:root {
    --primary-color: #4a6bff;
    --secondary-color: #6c757d;
    --dark-color: #343a40;
    --light-color: #f8f9fa;
    --border-color: #dee2e6;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

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

body {
    font-family: 'Roboto', sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f5f7fa;
    padding: 20px;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    background: white;
    border-radius: 8px;
    box-shadow: var(--shadow);
    padding: 25px;
    overflow: hidden;
}

h1 {
    color: var(--dark-color);
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 10px;
}

h1 i {
    color: var(--primary-color);
}

h3 {
    margin: 15px 0 10px;
    color: var(--dark-color);
    display: flex;
    align-items: center;
    gap: 8px;
}

h3 i {
    color: var(--primary-color);
    font-size: 0.9em;
}

.upload-section {
    margin-bottom: 25px;
    text-align: center;
}

#image-upload {
    display: none;
}

.upload-btn {
    display: inline-block;
    padding: 10px 20px;
    background-color: var(--primary-color);
    color: white;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 500;
}

.upload-btn:hover {
    background-color: #3a56d4;
    transform: translateY(-2px);
}

.upload-btn i {
    margin-right: 8px;
}

.editor-container {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.image-preview {
    width: 100%;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    overflow: hidden;
    background: #f0f0f0;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 300px;
}

#image-canvas {
    max-width: 100%;
    max-height: 600px;
    display: block;
}

.controls {
    width: 100%;
    padding: 15px;
    background: var(--light-color);
    border-radius: 4px;
    border: 1px solid var(--border-color);
}

.control-group {
    margin-bottom: 25px;
    padding-bottom: 15px;
    border-bottom: 1px solid var(--border-color);
}

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

.slider-control {
    margin-bottom: 15px;
}

.slider-control label {
    display: block;
    margin-bottom: 5px;
    font-weight: 500;
}

.slider-control input[type="range"] {
    width: 100%;
    height: 8px;
    -webkit-appearance: none;
    background: #ddd;
    border-radius: 4px;
    outline: none;
    margin-bottom: 5px;
}

.slider-control input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 18px;
    height: 18px;
    background: var(--primary-color);
    border-radius: 50%;
    cursor: pointer;
}

.slider-control span {
    display: inline-block;
    width: 40px;
    text-align: right;
    font-weight: 500;
}

.curve-controls {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
    justify-content: space-between;
}

.curve-container {
    flex: 1 1 45%;
    min-width: 200px;
    text-align: center;
    margin-bottom: 15px;
}

.curve-container canvas {
    border: 1px solid var(--border-color);
    border-radius: 4px;
    background: white;
    margin-bottom: 5px;
    width: 100%;
    height: auto;
}

.curve-container label {
    font-size: 0.9em;
    color: var(--secondary-color);
    display: block;
}

.action-buttons {
    display: flex;
    gap: 15px;
    margin-top: 25px;
    flex-wrap: wrap;
}

.btn {
    padding: 10px 20px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-weight: 500;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 8px;
}

.btn i {
    font-size: 0.9em;
}

.btn.primary {
    background-color: var(--primary-color);
    color: white;
}

.btn.primary:hover {
    background-color: #3a56d4;
}

.btn:not(.primary) {
    background-color: var(--light-color);
    color: var(--secondary-color);
    border: 1px solid var(--border-color);
}

.btn:not(.primary):hover {
    background-color: #e9ecef;
}

.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: transparent; /* 背景を透明に変更 */
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    display: none;
}

.loading-spinner {
    border: 5px solid #f3f3f3;
    border-top: 5px solid var(--primary-color);
    border-radius: 50%;
    width: 50px;
    height: 50px;
    animation: spin 1s linear infinite;
    margin-bottom: 15px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.2); /* スピナーに影を追加 */
}

.loading-text {
    color: var(--dark-color); /* テキスト色をダークに変更 */
    font-size: 1.2em;
    background-color: rgba(255,255,255,0.7); /* テキスト背景を半透明白に */
    padding: 5px 10px;
    border-radius: 4px;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

#apply-btn {
    background-color: #28a745;
}

#apply-btn:hover {
    background-color: #218838;
}

#download-btn {
    background-color: var(--secondary-color);
    color: white;
}

#download-btn:hover {
    background-color: #5a6268;
}

@media (max-width: 768px) {
    .curve-container {
        flex: 1 1 100%;
    }
    
    .action-buttons {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
        justify-content: center;
    }
}