/* 全局样式 */
:root {
    --primary-color: #1e3a8a;
    --secondary-color: #2563eb;
    --accent-color: #3b82f6;
    --light-color: #f3f4f6;
    --dark-color: #1f2937;
    --gray-color: #6b7280;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
    
    /* 深色模式变量 */
    --bg-color: #ffffff;
    --text-color: #1f2937;
    --card-bg: #ffffff;
    --card-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    --header-bg: #ffffff;
    --footer-bg: #1f2937;
    --footer-text: #ffffff;
    --border-color: #e5e7eb;
}

/* 深色模式样式 */
[data-theme="dark"] {
    --primary-color: #3b82f6;
    --secondary-color: #60a5fa;
    --accent-color: #93c5fd;
    --light-color: #374151;
    --dark-color: #f3f4f6;
    --gray-color: #9ca3af;
    --bg-color: #111827;
    --text-color: #f3f4f6;
    --card-bg: #1f2937;
    --card-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
    --header-bg: #1f2937;
    --footer-bg: #111827;
    --footer-text: #f3f4f6;
    --border-color: #374151;
    --section-bg: #1f2937;
    --section-alt-bg: #111827;
}

@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
        --primary-color: #3b82f6;
        --secondary-color: #60a5fa;
        --accent-color: #93c5fd;
        --light-color: #374151;
        --dark-color: #f3f4f6;
        --gray-color: #9ca3af;
        --bg-color: #111827;
        --text-color: #f3f4f6;
        --card-bg: #1f2937;
        --card-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
        --header-bg: #1f2937;
        --footer-bg: #111827;
        --footer-text: #f3f4f6;
        --border-color: #374151;
    }
}

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

body {
    font-family: 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    transition: background-color 0.3s ease, color 0.3s ease;
}

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

ul {
    list-style: none;
}

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

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 2rem;
    color: var(--primary-color);
    position: relative;
    padding-bottom: 1rem;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background-color: var(--accent-color);
}

.btn {
    display: inline-block;
    background-color: var(--primary-color);
    color: white;
    padding: 12px 25px;
    border-radius: 5px;
    text-transform: uppercase;
    font-weight: bold;
    letter-spacing: 1px;
    transition: var(--transition);
    border: none;
    cursor: pointer;
}

.btn:hover {
    background-color: var(--secondary-color);
    transform: translateY(-3px);
    box-shadow: var(--box-shadow);
}

.btn-small {
    padding: 8px 15px;
    font-size: 0.9rem;
}

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

/* 导航栏样式 */
header {
    background-color: var(--header-bg);  /* 使用CSS变量而不是固定颜色 */
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    transition: all 0.3s ease;
}

header .container {
    display: flex;
    justify-content: flex-start;
    align-items: center;
    padding: 15px 20px;
    height: 100%;
}

.logo {
    margin-right: 30px;
}

.logo a {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
}

.logo img {
    height: 40px;
    margin-bottom: 5px;
    display: block;
    width: auto;
}

.logo .logo-en {
    height: 20px;
    display: block;
    width: auto;
}

nav {
    flex-grow: 1;
    display: flex;
    align-items: center;
}

nav ul {
    display: flex;
    margin-left: auto;
}

nav ul li {
    margin-left: 30px;
}

nav ul li a {
    color: var(--dark-color);
    font-weight: 500;
    padding: 10px 0;
    position: relative;
}

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

nav ul li a:hover::after,
nav ul li a.active::after {
    width: 100%;
}

nav ul li a:hover,
nav ul li a.active {
    color: var(--primary-color);
}

/* 主横幅样式 */
.hero {
    height: 100vh;
    background-image: url('../img/hero_background.jpg');
    background-size: cover;
    background-position: center;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    color: white;
    position: relative;
    margin-top: 100px; /* 调整为与header高度一致 */
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, rgba(30, 58, 138, 0.8), rgba(37, 99, 235, 0.6));
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 900px;
    padding: 0 20px;
}

