:root {
    /* CSS変数でグリッドの線を管理 */
    --grid-gap: 2px;
    --grid-color: #cccccc;
}

body {
    font-family: 'Helvetica Neue', Arial, sans-serif;
    margin: 20px;
    background-color: #f4f4f9;
    color: #333;
}

h1 {
    text-align: center;
    width: 100%;
}

.main-container {
    display: flex;
    justify-content: center;
    gap: 30px;
    width: 100%;
    flex-wrap: wrap;
}

.settings-panel {
    background-color: #fff;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    min-width: 280px;
}

.control-group {
    margin-bottom: 25px;
    border-bottom: 1px solid #eee;
    padding-bottom: 20px;
}

.control-group:last-child {
    border-bottom: none;
    padding-bottom: 0;
}

h2,
h3 {
    margin-top: 0;
}

.settings-panel label {
    display: block;
    margin: 10px 0 5px;
}

.toggle-label {
    display: flex;
    align-items: center;
    cursor: pointer;
}

.toggle-label input[type="checkbox"] {
    margin-right: 8px;
}

.settings-panel input[type="number"],
.settings-panel input[type="range"],
.settings-panel input[type="color"] {
    width: 100%;
    box-sizing: border-box;
    /* paddingを含めて幅を100%にする */
}

.settings-panel button {
    width: 100%;
    padding: 10px;
    background-color: #007bff;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 16px;
    margin-top: 10px;
}

.settings-panel button:hover {
    background-color: #0056b3;
}

.grid-preview {
    display: flex;
    /* グリッドが画面からはみ出した際に、左端から表示されるように変更 */
    justify-content: flex-start;
    align-items: flex-start;
    /* はみ出した部分を横スクロールできるようにする */
    overflow-x: auto;
    /* iOSでの慣性スクロールを有効にする */
    -webkit-overflow-scrolling: touch;
    /* スクロールバーのための余白を追加 */
    padding-bottom: 15px;
    /* 親要素の幅を超えないように設定 */
    max-width: 100%;
    box-sizing: border-box;
}

#grid-container {
    display: grid;
    background-color: var(--grid-color);
    gap: var(--grid-gap);
    padding: var(--grid-gap);
}

.grid-item {
    position: relative;
    overflow: hidden;
    background-color: #e9e9e9;
    width: 250px;
    height: 250px;
    cursor: pointer;
}

.image-container {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    cursor: grab;
}

.grid-item img {
    position: absolute;
    top: 50%;
    left: 50%;
    max-width: none;
    transform-origin: center center;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.grid-item img.loaded {
    opacity: 1;
}

.item-controls {
    position: absolute;
    bottom: 10px;
    left: 10px;
    right: 10px;
    background: rgba(255, 255, 255, 0.85);
    padding: 8px;
    border-radius: 5px;
    display: flex;
    flex-direction: column;
    align-items: center;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s, visibility 0.3s;
    pointer-events: none;
}

.grid-item:hover .item-controls {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
}

.item-controls input[type="file"] {
    display: none;
}

.item-controls label {
    background-color: #007bff;
    color: white;
    padding: 8px 12px;
    border-radius: 5px;
    cursor: pointer;
    text-align: center;
    margin-bottom: 8px;
    width: 90%;
    font-size: 14px;
}

.item-controls label:hover {
    background-color: #0056b3;
}

.item-controls input[type="range"] {
    width: 90%;
}