/* 高中信息科技自学网站 - 主样式 */
:root {
    --primary: #6B2D8E;
    --primary-light: #8B4DB0;
    --secondary: #C9A227;
    --secondary-light: #E8C84A;
    --dark: #1a1a2e;
    --dark-light: #2d2d44;
    --light: #f8f9fa;
    --text: #333;
    --text-light: #666;
    --success: #28a745;
    --info: #17a2b8;
    --warning: #ffc107;
    --danger: #dc3545;
    --gradient-primary: linear-gradient(135deg, #6B2D8E 0%, #8B4DB0 100%);
    --gradient-secondary: linear-gradient(135deg, #C9A227 0%, #E8C84A 100%);
    --shadow: 0 4px 20px rgba(0,0,0,0.1);
    --shadow-hover: 0 8px 30px rgba(0,0,0,0.15);
    --radius: 12px;
    --radius-sm: 8px;
    --transition: all 0.3s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    background: var(--light);
    color: var(--text);
    line-height: 1.8;
    overflow-x: hidden;
}

/* 顶部导航 */
.navbar {
    background: var(--gradient-primary);
    padding: 0 30px;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    box-shadow: var(--shadow);
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.navbar-brand {
    color: #fff;
    font-size: 20px;
    font-weight: 700;
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 10px;
}

.navbar-brand i {
    font-size: 28px;
    color: var(--secondary);
}

.navbar-nav {
    display: flex;
    gap: 5px;
    list-style: none;
}

.nav-item {
    position: relative;
}

.nav-link {
    color: rgba(255,255,255,0.9);
    text-decoration: none;
    padding: 10px 16px;
    border-radius: var(--radius-sm);
    transition: var(--transition);
    font-size: 14px;
    display: flex;
    align-items: center;
    gap: 6px;
}

.nav-link:hover, .nav-link.active {
    background: rgba(255,255,255,0.15);
    color: #fff;
}

.nav-link i {
    font-size: 16px;
}

/* 下拉菜单 */
.dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    background: #fff;
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow-hover);
    min-width: 220px;
    padding: 8px 0;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: var(--transition);
    margin-top: 5px;
}

.nav-item:hover .dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-item {
    display: block;
    padding: 10px 20px;
    color: var(--text);
    text-decoration: none;
    font-size: 14px;
    transition: var(--transition);
    border-left: 3px solid transparent;
}

.dropdown-item:hover {
    background: var(--light);
    color: var(--primary);
    border-left-color: var(--primary);
}

.dropdown-divider {
    height: 1px;
    background: #e9ecef;
    margin: 8px 0;
}

.dropdown-header {
    display: block;
    padding: 8px 20px 4px;
    font-size: 13px;
    font-weight: 700;
    color: var(--primary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.dropdown-header i {
    margin-right: 6px;
    color: var(--secondary);
}

/* 主内容区 */
.main-content {
    margin-top: 60px;
    min-height: calc(100vh - 60px);
}

/* 英雄区域 */
.hero {
    background: var(--gradient-primary);
    color: #fff;
    padding: 80px 30px;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 600px;
    height: 600px;
    background: rgba(255,255,255,0.05);
    border-radius: 50%;
}

.hero::after {
    content: '';
    position: absolute;
    bottom: -30%;
    left: -10%;
    width: 400px;
    height: 400px;
    background: rgba(201, 162, 39, 0.1);
    border-radius: 50%;
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 800px;
    margin: 0 auto;
}

.hero h1 {
    font-size: 42px;
    margin-bottom: 20px;
    font-weight: 700;
}

.hero h1 span {
    color: var(--secondary);
}

.hero p {
    font-size: 18px;
    opacity: 0.9;
    margin-bottom: 30px;
    line-height: 1.8;
}

.hero-badges {
    display: flex;
    justify-content: center;
    gap: 15px;
    flex-wrap: wrap;
}

.badge {
    background: rgba(255,255,255,0.15);
    padding: 8px 20px;
    border-radius: 20px;
    font-size: 14px;
    backdrop-filter: blur(10px);
}

/* 章节卡片 */
.chapters-section {
    padding: 60px 30px;
    max-width: 1200px;
    margin: 0 auto;
}

.section-title {
    text-align: center;
    margin-bottom: 50px;
}

.section-title h2 {
    font-size: 32px;
    color: var(--dark);
    margin-bottom: 10px;
}

.section-title p {
    color: var(--text-light);
    font-size: 16px;
}

.chapters-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 25px;
}

.chapter-card {
    background: #fff;
    border-radius: var(--radius);
    padding: 30px;
    box-shadow: var(--shadow);
    transition: var(--transition);
    cursor: pointer;
    position: relative;
    overflow: hidden;
    border: 2px solid transparent;
}