.hero h1 {
    font-size: 4rem;
    margin-bottom: 1.5rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.5);
    font-weight: 700;
    letter-spacing: 2px;
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: #f0f9ff;
    font-weight: 500;
}

.hero-description {
    font-size: 1.1rem;
    margin-bottom: 1rem;
    text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.5);
    opacity: 0.9;
}

.hero-btn {
    margin-top: 2rem;
    padding: 15px 35px;
    font-size: 1.1rem;
    background-color: rgba(255, 255, 255, 0.2);
    border: 2px solid white;
    backdrop-filter: blur(10px);
}

.hero-btn:hover {
    background-color: white;
    color: var(--primary-color);
    transform: translateY(-3px);
}

/* 公司简介预览样式 */
.about-preview {
    padding: 5rem 0;
    background-color: var(--light-color);
}

.about-content {
    display: flex;
    align-items: center;
    gap: 40px;
}

.about-text {
    flex: 1;
}

.about-text p {
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
}

.about-image {
    flex: 1;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: var(--box-shadow);
}

/* 业务领域样式 */
.services {
    padding: 5rem 0;
}

.service-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.service-item {
    background-color: white;
    border-radius: 10px;
    padding: 30px;
    text-align: center;
    box-shadow: var(--box-shadow);
    transition: var(--transition);
}

.service-item:hover {
    transform: translateY(-10px);
}

.service-icon {
    width: 80px;
    height: 80px;
    background-color: var(--primary-color);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
}

.service-icon i {
    font-size: 2rem;
}

.service-item h3 {
    margin-bottom: 15px;
    color: var(--primary-color);
}

/* 案例展示样式 - 修复悬停效果文字显示问题 */
.cases {
    padding: 5rem 0;
    background-color: var(--light-color);
}

.case-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
    margin-top: 2rem;
}

.case-item {
    position: relative;
    border-radius: 15px;
    overflow: hidden;
    height: 300px;
    box-shadow: var(--box-shadow);
    transition: var(--transition);
}

.case-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.2);
}

.case-image {
    position: relative;
    width: 100%;
    height: 100%;
    overflow: hidden;
}

.case-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
}

.case-item:hover .case-image img {
    transform: scale(1.05);
}

.case-overlay {
    position: absolute;
    bottom: -15px;
    left: 0;
    width: 100%;
    padding: 25px;
    background: linear-gradient(to top, rgba(0, 0, 0, 0.5), rgba(0, 0, 0, 0.1), transparent);
    color: white;
    transition: var(--transition);
    opacity: 1; 
    border-bottom-left-radius: 15px;
    border-bottom-right-radius: 15px;
}

.case-item:hover .case-overlay {
    background: linear-gradient(to top, rgba(0, 0, 0, 0.8), rgba(0, 0, 0, 0.4), rgba(0, 0, 0, 0.2));
    transform: translateY(-15px);
}

.case-info {
    position: relative;
    z-index: 2;
}

.case-category {
    display: inline-block;
    background-color: var(--accent-color);
    color: white;
    padding: 4px 12px;
    border-radius: 15px;
    font-size: 0.8rem;
    font-weight: 500;
    margin-bottom: 10px;
    transform: translateY(0);
    transition: all 0.4s ease;
    opacity: 0; /* 默认隐藏 */
}

.case-info h3 {
    font-size: 1.2rem;
    margin-bottom: 8px;
    font-weight: 600;
    text-shadow: 1px 2px 3px rgba(0, 0, 0, 0.9);
    opacity: 1;
    transform: translateY(0);
    transition: transform 0.4s ease;
}

.case-info p {
    font-size: 0.9rem;
    line-height: 1.4;
    text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.9);
    transform: translateY(10px);
    transition: all 0.4s ease;
    opacity: 0; /* 默认隐藏 */
    max-height: 0;
    overflow: hidden;
}

