.container {
  width: 300px;
  margin: 50px auto;
  padding: 30px;
  background-color: #f7f7f7;
  border-radius: 8px;
  box-shadow: 0 0 15px rgba(0,0,0,0.2);
  font-family: Arial, sans-serif;
}

.container h2 {
  text-align: center;
  margin-bottom: 20px;
  color: black;
}

.container input[type="text"],
.container input[type="password"] {
  width: 100%;
  padding: 12px 15px;
  margin: 10px 0 20px 0;
  border: 1px solid white;
  border-radius: 4px;
  box-sizing: border-box;
  font-size: 14px;

}

.container input[type="checkbox"] {
  margin-right: 5px;
  vertical-align: middle;
}

.container label {
  font-size: 14px;
  color: #555;
}

.container button[type="submit"] {
  width: 100%;
  padding: 12px;
  background-color: #007bff;
  border: none;
  border-radius: 4px;
  color: white;
  font-size: 16px;
  cursor: pointer;
  transition: background-color 0.3s ease;
}

.container button[type="submit"]:hover {
  background-color: #0056b3;
}

.container p {
  text-align: center;
  font-size: 13px;
  color: #666;
}

.container a {
  color: #007bff;
  text-decoration: none;
}

.container a:hover {
  text-decoration: underline;
}

body {
    font-family: 'Poppins', sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f0f0f0; 
}

.header {
    text-align: center;
    padding: 20px 0;
    background-color: turquoise; 
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.header h1 {
    color: white;
    margin-bottom: 5px;
    font-weight: 700;
}

.header p {
    color: white;
    margin: 0;
    font-size: 14px;
}

.categories {
    display: flex;
    justify-content: center;
    padding: 15px 10px;
    background-color: turquoise;
    overflow-x: auto;
}

.categories button {
    border: 1px solid #ccc;
    background-color: white;
    color: #333;
    padding: 8px 15px;
    margin: 0 5px;
    border-radius: 20px;
    cursor: pointer;
    font-size: 14px;
    white-space: nowrap; 
}

.categories button.active {
    background-color: lightblue;
    color: white;
    border-color: lightblue;
}


.book-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    padding: 20px;
    max-width: 1200px;
    margin: 0 auto;
}

.book-item {
    background-color: white;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
    transition: transform 0.2s;
}

.book-item:hover {
    transform: translateY(-5px);
}


.book-cover {
    width: 100%;
    height: 280px; 
    background-size: cover;
    background-position: center;
    position: relative;
    display: flex;
    justify-content: center;
    align-items: flex-start; 
    color: white;
    font-weight: 700;
    text-align: center;
    padding-top: 10px;
    box-sizing: border-box;
}


.book-title-overlay {
    background-color: rgba(0, 0, 0, 0.4); 
    width: 100%;
    padding: 5px 0;
    font-size: 1.1em;
}

.smaller-title {
    font-size: 0.9em;
}

.book-details {
    padding: 10px;
    line-height: 1.4;
}

.book-subject {
    font-weight: 600;
    margin: 0 0 5px 0;
    color: #333;
}

.book-info {
    font-size: 12px;
    color: #777;
    margin: 2px 0;
}


.mathematics {
    background-color: #4CAF50; 
    background-image: url('img/bindo.jpg'); 
}
.olahraga {
    background-color: #2196F3; 
    background-image: url('img/inggris.jpg'); 
}

.agama, .agama-2 {
    background-color: #FF9800; 
    background-image: url('img/matematika.jpg'); 
}

.bahasa-indonesia {
    background-color: #F44336; 
    background-image: url('img/agamakristen.jpg');
}

.english-grammar {
    background-color: #9C27B0;
    background-image: url('img/bk.jpg'); 
}

.informatika {
    background-color: #607D8B; 
    background-image: url('placeholder-informatika.png'); 
}

.dasar-konsentrasi {
    background-color: #00BCD4; 
    background-image: url('placeholder-dasar.png'); 
}

section {
    margin: 20px;
     padding: 10px;
     background-color: #e0e2e1;
    border-radius: 5px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}
.welcome {
    color: rgb(64, 110, 179);
    font-size: 30px;
    font-weight: bold;
    margin-bottom: 10px;
}
.footer {
    text-align: center;
    padding: 10px;
    background-color: turquoise;
    color: white;
    position: relative;
    bottom: 0;
}

.back-button {
    background-color: rgb(22, 138, 138);
    color: white;
    border: none;
    padding: 10px 20px;
    cursor: pointer;
    font-size: 16px;
    border-radius: 5px;
    margin: 10px;
}