body {
    font-family: Arial, sans-serif;
    background-color: #f0f2f5;
    color: #333;
    padding: 20px;
    line-height: 1.6;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    background-color: #fff;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

h1 {
    color: #2c3e50;
    text-align: center;
    margin-bottom: 10px;
}

p {
    text-align: center;
    color: #666;
    margin-bottom: 20px;
}

.input-section {
    text-align: center;
    margin-bottom: 30px;
}

.file-label {
    display: inline-block;
    padding: 12px 25px;
    background-color: #3498db;
    color: #fff;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s;
}

.file-label:hover {
    background-color: #2980b9;
}

.file-label input[type="file"] {
    display: none; /* 元のファイル入力ボタンを非表示にする */
}

.chart-container {
    position: relative;
    height: 400px;
    width: 100%;
}

.status-message {
    text-align: center;
    margin-top: 20px;
    font-weight: bold;
    color: #e74c3c;
}

@media (max-width: 768px) {
    .container {
        padding: 15px;
    }
}