:root {
    --color-primary: #031867;
    --color-secondary: #0454f8;
    --color-accent: #1194f6;
    --color-text: #0A0A0A;
    --color-background: #F8FAFF;
}

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

body {
    font-family: 'Arial', sans-serif;
    background-color: var(--color-background);
    color: var(--color-text);
}

/* 导航栏样式 */
.main-nav {
    background-color: var(--color-primary);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    border-top: 0.5px solid rgba(4, 84, 248, 0.3);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-links a {
    color: white;
    text-decoration: none;
    padding: 0.5rem 1rem;
    position: relative;
    margin: 0 0.5rem;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--color-accent);
    transition: width 0.3s ease;
}

.nav-links a:hover::after {
    width: 100%;
}
.logo img{height: 2rem;}
.lang-btn{
    border: none;
    background-color: transparent;
    color: #F8FAFF;
}
/* Hero区域样式 */
.hero-section {
    position: relative;
    width: 100%;
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    text-align: center;
    overflow: hidden;
}

.background-layer {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 3;
}

#nodeCanvas {
    position: absolute;
    width: 100%;
    height: 100%;
}

.video-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
}

.video-overlay img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.glass-effect {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.2);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    z-index: 2;
}

.content {
    position: relative;
    z-index: 4;
    padding: 2rem;
}

.content h1 {
    font-size: 3.5rem;
    margin-bottom: 1rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.5);
}

.content h2 {
    font-size: 1.8rem;
    margin-bottom: 2rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.5);
}

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

/* 优化canvas在高分辨率屏幕上的显示 */
@media (min-resolution: 2dppx) {
    .background-layer canvas {
        transform: scale(0.5);
        transform-origin: 0 0;
    }
}

/* 按钮样式 */
.primary-btn {
    background: linear-gradient(180deg, var(--color-primary), var(--color-secondary));
    color: white;
    border: none;
    padding: 1rem 2rem;
    border-radius: 4px;
    cursor: pointer;
    text-decoration: none;
    transition: transform 0.3s ease;
}
.secondary-btn {
    background: linear-gradient(180deg, var(--color-primary), var(--color-secondary));
    color: white;
    border: none;
    padding: 1rem 2rem;
    border-radius: 4px;
    cursor: pointer;
    text-decoration: none;
    transition: transform 0.3s ease;
}
.primary-btn:hover {
    transform: translateY(-2px);
}

/* 通用 Section 样式 */
.section-padding {
    padding: 60px 0;
}

.section-title {
    text-align: center;
    margin-bottom: 40px;
    font-size: 2.5rem;
    color: var(--color-primary);
    font-weight: bold;
}

.section-title i {
    margin-right: 10px;
    color: var(--color-secondary);
}

.bg-light {
    background-color: #f8f9fa; /* Bootstrap 轻灰色背景 */
}

/* 产品介绍 (#products) */
.product-accordion .accordion-item {
    border: 1px solid #dee2e6;
    margin-bottom: 15px;
    border-radius: 5px;
    overflow: hidden; /* 确保圆角生效 */
}

.product-accordion .accordion-header {
   margin-bottom: 0; /* 移除默认 margin */
}

.product-accordion .accordion-button {
    background-color: #f8f9fa;
    color: var(--color-primary);
    font-weight: bold;
    font-size: 1.2rem;
    padding: 1rem 1.5rem;
}
.product-accordion .accordion-button:not(.collapsed) {
    background-color: var(--color-primary);
     color: white;
}
.product-accordion .accordion-button:focus {
    box-shadow: none; /* 移除 Bootstrap 默认的 focus 效果 */
}

.product-accordion .accordion-button i {
    color: var(--color-accent);
    transition: color 0.3s ease;
}
.product-accordion .accordion-button:not(.collapsed) i {
    color: white;
}

.product-accordion .accordion-body {
    padding: 1.5rem 1.8rem;
    background-color: #fdfdfd;
    border-top: 1px solid #eee;
}
.product-accordion .accordion-body p {
    margin-bottom: 1rem; /* Increased paragraph spacing */
    line-height: 1.7;   /* Improved line height for readability */
    font-size: 0.95rem; /* Slightly smaller font size */
    color: #555;       /* Softer text color */
}
.product-accordion .accordion-body strong {
    color: var(--color-primary);
    margin-right: 5px;
    display: block; /* Make category title block level */
    margin-bottom: 0.5rem;
}

