/* 重置样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #fff;
}

/* 容器 */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 头部导航 */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: #fff;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    z-index: 1000;
    transition: all 0.3s ease;
}

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

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo img {
    width: 40px;
    height: 40px;
    border-radius: 8px;
    object-fit: cover;
}

.logo span {
    font-size: 1.25rem;
    font-weight: bold;
    color: #2563eb;
}

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

.nav-link {
    text-decoration: none;
    color: #666;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

.nav-link:hover,
.nav-link.active {
    color: #2563eb;
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    right: 0;
    height: 2px;
    background: #2563eb;
}

.mobile-menu-btn {
    display: none;
    cursor: pointer;
    font-size: 1.5rem;
    color: #666;
    padding: 0.5rem;
    border: none;
    background: none;
    transition: all 0.3s ease;
    z-index: 1001;
}

.mobile-menu-btn:hover {
    color: #2563eb;
}

.mobile-menu-btn .fas {
    transition: transform 0.3s ease;
}

/* 面包屑导航 */
.breadcrumb {
    background: #eff6ff;
    padding: 12px 0;
    border-bottom: 1px solid #e5e7eb;
    margin-top: 80px;
}

.breadcrumb-nav {
    font-size: 0.875rem;
    color: #666;
}

.breadcrumb-item.active {
    color: #2563eb;
    font-weight: 500;
}

/* 主要内容区域 */
main {
    min-height: calc(100vh - 200px);
}

.section {
    padding: 4rem 0;
}

.section-header {
    text-align: center;
    margin-bottom: 3rem;
}

.section-title {
    font-size: 2.5rem;
    font-weight: bold;
    color: #1e40af;
    margin-bottom: 1rem;
}

.section-subtitle {
    font-size: 1.125rem;
    color: #666;
    max-width: 600px;
    margin: 0 auto;
}

/* 按钮样式 */
.btn {
    display: inline-block;
    padding: 12px 24px;
    background: #2563eb;
    color: #fff;
    text-decoration: none;
    border-radius: 8px;
    font-weight: 500;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
}

.btn:hover {
    background: #1d4ed8;
    transform: translateY(-2px);
}

.btn-secondary {
    background: #f3f4f6;
    color: #374151;
}

.btn-secondary:hover {
    background: #e5e7eb;
}

/* 卡片样式 */
.card {
    background: #fff;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    padding: 2rem;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

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

/* 网格布局 */
.grid {
    display: grid;
    gap: 2rem;
}

.grid-2 {
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.grid-3 {
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

.grid-4 {
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
}

/* 页脚 */
.footer {
    background: #1f2937;
    color: #fff;
    padding: 3rem 0 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3,
.footer-section h4 {
    margin-bottom: 1rem;
    color: #f9fafb;
}

.footer-section p {
    color: #d1d5db;
    margin-bottom: 0.5rem;
}

.footer-section i {
    margin-right: 8px;
    color: #60a5fa;
}

.footer-bottom {
    border-top: 1px solid #374151;
    padding-top: 1rem;
    text-align: center;
    color: #9ca3af;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav {
        display: none !important;
        position: fixed;
        top: 80px;
        left: 0;
        right: 0;
        background: rgba(255, 255, 255, 0.98);
        backdrop-filter: blur(15px);
        box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
        z-index: 1000;
        padding: 1rem 0;
        border-top: 1px solid #e5e7eb;
        max-height: calc(100vh - 80px);
        overflow-y: auto;
    }
    
    .nav.mobile-open {
        display: block !important;
        animation: slideDown 0.3s ease-out;
    }
    
    .nav-link {
        display: block !important;
        padding: 1.2rem 2rem;
        border-bottom: 1px solid #f3f4f6;
        text-align: center;
        font-size: 1.1rem;
        font-weight: 500;
        color: #374151;
        transition: all 0.3s ease;
        position: relative;
    }
    
    .nav-link:last-child {
        border-bottom: none;
    }
    
    .nav-link:hover {
        background: #f9fafb;
        color: #2563eb;
        transform: translateX(5px);
    }
    
    .nav-link.active {
        background: #eff6ff;
        color: #2563eb;
        border-left: 4px solid #2563eb;
    }
    
    .mobile-menu-btn {
        display: flex !important;
        align-items: center;
        justify-content: center;
        width: 44px;
        height: 44px;
        border-radius: 8px;
        transition: all 0.3s ease;
        background: transparent;
        cursor: pointer;
    }
    
    .mobile-menu-btn:hover {
        background: #f3f4f6;
    }
    
    .mobile-menu-btn.active {
        background: #eff6ff;
        color: #2563eb;
    }
    
    .mobile-menu-btn.active .fas {
        transform: rotate(90deg);
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .container {
        padding: 0 15px;
    }
    
    .section {
        padding: 2rem 0;
    }
}

@media (max-width: 480px) {
    .nav {
        top: 70px;
        padding: 0.5rem 0;
    }
    
    .nav-link {
        padding: 1rem 1.5rem;
        font-size: 1rem;
    }
    
    .mobile-menu-btn {
        width: 40px;
        height: 40px;
        font-size: 1.3rem;
    }
    
    .section-title {
        font-size: 1.8rem;
    }
    
    .container {
        padding: 0 10px;
    }
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 动画效果 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInLeft {
    from {
        opacity: 0;
        transform: translateX(-30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes fadeInRight {
    from {
        opacity: 0;
        transform: translateX(30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.animate-fade-in-up {
    animation: fadeInUp 0.8s ease-out;
}

.animate-fade-in-left {
    animation: fadeInLeft 0.8s ease-out;
}

.animate-fade-in-right {
    animation: fadeInRight 0.8s ease-out;
}

/* 工具类 */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mb-1 { margin-bottom: 0.25rem; }
.mb-2 { margin-bottom: 0.5rem; }
.mb-3 { margin-bottom: 0.75rem; }
.mb-4 { margin-bottom: 1rem; }
.mb-5 { margin-bottom: 1.25rem; }
.mb-6 { margin-bottom: 1.5rem; }

.mt-1 { margin-top: 0.25rem; }
.mt-2 { margin-top: 0.5rem; }
.mt-3 { margin-top: 0.75rem; }
.mt-4 { margin-top: 1rem; }
.mt-5 { margin-top: 1.25rem; }
.mt-6 { margin-top: 1.5rem; }

.p-1 { padding: 0.25rem; }
.p-2 { padding: 0.5rem; }
.p-3 { padding: 0.75rem; }
.p-4 { padding: 1rem; }
.p-5 { padding: 1.25rem; }
.p-6 { padding: 1.5rem; }