.top-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 20px;
    background-color: white;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
}

.nav-left {
    display: flex;
    align-items: center;
    gap: 20px;
}

.back-btn {
    text-decoration: none;
    color: var(--text-color);
}

.nav-right {
    display: flex;
    align-items: center;
    gap: 20px;
}

.search-container {
    display: flex;
    gap: 10px;
}

.search-container input {
    padding: 6px 12px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    width: 200px;
}

.tool-buttons {
    display: flex;
    gap: 10px;
}

.tool-buttons button {
    padding: 6px 15px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    background-color: white;
    cursor: pointer;
    transition: all 0.3s ease;
}

.tool-buttons button:hover {
    background-color: var(--secondary-color);
}

.tool-buttons button.active {
    background-color: var(--primary-color);
    color: white;
}

.content-container {
    display: flex;
    gap: 20px;
    padding: 20px;
    overflow-y: auto;
    margin-top: 60px;
}

.chapter-content {
    flex: 1;
    background: white;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    margin-bottom: 20px;
    word-wrap: break-word;
    overflow-wrap: break-word;
}

.chapter-content h2 {
    margin-top: 30px;
    margin-bottom: 15px;
    color: var(--text-color);
    word-wrap: break-word;
}

.chapter-content p {
    margin-bottom: 15px;
    line-height: 1.6;
    color: var(--text-color);
    word-wrap: break-word;
    white-space: pre-wrap;
}

.note-panel {
    width: 300px;
    background: white;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    display: flex;
    flex-direction: column;
}

.note-header {
    padding: 15px;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.note-buttons {
    display: flex;
    gap: 10px;
}

.note-buttons button {
    padding: 4px 10px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    background-color: white;
    cursor: pointer;
}

#noteContent {
    flex: 1;
    padding: 15px;
    border: none;
    resize: none;
    min-height: 300px;
}

.hidden {
    display: none;
}

.search-highlight {
    background-color: yellow;
    text-decoration: underline;
}

.highlight {
    background-color: #ffeb3b;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .content-container {
        flex-direction: column;
    }

    .note-panel {
        width: 100%;
    }
}

/* 确保所有文本元素都不会溢出 */
.chapter-content * {
    max-width: 100%;
}