.chapter-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
    border-color: var(--primary-light);
}

.chapter-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 5px;
    height: 100%;
    background: var(--gradient-primary);
}

.chapter-number {
    font-size: 48px;
    font-weight: 700;
    color: var(--primary);
    opacity: 0.15;
    position: absolute;
    top: 10px;
    right: 20px;
}

.chapter-card h3 {
    font-size: 20px;
    color: var(--dark);
    margin-bottom: 10px;
    padding-right: 60px;
}

.chapter-card p {
    color: var(--text-light);
    font-size: 14px;
    margin-bottom: 15px;
}

.chapter-topics {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.topic-tag {
    background: var(--light);
    color: var(--primary);
    padding: 4px 12px;
    border-radius: 15px;
    font-size: 12px;
    border: 1px solid rgba(107, 45, 142, 0.2);
}

.chapter-card .arrow {
    position: absolute;
    bottom: 20px;
    right: 20px;
    color: var(--primary);
    font-size: 20px;
    transition: var(--transition);
}

.chapter-card:hover .arrow {
    transform: translateX(5px);
}

/* 特色区域 */
.features-section {
    background: var(--dark);
    color: #fff;
    padding: 60px 30px;
}

.features-grid {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.feature-item {
    text-align: center;
    padding: 30px;
}

.feature-icon {
    width: 70px;
    height: 70px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    font-size: 30px;
}

.feature-item h4 {
    font-size: 18px;
    margin-bottom: 10px;
    color: var(--secondary);
}

.feature-item p {
    opacity: 0.8;
    font-size: 14px;
}

/* 页脚 */
.footer {
    background: var(--dark-light);
    color: rgba(255,255,255,0.7);
    padding: 30px;
    text-align: center;
    font-size: 14px;
}

.footer a {
    color: var(--secondary);
    text-decoration: none;
}

/* 章节页面样式 */
.chapter-page {
    display: flex;
    min-height: calc(100vh - 60px);
    margin-top: 60px;
}

/* 侧边栏 */
.sidebar {
    width: 280px;
    background: #fff;
    border-right: 1px solid #e9ecef;
    position: fixed;
    top: 60px;
    bottom: 0;
    left: 0;
    overflow-y: auto;
    padding: 20px 0;
    z-index: 100;
}

.sidebar-header {
    padding: 0 20px 20px;
    border-bottom: 2px solid var(--primary);
    margin-bottom: 15px;
}

.sidebar-header h3 {
    color: var(--primary);
    font-size: 16px;
}

.sidebar-header p {
    color: var(--text-light);
    font-size: 12px;
    margin-top: 5px;
}

.sidebar-menu {
    list-style: none;
}

.sidebar-item {
    margin: 2px 0;
}

.sidebar-link {
    display: block;
    padding: 12px 20px;
    color: var(--text);
    text-decoration: none;
    font-size: 14px;
    transition: var(--transition);
    border-left: 3px solid transparent;
}

.sidebar-link:hover, .sidebar-link.active {
    background: rgba(107, 45, 142, 0.08);
    color: var(--primary);
    border-left-color: var(--primary);
}

.sidebar-link i {
    margin-right: 8px;
    width: 20px;
    text-align: center;
}

/* 内容区域 */
.content-area {
    margin-left: 280px;
    flex: 1;
    padding: 40px;
    max-width: calc(100% - 280px);
}

.content-header {
    margin-bottom: 40px;
    padding-bottom: 20px;
    border-bottom: 2px solid var(--primary);
}

.content-header h1 {
    font-size: 32px;
    color: var(--dark);
    margin-bottom: 10px;
}

.content-header .breadcrumb {
    color: var(--text-light);
    font-size: 14px;
}

.content-header .breadcrumb a {
    color: var(--primary);
    text-decoration: none;
}

/* 知识卡片 */
.knowledge-card {
    background: #fff;
    border-radius: var(--radius);
    padding: 30px;
    margin-bottom: 30px;
    box-shadow: var(--shadow);
    border-left: 4px solid var(--primary);
}

.knowledge-card h2 {
    color: var(--primary);
    font-size: 24px;
    margin-bottom: 15px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.knowledge-card h3 {
    color: var(--dark);
    font-size: 20px;
    margin: 25px 0 15px;
    padding-bottom: 10px;
    border-bottom: 1px solid #e9ecef;
}

