/* 重置和基础样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #f7931a;
    --secondary-color: #4a90e2;
    --dark-bg: #1a1a2e;
    --light-bg: #f5f5f5;
    --text-dark: #2d2d2d;
    --text-light: #ffffff;
    --code-bg: #2d2d2d;
    --success: #4caf50;
    --warning: #ff9800;
    --danger: #f44336;
    --border-color: #e0e0e0;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: #ffffff;
}

/* 导航栏 */
.navbar {
    background: var(--dark-bg);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.2rem;
    font-weight: bold;
    color: var(--text-light);
}

.nav-brand .logo {
    font-size: 2rem;
    color: var(--primary-color);
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-links a {
    color: var(--text-light);
    text-decoration: none;
    transition: color 0.3s;
    font-weight: 500;
}

.nav-links a:hover {
    color: var(--primary-color);
}

/* 英雄区域 */
.hero {
    background: linear-gradient(135deg, var(--dark-bg) 0%, #16213e 100%);
    color: var(--text-light);
    padding: 4rem 0;
    text-align: center;
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    font-weight: 700;
}

.hero .subtitle {
    font-size: 1.3rem;
    opacity: 0.9;
    margin-bottom: 1rem;
    font-style: italic;
}

.hero .author,
.hero .date {
    font-size: 1rem;
    opacity: 0.8;
    margin-bottom: 0.3rem;
}

.hero-buttons {
    margin-top: 2rem;
    display: flex;
    gap: 1rem;
    justify-content: center;
}

/* 容器 */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* 章节 */
.section {
    padding: 4rem 0;
}

.section-dark {
    background-color: var(--light-bg);
}

.section h2 {
    font-size: 2rem;
    margin-bottom: 2rem;
    color: var(--text-dark);
    text-align: center;
}

.section-header {
    text-align: center;
    margin-bottom: 2rem;
}

.section-badge {
    display: inline-block;
    background: var(--primary-color);
    color: white;
    padding: 0.3rem 1rem;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: bold;
    margin-bottom: 0.5rem;
}

/* 内容盒子 */
.content-box {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    margin-bottom: 2rem;
}

.original-text {
    font-size: 1.1rem;
    line-height: 1.8;
    margin-bottom: 1.5rem;
    color: #333;
    text-align: justify;
}

/* 解释盒子 */
.explanation-box {
    background: linear-gradient(135deg, #e3f2fd 0%, #bbdefb 100%);
    padding: 2rem;
    border-radius: 10px;
    margin: 2rem 0;
    border-left: 4px solid var(--secondary-color);
}

.explanation-box h3 {
    color: var(--secondary-color);
    margin-bottom: 1rem;
    font-size: 1.4rem;
}

.explanation-box ul {
    margin-left: 1.5rem;
    margin-bottom: 1rem;
}

.explanation-box li {
    margin-bottom: 0.5rem;
}

/* 类比盒子 */
.analogy-box {
    background: linear-gradient(135deg, #fff3e0 0%, #ffe0b2 100%);
    padding: 2rem;
    border-radius: 10px;
    margin: 2rem 0;
    border-left: 4px solid var(--warning);
}

.analogy-box h3 {
    color: #e65100;
    margin-bottom: 1rem;
    font-size: 1.4rem;
}

.analogy-box ol,
.analogy-box ul {
    margin-left: 1.5rem;
    margin-bottom: 1rem;
}

.analogy-box li {
    margin-bottom: 0.5rem;
}

/* 演示盒子 */
.demo-box {
    background: #f8f9fa;
    padding: 2rem;
    border-radius: 10px;
    margin: 2rem 0;
    border: 2px solid var(--border-color);
}

.demo-box h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.4rem;
}

/* 按钮 */
.btn {
    display: inline-block;
    padding: 0.8rem 2rem;
    border-radius: 5px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s;
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background: #e68a00;
    transform: translateY(-2px);
    box-shadow: 0 4px 10px rgba(247, 147, 26, 0.3);
}

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

.btn-secondary:hover {
    background: var(--primary-color);
    color: white;
}

.btn-warning {
    background: var(--warning);
    color: white;
}

.btn-warning:hover {
    background: #f57c00;
}

/* 章节网格 */
.sections-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.section-card {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    text-decoration: none;
    color: var(--text-dark);
    transition: all 0.3s;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.section-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.15);
}

.section-number {
    font-size: 3rem;
    font-weight: bold;
    color: var(--primary-color);
    opacity: 0.3;
    margin-bottom: 0.5rem;
}

.section-card h3 {
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}

.section-card p {
    color: #666;
    font-size: 0.95rem;
}

/* 交易演示 */
.transaction-chain {
    display: flex;
    align-items: center;
    overflow-x: auto;
    padding: 1rem;
    gap: 0;
}

