:root {
    --primary: #009c75;
    --primary-light: #00c89b;
    --primary-dark: #007a5c;
    --accent: #fee9c5;
    --text-primary: #333333;
    --text-secondary: #666666;
    --text-light: #888888;
    --border: #e0e0e0;
    --background: #ffffff;
    --card-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
}

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

body {
    font-family: 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
    color: var(--text-primary);
    background-color: #f9f9f9;
    line-height: 1.6;
    padding-bottom: 80px;
}

/* 头部样式 */
header {
    background-color: var(--background);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 15px 20px;
    display: flex;
    flex-direction: column;
}

.header-top {
    display: flex;
    align-items: center;
    width: 100%;
}

.logo {
    display: flex;
    align-items: center;
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--primary);
    text-decoration: none;
    white-space: nowrap;
    margin-right: 20px;
}

.logo i {
    margin-right: 10px;
}

.search-container {
    display: flex;
    align-items: center;
    background-color: #f0f0f0;
    border-radius: 30px;
    padding: 8px 15px;
    min-width: 200px;
    flex-grow: 1;
    margin-left: 20px;
}

.search-container input {
    border: none;
    background: transparent;
    padding: 5px 10px;
    width: 100%;
    outline: none;
    font-size: 0.95rem;
}

.search-container button {
    background: transparent;
    border: none;
    color: var(--text-light);
    cursor: pointer;
    transition: color 0.3s;
}

.search-container button:hover {
    color: var(--primary);
}

.nav-links {
    display: flex;
    gap: 15px;
    margin-top: 15px;
    overflow-x: auto;
    white-space: nowrap;
    width: 100%;
    padding-bottom: 5px;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 500;
    position: relative;
    padding: 5px 0;
    transition: color 0.3s;
}

.nav-links a:hover {
    color: var(--primary);
}

.nav-links a.active {
    color: var(--primary);
}

.nav-links a.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background-color: var(--primary);
    border-radius: 3px;
}

/* 底部导航 */
.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    display: flex;
    justify-content: space-around;
    background-color: white;
    padding: 10px 0;
    box-shadow: 0 -2px 5px rgba(0,0,0,0.1);
}

.nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-decoration: none;
    color: #009c75;
    font-size: 12px;
    position: relative;
}

.nav-icon {
    width: 24px;
    height: 24px;
    margin-bottom: 4px;
}

.badge {
    position: absolute;
    top: -5px;
    right: -5px;
    background-color: red;
    color: white;
    border-radius: 50%;
    width: 16px;
    height: 16px;
    font-size: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .header-container {
        padding: 10px 15px;
    }
    
    .logo {
        font-size: 1.5rem;
        margin-right: 10px;
    }
    
    .search-container {
        margin-left: 10px;
        min-width: 150px;
    }
}

@media (max-width: 480px) {
    .articles-grid {
        grid-template-columns: 1fr;
    }
    
    .category-btn {
        padding: 6px 12px;
        font-size: 0.8rem;
    }
}