/* Reset and Base Styles */
:root {
    --primary-color: #6366F1;
    --primary-hover: #4F46E5;
    --secondary-color: #F59E0B;
    --dark-color: #1F2937;
    --light-color: #F9FAFB;
    --gray-color: #9CA3AF;
    --success-color: #10B981;
    --danger-color: #EF4444;
    --border-radius: 8px;
    --box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

img {
    max-width: 100%;
    height: auto;
}

ul {
    list-style: none;
}

/* Header and Navigation */
header {
    background-color: white;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 100;
    width: 100%;
    padding: 0;
}

.navbar {
    display: flex;
    justify-content: flex-start;
    align-items: center;
    padding: 0 2rem;
    max-width: 1280px;
    margin: 0 auto;
    height: 90px; /* 进一步增加导航栏高度，从80px到90px */
}

.logo {
    display: flex;
    align-items: center;
    font-weight: 700;
    font-size: 2.2rem; /* 进一步增大文字，从1.8rem到2.2rem */
    min-width: 220px; /* 增加logo区域最小宽度，从180px到220px */
    margin-right: 20px; /* 添加右侧间距，使logo与导航项分开 */
    padding-left: 0; /* 确保没有左侧内边距 */
}

.logo img {
    height: 48px; /* 进一步增大logo图标，从40px到48px */
    margin-right: 1rem; /* 增加右侧间距，从0.8rem到1rem */
}

.logo .side {
    color: #1a73e8;
}

.logo .panel {
    color: var(--dark-color);
}

.nav-links {
    display: flex;
    gap: 2rem;
    flex: 1;
    justify-content: center; /* 居中导航项 */
}

.nav-item {
    font-weight: 500;
    padding: 0.5rem 0;
    position: relative;
    white-space: nowrap; /* 防止文本换行 */
    font-size: 1.1rem; /* 减小导航项文字大小，从1.25rem到1.1rem */
}

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

.nav-item::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: 0;
    left: 0;
    background-color: var(--primary-color);
    transition: var(--transition);
}

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

.language-switch {
    min-width: 120px; /* 增加语言切换区域最小宽度，从100px到120px */
    text-align: right;
    margin-left: auto; /* 将语言切换推到最右边 */
}

.language-switch a {
    padding: 0.6rem 1.2rem; /* 增加内边距 */
    border-radius: var(--border-radius);
    border: 1px solid var(--gray-color);
    font-size: 1.1rem; /* 进一步增大语言切换文字，从1rem到1.1rem */
}

.language-switch a:hover {
    background-color: var(--light-color);
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 6px;
    cursor: pointer;
}

.mobile-menu-btn span {
    width: 24px;
    height: 2px;
    background-color: var(--dark-color);
    transition: var(--transition);
}

/* Hero Section */
.hero {
    display: flex;
    align-items: center;
    padding: 5rem 2rem;
    max-width: 1280px;
    margin: 0 auto;
    gap: 4rem;
}

.hero-content {
    flex: 1;
}

.hero h1 {
    font-size: 3rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 1.5rem;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero p {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    color: var(--gray-color);
}

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

.cta-primary, .cta-secondary {
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    font-weight: 500;
    transition: var(--transition);
}

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

.cta-primary:hover {
    background-color: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: var(--box-shadow);
}

.cta-secondary {
    border: 1px solid var(--primary-color);
    color: var(--primary-color);
}

.cta-secondary:hover {
    background-color: var(--primary-color);
    color: white;
    transform: translateY(-2px);
}

.hero-image {
    flex: 1;
}

.hero-image img {
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
}

/* Feature Sections */
.feature-section {
    padding: 5rem 2rem;
    max-width: 1280px;
    margin: 0 auto;
}

.feature-section h2 {
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: 3rem;
}

.features {
    display: flex;
    flex-wrap: wrap;
    gap: 2rem;
    justify-content: center;
}

.feature-card {
    flex: 0 0 calc(33.333% - 2rem);
    background-color: white;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    overflow: hidden;
    transition: var(--transition);
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

.feature-card img {
    width: 100%;
    aspect-ratio: 16 / 9;
    object-fit: cover;
}

.feature-card h3 {
    padding: 1.5rem 1.5rem 0.5rem;
    font-size: 1.25rem;
}

.feature-card p {
    padding: 0 1.5rem 1.5rem;
    color: var(--gray-color);
}

/* Pricing Section */
.pricing-section {
    padding: 5rem 2rem;
    max-width: 1280px;
    margin: 0 auto;
    text-align: center;
}

.pricing-section h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.pricing-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 3rem;
}

.switch {
    position: relative;
    display: inline-block;
    width: 50px;
    height: 24px;
}

.switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--gray-color);
    transition: var(--transition);
    border-radius: 24px;
}

.slider:before {
    position: absolute;
    content: "";
    height: 18px;
    width: 18px;
    left: 3px;
    bottom: 3px;
    background-color: white;
    transition: var(--transition);
    border-radius: 50%;
}

input:checked + .slider {
    background-color: var(--primary-color);
}

input:checked + .slider:before {
    transform: translateX(26px);
}

.discount {
    background-color: var(--secondary-color);
    color: white;
    padding: 0.25rem 0.5rem;
    border-radius: var(--border-radius);
    font-size: 0.75rem;
    margin-left: 0.5rem;
}

.pricing-cards {
    display: flex;
    flex-wrap: wrap;
    gap: 2rem;
    justify-content: center;
}

.pricing-card {
    flex: 0 0 calc(33.333% - 2rem);
    background-color: white;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    padding: 2rem;
    transition: var(--transition);
    display: flex;
    flex-direction: column;
}