.knowledge-card p {
    margin-bottom: 15px;
    text-align: justify;
}

.knowledge-card ul, .knowledge-card ol {
    margin: 15px 0 15px 25px;
}

.knowledge-card li {
    margin-bottom: 8px;
}

/* 互动组件 */
.interactive-box {
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    border-radius: var(--radius);
    padding: 25px;
    margin: 25px 0;
    border: 2px dashed var(--primary-light);
}

.interactive-box h4 {
    color: var(--primary);
    font-size: 18px;
    margin-bottom: 15px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.interactive-box h4 i {
    font-size: 22px;
}

/* 代码块 */
.code-block {
    background: var(--dark);
    color: #fff;
    border-radius: var(--radius-sm);
    padding: 20px;
    margin: 15px 0;
    overflow-x: auto;
    font-family: 'Consolas', 'Monaco', monospace;
    font-size: 14px;
    line-height: 1.6;
}

.code-block .comment {
    color: #6c757d;
}

.code-block .keyword {
    color: #ff7b72;
}

.code-block .string {
    color: #a5d6ff;
}

.code-block .function {
    color: #d2a8ff;
}

/* 练习区域 */
.quiz-container {
    background: #fff;
    border-radius: var(--radius);
    padding: 25px;
    margin: 20px 0;
    box-shadow: var(--shadow);
}

.quiz-question {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 15px;
    color: var(--dark);
}

.quiz-options {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.quiz-option {
    padding: 12px 15px;
    border: 2px solid #e9ecef;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 10px;
}

.quiz-option:hover {
    border-color: var(--primary-light);
    background: rgba(107, 45, 142, 0.05);
}

.quiz-option.correct {
    border-color: var(--success);
    background: rgba(40, 167, 69, 0.1);
}

.quiz-option.wrong {
    border-color: var(--danger);
    background: rgba(220, 53, 69, 0.1);
}

.quiz-option input {
    width: 20px;
    height: 20px;
}

/* 按钮 */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    text-decoration: none;
}

.btn-primary {
    background: var(--gradient-primary);
    color: #fff;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(107, 45, 142, 0.3);
}

.btn-secondary {
    background: var(--gradient-secondary);
    color: var(--dark);
}

.btn-outline {
    background: transparent;
    border: 2px solid var(--primary);
    color: var(--primary);
}

.btn-outline:hover {
    background: var(--primary);
    color: #fff;
}

/* 提示框 */
.tip-box {
    background: rgba(23, 162, 184, 0.1);
    border-left: 4px solid var(--info);
    padding: 15px 20px;
    margin: 20px 0;
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.tip-box.warning {
    background: rgba(255, 193, 7, 0.1);
    border-left-color: var(--warning);
}

.tip-box.danger {
    background: rgba(220, 53, 69, 0.1);
    border-left-color: var(--danger);
}

.tip-box.success {
    background: rgba(40, 167, 69, 0.1);
    border-left-color: var(--success);
}

.tip-box h5 {
    color: var(--info);
    margin-bottom: 8px;
    font-size: 14px;
}

/* 进度条 */
.progress-bar {
    width: 100%;
    height: 8px;
    background: #e9ecef;
    border-radius: 4px;
    overflow: hidden;
    margin: 10px 0;
}

.progress-fill {
    height: 100%;
    background: var(--gradient-primary);
    border-radius: 4px;
    transition: width 0.5s ease;
}

/* 标签页 */
.tabs {
    display: flex;
    gap: 5px;
    margin-bottom: 20px;
    border-bottom: 2px solid #e9ecef;
}

.tab {
    padding: 12px 20px;
    cursor: pointer;
    border-bottom: 2px solid transparent;
    margin-bottom: -2px;
    transition: var(--transition);
    font-weight: 500;
}

.tab.active {
    color: var(--primary);
    border-bottom-color: var(--primary);
}

.tab:hover {
    color: var(--primary);
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

/* 响应式 */
@media (max-width: 768px) {
    .navbar {
        padding: 0 15px;
    }
    
    .navbar-brand {
        font-size: 16px;
    }
    
    .navbar-nav {
        display: none;
    }
    
    .hero h1 {
        font-size: 28px;
    }
    
    .chapters-grid {
        grid-template-columns: 1fr;
    }
    
    .sidebar {
        width: 100%;
        position: relative;
        top: 0;
        border-right: none;
        border-bottom: 1px solid #e9ecef;
    }
    
    .content-area {
        margin-left: 0;
        max-width: 100%;
        padding: 20px;
    }
    
    .chapter-page {
        flex-direction: column;
    }
}

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

.fade-in {
    animation: fadeIn 0.6s ease forwards;
}

/* 滚动条美化 */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: #f1f1f1;
}

::-webkit-scrollbar-thumb {
    background: var(--primary-light);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--primary);
}