body {
    background: #fff8e1;
    background-image: linear-gradient(#e0d5a8 1px, transparent 1px),
    linear-gradient(90deg, transparent 99%, #e0d5a8 99%);
    background-size: 100% 30px, 30px 100%;
    background-attachment: fixed;
    transition: background 0.3s, color 0.3s;
}

/* 深色模式 */
body.dark-mode {
    background: #2b2b2b;
    color: #e0e0e0;
}

body.dark-mode .stars-container {
    display: block;
}

/* 书页内容背景 */
.book-page {
    background: #fffbe6;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15), inset 0 0 10px rgba(0, 0, 0, 0.05);
    border: 1px solid #e0d5a8;
}

body.dark-mode .book-page {
    background: #3c3c3c;
    border: 1px solid #555;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.3);
}

header {
    border-bottom: 1px solid #e0d5a8;
}

body.dark-mode header {
    border-bottom: 1px solid #555;
}

h1 {
    color: #4a2f1a;
}

body.dark-mode h1 {
    color: #d4d4d4;
}

nav a {
    color: #6b4527;
}

body.dark-mode nav a {
    color: #d4d4d4;
}

body.dark-mode nav a:hover {
    color: #ffffff;
}

/* 主题选择框 */
.theme-selector {
    display: inline-block;
    position: relative;
}

.theme-options {
    display: none;
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    background: #fffbe6;
    border: 1px solid #e0d5a8;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    z-index: 1000;
    padding: 10px;
    border-radius: 4px;
}

body.dark-mode .theme-options {
    background: #3c3c3c;
    border: 1px solid #555;
}

.theme-options button {
    display: block;
    width: 100px;
    padding: 8px;
    margin: 5px 0;
    background: #9c6a3b;
    color: #fff;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    text-align: center;
}

body.dark-mode .theme-options button {
    background: #d4d4d4;
    color: #2b2b2b;
}

.theme-options button:hover {
    background: #6b4527;
}

body.dark-mode .theme-options button:hover {
    background: #ffffff;
}

h2 {
    color: #6b4527;
    border-left: 4px solid #9c6a3b;
}

body.dark-mode h2 {
    color: #d4d4d4;
    border-left: 4px solid #ffffff;
}

p, li {
    color: #4a2f1a;
}

body.dark-mode p, body.dark-mode li {
    color: #e0e0e0;
}

/* 联系表单 */
.contact-form label {
    color: #4a2f1a;
}

body.dark-mode .contact-form label {
    color: #e0e0e0;
}

.contact-form input, .contact-form textarea {
    border: 1px solid #e0d5a8;
    background: #fefbe9;
}

body.dark-mode .contact-form input, body.dark-mode .contact-form textarea {
    border: 1px solid #555;
    background: #4a4a4a;
    color: #e0e0e0;
}

.contact-form button {
    background: #9c6a3b;
    color: #fff;
}

body.dark-mode .contact-form button {
    background: #d4d4d4;
    color: #2b2b2b;
}

.contact-form button:hover {
    background: #6b4527;
}

body.dark-mode .contact-form button:hover {
    background: #ffffff;
}

/* 每日一言 */
.daily-quote {
    text-align: center;
    margin: 20px 0;
    padding: 15px;
    background: rgba(255, 251, 230, 0.6);
    border-radius: 10px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

body.dark-mode .daily-quote {
    background: rgba(60, 60, 90, 0.6);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.daily-quote p {
    font-size: 1em;
    color: #4a2f1a;
    margin: 0;
}

body.dark-mode .daily-quote p {
    color: #e0e0e0;
}

#daily-quote-text {
    font-style: italic;
    color: #9c6a3b;
}

body.dark-mode #daily-quote-text {
    color: #d4d4d4;
}

/* 页脚 */
footer {
    text-align: center;
    padding: 20px 0;
    border-top: 1px solid #e0d5a8;
    margin-top: 40px;
}

body.dark-mode footer {
    border-top: 1px solid #555;
}

.footer-links a {
    margin: 0 10px;
    text-decoration: none;
    color: #6b4527;
}

body.dark-mode .footer-links a {
    color: #d4d4d4;
}

.footer-links a:hover {
    color: #9c6a3b;
}

body.dark-mode .footer-links a:hover {
    color: #ffffff;
}

.footer-icp p {
    font-size: 0.9em;
    color: #4a2f1a;
    margin: 10px 0 0;
}

body.dark-mode .footer-icp p {
    color: #e0e0e0;
}

.footer-icp a {
    color: #6b4527;
    text-decoration: none;
}

body.dark-mode .footer-icp a {
    color: #d4d4d4;
}

.footer-icp a:hover {
    color: #9c6a3b;
}

body.dark-mode .footer-icp a:hover {
    color: #ffffff;
}

/* 回到顶部按钮 */
#back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    padding: 10px 15px;
    background: #9c6a3b;
    color: #fff;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    opacity: 0;
    transition: opacity 0.3s, transform 0.5s ease-in-out;
}

body.dark-mode #back-to-top {
    background: #d4d4d4;
    color: #2b2b2b;
}

#back-to-top.visible {
    opacity: 1;
}

#back-to-top:hover {
    transform: scale(1.1);
}