/* ===== 基础重置 ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
    line-height: 1.8;
    color: #2d3748;
    background: #f7fafc;
}

/* ===== 顶部导航栏 ===== */
.top-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 60px;
    background: linear-gradient(135deg, #306998 0%, #FFD43B 100%);
    display: flex;
    align-items: center;
    padding: 0 24px;
    z-index: 1000;
    box-shadow: 0 2px 15px rgba(0, 0, 0, 0.15);
}

.nav-back {
    color: white;
    text-decoration: none;
    font-weight: bold;
    font-size: 0.95rem;
    padding: 8px 16px;
    border-radius: 20px;
    background: rgba(255, 255, 255, 0.2);
    transition: all 0.3s ease;
    white-space: nowrap;
}

.nav-back:hover {
    background: rgba(255, 255, 255, 0.35);
}

.nav-title {
    flex: 1;
    text-align: center;
    color: white;
    font-size: 1.3rem;
    text-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
}

.progress-bar {
    width: 120px;
    height: 6px;
    background: rgba(255, 255, 255, 0.3);
    border-radius: 3px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    width: 0%;
    background: white;
    border-radius: 3px;
    transition: width 0.4s ease;
}

/* ===== 侧边栏 ===== */
.sidebar {
    position: fixed;
    top: 60px;
    left: 0;
    width: 260px;
    height: calc(100vh - 60px);
    background: white;
    border-right: 1px solid #e2e8f0;
    overflow-y: auto;
    z-index: 900;
    transition: transform 0.3s ease;
    box-shadow: 2px 0 10px rgba(0, 0, 0, 0.05);
}

.sidebar.hidden {
    transform: translateX(-260px);
}

.sidebar-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 20px 15px;
    font-size: 1.1rem;
    font-weight: bold;
    color: #2d3748;
    border-bottom: 1px solid #e2e8f0;
}

.sidebar-toggle {
    background: none;
    border: none;
    font-size: 1.2rem;
    cursor: pointer;
    color: #718096;
    padding: 4px 8px;
    border-radius: 4px;
    transition: background 0.2s;
}

.sidebar-toggle:hover {
    background: #f0f0f0;
}

.chapter-list {
    list-style: none;
    padding: 10px 0;
}

.chapter-list li {
    margin: 2px 0;
}

.chapter-link {
    display: block;
    padding: 10px 20px;
    color: #4a5568;
    text-decoration: none;
    font-size: 0.92rem;
    transition: all 0.2s ease;
    border-left: 3px solid transparent;
}

.chapter-link:hover {
    background: #f7fafc;
    color: #306998;
    border-left-color: #FFD43B;
}

.chapter-link.active {
    background: linear-gradient(90deg, rgba(48, 105, 152, 0.08), transparent);
    color: #306998;
    font-weight: 600;
    border-left-color: #306998;
}

/* ===== 主内容区 ===== */
.content {
    margin-left: 260px;
    margin-top: 60px;
    padding: 40px;
    max-width: 900px;
    transition: margin-left 0.3s ease;
}

.content.full-width {
    margin-left: 0;
}

/* ===== 章节样式 ===== */
.chapter {
    background: white;
    border-radius: 16px;
    padding: 40px;
    margin-bottom: 40px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
    border: 1px solid #e2e8f0;
    animation: fadeInUp 0.5s ease;
}

.chapter-badge {
    display: inline-block;
    background: linear-gradient(135deg, #306998, #4B8BBE);
    color: white;
    padding: 4px 14px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
    margin-bottom: 12px;
}

.chapter h2 {
    font-size: 1.8rem;
    color: #1a202c;
    margin-bottom: 24px;
    padding-bottom: 12px;
    border-bottom: 2px solid #FFD43B;
}

.chapter h3 {
    font-size: 1.2rem;
    color: #2d3748;
    margin: 28px 0 14px;
    padding-left: 12px;
    border-left: 4px solid #306998;
}

