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

:root {
    --primary-blue: #1946BA;
    --text-gray: #8E8E93;
    --bg-gradient: linear-gradient(180deg, #1946BA 0%, #F5F5F5 200px);
    --card-bg: #FFFFFF;
    --border-radius: 20px;
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Microsoft YaHei', sans-serif;
    background: #F5F5F5;
    min-height: 100vh;
}

.page-container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 20px;
}

.header-bg {
    background: var(--bg-gradient);
    padding: 40px 20px 100px;
    text-align: center;
    position: relative;
}

.header-bg::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 80px;
    background: linear-gradient(to bottom, transparent, rgba(245, 245, 245, 0.3));
    pointer-events: none;
}

.header-title {
    font-size: 28px;
    font-weight: 600;
    color: #FFFFFF;
    margin-bottom: 10px;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.header-subtitle {
    font-size: 26px;
    font-weight: 600;
    color: #FFFFFF;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.15);
}

.main-card {
    background: var(--card-bg);
    border-radius: 20px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.08), 0 2px 10px rgba(0, 0, 0, 0.04);
    margin-top: -60px;
    padding: 30px;
    position: relative;
    border: 1px solid rgba(255, 255, 255, 0.8);
}

.announcement-bar {
    background: linear-gradient(135deg, #FFF5E6 0%, #FFE8CC 100%);
    border-radius: 12px;
    padding: 15px 20px;
    margin-bottom: 25px;
    display: flex;
    align-items: flex-start;
    gap: 12px;
}

.announcement-icon {
    width: 24px;
    height: 24px;
    color: #FF9500;
    flex-shrink: 0;
}

.announcement-text {
    color: #FF9500;
    font-size: 14px;
    line-height: 1.5;
    white-space: pre-line;
}

.category-tabs {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 30px;
    justify-content: center;
}

.category-tab-group {
    display: flex;
    gap: 10px;
}

.category-tab {
    min-width: 100px;
    max-width: 120px;
    width: 100px;
    padding: 12px 10px;
    border-radius: 12px;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    border: none;
    background: #F5F5F5;
    color: var(--text-gray);
    text-align: center;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    display: flex;
    align-items: center;
    justify-content: center;
}

.category-tab.long-text {
    font-size: 13px;
    padding: 12px 8px;
}

.category-tab.active {
    background: var(--primary-blue);
    color: #FFFFFF;
}

.category-tab:hover:not(.active) {
    background: #E8E8E8;
}

.links-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 25px;
}

.link-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-decoration: none;
    color: inherit;
    transition: transform 0.2s ease;
    cursor: pointer;
}

.link-item:hover {
    transform: translateY(-5px);
}

.link-icon-wrapper {
    width: 80px;
    height: 80px;
    border-radius: 16px;
    background: #F8F9FA;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 12px;
    overflow: hidden;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.link-icon-wrapper img {
    width: 50px;
    height: 50px;
    object-fit: contain;
}

.link-icon-wrapper svg {
    width: 40px;
    height: 40px;
    color: var(--primary-blue);
}

.link-title {
    font-size: 15px;
    color: #333333;
    text-align: center;
    font-weight: 500;
    line-height: 1.4;
    max-width: 100%;
    overflow: hidden;
    text-overflow: ellipsis;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
}

.footer {
    text-align: center;
    padding: 30px 20px;
    color: #999999;
    font-size: 13px;
}

.admin-link {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: var(--primary-blue);
    color: white;
    padding: 12px 24px;
    border-radius: 25px;
    text-decoration: none;
    font-size: 14px;
    box-shadow: 0 4px 15px rgba(25, 70, 186, 0.4);
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 8px;
}

.admin-link:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(25, 70, 186, 0.5);
}

.admin-link svg {
    width: 16px;
    height: 16px;
}

.category-content {
    display: none;
}

.category-content.active {
    display: block;
}