/* 基础重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f8f9fa;
    scroll-behavior: smooth; /* 启用平滑滚动 */
}

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

/* 工具类 */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* 头部样式 */
.header {
    background-color: #7d0000;
    color: white;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

.logo {
    height: 40px;
    width: auto;
}

.nav {
    display: flex;
    gap: 2rem;
}

.nav-link {
    color: white;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
    padding: 0.5rem 0;
    border-bottom: 2px solid transparent;
}

.nav-link:hover,
.nav-link.active {
    color: #ffd700;
    border-bottom-color: #ffd700;
}

.menu-toggle {
    display: none;
    background: none;
    border: none;
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
}

/* 英雄区域 */
.hero {
    background: linear-gradient(135deg, #7d0000 0%, #a00000 100%);
    color: white;
    text-align: center;
    padding: 120px 20px 80px;
    margin-top: 70px; /* 预留头部高度 */
}

.hero-content h1 {
    font-size: 2.8rem;
    margin-bottom: 1rem;
    font-weight: 700;
}

.hero-content p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    opacity: 0.9;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.cta-button {
    display: inline-block;
    background-color: white;
    color: #7d0000;
    padding: 12px 30px;
    border-radius: 30px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.cta-button:hover {
    background-color: transparent;
    color: white;
    border-color: white;
}

/* 通用区块样式 */
.section {
    padding: 80px 0;
}

.section-title {
    text-align: center;
    font-size: 2.2rem;
    color: #7d0000;
    margin-bottom: 1.5rem;
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 80px;
    height: 4px;
    background-color: #7d0000;
    margin: 15px auto 30px;
    border-radius: 2px;
}

.section-subtitle {
    text-align: center;
    font-size: 1.1rem;
    color: #666;
    margin-bottom: 3rem;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

/* 关于我们 */
.about-content {
    max-width: 800px;
    margin: 0 auto;
    font-size: 1.1rem;
    text-align: justify;
}

.about-content p {
    margin-bottom: 1.5rem;
}

/* 使用场景网格 */
.use-cases-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
}

.use-case-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.use-case-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.15);
}

.use-case-image {
    width: 100%;
    height: 180px;
	display:none;
    object-fit: cover;
    background-color: #e0e0e0; /* 占位背景色 */
}

.use-case-content {
    padding: 1.5rem;
}

.use-case-title {
    font-size: 1.2rem;
    color: #7d0000;
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.use-case-desc {
    color: #555;
    font-size: 0.95rem;
    line-height: 1.5;
}

/* 成功案例网格 */
.stories-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 2rem;
}

.story-card {
    background: white;
    border-radius: 12px;
    padding: 2rem;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.story-client {
    font-weight: 600;
    color: #7d0000;
    margin-bottom: 0.5rem;
    font-size: 1.1rem;
}

.story-problem,
.story-solution,
.story-result {
    margin-bottom: 1rem;
}

.story-problem h4,
.story-solution h4,
.story-result h4 {
    font-size: 1rem;
    color: #333;
    margin-bottom: 0.3rem;
    font-weight: 600;
}

.story-problem p,
.story-solution p,
.story-result p {
    color: #666;
    font-size: 0.95rem;
    line-height: 1.5;
}

/* 联系我们 */
.contact-info {
    text-align: center;
    margin-bottom: 1.5rem;
}

.contact-info p {
    margin-bottom: 1rem;
    font-size: 1.1rem;
}

.contact-info a {
    color: #7d0000;
    text-decoration: none;
    font-weight: 600;
}

.contact-info a:hover {
    text-decoration: underline;
}

.contact-note {
    text-align: center;
    color: #666;
    font-style: italic;
    max-width: 600px;
    margin: 0 auto;
}

/* 页脚 */
.footer {
    background-color: #333;
    color: white;
    text-align: center;
    padding: 2rem 0;
    margin-top: 80px;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .header-container {
        padding: 0.8rem 0;
    }

    .nav {
        display: none;
        flex-direction: column;
        background-color: #7d0000;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        padding: 1rem 0;
        box-shadow: 0 5px 10px rgba(0, 0, 0, 0.1);
    }

    .nav.active {
        display: flex;
    }

    .nav-link {
        display: block;
        padding: 0.8rem 2rem;
        border-bottom: 1px solid rgba(255, 255, 255, 0.1);
        border-bottom-width: 0;
    }

    .nav-link:first-child {
        border-top: none;
    }

    .menu-toggle {
        display: block;
    }

    .hero-content h1 {
        font-size: 2.2rem;
    }

    .hero-content p {
        font-size: 1.1rem;
    }

    .section {
        padding: 60px 0;
    }

    .section-title {
        font-size: 1.8rem;
    }

    .use-cases-grid,
    .stories-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .story-card {
        padding: 1.5rem;
    }
}

@media (min-width: 769px) and (max-width: 1024px) {
    .use-cases-grid {
        grid-template-columns: repeat(2, 1fr);
    }

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

/* 图片占位符动画（可选） */
.use-case-image.loading {
    background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
    background-size: 200% 100%;
    animation: loadingShimmer 1.5s infinite;
}

@keyframes loadingShimmer {
    0% {
        background-position: 200% 0;
    }
    100% {
        background-position: -200% 0;
    }
}