.chapter-body p {
    margin-bottom: 16px;
    color: #4a5568;
}

.chapter-body ul {
    margin: 12px 0 20px 24px;
}

.chapter-body li {
    margin-bottom: 8px;
    color: #4a5568;
}

.chapter-body code {
    background: #edf2f7;
    color: #e53e3e;
    padding: 2px 6px;
    border-radius: 4px;
    font-family: 'Consolas', 'Monaco', monospace;
    font-size: 0.9em;
}

/* ===== 代码块 ===== */
.code-block {
    background: #1e1e2e;
    border-radius: 12px;
    margin: 16px 0 24px;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.15);
}

.code-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 16px;
    background: #313244;
    color: #cdd6f4;
    font-size: 0.85rem;
}

.code-header span {
    font-family: 'Consolas', 'Monaco', monospace;
}

.copy-btn {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: #cdd6f4;
    padding: 4px 12px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.8rem;
    transition: all 0.2s;
}

.copy-btn:hover {
    background: rgba(255, 255, 255, 0.2);
}

.code-block pre {
    padding: 20px;
    overflow-x: auto;
    margin: 0;
}

.code-block code {
    color: #cdd6f4;
    font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
    font-size: 0.9rem;
    line-height: 1.7;
    background: none;
    padding: 0;
}

/* 语法高亮 */
.code-block .comment { color: #6c7086; font-style: italic; }
.code-block .keyword { color: #cba6f7; }
.code-block .string { color: #a6e3a1; }
.code-block .function { color: #89b4fa; }
.code-block .number { color: #fab387; }
.code-block .builtin { color: #f9e2af; }
.code-block .operator { color: #89dceb; }
.code-block .decorator { color: #f5c2e7; }

/* ===== 输出块 ===== */
.output-block {
    background: #f0fff4;
    border: 1px solid #c6f6d5;
    border-left: 4px solid #48bb78;
    border-radius: 8px;
    margin: 12px 0 24px;
    overflow: hidden;
}

.output-header {
    background: #c6f6d5;
    color: #276749;
    padding: 6px 16px;
    font-size: 0.85rem;
    font-weight: 600;
}

.output-block pre {
    padding: 14px 16px;
    margin: 0;
    color: #276749;
    font-family: 'Consolas', 'Monaco', monospace;
    font-size: 0.88rem;
    line-height: 1.6;
}

/* ===== 数据类型表格 ===== */
.type-table {
    margin: 16px 0 24px;
    overflow-x: auto;
}

.type-table table {
    width: 100%;
    border-collapse: collapse;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.06);
}

.type-table th {
    background: linear-gradient(135deg, #306998, #4B8BBE);
    color: white;
    padding: 12px 16px;
    text-align: left;
    font-size: 0.9rem;
}

.type-table td {
    padding: 10px 16px;
    border-bottom: 1px solid #e2e8f0;
    font-size: 0.9rem;
}

.type-table tr:nth-child(even) {
    background: #f7fafc;
}

.type-table tr:hover {
    background: #edf2f7;
}

/* ===== 恭喜框 ===== */
.congrats-box {
    background: linear-gradient(135deg, #fff9db, #fef3c7);
    border: 2px solid #f59e0b;
    border-radius: 12px;
    padding: 24px;
    margin: 24px 0;
    text-align: center;
}

.congrats-box p {
    font-size: 1.1rem;
    color: #92400e;
    margin-bottom: 12px;
}

.congrats-box ul {
    text-align: left;
    display: inline-block;
    list-style: none;
    padding: 0;
}

.congrats-box li {
    padding: 4px 0;
    color: #92400e;
}

.congrats-box li::before {
    content: "✅ ";
}

/* ===== 大纲章节样式 ===== */
.outline-header {
    background: linear-gradient(135deg, #ebf8ff, #e9d8fd);
    border: 2px solid #90cdf4;
    border-radius: 12px;
    padding: 24px;
    margin-bottom: 28px;
    text-align: center;
}

