.fixed-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: 8px 12px;
    display: flex;
    justify-content: center;
    gap: 8px;
    z-index: 1000;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
    flex-wrap: wrap;
    transition: transform 0.3s ease;
}

.fixed-nav.hidden {
    transform: translateY(-100%);
}

.nav-btn {
    background: rgba(255, 255, 255, 0.95);
    color: #667eea;
    border: none;
    padding: 8px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-family: "Microsoft YaHei", sans-serif;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
    font-weight: bold;
    flex: 1;
    min-width: 80px;
    text-align: center;
}

.nav-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
    background: white;
}

.nav-btn:active {
    transform: translateY(0);
}

body {
    padding-top: 80px;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .fixed-nav {
        padding: 6px 8px;
        gap: 6px;
    }
    
    .nav-btn {
        padding: 6px 10px;
        font-size: 10px;
        min-width: 70px;
    }
    
    body {
        padding-top: 70px;
    }
}

/* 手机设备 */
@media (max-width: 480px) {
    .fixed-nav {
        flex-wrap: wrap;
        gap: 4px;
        padding: 6px 8px;
    }
    
    .nav-btn {
        flex: 1 1 calc(50% - 4px);
        min-width: 0;
        font-size: 10px;
        padding: 8px 10px;
        border-radius: 20px;
        min-height: 40px;
        display: flex;
        align-items: center;
        justify-content: center;
    }
    
    body {
        padding-top: 80px;
    }
}