:root {
    --biru-penabur: #1E3A8A;
    --merah-penabur: #DC2626;
    --kuning-penabur: #F59E0B;
    --abu: #F3F4F6;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--abu);
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header dengan Banner */
.header-banner {
    position: relative;
    background: linear-gradient(135deg, var(--biru-penabur), var(--merah-penabur));
    color: white;
    text-align: center;
    overflow: hidden;
}

.banner-img {
    width: 100%;
    height: auto;
    max-height: 450px;
    object-fit: cover;
    display: block;
}

/* Navbar */
.navbar {
    background-color: var(--biru-penabur);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
}

.logo {
    color: var(--kuning-penabur);
    font-size: 1.5rem;
    font-weight: bold;
    text-decoration: none;
}

.nav-links a {
    color: white;
    text-decoration: none;
    margin-left: 1.5rem;
    transition: color 0.3s;
}

.nav-links a:hover {
    color: var(--kuning-penabur);
}

/* Search Box */
.search-box {
    background: white;
    padding: 2rem 0;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    margin-bottom: 2rem;
}

.search-form {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    justify-content: center;
}

.search-form input, .search-form select {
    padding: 0.75rem 1rem;
    border: 1px solid #ddd;
    border-radius: 8px;
    font-size: 1rem;
}

.search-form button {
    background-color: var(--merah-penabur);
    color: white;
    border: none;
    padding: 0.75rem 2rem;
    border-radius: 8px;
    cursor: pointer;
    transition: background 0.3s;
}

.search-form button:hover {
    background-color: #b91c1c;
}

/* Grid Ebook */
.ebook-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 2rem;
    margin: 2rem 0;
}

.ebook-card {
    background: white;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    transition: transform 0.3s, box-shadow 0.3s;
}

.ebook-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 20px rgba(0,0,0,0.15);
}

.card-header {
    background: linear-gradient(135deg, var(--biru-penabur), var(--merah-penabur));
    padding: 1rem;
    color: white;
}

.card-header h3 {
    font-size: 1.2rem;
    margin-bottom: 0.5rem;
}

.card-header h3 a {
    color: var(--kuning-penabur);
    text-decoration: none;
}

.card-body {
    padding: 1rem;
}

.card-body p {
    margin: 0.5rem 0;
    color: #555;
}

.badge {
    background: var(--kuning-penabur);
    color: #333;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    display: inline-block;
}

.read-btn {
    display: inline-block;
    margin-top: 1rem;
    background-color: var(--biru-penabur);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    text-decoration: none;
    transition: background 0.3s;
}

.read-btn:hover {
    background-color: #0f2a5c;
}

/* Footer */
footer {
    background-color: var(--biru-penabur);
    color: white;
    text-align: center;
    padding: 1.5rem;
    margin-top: auto;
    font-size: 0.9rem;
}

footer span {
    color: var(--kuning-penabur);
}

/* Admin Panel */
.admin-container {
    background: white;
    border-radius: 16px;
    padding: 2rem;
    margin: 2rem auto;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
}

.admin-form {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    max-width: 500px;
}

.admin-form input, .admin-form textarea, .admin-form select {
    padding: 0.75rem;
    border: 1px solid #ddd;
    border-radius: 8px;
}

.btn-primary {
    background-color: var(--biru-penabur);
    color: white;
    border: none;
    padding: 0.75rem;
    border-radius: 8px;
    cursor: pointer;
}

.btn-danger {
    background-color: var(--merah-penabur);
    color: white;
}

.btn-warning {
    background-color: var(--kuning-penabur);
    color: #333;
}

.table-responsive {
    overflow-x: auto;
}

table {
    width: 100%;
    border-collapse: collapse;
}

th, td {
    padding: 0.75rem;
    text-align: left;
    border-bottom: 1px solid #ddd;
}

th {
    background-color: var(--biru-penabur);
    color: white;
}

/* Flipbook Reader */
.reader-container {
    background: #2c2c2c;
    min-height: 80vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 2rem;
}

#viewer {
    background: #fff;
    box-shadow: 0 20px 40px rgba(0,0,0,0.3);
    border-radius: 8px;
    overflow: hidden;
}

.controls {
    margin-top: 1rem;
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    justify-content: center;
}

.controls button {
    background: var(--biru-penabur);
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    cursor: pointer;
}

.page-info {
    background: white;
    padding: 0.5rem 1rem;
    border-radius: 20px;
}

/* Responsive */
@media (max-width: 768px) {
    .navbar .container {
        flex-direction: column;
        gap: 1rem;
    }
    .nav-links a {
        margin: 0 0.75rem;
    }
    .search-form {
        flex-direction: column;
        align-items: stretch;
    }
}