body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    text-align: center;
    background-color: #f0f2f5;
    color: #333;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 20px;
}

h2 {
    color: #1a73e8;
    margin-bottom: 20px;
}

/* 新しいコンテナのスタイル */
.main-container {
    display: flex;
    flex-direction: row; 
    gap: 30px; 
    align-items: flex-start; 
    width: 90%; 
    max-width: 1200px; 
    margin: 0 auto; 
}

.controls {
    display: flex;
    flex-direction: column; 
    gap: 15px;
    background: #fff;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    flex: 0 0 300px; 
}

.input-group {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
}

label {
    font-weight: 600;
    margin-bottom: 5px;
}

input[type="number"] {
    padding: 8px;
    border: 1px solid #ccc;
    border-radius: 4px;
    font-size: 14px;
    width: 100px;
}

input[type="color"] {
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
    background-color: transparent;
    border: 1px solid #ccc;
    border-radius: 4px;
    width: 60px;
    height: 30px;
    padding: 0;
    cursor: pointer;
}

input[type="color"]::-webkit-color-swatch-wrapper {
    padding: 0;
}
input[type="color"]::-webkit-color-swatch {
    border: none;
    border-radius: 3px;
}

button {
    padding: 10px 15px;
    border: none;
    border-radius: 4px;
    background-color: #4285f4;
    color: white;
    font-size: 16px;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

button:hover {
    background-color: #357ae8;
}

.button-group {
    display: flex;
    gap: 10px;
    align-self: flex-end;
}

/* ★モバイル対応のためのレスポンシブなSVGコンテナ設定 */
#svgContainer {
    flex-grow: 1; 
    border: 2px solid #ddd;
    background-color: #fff;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
    border-radius: 8px;
    overflow: hidden;
    
    position: relative;
    padding-bottom: 100%; 
    height: 0; 
    min-width: 250px; 
}

/* SVGはコンテナにフィット */
svg {
    position: absolute; 
    top: 0;
    left: 0;
    width: 100%; 
    height: 100%; 
    display: block;
}

/* 画面幅が小さい場合のレイアウト調整 */
@media (max-width: 900px) {
    .main-container {
        flex-direction: column; 
        align-items: center;
    }
    .controls, #svgContainer {
        flex: auto; 
        width: 100%; 
    }
    #svgContainer {
        max-width: 90vw;
        padding-bottom: 90vw;
    }
}