    box-shadow: none;
}

/* Playlist link */
.playlist {
    display: block;
    text-align: center;
    margin: 24px auto 0 auto;
    font-weight: bold;
    background: #2a4d69;
    color: #fff !important;
    padding: 10px 0;
    border-radius: 6px;
    max-width: 420px;
    box-shadow: 0 2px 8px rgba(44,62,80,0.07);
    text-decoration: none;
}

.playlist:hover {
    background: #173f5f;
    color: #fff !important;
}

@media (max-width: 600px) {
    main {
        padding: 12px 2vw 0 2vw;
    }
    ol, ul {
        padding: 12px 10px 12px 18px;
        max-width: 98vw;
    }
    h2, h3, h4 {
        margin-left: 2vw;
    }
}