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

:root {
    --primary-color: #2196F3;
    --primary-dark: #1976D2;
    --secondary-color: #4CAF50;
    --bg-color: #f5f7fa;
    --card-bg: #ffffff;
    --text-primary: #333333;
    --text-secondary: #666666;
    --border-color: #e0e0e0;
    --shadow: 0 2px 8px rgba(0,0,0,0.1);
    --shadow-hover: 0 4px 16px rgba(0,0,0,0.15);
}

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

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

/* 头部 */
.header {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    padding: 15px 0;
    box-shadow: var(--shadow);
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo-icon {
    font-size: 28px;
}

.logo-text {
    font-size: 20px;
    font-weight: 700;
}

/* 主要内容 */
.main {
    padding: 40px 0;
}

/* Hero 区域 */
.hero {
    text-align: center;
    padding: 60px 0;
}

.app-icon {
    font-size: 80px;
    margin-bottom: 20px;
}

.app-name {
    font-size: 42px;
    font-weight: 700;
    margin-bottom: 10px;
    color: var(--text-primary);
}

.app-version {
    font-size: 16px;
    color: var(--text-secondary);
    margin-bottom: 15px;
}

.app-description {
    font-size: 18px;
    color: var(--text-secondary);
    margin-bottom: 40px;
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
}

/* 下载按钮 */
.download-section {
    margin-top: 30px;
}

.download-btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    background: linear-gradient(135deg, var(--secondary-color), #45a049);
    color: white;
    padding: 18px 50px;
    border-radius: 50px;
    text-decoration: none;
    font-size: 20px;
    font-weight: 600;
    box-shadow: 0 4px 15px rgba(76, 175, 80, 0.4);
    transition: all 0.3s ease;
}

.download-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(76, 175, 80, 0.5);
}

.btn-icon {
    font-size: 24px;
}

.file-info {
    margin-top: 15px;
    font-size: 14px;
    color: var(--text-secondary);
}

/* 功能特性 */
.features {
    padding: 60px 0;
}

.section-title {
    text-align: center;
    font-size: 32px;
    font-weight: 700;
    margin-bottom: 40px;
    color: var(--text-primary);
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.feature-card {
    background: var(--card-bg);
    padding: 30px;
    border-radius: 16px;
    box-shadow: var(--shadow);
    text-align: center;
    transition: all 0.3s ease;
}

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

.feature-icon {
    font-size: 48px;
    margin-bottom: 15px;
}

.feature-card h3 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 10px;
    color: var(--text-primary);
}

.feature-card p {
    font-size: 15px;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* 安装说明 */
.install-guide {
    padding: 60px 0;
    background: var(--card-bg);
    border-radius: 24px;
    margin: 40px 0;
    box-shadow: var(--shadow);
}

.steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    max-width: 1000px;
    margin: 0 auto;
}

.step {
    display: flex;
    gap: 15px;
    align-items: flex-start;
}

.step-number {
    width: 40px;
    height: 40px;
    background: var(--primary-color);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    font-weight: 700;
    flex-shrink: 0;
}

.step-content h4 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 5px;
    color: var(--text-primary);
}

.step-content p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.5;
}

/* 注意事项 */
.notice {
    padding: 40px 0;
}

.notice-content {
    max-width: 800px;
    margin: 0 auto;
}

.notice-item {
    display: flex;
    align-items: center;
    gap: 15px;
    background: #fff3cd;
    border-left: 4px solid #ffc107;
    padding: 15px 20px;
    margin-bottom: 15px;
    border-radius: 8px;
}

.notice-item:nth-child(2) {
    background: #d1ecf1;
    border-left-color: #17a2b8;
}

.notice-item:nth-child(3) {
    background: #f8d7da;
    border-left-color: #dc3545;
}

.notice-icon {
    font-size: 24px;
    flex-shrink: 0;
}

.notice-item p {
    font-size: 15px;
    color: var(--text-primary);
}

/* 页脚 */
.footer {
    background: var(--text-primary);
    color: #999;
    padding: 30px 0;
    text-align: center;
    margin-top: 60px;
}

.footer p {
    font-size: 14px;
}

/* 响应式 */
@media (max-width: 768px) {
    .app-name {
        font-size: 32px;
    }
    
    .app-icon {
        font-size: 60px;
    }
    
    .download-btn {
        padding: 15px 40px;
        font-size: 18px;
    }
    
    .feature-grid,
    .steps {
        grid-template-columns: 1fr;
    }
    
    .section-title {
        font-size: 26px;
    }
    
    .install-guide {
        padding: 40px 20px;
    }
}

/* 动画 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hero,
.features,
.install-guide,
.notice {
    animation: fadeInUp 0.6s ease-out;
}