.transaction-box {
    flex-shrink: 0;
    background: white;
    border: 2px solid var(--primary-color);
    border-radius: 10px;
    padding: 1rem;
    min-width: 200px;
    display: flex;
    flex-direction: column;
}

.tx-header {
    font-weight: bold;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
    font-size: 1.1rem;
}

.tx-content p {
    margin: 0.3rem 0;
    font-size: 0.9rem;
}

.tx-arrow {
    font-size: 2rem;
    color: var(--primary-color);
    margin: 0 0.5rem;
}

.signature {
    background: var(--code-bg);
    color: #4caf50;
    padding: 0.2rem 0.4rem;
    border-radius: 3px;
    font-family: 'Courier New', monospace;
    font-size: 0.85rem;
}

/* 问题解决方案 */
.problem-solution {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    margin-top: 1rem;
}

.problem,
.solution {
    padding: 1rem;
    border-radius: 8px;
}

.problem {
    background: rgba(244, 67, 54, 0.1);
    border-left: 4px solid var(--danger);
}

.solution {
    background: rgba(76, 175, 80, 0.1);
    border-left: 4px solid var(--success);
}

.problem h4,
.solution h4 {
    margin-bottom: 1rem;
}

/* 关键概念 */
.key-concept {
    background: white;
    padding: 1.5rem;
    border-radius: 8px;
    margin-top: 1rem;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

.key-concept h4 {
    color: var(--secondary-color);
    margin-bottom: 1rem;
}

.example-box {
    background: #f5f5f5;
    padding: 1rem;
    border-radius: 5px;
    margin: 1rem 0;
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
}

.example-box code {
    background: var(--code-bg);
    color: #4caf50;
    padding: 0.2rem 0.4rem;
    border-radius: 3px;
}

/* 哈希演示 */
.hash-demo {
    max-width: 700px;
    margin: 0 auto;
}

.hash-demo label {
    display: block;
    font-weight: bold;
    margin-bottom: 0.5rem;
}

.hash-demo textarea {
    width: 100%;
    padding: 1rem;
    border: 2px solid var(--border-color);
    border-radius: 5px;
    font-size: 1rem;
    margin-bottom: 1rem;
    font-family: inherit;
}

.hash-output {
    background: var(--code-bg);
    padding: 1rem;
    border-radius: 5px;
    margin: 1rem 0;
}

.hash-output p {
    color: #4caf50;
    margin-bottom: 0.5rem;
    font-weight: bold;
}

.hash-output code {
    color: #4caf50;
    word-break: break-all;
    font-size: 0.9rem;
    display: block;
}

.demo-tips {
    background: #e3f2fd;
    padding: 1rem;
    border-radius: 5px;
    margin-top: 1rem;
}

.demo-tips ul {
    margin-left: 1.5rem;
    margin-top: 0.5rem;
}

/* 时间戳链 */
.timestamp-chain {
    display: flex;
    align-items: center;
    overflow-x: auto;
    padding: 1rem;
    gap: 0;
}

.block {
    flex-shrink: 0;
    background: white;
    border: 3px solid var(--secondary-color);
    border-radius: 10px;
    padding: 1.5rem;
    min-width: 250px;
}

.block-header {
    font-weight: bold;
    color: var(--secondary-color);
    font-size: 1.2rem;
    margin-bottom: 1rem;
}

.block-content p {
    margin: 0.5rem 0;
    font-size: 0.9rem;
}

.hash {
    background: var(--code-bg);
    color: #ffeb3b;
    padding: 0.2rem 0.4rem;
    border-radius: 3px;
    font-family: 'Courier New', monospace;
    font-size: 0.85rem;
}

.chain-arrow {
    font-size: 2rem;
    margin: 0 0.5rem;
}

/* 挖矿演示 */
.mining-demo {
    max-width: 800px;
    margin: 0 auto;
}

.mining-config {
    background: white;
    padding: 1.5rem;
    border-radius: 8px;
    margin-bottom: 1rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.mining-config label {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    font-weight: bold;
}

.mining-config select,
.mining-config input {
    padding: 0.5rem;
    border: 2px solid var(--border-color);
    border-radius: 5px;
    font-size: 1rem;
}

.mining-status {
    background: var(--code-bg);
    padding: 1.5rem;
    border-radius: 8px;
    margin-bottom: 1rem;
}

.stat {
    margin-bottom: 1rem;
    color: white;
}

.stat-label {
    font-weight: bold;
    color: #4caf50;
    margin-right: 0.5rem;
}

.stat-value {
    color: #ffeb3b;
    font-family: 'Courier New', monospace;
}

.mining-result {
    background: linear-gradient(135deg, #c8e6c9 0%, #a5d6a7 100%);
    padding: 1.5rem;
    border-radius: 8px;
    border-left: 4px solid var(--success);
}

