/* 基础变量 */
:root {
    --primary-color: #436EFF;
    --primary-light: #5B7FFF;
    --primary-dark: #2B5BFF;
    --success-color: #67C23A;
    --warning-color: #E6A23C;
    --danger-color: #F56C6C;
    --info-color: #909399;
    --text-primary: #333;
    --text-regular: #666;
    --text-secondary: #999;
    --text-light: #ccc;
    --border-light: #e5e5e5;
    --border-lighter: #f0f0f0;
    --background-color: #FFFFFF;
    --background-light: #f8f9fa;
    --background-gray: #f5f5f5;
    --shadow-light: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-medium: 0 4px 16px rgba(0, 0, 0, 0.12);
    --border-radius: 8px;
    --border-radius-large: 12px;
    --transition: all 0.3s ease;
}

/* 页面容器 */
.extension-download-page {
    background-color: var(--background-color);
    min-height: 100vh;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-primary);
}

/* 确保所有文字最小16px */
* {
    font-size: inherit;
}

p, span, div, a, li, td, th, label, input, textarea, select, button {
    font-size: 16px;
}

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

/* 页面标题区域 */
.page-header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-light) 100%);
    color: white;
    padding: 80px 0;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.page-header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="dots" width="20" height="20" patternUnits="userSpaceOnUse"><circle cx="10" cy="10" r="1" fill="white" opacity="0.1"/></pattern></defs><rect width="100" height="100" fill="url(%23dots)"/></svg>');
    opacity: 0.3;
}

.header-content {
    position: relative;
    z-index: 1;
}

.page-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin: 0 0 20px 0;
    letter-spacing: -0.02em;
}

.page-subtitle {
    font-size: 1.5rem;
    margin: 0 0 15px 0;
    opacity: 0.95;
    font-weight: 400;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.page-note {
    font-size: 16px;
    margin: 0;
    opacity: 0.8;
    font-weight: 300;
}

/* 下载区域 */
.download-section {
    padding: 80px 0;
    background: var(--background-light);
}

.download-main {
    display: flex;
    justify-content: center;
}

.download-card {
    position: relative;
    background: white;
    border-radius: var(--border-radius-large);
    box-shadow: var(--shadow-medium);
    overflow: hidden;
    max-width: 600px;
    width: 100%;
    border: 1px solid var(--border-lighter);
}

.card-header {
    padding: 40px 40px 30px;
    text-align: center;
    border-bottom: 1px solid var(--border-lighter);
}

.card-header h2 {
    font-size: 2.2rem;
    font-weight: 700;
    margin: 0 0 15px 0;
    color: var(--text-primary);
}

.card-desc {
    font-size: 18px;
    color: var(--text-regular);
    margin: 0;
    line-height: 1.5;
}

.card-content {
    padding: 30px 40px 40px;
}

.download-info {
    margin-bottom: 35px;
}

.info-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 0;
    border-bottom: 1px solid var(--border-lighter);
}

.info-row:last-child {
    border-bottom: none;
}

.info-label {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-primary);
}

.info-value {
    font-size: 16px;
    font-weight: 500;
    color: var(--text-regular);
}

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

.btn-primary {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    color: white;
    padding: 18px 40px;
    border-radius: var(--border-radius);
    text-decoration: none;
    font-size: 18px;
    font-weight: 600;
    transition: var(--transition);
    box-shadow: 0 4px 12px rgba(67, 110, 255, 0.3);
    border: none;
    cursor: pointer;
    margin-bottom: 25px;
    min-width: 200px;
    justify-content: center;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(67, 110, 255, 0.4);
    color: white;
    text-decoration: none;
}

.btn-primary:active {
    transform: translateY(0);
}

.video-links {
    display: flex;
    gap: 15px;
    justify-content: center;
    flex-wrap: wrap;
}

.btn-secondary {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: white;
    color: var(--primary-color);
    padding: 14px 24px;
    border-radius: var(--border-radius);
    text-decoration: none;
    font-size: 16px;
    font-weight: 500;
    transition: var(--transition);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    border: 1px solid var(--border-light);
}

.btn-secondary:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(67, 110, 255, 0.2);
    text-decoration: none;
}

.btn-secondary:active {
    transform: translateY(0);
}

/* 备用下载区域 */
.backup-downloads {
    margin-top: 20px;
    text-align: center;
}

.backup-text {
    font-size: 14px;
    color: var(--text-secondary);
    margin: 0;
    line-height: 1.5;
}

.backup-link {
    color: var(--primary-color);
    text-decoration: underline;
    font-weight: 500;
    transition: var(--transition);
}

