/* 简化样式变量 */
:root {
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --border-color: #e5e7eb;
    --border-radius: 8px;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    font-size: 16px;
}

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

/* 标题样式 */
h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }

h1, h2, h3 {
    font-weight: 600;
    margin-bottom: 1rem;
}

p {
    margin-bottom: 1rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

a {
    color: inherit;
    text-decoration: none;
}

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

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

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

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

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

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

/* 导航栏 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: white;
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
}

.nav-brand h2 {
    color: var(--primary);
}

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

.nav-menu a {
    color: var(--text-primary);
    font-weight: 500;
}

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

/* 英雄区域 */
.hero {
    padding: 140px 0 80px;
    background: linear-gradient(135deg, var(--primary) 0%, #1d4ed8 100%);
    color: white;
    min-height: 600px;
    display: flex;
    align-items: center;
}

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.hero-content h1 {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    line-height: 1.1;
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    opacity: 0.9;
    font-weight: 500;
    color: #000000;
}

.hero-description {
    font-size: 1.1rem;
    margin-bottom: 2.5rem;
    opacity: 0.8;
    line-height: 1.6;
    color: #000000;
}

.hero-buttons {
    display: flex;
    gap: 1.5rem;
    margin-bottom: 2.5rem;
}

.version-info {
    display: flex;
    gap: 2rem;
    font-size: 0.9rem;
    opacity: 0.8;
}

.version-info span {
    display: flex;
    align-items: center;
}

.version-info span::before {
    content: "✓";
    margin-right: 0.5rem;
    font-weight: bold;
}

/* 移动设备预览 */
.hero-image {
    position: relative;
    display: flex;
    justify-content: center;
}

.mobile-preview {
    position: relative;
    width: 300px;
    height: 600px;
}

.mobile-device {
    width: 100%;
    height: 100%;
    background: #1f2937;
    border-radius: 40px;
    padding: 20px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
    position: relative;
}

.mobile-screen {
    width: 100%;
    height: 100%;
    background: white;
    border-radius: 25px;
    overflow: hidden;
    position: relative;
}

.mobile-content {
    width: 100%;
    height: 100%;
    padding: 0;
}

.chat-interface {
    height: 100%;
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.message {
    display: flex;
    gap: 10px;
    align-items: flex-start;
}

.message-avatar {
    width: 35px;
    height: 35px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
}

.ai-message .message-avatar {
    background: var(--primary);
    color: white;
}

.user-message .message-avatar {
    background: #e5e7eb;
}

.message-content {
    background: #f8fafc;
    padding: 12px 16px;
    border-radius: 18px;
    max-width: 70%;
    font-size: 0.9rem;
    line-height: 1.4;
}

.ai-message .message-content {
    background: var(--primary);
    color: white;
}

.typing-indicator {
    display: flex;
    gap: 4px;
    align-items: center;
    padding-left: 45px;
}

.typing-indicator span {
    width: 8px;
    height: 8px;
    background: var(--primary);
    border-radius: 50%;
    animation: typing 1.4s infinite ease-in-out;
}

.typing-indicator span:nth-child(1) { animation-delay: 0s; }
.typing-indicator span:nth-child(2) { animation-delay: 0.2s; }
.typing-indicator span:nth-child(3) { animation-delay: 0.4s; }

@keyframes typing {
    0%, 60%, 100% { transform: scale(0.8); opacity: 0.5; }
    30% { transform: scale(1); opacity: 1; }
}

/* 功能特性 */
.features {
    padding: 80px 0;
}

.features h2 {
    text-align: center;
    margin-bottom: 3rem;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.feature-card {
    background: white;
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    text-align: center;
}

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

.feature-card h3 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
}

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

/* 应用演示区域 */
.screenshots {
    padding: 80px 0;
    background: var(--bg-secondary);
}

.screenshots h2 {
    text-align: center;
    margin-bottom: 1rem;
}

.section-subtitle {
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: 3rem;
}

.screenshots-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.screenshot-item {
    background: white;
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.screenshot-item img {
    width: 100%;
    height: 400px;
    object-fit: contain;
}

.screenshot-caption {
    padding: 1rem;
    text-align: center;
    font-weight: 600;
}

/* 下载区域 */
.download {
    padding: 80px 0;
}

.download h2 {
    text-align: center;
    margin-bottom: 3rem;
}

.download-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.download-card {
    background: white;
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    text-align: center;
}

.download-card h3 {
    margin-bottom: 1rem;
}

.download-btn {
    display: block;
    width: 100%;
    margin: 1rem 0;
    padding: 1rem;
}

.system-requirements {
    background: var(--bg-secondary);
    padding: 2rem;
    border-radius: var(--border-radius);
}

.system-requirements h3 {
    margin-bottom: 1rem;
}

.system-requirements ul {
    list-style: none;
}

.system-requirements li {
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
}

/* 常见问题 */
.faq {
    padding: 80px 0;
    background: var(--bg-secondary);
}

.faq h2 {
    text-align: center;
    margin-bottom: 3rem;
}

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

.faq-item {
    background: white;
    margin-bottom: 1rem;
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.faq-question {
    padding: 1.5rem;
    background: white;
    border: none;
    width: 100%;
    text-align: left;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.faq-answer {
    padding: 0 1.5rem;
    max-height: 0;
    overflow: hidden;
    transition: all 0.3s ease;
}

.faq-item.active .faq-answer {
    padding: 0 1.5rem 1.5rem;
    max-height: 300px;
}

/* 联系我们 */
.contact {
    padding: 80px 0;
}

.contact h2 {
    text-align: center;
    margin-bottom: 3rem;
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.contact-icon {
    font-size: 2rem;
}

.newsletter {
    background: var(--bg-secondary);
    padding: 2rem;
    border-radius: var(--border-radius);
}

.newsletter h3 {
    margin-bottom: 1rem;
}

.newsletter-form {
    display: flex;
    gap: 1rem;
}

.newsletter-form input {
    flex: 1;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
}

.newsletter-form button {
    padding: 0.75rem 1.5rem;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
}

/* 页脚 */
.footer {
    background: var(--text-primary);
    color: white;
    padding: 3rem 0;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
}

.footer-section h3,
.footer-section h4 {
    margin-bottom: 1rem;
    color: white;
}

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

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

.footer-section a {
    color: rgba(255, 255, 255, 0.8);
}

.footer-section a:hover {
    color: white;
}

.footer-bottom {
    text-align: center;
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.8);
}

/* 响应式设计 */
@media (max-width: 768px) {
    .container {
        padding: 0 1rem;
    }
    
    .nav-menu {
        display: none;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .version-info {
        flex-direction: column;
        gap: 1rem;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .screenshots-grid {
        grid-template-columns: 1fr;
    }
    
    .download-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .contact-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .newsletter-form {
        flex-direction: column;
    }
}