body {
    font-family: sans-serif;
    background: #f4f6f9;
    margin: 0;
    padding: 0;
    font-size: 16px;
    line-height: 1.6;
}

/* HEADER */
header {
    background: #303e54;
    color: white;
    padding: 10px;
    text-align: center;
}

header h1 {
    font-size: 1.5rem;
    margin: 0;
}

header img {
    width: 80px;
    height: auto;
    margin-bottom: 5px;
}


/* NAV */
nav {
    background: #39485d;
}

.nav-links {
    display: flex;
    justify-content: center;
}

.nav-links a {
    color: white;
    padding: 12px 15px;
    text-decoration: none;
    display: block;
    font-size: 0.9rem;
}

.menu-toggle {
    display: none;
    background: #475569;
    border: none;
    color: white;
    padding: 12px;
    width: 100%;
    text-align: left;
    font-size: 18px;
    cursor: pointer;
}


@media (max-width: 600px) {
    .menu-toggle {
        display: block;
    }

    .nav-links {
        display: none;
        flex-direction: column;
        text-align: center;
    }

    .nav-links.active {
        display: flex;
    }
}


/* MAIN CONTAINER */
.container {
    max-width: 1000px;
    margin: 20px auto;
    background: #fff;
    padding: 25px;
    border-radius: 8px;
    box-shadow: 0 2px 5px rgba(0,0,0,.1);
}


/* BOOKS */
.intro {
    text-align: center;
    color: #666;
    margin-bottom: 25px;
}

.disclosure {
    background: #fff8e6;
    border: 1px solid #f0d98c;
    padding: 15px;
    border-radius: 8px;
    margin: 20px 0;
    text-align: center;
}


.book-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 20px;
}


.book-card {
    background: #ffffff;
    border-radius: 8px;
    overflow: hidden;
    border: 1px solid #ddd;
    box-shadow: 0 2px 5px rgba(0,0,0,.08);
    transition: transform .2s;
}


.book-card:hover {
    transform: translateY(-4px);
}


.book-cover {
    width: 100%;
    height: 320px;
    object-fit: cover;
    background: #eee;
}


.book-content {
    padding: 15px;
}


.book-title {
    font-size: 1.1rem;
    margin: 0 0 5px;
    color: #303e54;
}


.book-author {
    color: #777;
    font-style: italic;
    margin-bottom: 10px;
}


.book-description {
    font-size: 14px;
    color: #555;
}


/* BUTTONS */
button,
.amazon-btn {
    margin-top: 15px;
    padding: 12px;
    background: #ff9900;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    text-decoration: none;
    display: inline-block;
    width: 100%;
    text-align: center;
    font-weight: bold;
}


button:hover,
.amazon-btn:hover {
    background: #e68a00;
}


/* FORMS */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px,1fr));
    gap: 15px;
}

.field {
    display: flex;
    flex-direction: column;
}

input,
select {
    padding: 8px;
    margin-top: 5px;
    border: 1px solid #ccc;
    border-radius: 4px;
}


/* CARDS */
.cards {
    margin-top: 25px;
    display: grid;
    grid-template-columns: repeat(auto-fit,minmax(200px,1fr));
    gap: 15px;
}

.card {
    background:#eff6ff;
    padding:15px;
    border-radius:6px;
    border:1px solid #dbeafe;
}

.card.green {
    background:#f0fdf4;
    border:1px solid #bbf7d0;
    color:#166534;
}


/* TABLE */
.scroll {
    max-height:400px;
    overflow:auto;
    margin-top:20px;
    border:1px solid #ddd;
}

table {
    width:100%;
    border-collapse:collapse;
    font-size:14px;
}

th {
    background:#374151;
    color:white;
    padding:10px;
    position:sticky;
    top:0;
    text-align:right;
}

td {
    padding:8px;
    border-bottom:1px solid #eee;
    text-align:right;
}


/* TABS */
.tabs {
    display:flex;
    cursor:pointer;
    border-bottom:2px solid #ddd;
}

.tab {
    padding:10px 20px;
    margin-right:10px;
    color:#fff;
    border:1px solid #ccc;
    border-radius:5px 5px 0 0;
    background:#ff7f00;
    text-decoration:none;
}

a.tab:hover,
a.tab:visited {
    text-decoration:none;
    color:#ffffff;
}


/* FOOTER */
footer {
    background:#303e54;
    color:#94a3b8;
    padding:20px;
    text-align:center;
    font-size:.9rem;
}

footer a {
    color:#cbd5e1;
    margin:0 10px;
    text-decoration:none;
}


/* COLORS */
.red {
    color:#ee4b04;
    font-weight:bold;
}

.green {
    color:#157c04;
    font-weight:bold;
}