.mining-result h4 {
    color: #2e7d32;
    margin-bottom: 1rem;
}

/* 重要性网格 */
.importance-grid {
    display: grid;
    gap: 1.5rem;
    margin-top: 1rem;
}

.importance-item {
    background: white;
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

.importance-item h4 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.2rem;
}

.importance-item ul {
    margin-left: 1.5rem;
}

/* 演示卡片网格 */
.demos-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.demo-card {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    text-align: center;
    transition: all 0.3s;
}

.demo-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.15);
}

.demo-card h3 {
    color: var(--text-dark);
    margin-bottom: 1rem;
}

.demo-card p {
    color: #666;
    margin-bottom: 1.5rem;
}

/* 数字签名演示 */
.signature-demo-container {
    max-width: 900px;
    margin: 0 auto;
}

.demo-step {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    margin-bottom: 2rem;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

.demo-step h3 {
    color: var(--secondary-color);
    margin-bottom: 1.5rem;
}

.keys-display {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
    margin-top: 1rem;
}

.key-box {
    background: #f8f9fa;
    padding: 1.5rem;
    border-radius: 8px;
    border: 2px solid var(--border-color);
}

.key-box h4 {
    margin-bottom: 0.5rem;
}

.key-description {
    font-size: 0.9rem;
    color: #666;
    margin-bottom: 1rem;
}

.key-code {
    display: block;
    background: var(--code-bg);
    color: #4caf50;
    padding: 1rem;
    border-radius: 5px;
    font-family: 'Courier New', monospace;
    font-size: 0.85rem;
    word-break: break-all;
    margin: 1rem 0;
}

.warning {
    color: var(--danger);
    font-size: 0.9rem;
    font-weight: bold;
}

.info {
    color: var(--success);
    font-size: 0.9rem;
    font-weight: bold;
}

.signature-display,
.verification-result {
    margin-top: 1rem;
    padding: 1rem;
    border-radius: 5px;
}

.signature-display {
    background: var(--code-bg);
}

.signature-display h4 {
    color: #4caf50;
    margin-bottom: 0.5rem;
}

.tampering-test {
    margin-top: 2rem;
    padding: 1rem;
    background: #fff3e0;
    border-radius: 8px;
    border-left: 4px solid var(--warning);
}

.tampering-test h4 {
    color: #e65100;
    margin-bottom: 1rem;
}

.tampering-test textarea {
    width: 100%;
    padding: 0.8rem;
    border: 2px solid var(--border-color);
    border-radius: 5px;
    font-family: inherit;
    margin: 0.5rem 0;
}

/* 区块链演示 */
.blockchain-demo-container {
    max-width: 100%;
}

.demo-controls {
    text-align: center;
    margin-bottom: 2rem;
    display: flex;
    gap: 1rem;
    justify-content: center;
}

.blockchain-display {
    overflow-x: auto;
    padding: 2rem 0;
}

.tampering-section {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    margin-top: 2rem;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

.tampering-section h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.tamper-controls {
    display: flex;
    gap: 1rem;
    margin: 1rem 0;
    flex-wrap: wrap;
}

.tamper-controls label {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    font-weight: bold;
}

.tamper-controls select,
.tamper-controls input {
    padding: 0.5rem;
    border: 2px solid var(--border-color);
    border-radius: 5px;
    font-size: 1rem;
}

.tamper-explanation {
    margin-top: 1rem;
    padding: 1rem;
    border-radius: 5px;
}

.demo-explanation {
    background: #e3f2fd;
    padding: 1.5rem;
    border-radius: 8px;
    margin-top: 1.5rem;
}

.demo-explanation h3 {
    color: var(--secondary-color);
    margin-bottom: 1rem;
}

.demo-explanation ul {
    margin-left: 1.5rem;
}

.demo-explanation li {
    margin-bottom: 0.5rem;
}

/* 术语表 */
.glossary-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.glossary-item {
    background: white;
    padding: 1.5rem;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    border-top: 4px solid var(--primary-color);
}

.glossary-item h3 {
    color: var(--text-dark);
    margin-bottom: 0.8rem;
    font-size: 1.2rem;
}

.definition {
    color: #333;
    margin-bottom: 0.8rem;
    font-weight: 500;
}

.simple {
    color: #666;
    font-style: italic;
    background: #f8f9fa;
    padding: 0.8rem;
    border-radius: 5px;
    border-left: 3px solid var(--primary-color);
}

/* CTA 盒子 */
.cta-box {
    background: linear-gradient(135deg, var(--dark-bg) 0%, #16213e 100%);
    color: var(--text-light);
    padding: 3rem;
    border-radius: 10px;
    text-align: center;
}

