/* 全局重置与基础样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --color-primary: #2C2C2C;
    --color-secondary: #F5F5F5;
    --color-white: #FFFFFF;
    --color-accent: #0A2463;
    --color-text: #333333;
    --color-text-light: #777777;
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 6rem;
    --transition-smooth: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

body {
    font-family: "Source Han Sans CN", "Noto Sans SC", -apple-system, BlinkMacSystemFont, sans-serif;
    color: var(--color-text);
    background-color: var(--color-white);
    line-height: 1.6;
    overflow-x: hidden;
}

/* 导航栏 */
.nav-container {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    border-bottom: 1px solid rgba(44, 44, 44, 0.1);
}

.nav-wrapper {
    max-width: 1400px;
    margin: 0 auto;
    padding: var(--spacing-sm) var(--spacing-md);
    display: flex;
    justify-content: center;
    align-items: center;
}

.nav-menu {
    display: flex;
    gap: var(--spacing-lg);
    list-style: none;
}

.nav-link {
    font-size: 16px;
    font-weight: 400;
    color: var(--color-text);
    text-decoration: none;
    padding: var(--spacing-xs) var(--spacing-sm);
    transition: var(--transition-smooth);
    position: relative;
}

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

.nav-link.active {
    color: var(--color-accent);
    font-weight: 500;
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 50%;
    transform: translateX(-50%);
    width: 30px;
    height: 2px;
    background: var(--color-accent);
}

/* 页面容器 */
.page-section {
    display: none;
    min-height: 100vh;
    padding-top: 80px;
}

.page-section.active {
    display: block;
}

/* 英雄区域 */
.hero-section {
    height: 100vh;
    position: relative;
    overflow: hidden;
}

.hero-slider {
    height: 100%;
    position: relative;
}

.hero-slide {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    transition: opacity 1s ease-in-out;
}

.hero-slide.active {
    opacity: 1;
}

.hero-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center;
}

.hero-caption {
    position: absolute;
    bottom: var(--spacing-xl);
    left: 50%;
    transform: translateX(-50%);
    text-align: center;
    color: var(--color-white);
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
}

.hero-caption h2 {
    font-size: 42px;
    font-weight: 300;
    letter-spacing: 2px;
    margin: 0;
}

/* 内容区域 */
.content-section {
    max-width: 1400px;
    margin: 0 auto;
    padding: var(--spacing-xl) var(--spacing-md);
}

.section-title {
    font-size: 36px;
    font-weight: 300;
    text-align: center;
    margin-bottom: var(--spacing-lg);
    letter-spacing: 1px;
    color: var(--color-primary);
}

/* 网格布局 */
.grid-container {
    display: grid;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.grid-3 {
    grid-template-columns: repeat(3, 1fr);
}

.grid-2 {
    grid-template-columns: repeat(2, 1fr);
}

.grid-4 {
    grid-template-columns: repeat(4, 1fr);
}

/* 卡片组件 */
.card {
    background: var(--color-white);
    overflow: hidden;
    transition: var(--transition-smooth);
    cursor: pointer;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.card-image {
    width: 100%;
    height: 400px;
    object-fit: cover;
    transition: var(--transition-smooth);
}

.card:hover .card-image {
    transform: scale(1.05);
}

.card-content {
    padding: var(--spacing-md);
}

.card-title {
    font-size: 22px;
    font-weight: 400;
    margin-bottom: var(--spacing-xs);
    color: var(--color-primary);
}

.card-description {
    font-size: 16px;
    color: var(--color-text-light);
    line-height: 1.8;
}

/* 理念区域 */
.philosophy-section {
    background: var(--color-secondary);
    padding: var(--spacing-xl) 0;
}

.philosophy-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.philosophy-item {
    text-align: center;
    padding: var(--spacing-md);
}

.philosophy-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto var(--spacing-md);
    background: var(--color-accent);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 36px;
    color: var(--color-white);
}

.philosophy-item h3 {
    font-size: 24px;
    font-weight: 400;
    margin-bottom: var(--spacing-sm);
    color: var(--color-primary);
}

.philosophy-item p {
    font-size: 16px;
    color: var(--color-text-light);
    line-height: 1.8;
}

/* 页脚 */
.footer {
    background: var(--color-primary);
    color: var(--color-white);
    text-align: center;
    padding: var(--spacing-md);
    font-size: 14px;
    margin-top: var(--spacing-xl);
}

/* 响应式设计 */
@media (max-width: 1024px) {
    .grid-3, .grid-4, .philosophy-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .hero-caption h2 {
        font-size: 32px;
    }
    
    .section-title {
        font-size: 28px;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        gap: var(--spacing-md);
    }
    
    .nav-link {
        font-size: 14px;
    }
    
    .grid-2, .grid-3, .grid-4, .philosophy-grid {
        grid-template-columns: 1fr;
    }
    
    .hero-caption h2 {
        font-size: 24px;
    }
    
    .section-title {
        font-size: 24px;
    }
    
    .card-image {
        height: 300px;
    }
    
    .content-section {
        padding: var(--spacing-md) var(--spacing-sm);
    }
}

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

.fade-in {
    animation: fadeIn 0.6s ease-out;
}

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

/* 图片懒加载占位 */
img[data-src] {
    background: var(--color-secondary);
}