#upload-area.drag-over {
    border-color: #2563eb;
    background-color: #eff6ff;
}

#file-input {
    display: none;
}

.hidden {
    display: none !important;
}

.opacity-50 {
    opacity: 0.5;
}

.ad-slot {
    min-height: 90px;
}

/* 新增：模式提示样式 */
#mode-tip {
    background-color: #fff7e6;
    padding: 8px;
    border-radius: 4px;
    border: 1px solid #ffc107;
}

@media (max-width: 640px) {
    h1 {
        font-size: 1.8rem !important;
    }
    #upload-btn, #download-btn, #reset-btn {
        width: 100% !important;
        margin-bottom: 8px !important;
    }
}