.cta-box h2 {
    color: var(--text-light);
    margin-bottom: 1rem;
}

.cta-box p {
    font-size: 1.1rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.cta-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
}

/* 页脚 */
.footer {
    background: var(--dark-bg);
    color: var(--text-light);
    padding: 3rem 0 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section a {
    color: var(--text-light);
    text-decoration: none;
    opacity: 0.8;
    transition: opacity 0.3s;
}

.footer-section a:hover {
    opacity: 1;
    color: var(--primary-color);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    opacity: 0.7;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 1.8rem;
    }

    .hero .subtitle {
        font-size: 1rem;
    }

    .nav-links {
        gap: 1rem;
        font-size: 0.9rem;
    }

    .sections-grid {
        grid-template-columns: 1fr;
    }

    .problem-solution {
        grid-template-columns: 1fr;
    }

    .keys-display {
        grid-template-columns: 1fr;
    }

    .transaction-chain,
    .timestamp-chain {
        flex-direction: column;
        align-items: stretch;
    }

    .tx-arrow,
    .chain-arrow {
        transform: rotate(90deg);
        margin: 0.5rem 0;
    }

    .container {
        padding: 0 1rem;
    }

    .cta-buttons {
        flex-direction: column;
    }

    .demo-controls {
        flex-direction: column;
    }

    .tamper-controls {
        flex-direction: column;
    }
}

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

.content-box,
.demo-box,
.explanation-box,
.analogy-box {
    animation: fadeIn 0.6s ease-out;
}

/* 互动元素状态 */
.interactive-demo {
    position: relative;
}

.block.invalid {
    border-color: var(--danger);
    background: #ffebee;
}

.block.valid {
    border-color: var(--success);
    background: #e8f5e9;
}

/* 滚动行为 */
html {
    scroll-behavior: smooth;
}

/* 代码块 */
code {
    font-family: 'Courier New', monospace;
}

/* 强调文本 */
strong {
    color: var(--primary-color);
}

/* 选择文本颜色 */
::selection {
    background: var(--primary-color);
    color: white;
}

/* 链接 */
a {
    color: var(--secondary-color);
}

/* Pre标签样式 */
pre {
    background: #f5f5f5;
    padding: 1rem;
    border-radius: 5px;
    overflow-x: auto;
    font-family: 'Courier New', monospace;
    line-height: 1.4;
}

/* 问题示例样式 */
.problem-example {
    background: white;
    padding: 1.5rem;
    border-radius: 8px;
    margin-top: 1rem;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

.problem-example h4 {
    color: var(--primary-color);
    margin-bottom: 0.8rem;
}

.problem-example ol,
.problem-example ul {
    margin-left: 1.5rem;
    margin-top: 0.5rem;
}

/* 渐变背景 */
.gradient-bg {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
}

/* 卡片悬停效果增强 */
.section-card,
.demo-card,
.glossary-item {
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 加载动画 */
@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

.loading-pulse {
    animation: pulse 2s ease-in-out infinite;
}

/* 进度条 */
.progress-bar {
    position: fixed;
    top: 0;
    left: 0;
    width: 0;
    height: 3px;
    background: var(--primary-color);
    z-index: 9999;
    transition: width 0.3s ease;
}

/* 返回顶部按钮 */
.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    background: var(--primary-color);
    color: white;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
    z-index: 1000;
}

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

.back-to-top:hover {
    background: #e68a00;
    transform: translateY(-5px);
}

/* 打印样式 */
@media print {
    .navbar,
    .hero-buttons,
    .demo-controls,
    .footer,
    .back-to-top {
        display: none;
    }
    
    body {
        font-size: 12pt;
    }
    
    .section {
        page-break-inside: avoid;
    }
}

/* 表格样式（如果需要） */
table {
    width: 100%;
    border-collapse: collapse;
    margin: 1rem 0;
}

th, td {
    padding: 0.8rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

th {
    background: var(--light-bg);
    font-weight: bold;
}

/* 加载状态 */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(0, 0, 0, 0.1);
    border-radius: 50%;
    border-top-color: var(--primary-color);
    animation: spin 1s ease-in-out infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* 工具提示 */
.tooltip {
    position: relative;
    display: inline-block;
    border-bottom: 1px dotted var(--text-dark);
    cursor: help;
}

.tooltip .tooltiptext {
    visibility: hidden;
    width: 200px;
    background-color: var(--dark-bg);
    color: var(--text-light);
    text-align: center;
    border-radius: 6px;
    padding: 0.5rem;
    position: absolute;
    z-index: 1;
    bottom: 125%;
    left: 50%;
    margin-left: -100px;
    opacity: 0;
    transition: opacity 0.3s;
    font-size: 0.9rem;
}

.tooltip:hover .tooltiptext {
    visibility: visible;
    opacity: 1;
}