/* ====== Base Reset ====== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: system-ui, -apple-system, sans-serif;
  line-height: 1.6;
  background-color: #f9fafb;
  color: #333;
}

/* ====== Header & Navigation ====== */
header {
  background: #2c3e50;
  color: #fff;
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

header h1 {
  font-size: 1.5rem;
}

nav a {
  color: #fff;
  text-decoration: none;
  margin-left: 1rem;
  font-weight: 500;
}

nav a:hover {
  text-decoration: underline;
  color: #1abc9c;
}

/* ====== Container / Main Layout ====== */
.container {
  max-width: 1200px;
  margin: 2rem auto;
  padding: 2rem;
  background: #fff;
  border-radius: 8px;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.08);
}

/* ====== Headings ====== */
h2 {
  margin-bottom: 1rem;
  color: #2c3e50;
}

/* ====== Buttons ====== */
.btn {
  padding: 0.5rem 2rem;
  border-radius: 5px;
  text-decoration: none;
  font-weight: 500;
  margin-right: 0.5rem;
  cursor: pointer;
  border: none;
  transition: 0.2s;
  font-size: 15px;
}

.btn-primary {
  background: #007bff;
  color: #fff;
}

.btn-primary:hover {
  background: #3995f7;
}

.btn-danger {
  background: #dc3545;
  color: #fff;
}

.btn-danger:hover {
  background: #f55f6e;
}

.btn-secondary {
  background: #6c757d;
  color: #fff;
  text-align: center;
}

.btn-secondary:hover {
  background: #8d8d8d;
}

.btn-success {
  background: #28a745;
  color: #fff;
  height: 40px;
}

.btn-success:hover {
  background: #30c352;
}

.btn-sm {
  font-size: 0.85rem;
  padding: 0.25rem 0.5rem;
}

/* ====== Forms ====== */
.form-container {
  background: #fff;
  padding: 1.5rem;
  border-radius: 8px;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.1);
  margin-bottom: 2rem;
}

.form-container form {
  display: grid;
  gap: 1rem;
}

label {
  font-weight: 500;
}

input,
select,
textarea {
  width: 100%;
  padding: 0.6rem;
  border: 1px solid #d1d5db;
  border-radius: 4px;
  font-size: 1rem;
}

input:focus,
select:focus,
textarea:focus {
  outline: none;
  border-color: #1abc9c;
  box-shadow: 0 0 0 2px rgba(26, 188, 156, 0.2);
}

/* ====== Lists ====== */
.category-list {
  list-style: none;
  padding: 0;
}

.category-item {
  display: flex;
  justify-content: space-between;
  padding: 0.5rem 0;
  border-bottom: 1px solid #eee;
}

.category-item a {
  margin-left: 0.5rem;
}

/* ====== Tables ====== */
.list-container {
  margin-top: 1rem;
  overflow-x: auto;
}

.list-container table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.95rem;
}

.list-container th,
.list-container td {
  padding: 0.75rem;
  border: 1px solid #e5e7eb;
  text-align: left;
}

.list-container th {
  background: #f3f4f6;
  font-weight: 600;
}

.list-container tr:nth-child(even) {
  background: #fafafa;
}

/* ====== Pagination ====== */
.pagination {
  margin-top: 1.5rem;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: nowrap;
}

.pagination a,
.pagination strong {
  padding: 0.4rem 0.7rem;
  border: 1px solid #d1d5db;
  border-radius: 4px;
  text-decoration: none;
  font-size: 0.9rem;
}

.pagination a {
  background: #ffffff;
  color: #000000;
}

.pagination a:hover {
  background: #1abc9c;
  color: #ffffff;
}

.pagination strong {
  background: #1abc9c;
  color: #fff;
}

/* ====== Delete Confirm ====== */
.delete-container {
  background: #fff;
  padding: 1.5rem;
  border-radius: 8px;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.1);
  margin-bottom: 2rem;
}

/* ====== Charts / Reports ====== */
.report-container {
  background: #fff;
  padding: 1.5rem;
  border-radius: 8px;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.1);
  margin-bottom: 2rem;
  width: 90%;
  max-width: 1200px;
}

.chart {
  margin: 1rem auto;
  width: 100%;
  height: 800px;
}

.report-list {
  list-style: none;
  padding: 0;
  margin: 1rem 0;
}

.report-list li {
  padding: 0.5rem 1rem;
  margin-left: 20px;
  margin-bottom: 0.5rem;
  background: #f8f9fa;
  border-left: 4px solid;
  border-image: linear-gradient(to bottom, #007bff, #00c6ff) 1;
  border-radius: 6px;
  font-weight: 500;
}

/* ====== Links ====== */
a {
  color: #fbfbfb;
  text-decoration: none;
}

a:hover {
  color: #fbfbfb;
}

.books-container {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  margin-top: 1rem;
}

.book-card {
  flex: 1 1 calc(35% - 1.5rem); /* 4 cards per row */
  background: #fff;
  border-radius: 8px;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.08);
  padding: 1rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.book-card h3 {
  margin-bottom: 0.5rem;
  color: #2c3e50;
  font-size: 1.2rem;
}

.book-card .subtitle {
  font-style: italic;
  color: #555;
  margin-bottom: 0.5rem;
}

.book-card p {
  margin: 0.25rem 0;
  font-size: 0.95rem;
}

.book-card .actions {
  margin-top: 1rem;
  display: flex;
  gap: 10rem;
  justify-content: flex-start;
}

.down {
  margin-top: 20px;
}

.side-by-side {
  display: flex;
  flex-direction: row;
  justify-content: space-between;
}

.search-form input {
  width: 450px;
}

.delete-warning {
  text-align: center;
  padding: 20px;
  font-size: 20px;
}

.btn-div {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 0.5em;
}

/* Responsive */
@media (max-width: 1200px) {
  .book-card {
    flex: 1 1 calc(33.33% - 1rem);
  }
}
@media (max-width: 900px) {
  .book-card {
    flex: 1 1 calc(50% - 1rem);
  }
}
@media (max-width: 600px) {
  .book-card {
    flex: 1 1 100%;
  }
}