:root {
    color-scheme: light;
    --bg-body: #ffffff;
    --bg-section: #f2f4f8;
    --bg-card: #ffffff;
    --bg-header: #2f4f7f;
    --bg-placeholder: #cccccc;
    --text: #1a1a1a;
    --text-header: #ffffff;
    --accent: #2f4f7f;
    --accent-text: #ffffff;
    --shadow: rgba(0, 0, 0, 0.15);
}

body {
    display: flex;
    flex-direction: column;
    margin: 0;
    height: 100vh;
    background-color: var(--bg-body);
    color: var(--text);
}

.site-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 30px 30px;
    padding-bottom: 0;
    background-color: var(--bg-header);
    color: var(--text-header);
}

/* khối trống bên phải, rộng bằng logo để tiêu đề nằm giữa */
.site-header::after {
    content: "";
    flex: 1;
}

.logo {
    flex: 1;
    display: flex;
    align-items: center;
    gap: 20px;
    font-weight: bold;
}

.desc {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.desc .name {
    font-size: 3rem;
    margin-bottom: 0;
}

.desc .short-description {
    font-size: 1.5rem;
    margin-bottom: 60px;
}

.logo .image .logo1 {
    max-width: 100%;
    height: auto;
    width: 90px;
}

.logo .image {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.book-view {
    padding: 20px 30px;
    background-color: var(--bg-section);
}

#book-preview {
    display: flex;
    flex-wrap: wrap;
    gap: 30px;
    background-color: var(--bg-card);
    border-radius: 10px;
    box-shadow: 0 2px 8px var(--shadow);
    padding: 20px;
}

.book-cover {
    flex: 0 0 220px;
}

.book-cover img {
    width: 100%;
    height: auto;
    border-radius: 6px;
    background-color: var(--bg-placeholder);
}

.book-info {
    flex: 1;
    min-width: 250px;
}

.book-title {
    margin-top: 0;
}

.book-author,
.book-category {
    color: var(--accent);
}

/* ===== nhận sách ===== */
.request-box {
    margin-top: 20px;
    padding: 15px;
    border-radius: 10px;
    background-color: var(--bg-section);
}

.request-button {
    padding: 10px 20px;
    border: none;
    border-radius: 20px;
    background-color: var(--accent);
    color: var(--accent-text);
    font-size: 1rem;
    cursor: pointer;
}

.request-button[hidden] {
    display: none;
}

.request-button:hover {
    opacity: 0.85;
}

.request-button:disabled {
    opacity: 0.6;
    cursor: wait;
}

.request-secondary {
    padding: 10px 20px;
    border: 2px solid var(--accent);
    border-radius: 20px;
    background: none;
    color: var(--accent);
    font-size: 1rem;
    cursor: pointer;
}

.request-form[hidden] {
    display: none;
}

.request-form label {
    display: block;
    margin-bottom: 6px;
    font-weight: bold;
    font-size: 0.9rem;
}

.request-form textarea {
    width: 100%;
    box-sizing: border-box;
    padding: 8px 12px;
    border: 1px solid var(--bg-placeholder);
    border-radius: 6px;
    font-family: inherit;
    font-size: 1rem;
    resize: vertical;
}

.request-actions {
    display: flex;
    gap: 10px;
    margin-top: 10px;
}

.request-status {
    margin: 0;
    min-height: 1.2em;
}

.request-status.error {
    color: #d64545;
}

.request-link {
    display: inline-block;
    margin-top: 8px;
    color: var(--accent);
    font-weight: bold;
    text-decoration: none;
}

.request-link[hidden] {
    display: none;
}

.request-link:hover {
    text-decoration: underline;
}

/* ===== xoá sách ===== */
.delete-button {
    margin-top: 20px;
    padding: 10px 20px;
    border: none;
    border-radius: 20px;
    background-color: #d64545;
    color: #ffffff;
    font-size: 1rem;
    cursor: pointer;
}

.delete-button[hidden] {
    display: none;
}

.delete-button:hover {
    opacity: 0.85;
}

.delete-button:disabled {
    opacity: 0.6;
    cursor: wait;
}