html, body {
    margin: 0;
    height: 100%;
    overflow: hidden;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: #f4f7f6;
    display: flex;
    flex-direction: column;
}

.header {
    background-color: #333;
    color: white;
    padding: 10px 20px;
    text-align: center;
    flex-shrink: 0;
}

#app-container {
    display: flex;
    flex: 1;
    min-height: 0;
}

#markdown-input, #preview-output {
    flex: 1;
    padding: 15px;
    box-sizing: border-box;
    overflow-y: auto;
    border: none;
    font-size: 16px;
    line-height: 1.6;
}

#markdown-input {
    background-color: #fff;
    border-right: 1px solid #ccc;
    font-family: 'Courier New', Courier, monospace; /* 入力しやすいフォント */
    resize: none; /* サイズ変更を不可にする */
}

#preview-output {
    background-color: #e8eded;
}

/* プレビュー内のMarkdown要素のスタイル調整 */
#preview-output h1 {
    border-bottom: 2px solid #ccc;
    padding-bottom: 5px;
}

#preview-output pre {
    background-color: #2d2d2d;
    color: #f8f8f2;
    padding: 10px;
    border-radius: 5px;
    overflow-x: auto;
}

footer {
    background-color: #333;
    color: #888;
    text-align: center;
    padding: 10px;
    font-size: 14px;
    flex-shrink: 0;
}