.case-item:hover .case-category {
    opacity: 1; /* 悬停时显示 */
    transform: translateY(0);
}

.case-item:hover .case-info h3 {
    transform: translateY(-5px);
}

.case-item:hover .case-info p {
    opacity: 0.9; /* 悬停时显示 */
    transform: translateY(0);
    max-height: 60px; /* 足够显示描述文本 */
    margin-top: 8px;
}

/* 工程流程样式 */
.engineering-process {
    padding: 5rem 0;
    background-color: #f8fafc;
}

.process-timeline {
    position: relative;
    max-width: 1100px;
    margin: 0 auto;
    padding: 2rem 0;
    overflow: visible; /* 确保内容不被裁剪 */
}

.process-timeline:before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 4px;
    height: 100%;
    background-color: #e2e8f0;
    z-index: 1;
}

/* 移除可能的装饰性元素 */
.process-timeline:after {
    display: none;
}

.timeline-step {
    position: relative;
    margin-bottom: 4rem;
    z-index: 2;
    display: flex;
    align-items: center;
}

.timeline-step:last-child {
    margin-bottom: 0;
}

.timeline-icon {
    width: 100px;
    height: 100px;
    background: var(--primary-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 2.5rem;
    box-shadow: 0 10px 25px rgba(30, 58, 138, 0.3);
    z-index: 3;
    margin: 0 2rem;
}

.timeline-content {
    flex: 1;
    background-color: white;
    padding: 1.5rem 2rem;
    border-radius: 10px;
    box-shadow: var(--box-shadow);
}

.timeline-content h3 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
    font-size: 1.3rem;
}

/* 设计流程样式 */
.design-process {
    padding: 5rem 0;
    background-color: white;
}

.process-chart {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-top: 3rem;
    position: relative;
    max-width: 1100px;
    margin: 2rem auto;
}

.process-chart:before {
    content: '';
    position: absolute;
    top: 60px;
    left: 0;
    width: 100%;
    height: 4px;
    background-color: #e2e8f0;
    z-index: 1;
}

.process-step {
    position: relative;
    z-index: 2;
    width: calc(100% / 6 - 20px);
    text-align: center;
    padding-top: 80px;
    cursor: pointer;
}

.process-dot {
    position: absolute;
    top: 58px;
    left: 50%;
    transform: translateX(-50%);
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background-color: #e2e8f0;
    border: 2px solid white;
    z-index: 3;
    transition: all 0.4s ease;
}

.process-dot.active, .process-step:hover .process-dot {
    background-color: var(--primary-color);
    transform: translateX(-50%) scale(1.5);
    box-shadow: 0 0 0 5px rgba(30, 58, 138, 0.2);
}

.process-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 15px;
    font-size: 1.8rem;
    position: absolute;
    top: -40px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 2;
    box-shadow: 0 10px 20px rgba(37, 99, 235, 0.3);
    transition: all 0.4s ease;
}

.process-step:hover .process-icon {
    transform: translateX(-50%) scale(1.15);
    box-shadow: 0 15px 30px rgba(37, 99, 235, 0.4);
}

.process-step h3 {
    color: var(--primary-color);
    margin-bottom: 10px;
    font-size: 1.1rem;
    transition: all 0.4s ease;
}

.process-step p {
    font-size: 0.9rem;
    color: var(--gray-color);
    transition: all 0.4s ease;
}

.process-step:hover h3 {
    color: var(--primary-color);
    transform: scale(1.15);
    font-weight: 600;
}

.process-step:hover p {
    transform: scale(1.05);
    color: var(--dark-color);
}

/* 工程管理样式 */
.engineering-management {
    padding: 5rem 0;
    background-color: #f8fafc;
}

.management-process {
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: relative;
    margin: 3rem auto;
    max-width: 1100px;
}

.management-process:before {
    content: '';
    position: absolute;
    top: 50%;
    left: 0;
    width: 100%;
    height: 4px;
    background: var(--accent-color);
    z-index: 1;
}

