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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: #f0f2f5;
    color: #333;
    line-height: 1.6;
}

.container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

header {
    background-color: #fff;
    padding: 20px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

h1 {
    font-size: 24px;
    color: #1a1a1a;
}

.language-selector select {
    padding: 8px 12px;
    border: 1px solid #ddd;
    border-radius: 4px;
    background-color: #fff;
    cursor: pointer;
    font-size: 14px;
}

main {
    flex: 1;
    display: flex;
    flex-direction: column;
    padding: 20px;
    gap: 20px;
}

.input-section {
    display: flex;
    gap: 10px;
    max-width: 600px;
    margin: 0 auto;
    width: 100%;
}

#centralIdea {
    flex: 1;
    padding: 12px 16px;
    border: 2px solid #4a90e2;
    border-radius: 8px;
    font-size: 16px;
    transition: border-color 0.3s;
}

#centralIdea:focus {
    outline: none;
    border-color: #357abd;
}

#startBrainstorm {
    padding: 12px 24px;
    background-color: #4a90e2;
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    cursor: pointer;
    transition: background-color 0.3s;
}

#startBrainstorm:hover {
    background-color: #357abd;
}

.tools-section {
    display: flex;
    gap: 10px;
    justify-content: center;
}

.tool-btn {
    padding: 8px 16px;
    background-color: #fff;
    border: 1px solid #ddd;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.3s;
}

.tool-btn:hover {
    background-color: #f5f5f5;
    border-color: #4a90e2;
}

.mindmap-container {
    flex: 1;
    background-color: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    position: relative;
    min-height: 500px;
    overflow: hidden;
}

#mindmapCanvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

#nodes {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

.node {
    position: absolute;
    background-color: #fff;
    border: 2px solid #4a90e2;
    border-radius: 20px;
    padding: 10px 20px;
    cursor: move;
    transition: all 0.3s;
    display: flex;
    align-items: center;
    gap: 10px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    white-space: nowrap;
}

.node:hover {
    transform: scale(1.05);
    box-shadow: 0 4px 8px rgba(0,0,0,0.2);
}

.node.central {
    background-color: #4a90e2;
    color: white;
    font-weight: bold;
    font-size: 18px;
}

.node.selected {
    border-color: #ff6b6b;
    box-shadow: 0 0 0 3px rgba(255,107,107,0.3);
}

.add-btn {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    border: none;
    background-color: #4caf50;
    color: white;
    cursor: pointer;
    font-size: 18px;
    line-height: 1;
    transition: all 0.3s;
}

.add-btn:hover {
    background-color: #45a049;
    transform: scale(1.1);
}

.sidebar {
    background-color: #fff;
    border-radius: 8px;
    padding: 20px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    max-height: 300px;
    overflow-y: auto;
}

.sidebar h2 {
    font-size: 18px;
    margin-bottom: 15px;
    color: #1a1a1a;
}

#ideaList {
    list-style: none;
}

#ideaList li {
    padding: 8px 12px;
    margin-bottom: 5px;
    background-color: #f8f9fa;
    border-radius: 4px;
    cursor: pointer;
    transition: background-color 0.3s;
}

#ideaList li:hover {
    background-color: #e9ecef;
}

footer {
    background-color: #fff;
    padding: 20px;
    text-align: center;
    border-top: 1px solid #e0e0e0;
    color: #666;
    font-size: 14px;
}

/* レスポンシブ対応 */
@media (max-width: 768px) {
    .input-section {
        flex-direction: column;
    }
    
    .tools-section {
        flex-wrap: wrap;
    }
    
    .mindmap-container {
        min-height: 400px;
    }
    
    .node {
        font-size: 14px;
        padding: 8px 16px;
    }
    
    .node.central {
        font-size: 16px;
    }
}

/* スクロールバースタイル */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: #f1f1f1;
}

::-webkit-scrollbar-thumb {
    background: #888;
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: #555;
}