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

/* CSS变量定义 - 主题色彩 */
:root {
    /* 白天主题 */
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-card: #ffffff;
    --text-primary: #1a202c;
    --text-secondary: #4a5568;
    --text-muted: #718096;
    --border-color: #e2e8f0;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --accent: #3b82f6;
    --accent-hover: #2563eb;
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-secondary: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
}

/* 夜晚主题 */
[data-theme="dark"] {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-card: #334155;
    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;
    --border-color: #475569;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3), 0 4px 6px -2px rgba(0, 0, 0, 0.2);
    --accent: #60a5fa;
    --accent-hover: #3b82f6;
    --success: #34d399;
    --warning: #fbbf24;
    --error: #f87171;
    --gradient-primary: linear-gradient(135deg, #4c51bf 0%, #553c9a 100%);
    --gradient-secondary: linear-gradient(135deg, #ed64a6 0%, #d53f8c 100%);
}

/* 基础样式 */
body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 主题切换按钮 */
.theme-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1000;
    background: var(--bg-card);
    border: 2px solid var(--border-color);
    border-radius: 50%;
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: var(--shadow);
}

.theme-toggle:hover {
    transform: scale(1.1);
    box-shadow: var(--shadow-lg);
}

.theme-toggle svg {
    width: 24px;
    height: 24px;
    stroke: var(--text-primary);
}

.theme-toggle .moon-icon {
    display: none;
}

[data-theme="dark"] .theme-toggle .sun-icon {
    display: none;
}

[data-theme="dark"] .theme-toggle .moon-icon {
    display: block;
}

/* 头部导航 */
.header {
    background: var(--bg-card);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(10px);
    background-color: rgba(var(--bg-card), 0.8);
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo {
    width: 40px;
    height: 40px;
    object-fit: contain;
}

.brand-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

.version {
    background: var(--accent);
    color: white;
    padding: 4px 8px;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 600;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2rem;
}

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

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

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent);
    transition: width 0.3s ease;
}

.nav-links a:hover::after {
    width: 100%;
}

/* 主要内容 */
.main {
    min-height: calc(100vh - 200px);
}

/* 英雄区域 */
.hero {
    padding: 4rem 0;
    background: var(--gradient-primary);
    color: white;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.1'%3E%3Ccircle cx='30' cy='30' r='2'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E") repeat;
    opacity: 0.3;
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    position: relative;
    z-index: 1;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.25rem;
    margin-bottom: 1.5rem;
    opacity: 0.9;
}

.hero-description {
    font-size: 1.1rem;
    margin-bottom: 2rem;
    opacity: 0.8;
    line-height: 1.7;
}

.hero-actions {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

/* 按钮样式 */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 1rem;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2);
}

.btn-secondary {
    background: transparent;
    color: white;
    border: 2px solid white;
}

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

.btn-download {
    background: var(--success);
    color: white;
    font-size: 1.1rem;
    padding: 16px 32px;
}

.btn-download:hover {
    background: #059669;
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-download svg {
    width: 20px;
    height: 20px;
}

/* 英雄区域插图 */
.hero-illustration {
    width: 100%;
    max-width: 400px;
    height: auto;
    stroke: white;
    fill: white;
}

/* 功能区域 */
.features {
    padding: 5rem 0;
    background: var(--bg-secondary);
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 3rem;
    color: var(--text-primary);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.feature-card {
    background: var(--bg-card);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
    border: 1px solid var(--border-color);
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.feature-icon {
    width: 60px;
    height: 60px;
    background: var(--gradient-primary);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
}

.feature-icon svg {
    width: 30px;
    height: 30px;
    stroke: white;
}

.feature-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.feature-card p {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* 适用场景 */
.scenarios {
    padding: 5rem 0;
    background: var(--bg-primary);
}

.scenarios-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.scenario-item {
    text-align: center;
    padding: 2rem;
    background: var(--bg-card);
    border-radius: 12px;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
    border: 1px solid var(--border-color);
}

.scenario-item:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.scenario-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.scenario-item h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.scenario-item p {
    color: var(--text-secondary);
}

/* 下载区域 */
.download {
    padding: 5rem 0;
    background: var(--gradient-secondary);
    color: white;
}

.download-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.download-info h3 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

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

.download-specs {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin-bottom: 2rem;
}

.spec-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.5rem 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.2);
}

.spec-label {
    font-weight: 500;
    opacity: 0.8;
}

.spec-value {
    font-weight: 600;
}

.download-actions {
    text-align: center;
}

.download-notice {
    margin-top: 1.5rem;
    padding: 1rem;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    backdrop-filter: blur(10px);
}

.download-notice p {
    font-size: 0.9rem;
    opacity: 0.9;
    margin: 0;
}

/* 页脚 */
.footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: 3rem 0 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    margin-bottom: 2rem;
}

.footer-section h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

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

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

.footer-section a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section a:hover {
    color: var(--accent);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
}

.footer-bottom p {
    margin-bottom: 0.5rem;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav {
        flex-direction: column;
        gap: 1rem;
        padding: 1rem;
    }
    
    .nav-links {
        gap: 1rem;
    }
    
    .hero-content {
        grid-template-columns: 1fr;
        gap: 2rem;
        text-align: center;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-actions {
        justify-content: center;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
        padding: 0 1rem;
    }
    
    .scenarios-list {
        grid-template-columns: 1fr;
        padding: 0 1rem;
    }
    
    .download-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .container {
        padding: 0 1rem;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .hero-actions {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 100%;
        justify-content: center;
    }
}

/* 平滑滚动 */
html {
    scroll-behavior: smooth;
}

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

.feature-card,
.scenario-item {
    animation: fadeIn 0.6s ease-out;
}

/* 焦点样式 */
button:focus,
a:focus {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

/* 打印样式 */
@media print {
    .theme-toggle,
    .nav-links {
        display: none;
    }
    
    body {
        background: white;
        color: black;
    }
}