.backup-link:hover {
    color: var(--primary-dark);
    text-decoration: none;
}

/* 隐私政策链接 */
.privacy-link {
    color: whitesmoke;
    text-decoration: underline;
    cursor: pointer;
    transition: var(--transition);
}

.privacy-link:hover {
    color: white;
    text-decoration: none;
}

/* 隐私政策弹出层 */
.privacy-modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 9999;
    display: none;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.privacy-modal.show {
    display: flex;
    opacity: 1;
}

.privacy-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(4px);
}

.privacy-content {
    position: relative;
    background: white;
    border-radius: var(--border-radius-large);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    max-width: 800px;
    width: 90%;
    max-height: 90vh;
    margin: auto;
    display: flex;
    flex-direction: column;
    transform: scale(0.9);
    transition: transform 0.3s ease;
}

.privacy-modal.show .privacy-content {
    transform: scale(1);
}

.privacy-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 25px 30px;
    border-bottom: 1px solid var(--border-lighter);
    background: var(--background-light);
    border-radius: var(--border-radius-large) var(--border-radius-large) 0 0;
}

.privacy-header h2 {
    font-size: 1.8rem;
    font-weight: 700;
    margin: 0;
    color: var(--text-primary);
}

.privacy-close {
    background: none;
    border: none;
    font-size: 2rem;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    transition: var(--transition);
}

.privacy-close:hover {
    background: var(--border-light);
    color: var(--text-primary);
}

.privacy-body {
    flex: 1;
    overflow-y: auto;
    padding: 30px;
    max-height: 60vh;
}

.privacy-section {
    margin-bottom: 30px;
}

.privacy-section:last-child {
    margin-bottom: 0;
}

.privacy-section h3 {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--primary-color);
    margin: 0 0 15px 0;
    padding-bottom: 8px;
    border-bottom: 2px solid var(--primary-color);
}

.privacy-section p {
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-regular);
    margin: 0 0 15px 0;
}

.privacy-section ul {
    margin: 0 0 15px 0;
    padding-left: 20px;
}

.privacy-section li {
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-regular);
    margin-bottom: 8px;
}

.privacy-section strong {
    color: var(--text-primary);
    font-weight: 700;
}

.privacy-footer {
    padding: 25px 30px;
    border-top: 1px solid var(--border-lighter);
    background: var(--background-light);
    border-radius: 0 0 var(--border-radius-large) var(--border-radius-large);
    text-align: center;
}

.privacy-footer .btn-primary {
    margin: 0;
    min-width: 180px;
}

/* 功能特性区域 */
.features-section {
    padding: 80px 0;
    background: white;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
    margin-top: 0;
}

.feature-card {
    background: var(--background-light);
    padding: 40px 30px;
    border-radius: var(--border-radius-large);
    text-align: center;
    transition: var(--transition);
    border: 1px solid var(--border-lighter);
}

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

.feature-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 25px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.2rem;
    color: white;
}

.feature-card h3 {
    font-size: 1.4rem;
    font-weight: 700;
    margin: 0 0 15px 0;
    color: var(--text-primary);
}

.feature-card p {
    color: var(--text-regular);
    margin: 0;
    font-size: 16px;
    line-height: 1.6;
}

/* 安装教程区域 */
.tutorial-section {
    padding: 80px 0;
    background: var(--background-light);
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 700;
    margin: 0 0 60px 0;
    color: var(--text-primary);
}

.tutorial-steps {
    max-width: 800px;
    margin: 0 auto;
}

.step-item {
    display: flex;
    align-items: flex-start;
    margin-bottom: 30px;
    padding: 30px;
    background: white;
    border-radius: var(--border-radius-large);
    box-shadow: var(--shadow-light);
    border: 1px solid var(--border-lighter);
    transition: var(--transition);
}

.step-item:hover {
    transform: translateX(10px);
    box-shadow: var(--shadow-medium);
}

.step-number {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.3rem;
    font-weight: 700;
    margin-right: 25px;
    flex-shrink: 0;
}

.step-content h3 {
    font-size: 1.3rem;
    font-weight: 700;
    margin: 0 0 10px 0;
    color: var(--text-primary);
}

.step-content p {
    color: var(--text-regular);
    margin: 0;
    font-size: 16px;
    line-height: 1.6;
}

.step-content code {
    background: var(--background-gray);
    padding: 4px 8px;
    border-radius: 4px;
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    font-size: 16px;
    color: var(--primary-color);
    border: 1px solid var(--border-light);
}