.management-step {
    position: relative;
    z-index: 2;
    width: calc(100% / 6 - 20px);
    text-align: center;
}

.step-number {
    width: 60px;
    height: 60px;
    background: var(--primary-color);
    color: white;
    border-radius: 50%;
    font-size: 1.5rem;
    font-weight: bold;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 15px;
    box-shadow: 0 8px 15px rgba(30, 58, 138, 0.3);
    transition: var(--transition);
}

.management-step:hover .step-number {
    transform: scale(1.1);
    box-shadow: 0 12px 20px rgba(30, 58, 138, 0.4);
}

.management-step h3 {
    color: var(--primary-color);
    margin-bottom: 8px;
    font-size: 1rem;
}

.management-step p {
    font-size: 0.85rem;
    color: var(--gray-color);
}

/* 响应式设计 */
@media (max-width: 992px) {
    .process-chart, .management-process {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .process-chart:before, .management-process:before {
        display: none;
    }
    
    .process-step, .management-step {
        width: calc(50% - 30px);
        margin-bottom: 50px;
        padding-top: 60px;
    }
    
    .process-dot {
        display: none;
    }
    
    .timeline-step {
        flex-direction: column;
        text-align: center;
    }
    
    .timeline-icon {
        margin: 0 auto 20px;
    }
}

/* 合作品牌预览样式 */
.partners-preview {
    padding: 5rem 0;
    background-color: #f8fafc;
}

.section-description {
    text-align: center;
    font-size: 1.1rem;
    color: var(--gray-color);
    margin-bottom: 3rem;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.partners-slider {
    margin-bottom: 3rem;
}

.partner-logos {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 30px;
    max-width: 1000px;
    margin: 0 auto;
}

.partner-logo {
    background-color: white;
    border-radius: 10px;
    padding: 20px;
    text-align: center;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    transition: var(--transition);
    border: 1px solid #e5e7eb;
}

.partner-logo:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.15);
}

.partner-logo img {
    width: 100%;
    height: 80px;
    object-fit: contain;
    margin-bottom: 10px;
}

.partner-logo p {
    font-size: 0.9rem;
    color: var(--gray-color);
    margin: 0;
    font-weight: 500;
}

.main-logo {
    width: 200px;
    height: auto;
}

/* 页脚样式 */
footer {
    background-color: var(--footer-bg);
    color: var(--footer-text);
    padding: 3rem 0;
    margin-top: 0; /* 移除底部白条 */
}

.footer-content {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 30px;
}

.footer-logo {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
}

.footer-logo img {
    height: 40px;
    margin-bottom: 5px;
    filter: brightness(0) invert(1);
}

.footer-logo .logo-en {
    height: 20px;
}

.footer-info {
    max-width: 400px;
}

.footer-info p {
    margin-bottom: 10px;
    opacity: 0.8;
}

.footer-contact h3 {
    margin-bottom: 15px;
    color: var(--accent-color);
}

.footer-contact p {
    margin-bottom: 10px;
    display: flex;
    align-items: center;
}

.footer-contact i {
    margin-right: 10px;
    color: var(--accent-color);
}

/* 新增的页脚两栏布局样式 */
.contact-branches {
    display: flex;
    gap: 40px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.branch-info {
    flex: 1;
    min-width: 250px;
    background-color: rgba(255, 255, 255, 0.05);
    padding: 20px;
    border-radius: 8px;
    border-left: 4px solid var(--accent-color);
    transition: var(--transition);
}

.branch-info:hover {
    background-color: rgba(255, 255, 255, 0.08);
    transform: translateY(-2px);
}

.branch-info h4 {
    color: var(--accent-color);
    margin-bottom: 15px;
    font-size: 1.1rem;
    font-weight: 600;
    display: flex;
    align-items: center;
}