.outline-subtitle {
    font-size: 1.1rem;
    font-weight: 700;
    color: #2b6cb0;
    margin-bottom: 10px;
    letter-spacing: 1px;
}

.outline-header p:last-child {
    color: #4a5568;
    line-height: 1.8;
}

.outline-section {
    background: #f7fafc;
    border: 1px solid #e2e8f0;
    border-left: 4px solid #4299e1;
    border-radius: 8px;
    padding: 20px 24px;
    margin: 16px 0 24px;
}

.outline-section h4 {
    font-size: 1.05rem;
    color: #2d3748;
    margin-bottom: 10px;
}

.outline-goal {
    font-size: 0.9rem;
    color: #2b6cb0;
    font-weight: 600;
    margin-bottom: 12px;
    padding: 4px 0;
}

.outline-section ul {
    margin: 8px 0 8px 20px;
}

.outline-section li {
    margin-bottom: 8px;
    color: #4a5568;
    line-height: 1.7;
}

.outline-section ul ul {
    margin-top: 6px;
    margin-bottom: 6px;
}

.outline-section ul ul li {
    font-size: 0.92rem;
    color: #718096;
}

/* ===== 章节导航 ===== */
.chapter-nav {
    display: flex;
    justify-content: space-between;
    margin-top: 30px;
    padding-top: 20px;
    border-top: 1px solid #e2e8f0;
}

.nav-prev, .nav-next {
    color: #306998;
    text-decoration: none;
    font-weight: 600;
    font-size: 0.95rem;
    padding: 8px 16px;
    border-radius: 8px;
    transition: all 0.2s;
}

.nav-prev:hover, .nav-next:hover {
    background: rgba(48, 105, 152, 0.08);
}

/* ===== 回到顶部 ===== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, #306998, #FFD43B);
    color: white;
    border: none;
    border-radius: 50%;
    font-size: 1.3rem;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(48, 105, 152, 0.4);
    opacity: 0;
    transform: translateY(20px);
    transition: all 0.3s ease;
    z-index: 800;
}

.back-to-top.visible {
    opacity: 1;
    transform: translateY(0);
}

.back-to-top:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(48, 105, 152, 0.5);
}

/* ===== 动画 ===== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ===== 移动端菜单按钮 ===== */
.menu-btn {
    display: none;
    position: fixed;
    bottom: 30px;
    left: 30px;
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, #306998, #4B8BBE);
    color: white;
    border: none;
    border-radius: 50%;
    font-size: 1.3rem;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(48, 105, 152, 0.4);
    z-index: 800;
}

/* ===== 响应式 ===== */
@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-260px);
    }

    .sidebar.show {
        transform: translateX(0);
    }

    .content {
        margin-left: 0;
        padding: 20px;
    }

    .chapter {
        padding: 24px;
    }

    .chapter h2 {
        font-size: 1.4rem;
    }

    .menu-btn {
        display: block;
    }

    .nav-title {
        font-size: 1rem;
    }

    .progress-bar {
        width: 80px;
    }

    .chapter-nav {
        flex-direction: column;
        gap: 10px;
    }

    .nav-prev, .nav-next {
        text-align: center;
        display: block;
    }
}

/* ===== 悬浮代码运行器 ===== */
.code-runner {
    position: fixed;
    bottom: 20px;
    right: 20px;
    width: 420px;
    max-height: 520px;
    background: #1e1e2e;
    border-radius: 12px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    z-index: 9999;
    font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
    overflow: hidden;
    transition: all 0.3s ease;
}

.code-runner.minimized {
    max-height: 48px;
}

.code-runner.hidden {
    display: none;
}

/* 运行器头部 */
.runner-header {
    background: linear-gradient(135deg, #306998, #4B8BBE);
    padding: 12px 16px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: move;
    user-select: none;
}