/* 使用说明区域 */
.usage-section {
    padding: 80px 0;
    background: white;
}

.usage-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 0;
}

.usage-card {
    background: var(--background-light);
    padding: 30px;
    border-radius: var(--border-radius-large);
    border: 1px solid var(--border-lighter);
    transition: var(--transition);
}

.usage-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-light);
    background: white;
}

.usage-card h3 {
    font-size: 1.2rem;
    font-weight: 700;
    margin: 0 0 20px 0;
    color: var(--text-primary);
}

.usage-card ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.usage-card li {
    position: relative;
    padding-left: 25px;
    margin-bottom: 12px;
    color: var(--text-regular);
    line-height: 1.6;
    font-size: 16px;
}

.usage-card li::before {
    content: '✓';
    position: absolute;
    left: 0;
    top: 0;
    color: var(--success-color);
    font-weight: bold;
    font-size: 1rem;
}

/* 常见问题区域 */
.faq-section {
    padding: 80px 0;
    background: var(--background-light);
}

.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    background: white;
    margin-bottom: 15px;
    border-radius: var(--border-radius-large);
    box-shadow: var(--shadow-light);
    border: 1px solid var(--border-lighter);
    overflow: hidden;
    transition: var(--transition);
}

.faq-item:hover {
    box-shadow: var(--shadow-medium);
}

.faq-question {
    padding: 25px 30px;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: var(--transition);
}

.faq-question:hover {
    background-color: var(--background-light);
}

.faq-question h3 {
    font-size: 16px;
    font-weight: 600;
    margin: 0;
    color: var(--text-primary);
}

.faq-question .icon-arrow-down {
    font-size: 1.2rem;
    color: var(--text-secondary);
    transition: var(--transition);
}

.faq-item.active .icon-arrow-down {
    transform: rotate(180deg);
}

.faq-answer {
    padding: 0 30px;
    max-height: 0;
    overflow: hidden;
    transition: all 0.3s ease;
}

.faq-item.active .faq-answer {
    padding: 0 30px 25px;
    max-height: 200px;
}

.faq-answer p {
    color: var(--text-regular);
    margin: 0;
    line-height: 1.6;
    font-size: 16px;
}

/* 图标样式 */
.icon-download::before {
    content: '⬇';
}

.icon-play::before {
    content: '▶';
}

.icon-coverage::before {
    content: '📊';
}

.icon-clean::before {
    content: '✨';
}

.icon-efficient::before {
    content: '⚡';
}

.icon-feedback::before {
    content: '💬';
}

.icon-arrow-down::before {
    content: '▼';
}

/* 响应式设计 */
@media (max-width: 768px) {
    .page-title {
        font-size: 2.5rem;
    }
    
    .page-subtitle {
        font-size: 1.2rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .download-card {
        margin: 0 10px;
    }
    
    .card-header,
    .card-content {
        padding: 30px 25px;
    }
    
    .step-item {
        flex-direction: column;
        text-align: center;
    }
    
    .step-number {
        margin-right: 0;
        margin-bottom: 20px;
    }
    
    .usage-content {
        grid-template-columns: 1fr;
    }
    
    .video-links {
        flex-direction: column;
        align-items: center;
    }
    
    .btn-secondary {
        width: 100%;
        max-width: 200px;
        justify-content: center;
    }
    
    .backup-text {
        font-size: 16px;
    }
    
    .privacy-content {
        width: 95%;
        max-height: 95vh;
    }
    
    .privacy-header,
    .privacy-body,
    .privacy-footer {
        padding: 20px;
    }
    
    .privacy-section h3 {
        font-size: 1.2rem;
    }
    
    .container {
        padding: 0 15px;
    }
}

@media (max-width: 480px) {
    .page-header {
        padding: 60px 0;
    }
    
    .page-title {
        font-size: 2rem;
    }
    
    .features-section,
    .download-section,
    .tutorial-section,
    .usage-section,
    .faq-section {
        padding: 60px 0;
    }
    
    .card-header,
    .card-content {
        padding: 25px 20px;
    }
    
    .step-item {
        padding: 20px;
    }
    
    .faq-question {
        padding: 20px;
    }
    
    .faq-answer {
        padding: 0 20px 20px;
    }
}

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

.feature-card,
.step-item,
.usage-card,
.faq-item {
    animation: fadeInUp 0.6s ease-out;
}

.feature-card:nth-child(2) { animation-delay: 0.1s; }
.feature-card:nth-child(3) { animation-delay: 0.2s; }
.feature-card:nth-child(4) { animation-delay: 0.3s; }

/* 滚动条样式 */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--background-light);
}

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

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