.pricing-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

.pricing-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.price {
    margin-bottom: 2rem;
}

.amount {
    font-size: 2.5rem;
    font-weight: 700;
}

.amount.yearly {
    display: none;
}

.period {
    font-size: 1rem;
    color: var(--gray-color);
}

.pricing-card ul {
    margin-bottom: 2rem;
    text-align: left;
}

.pricing-card li {
    padding: 0.5rem 0;
    display: flex;
    align-items: center;
}

.pricing-card li::before {
    content: "✓";
    color: var(--success-color);
    margin-right: 0.5rem;
    font-weight: bold;
}

.subscribe-btn {
    margin-top: auto;
    padding: 0.75rem 1.5rem;
    background-color: var(--primary-color);
    color: white;
    border-radius: var(--border-radius);
    font-weight: 500;
    transition: var(--transition);
}

.subscribe-btn:hover {
    background-color: var(--primary-hover);
    transform: translateY(-2px);
}

/* Footer Styles */
footer {
    background-color: var(--dark-color);
    color: white;
    padding: 3rem 2rem;
    margin-top: 5rem;
}

.footer-content {
    max-width: 1280px;
    margin: 0 auto;
    display: flex;
    flex-wrap: wrap;
    gap: 4rem;
    margin-bottom: 2rem;
}

.footer-logo {
    display: flex;
    align-items: center;
    font-weight: 700;
    font-size: 2.2rem; /* 与导航栏logo字体大小一致 */
    margin-bottom: 1.8rem;
    flex: 0 0 100%; /* 让logo占据整行 */
}

.footer-logo img {
    height: 48px; /* 与导航栏logo图标大小一致 */
    margin-right: 1rem;
    filter: brightness(0) invert(1); /* 保持图标在深色背景上为白色 */
}

.footer-links {
    display: flex;
    flex: 1;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 2rem;
}

.footer-column h4 {
    margin-bottom: 1rem;
    font-size: 1rem;
    color: var(--gray-color);
}

.footer-column a {
    display: block;
    margin-bottom: 0.5rem;
    color: white;
    transition: var(--transition);
}

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

.copyright {
    max-width: 1280px;
    margin: 0 auto;
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: var(--gray-color);
    font-size: 0.875rem;
}

/* Responsive Design */
@media (max-width: 1024px) {
    .hero h1 {
        font-size: 2.5rem;
    }
    
    .feature-card {
        flex: 0 0 calc(50% - 2rem);
    }
    
    .pricing-card {
        flex: 0 0 calc(50% - 2rem);
    }
}

@media (max-width: 768px) {
    .navbar {
        padding: 1rem;
    }
    
    .nav-links {
        position: fixed;
        top: 0;
        left: 0;
        height: 100vh;
        width: 250px;
        background-color: white;
        flex-direction: column;
        padding: 2rem;
        transform: translateX(-100%);
        transition: var(--transition);
        z-index: 200;
    }
    
    .nav-links.active {
        transform: translateX(0);
        box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    }
    
    .mobile-menu-btn {
        display: flex;
        z-index: 300;
    }
    
    .mobile-menu-btn.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }
    
    .mobile-menu-btn.active span:nth-child(2) {
        opacity: 0;
    }
    
    .mobile-menu-btn.active span:nth-child(3) {
        transform: rotate(-45deg) translate(5px, -5px);
    }
    
    .hero {
        flex-direction: column;
        padding: 3rem 1rem;
        gap: 2rem;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
    
    .feature-section {
        padding: 3rem 1rem;
    }
    
    .feature-section h2 {
        font-size: 2rem;
    }
    
    .feature-card {
        flex: 0 0 100%;
    }
    
    .pricing-section {
        padding: 3rem 1rem;
    }
    
    .pricing-section h2 {
        font-size: 2rem;
    }
    
    .pricing-card {
        flex: 0 0 100%;
    }
    
    .footer-content {
        flex-direction: column;
        gap: 2rem;
    }
    
    .footer-links {
        flex-direction: column;
        gap: 2rem;
    }
}

/* Toggle for yearly billing */
body.yearly .amount.monthly {
    display: none;
}

body.yearly .amount.yearly {
    display: inline;
}

/* 积分部分的样式 */
.feature-item {
    display: flex;
    align-items: flex-start;
    margin-bottom: 1rem;
    font-size: 0.85rem;
}

/* 基础模型和高级模型的文字样式 */
.model-text {
    color: #999;
    font-size: 0.8rem;
    margin-top: 0.2rem;
    display: block;
    line-height: 1.4;
}

/* 积分数字的样式 */
.feature-item > span:first-of-type {
    font-weight: 500;
}

/* 无限文字的紫色样式 */
.unlimited-text {
    color: #6366F1;
    font-weight: 500;
}

/* 信息图标样式调整 */
.feature-item .info-icon {
    color: #999;
    font-size: 0.75rem;
    margin-left: 0.3rem;
    cursor: help;
    opacity: 0.8;
}

/* 积分部分下方的虚线分隔符 */
.credits-divider {
    width: 100%;
    height: 1px;
    border-bottom: 1px dashed rgba(0, 0, 0, 0.1);
    margin: 1.5rem 0;
}

/* 高亮卡片中的虚线颜色调整 */
.pricing-card.highlighted .credits-divider {
    border-bottom: 1px dashed rgba(255, 255, 255, 0.2);
}

/* 确保至尊版中模型文本颜色与其他版本一致 */
.pricing-card.highlighted .model-text {
    color: #999;
}

/* 确保至尊版中第一行积分文本颜色正确 */
.pricing-card.highlighted .feature-item > span:first-of-type {
    color: #333;
}