.runner-title {
    color: #FFD43B;
    font-weight: bold;
    font-size: 0.95rem;
}

.runner-controls {
    display: flex;
    gap: 8px;
}

.runner-btn {
    background: rgba(255, 255, 255, 0.15);
    border: none;
    color: white;
    width: 28px;
    height: 28px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 1.1rem;
    line-height: 1;
    transition: background 0.2s;
}

.runner-btn:hover {
    background: rgba(255, 255, 255, 0.25);
}

.runner-close:hover {
    background: #e53e3e;
}

/* 运行器主体 */
.runner-body {
    padding: 12px;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

/* 编辑区 */
.runner-editor {
    background: #2d2d3d;
    border-radius: 8px;
    overflow: hidden;
}

.editor-header, .output-header {
    background: #252535;
    padding: 8px 12px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.8rem;
    color: #888;
}

.clear-btn {
    background: transparent;
    border: 1px solid #555;
    color: #aaa;
    padding: 2px 10px;
    border-radius: 4px;
    font-size: 0.75rem;
    cursor: pointer;
    transition: all 0.2s;
}

.clear-btn:hover {
    border-color: #4B8BBE;
    color: #4B8BBE;
}

#codeInput {
    width: 100%;
    height: 120px;
    background: #1e1e2e;
    border: none;
    padding: 12px;
    color: #e0e0e0;
    font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
    font-size: 0.9rem;
    resize: vertical;
    outline: none;
    line-height: 1.5;
}

#codeInput::placeholder {
    color: #666;
}

/* 运行按钮 */
.runner-actions {
    display: flex;
    align-items: center;
    gap: 12px;
}

.run-btn {
    background: linear-gradient(135deg, #4B8BBE, #306998);
    border: none;
    color: white;
    padding: 10px 20px;
    border-radius: 8px;
    font-size: 0.9rem;
    font-weight: bold;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: all 0.2s;
}

.run-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(74, 139, 190, 0.4);
}

.run-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.run-icon {
    font-size: 0.8rem;
}

.runner-status {
    color: #888;
    font-size: 0.8rem;
}

.runner-status.loading {
    color: #FFD43B;
}

.runner-status.ready {
    color: #48bb78;
}

/* 输出区 */
.runner-output {
    background: #2d2d3d;
    border-radius: 8px;
    overflow: hidden;
}

#codeOutput {
    background: #1e1e2e;
    padding: 12px;
    min-height: 80px;
    max-height: 150px;
    overflow-y: auto;
    color: #e0e0e0;
    font-size: 0.85rem;
    line-height: 1.5;
    white-space: pre-wrap;
    word-break: break-all;
    margin: 0;
}

.output-placeholder {
    color: #666;
    font-style: italic;
}

/* 错误输出 */
#codeOutput.error {
    color: #fc8181;
}

/* 最小化时的展开按钮 */
.runner-toggle {
    position: fixed;
    bottom: 20px;
    right: 20px;
    width: 56px;
    height: 56px;
    background: linear-gradient(135deg, #306998, #4B8BBE);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.8rem;
    cursor: pointer;
    box-shadow: 0 4px 16px rgba(48, 105, 152, 0.4);
    z-index: 9998;
    transition: transform 0.2s;
}

.runner-toggle:hover {
    transform: scale(1.1);
}

/* 滚动条美化 */
#codeOutput::-webkit-scrollbar,
#codeInput::-webkit-scrollbar {
    width: 6px;
}

#codeOutput::-webkit-scrollbar-track,
#codeInput::-webkit-scrollbar-track {
    background: #1e1e2e;
}

#codeOutput::-webkit-scrollbar-thumb,
#codeInput::-webkit-scrollbar-thumb {
    background: #4B8BBE;
    border-radius: 3px;
}

/* 响应式 */
@media (max-width: 480px) {
    .code-runner {
        width: calc(100% - 20px);
        left: 10px;
        right: 10px;
        bottom: 10px;
    }
}