.drop-zone {
    border: 3px dashed var(--border-color);
    border-radius: 8px;
    padding: 30px;
    text-align: center;
    color: #888;
    transition: background-color 0.3s, border-color 0.3s;
    margin-bottom: 30px;
}
.drop-zone.drag-over {
    border-color: var(--primary-color);
    background-color: #e9f5ff;
}
.drop-zone i {
    font-size: 3rem;
    margin-bottom: 15px;
    display: block;
}
.drop-zone .button {
    margin: 10px 0;
}
.file-name {
    margin-top: 15px;
    font-weight: bold;
    color: var(--text-color);
    word-break: break-all;
}
#watermark-file-name {
    display: none !important;
}
.image-options-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 20px;
    margin-bottom: 20px;
}
@media (min-width: 768px) {
    .image-options-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}
.options-fieldset {
    border: 1px solid var(--border-color);
    border-radius: 5px;
    padding: 15px;
}
.options-fieldset legend {
    font-weight: bold;
    padding: 0 10px;
}
.options-fieldset legend label {
    cursor: pointer;
}
.options-fieldset .sub-options {
    margin-top: 10px;
    padding-top: 10px;
    border-top: 1px solid #eee;
}
.options-fieldset label {
    display: block;
    margin-bottom: 5px;
}
.radio-group {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
}
.resize-input-group {
    display: flex;
    align-items: center;
    gap: 5px;
    margin-bottom: 5px;
}
.resize-input-group label {
    margin-bottom: 0;
    flex-shrink: 0;
}
.resize-input-group input {
    width: 80px;
    padding: 5px;
}
.transform-options-container {
    display: flex;
    flex-direction: column;
    gap: 10px;
}
.flip-group {
    display: flex;
    gap: 15px;
}
#quality-options {
    display: none;
}
#quality-options input[type="range"] {
    vertical-align: middle;
}
.log-area {
    margin-top: 20px;
}
.log-area textarea {
    width: 100%;
    resize: vertical;
    font-family: 'Courier New', Courier, monospace;
    font-size: 0.9rem;
    background-color: #f8f9fa;
    border: 1px solid var(--border-color);
    padding: 10px;
}
.advanced-options-details {
    margin-top: 20px;
    border: 1px solid var(--border-color);
    border-radius: 5px;
}
.advanced-options-details summary {
    font-weight: bold;
    font-size: 1.1rem;
    padding: 15px;
    cursor: pointer;
    background-color: #f8f9fa;
}
.advanced-options-details[open] summary {
    border-bottom: 1px solid var(--border-color);
}
.advanced-options-content {
    padding: 20px;
    display: grid;
    grid-template-columns: 1fr;
    gap: 20px;
}
.prefix-input-group {
    display: flex;
    gap: 10px;
}
.prefix-input-group input {
    flex-grow: 1;
    padding: 8px;
}
.watermark-file-selector {
    display: flex;
    gap: 10px;
    margin-bottom: 5px;
}
.watermark-layout {
    display: grid;
    grid-template-columns: 1fr;
    gap: 20px;
}
@media (min-width: 600px) {
    .watermark-layout {
        grid-template-columns: 1fr auto;
    }
}
.watermark-controls {
    display: flex;
    flex-direction: column;
    gap: 10px;
}
.watermark-preview-container {
    display: flex;
    align-items: center;
    justify-content: center;
    background: repeating-conic-gradient(#eee 0% 25%, #fff 0% 50%) 50% / 20px 20px;
    border: 1px dashed #ccc;
    min-height: 100px;
    padding: 10px;
    min-width: 200px;
}
.watermark-preview-container img {
    max-width: 150px;
    max-height: 150px;
    display: none;
}
.button-small {
    padding: 5px 10px;
    font-size: 0.9rem;
}