.branch-info h4 i {
    margin-right: 8px;
    font-size: 1rem;
}

.branch-info p {
    margin-bottom: 8px;
    display: flex;
    align-items: center;
    opacity: 0.9;
}

.branch-info p i {
    margin-right: 10px;
    color: var(--accent-color);
    width: 16px;
    text-align: center;
}

.shared-contact {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    margin-top: 10px;
}

.shared-contact p {
    margin: 0;
    font-size: 1.1rem;
    font-weight: 500;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent-color);
}

.shared-contact p i {
    margin-right: 10px;
    font-size: 1.2rem;
}

/* 响应式设计 */
@media (max-width: 992px) {
    .about-content {
        flex-direction: column;
    }
    
    .hero h1 {
        font-size: 2.5rem;
    }
}

@media (max-width: 768px) {
    header {
        height: auto;
    }
    
    header .container {
        flex-direction: column;
        padding: 10px 20px;
    }
    
    .logo {
        margin-bottom: 10px;
    }
    
    nav ul {
        margin-top: 10px;
        flex-wrap: wrap;
        justify-content: center;
    }
    
    nav ul li {
        margin: 5px 10px;
    }
    
    .hero {
        height: 70vh;
        margin-top: 120px; /* 调整移动端顶部间距 */
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .footer-content {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }
    
    .footer-logo {
        align-items: center;
    }
    
    /* 移动端页脚两栏布局调整 */
    .contact-branches {
        flex-direction: column;
        gap: 20px;
    }
    
    .branch-info {
        min-width: 100%;
        text-align: left;
    }
    
    .shared-contact p {
        flex-direction: column;
        gap: 5px;
    }
    
    .shared-contact p i {
        margin-right: 0;
        margin-bottom: 5px;
    }
}

@media (max-width: 576px) {
    .hero h1 {
        font-size: 2rem;
    }
    
    .hero p {
        font-size: 1rem;
    }
    
    .service-grid,
    .case-grid {
        grid-template-columns: 1fr;
    }
}

/* 添加新的样式类 */
.full-width-img {
    width: 100%;
    height: auto;
    display: block;
    margin: 0 auto;
    border-radius: 8px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

.timeline-image {
    width: 100%;
    max-width: 1000px;
    margin: 2rem auto;
}

.partners-showcase {
    width: 100%;
    max-width: 1200px;
    margin: 2rem auto;
}

.brand-showcase {
    width: 100%;
    max-width: 1200px;
    margin: 2rem auto;
}

/* 页面头部样式调整 */
.page-header {
    height: 300px;
    background-image: url('../img/hero_background.jpg');
    background-size: cover;
    background-position: center;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    color: white;
    position: relative;
    margin-top: 100px;
}

.page-header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.6);
}

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

.page-header h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.breadcrumb {
    display: flex;
    justify-content: center;
}

.breadcrumb li {
    margin: 0 10px;
}

.breadcrumb a {
    color: rgba(255, 255, 255, 0.8);
}

.breadcrumb a:hover {
    color: white;
}

/* 设计理念样式 */
.design-philosophy {
    padding: 5rem 0;
    background-color: white;
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-header h2 {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.section-header p {
    font-size: 1.1rem;
    color: var(--gray-color);
}

.philosophy-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.philosophy-item {
    text-align: center;
    padding: 2rem;
    background-color: white;
    border-radius: 10px;
    box-shadow: var(--box-shadow);
    transition: var(--transition);
}

.philosophy-item:hover {
    transform: translateY(-10px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
}

.philosophy-item .icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    font-size: 2rem;
}

.philosophy-item h3 {
    font-size: 1.3rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.philosophy-item p {
    color: var(--gray-color);
    line-height: 1.6;
}

/* 案例筛选按钮样式 */
.case-filters {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 15px;
    margin-bottom: 3rem;
}