.product-accordion .category-item {
    cursor: pointer;
    text-decoration: none;
    border-bottom: 1px dotted var(--color-secondary);
    transition: color 0.2s ease, border-color 0.2s ease;
    margin-right: 5px; /* Add some space between category items */
}
.product-accordion .category-item:hover {
    color: var(--color-accent);
    border-color: var(--color-accent);
}

/* Style for product images - Reduced Size and Margins */
.product-image {
    max-width: 85%;  /* Reduce max width */
    height: auto;
    display: block; /* Needed for margin auto to work */
    margin: 0 auto 1rem auto; /* Center image horizontally, add bottom margin */
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.12); /* Slightly stronger shadow */
}

/* Adjust spacing within accordion body row */
.product-accordion .accordion-body .row {
    padding: 1rem 0;
}

/* Ensure text column has padding */
.product-accordion .accordion-body .col-md-6 {
    padding-left: 1.5rem;
    padding-right: 1.5rem;
}

/* Responsive adjustments for product section */
@media (max-width: 767.98px) {
    .product-accordion .accordion-body .col-md-6 {
        padding-left: 1rem; /* Less padding on mobile */
        padding-right: 1rem;
    }
     .product-image {
        max-width: 90%; /* Slightly larger max-width on mobile relative to column */
        margin-bottom: 1.5rem; /* More space below image on mobile */
     }
     .product-accordion .accordion-body p {
        font-size: 0.9rem; /* Adjust font size for mobile */
     }
     /* Stack order remains correct due to Bootstrap defaults */
}

.product-model-placeholder {
    margin-top: 1rem;
    padding: 2rem;
    background-color: #e9ecef;
    text-align: center;
    border-radius: 4px;
    font-style: italic;
    color: #6c757d;
}

/* 关于我们 (#about) */
.feature-box {
    text-align: center;
    padding: 20px;
    border: 1px solid #e0e0e0;
    border-radius: 5px;
    background-color: #fff;
    height: 100%; /* 确保同行列高一致 */
}

.feature-box h4 {
    margin-top: 15px;
    color: var(--color-primary);
}

.placeholder-map, .placeholder-signboard, .team-placeholder, .logo-wall-placeholder {
    margin-top: 1rem;
    padding: 2rem;
    background-color: #e9ecef;
    text-align: center;
    border-radius: 4px;
    font-style: italic;
    color: #6c757d;
    min-height: 100px; /* 给占位符一个最小高度 */
}

/* 页脚 (#contact) */
.footer-section {
    background-color: var(--color-primary);
    color: rgba(255, 255, 255, 0.8);
    padding: 40px 0 20px;
}

.footer-section h5 {
    color: white;
    margin-bottom: 15px;
}

.footer-section a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    transition: color 0.3s ease;
}

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

.footer-section hr {
    border-top: 1px solid rgba(255, 255, 255, 0.2);
    margin-top: 20px;
    margin-bottom: 20px;
}

.footer-section .small {
     color: rgba(255, 255, 255, 0.6);
}

/* About Us Section Styles */
#about {
    position: relative;
    padding: 100px 0;
    overflow: hidden;
}

.about-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
}

.about-background img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.about-background .overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(255, 255, 255, 0.85);
}

.stats-row {
    position: relative;
    z-index: 2;
}

.stat-item {
    text-align: center;
    padding: 20px;
}

.stat-number {
    font-size: 3.5rem;
    font-weight: 700;
    color: var(--color-primary);
    line-height: 1.2;
    margin-bottom: 10px;
}

.stat-number .plus {
    font-size: 2.5rem;
    font-weight: 500;
}

.stat-label {
    font-size: 1.2rem;
    color: var(--color-text);
    font-weight: 500;
}

/* 响应式调整 */
@media (max-width: 768px) {
    .stat-number {
        font-size: 2.5rem;
    }
    .stat-number .plus {
        font-size: 2rem;
    }
    .stat-label {
        font-size: 1rem;
    }
}