.filter-btn {
    padding: 12px 24px;
    background-color: white;
    border: 2px solid var(--primary-color);
    border-radius: 25px;
    color: var(--primary-color);
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 500;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.filter-btn:hover,
.filter-btn.active {
    background: linear-gradient(45deg, var(--primary-color), var(--secondary-color));
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 5px 20px rgba(0,0,0,0.2);
}

/* 案例筛选功能 */
.case-item {
    transition: all 0.3s ease;
}

.case-item.hidden {
    display: none;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .page-header {
        height: 250px;
    }
    
    .page-header h1 {
        font-size: 2.2rem;
    }
    
    .philosophy-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .case-filters {
        gap: 10px;
    }
    
    .filter-btn {
        padding: 10px 20px;
        font-size: 0.85rem;
    }
    
    .case-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .case-item {
        height: 250px;
    }
}

@media (max-width: 480px) {
    .case-filters {
        flex-direction: column;
        align-items: center;
    }
    
    .filter-btn {
        width: 220px;
        text-align: center;
        margin-bottom: 5px;
    }
}

/* 主题切换按钮样式 */
.theme-toggle {
    position: relative;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: transparent;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-color);
    font-size: 20px;
    transition: all 0.3s ease;
    margin-left: 20px;
    margin-right: 20px;
}

.theme-toggle:hover {
    background-color: rgba(0, 0, 0, 0.05);
}

[data-theme="dark"] .theme-toggle:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

/* 回到顶部按钮样式 */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background-color: #3b82f6;
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, visibility 0.3s ease, transform 0.3s ease;
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.4);
    z-index: 999;
    border: none;
}

.back-to-top.visible {
    opacity: 0.9;
    visibility: visible;
}

.back-to-top:hover {
    transform: translateY(-5px);
}

.back-to-top:active {
    transform: scale(0.95);
}

.back-to-top i {
    font-size: 20px;
}

/* 页面加载动画 */
.page-loader {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--bg-color);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 9999;
    transition: opacity 0.5s ease, visibility 0.5s ease;
}

.page-loader.fade-out {
    opacity: 0;
    visibility: hidden;
}

.loader-content {
    position: relative;
    width: 60px;
    height: 60px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.loader-circle {
    position: absolute;
    width: 100%;
    height: 100%;
    border: 4px solid transparent;
    border-top-color: #3b82f6;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* 深色模式下的特殊样式调整 */
[data-theme="dark"] .about-section:nth-child(even),
[data-theme="dark"] .operation-section:nth-child(even),
[data-theme="dark"] .contact-section:nth-child(even),
[data-theme="dark"] .partners-section:nth-child(even) {
    background-color: var(--section-bg);
}

[data-theme="dark"] .about-section:nth-child(odd),
[data-theme="dark"] .operation-section:nth-child(odd),
[data-theme="dark"] .contact-section:nth-child(odd),
[data-theme="dark"] .partners-section:nth-child(odd) {
    background-color: var(--section-alt-bg);
}

[data-theme="dark"] .about-card,
[data-theme="dark"] .contact-card,
[data-theme="dark"] .project-card,
[data-theme="dark"] .partner-card,
[data-theme="dark"] .case-item {
    background-color: var(--card-bg);
    border-color: var(--border-color);
}

[data-theme="dark"] .footer-info p {
    color: var(--footer-text);
}

[data-theme="dark"] footer {
    background-color: #0D1117; /* 使用一个与页面主体明显区分的深色 */
    color: #f3f4f6;
    box-shadow: 0 -5px 25px rgba(0, 0, 0, 0.2);
    border-top: 1px solid rgba(59, 130, 246, 0.2); /* 添加微妙的边框 */
}

/* 确保深色模式下所有文字可见 */
[data-theme="dark"] .section-title,
[data-theme="dark"] h1, 
[data-theme="dark"] h2, 
[data-theme="dark"] h3, 
[data-theme="dark"] h4, 
[data-theme="dark"] h5, 
[data-theme="dark"] h6 {
    color: #f3f4f6;
}

[data-theme="dark"] p,
[data-theme="dark"] li,
[data-theme="dark"] span {
    color: #e5e7eb;
}

[data-theme="dark"] .about-section:nth-child(even),
[data-theme="dark"] .operation-section:nth-child(even),
[data-theme="dark"] .contact-section:nth-child(even),
[data-theme="dark"] .partners-section:nth-child(even) {
    background-color: var(--section-bg);
}

[data-theme="dark"] .about-section:nth-child(odd),
[data-theme="dark"] .operation-section:nth-child(odd),
[data-theme="dark"] .contact-section:nth-child(odd),
[data-theme="dark"] .partners-section:nth-child(odd) {
    background-color: var(--section-alt-bg);
}

/* 调整导航栏布局 */
header .container {
    display: flex;
    justify-content: flex-start;
    align-items: center;
    padding: 15px 20px;
    height: 100%;
}

.logo {
    margin-right: 30px;
}

nav {
    flex-grow: 1;
    display: flex;
    align-items: center;
}

nav ul {
    display: flex;
    margin-left: auto;
}

.theme-toggle {
    margin-left: 20px;
    margin-right: 20px;
}

/* 深色模式下卡片和其他元素的调整 */
[data-theme="dark"] .about-card,
[data-theme="dark"] .contact-card,
[data-theme="dark"] .project-card,
[data-theme="dark"] .partner-card,
[data-theme="dark"] .case-item,
[data-theme="dark"] .service-item {
    background-color: var(--card-bg);
    border-color: var(--border-color);
}

[data-theme="dark"] .contact-form-container,
[data-theme="dark"] .map-container,
[data-theme="dark"] .organization-chart {
    background-color: var(--card-bg);
}

/* 修复工程页面（engineering）在黑夜模式下模块的背景色差 */
[data-theme="dark"] .design-philosophy {
    background-color: var(--section-bg) !important;
}

[data-theme="dark"] .design-process {
    background-color: var(--section-alt-bg) !important;
}

[data-theme="dark"] .engineering-process {
    background-color: var(--section-bg) !important;
}

[data-theme="dark"] .cases {
    background-color: var(--section-alt-bg) !important;
}

/* 修复工程流程图在深色模式下的样式 */
[data-theme="dark"] .process-timeline:before {
    background-color: #374151;
}

[data-theme="dark"] .timeline-icon {
    background-color: var(--primary-color);
    box-shadow: 0 10px 25px rgba(59, 130, 246, 0.3);
}

[data-theme="dark"] .timeline-step .timeline-content {
    background-color: var(--card-bg);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
}

/* 修复设计流程图在深色模式下的样式 */
[data-theme="dark"] .process-chart:before {
    background-color: #374151;
}

[data-theme="dark"] .process-dot {
    background-color: #374151;
    border: 2px solid #4b5563;
}

[data-theme="dark"] .process-icon {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    box-shadow: 0 10px 20px rgba(59, 130, 246, 0.3);
}

/* 修复发展历程在深色模式下的样式 */
[data-theme="dark"] .timeline {
    background: linear-gradient(135deg, #111827 0%, #1f2937 100%) !important;
    box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.3);
}

[data-theme="dark"] .timeline-item .timeline-content {
    background-color: var(--card-bg);
    color: var(--text-color);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
}

[data-theme="dark"] .timeline-item .timeline-content h3 {
    color: #f3f4f6;
}

[data-theme="dark"] .timeline-item .timeline-content h4 {
    color: var(--accent-color);
}

[data-theme="dark"] .timeline-item .timeline-content p {
    color: #d1d5db;
}

/* 适配小屏幕 */
@media (max-width: 768px) {
    header .container {
        justify-content: space-between;
    }
    
    .theme-toggle {
        margin-left: 10px;
        margin-right: 10px;
    }
}

/* 合作品牌特定样式 */
.partner-image {
    background-color: #fff;
    border-radius: 5px;
    padding: 10px;
    transition: var(--transition);
}

[data-theme="dark"] .partner-logo p {
    color: #f3f4f6;
}

[data-theme="dark"] .partner-image {
    background-color: #1f2937;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
    filter: brightness(0.9) contrast(1.1);
}

/* 深色模式下的额外修复 - 案例展示区域 */
[data-theme="dark"] .cases {
    background-color: var(--section-bg);
}

[data-theme="dark"] .case-image {
    background-color: var(--card-bg);
}

/* 深色模式下的额外修复 - 服务区域 */
[data-theme="dark"] .services {
    background-color: var(--section-alt-bg);
}

/* 深色模式下的额外修复 - 公司简介区域 */
[data-theme="dark"] .about-preview {
    background-color: var(--section-bg);
}

/* 深色模式下的额外修复 - 合作品牌区域 */
[data-theme="dark"] .partners-preview {
    background-color: var(--section-alt-bg);
}

/* 深色模式下的额外修复 - about页面的企业概况等部分 */
[data-theme="dark"] .about-section {
    background-color: var(--section-bg);
}

[data-theme="dark"] .about-section:nth-child(even) {
    background-color: var(--section-alt-bg);
}

[data-theme="dark"] .about-content {
    background-color: transparent;
}

[data-theme="dark"] .about-text {
    color: var(--text-color);
}

[data-theme="dark"] .about-text p {
    color: var(--text-color);
}

[data-theme="dark"] .certificates-container {
    background-color: transparent;
}

/* 证书导航按钮在深色模式下的样式 */
[data-theme="dark"] .cert-nav {
    background: rgba(31, 41, 55, 0.8);
    color: var(--accent-color);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

[data-theme="dark"] .cert-nav:hover {
    background: rgba(31, 41, 55, 1);
    color: var(--primary-color);
}

/* 深色模式下的额外修复 - 组织架构、管理体系等 */
[data-theme="dark"] .operation-model {
    background-color: transparent;
}

[data-theme="dark"] .operation-model-item {
    background-color: var(--card-bg);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
}

[data-theme="dark"] .organization-chart {
    background-color: var(--card-bg);
}

[data-theme="dark"] .management-system {
    background-color: transparent;
}

[data-theme="dark"] .management-card {
    background-color: var(--card-bg);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
}

[data-theme="dark"] .management-card-header {
    background-color: var(--primary-color);
}

[data-theme="dark"] .management-card-body {
    color: var(--text-color);
}

/* 确保所有区域在深色模式下都有正确的文字颜色 */
[data-theme="dark"] .case-overlay {
    background: linear-gradient(to top, rgba(0, 0, 0, 0.8), rgba(0, 0, 0, 0.4), rgba(0, 0, 0, 0.2));
}

/* 修复团队成员卡片 */
[data-theme="dark"] .team-member {
    background-color: var(--card-bg);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
}

[data-theme="dark"] .team-member-info {
    color: var(--text-color);
}

/* 深色模式下对图片的处理 */
[data-theme="dark"] img:not(.no-dark-filter) {
    filter: brightness(0.9);
}

[data-theme="dark"] .logo img {
    filter: none;
}

/* 全局修复合作品牌卡片背景 */
[data-theme="dark"] .partner-logo {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
}

[data-theme="dark"] .partner-logo img {
    filter: brightness(0.9) contrast(1.1);
}

/* 移除任何可能的透明背景设置 */
header.scrolled {
    background-color: var(--header-bg) !important;  /* 保持使用CSS变量 */
}

[data-theme="dark"] header.scrolled {
    background-color: #0f172a !important;
}

[data-theme="dark"] .filter-btn {
    background-color: var(--card-bg);
    border-color: var(--primary-color);
    color: var(--primary-color);
}

[data-theme="dark"] .filter-btn:hover,
[data-theme="dark"] .filter-btn.active {
    background: linear-gradient(45deg, var(--primary-color), var(--secondary-color));
    color: white;
}