/* リセットとベーススタイル */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Noto Sans JP', sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
    color: #333;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    background: white;
    border-radius: 12px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    overflow: hidden;
}

/* ヘッダー */
header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 30px;
    text-align: center;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
}

.subtitle {
    font-size: 1.1rem;
    opacity: 0.9;
}

/* コントロールボタン */
.controls {
    padding: 20px 30px;
    background: #f8f9fa;
    border-bottom: 2px solid #e9ecef;
    display: flex;
    justify-content: flex-end;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
}

.control-buttons {
    display: flex;
    gap: 10px;
}

.btn {
    padding: 10px 20px;
    border: none;
    border-radius: 6px;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 600;
    background: #667eea;
    color: white;
}

.btn:hover {
    background: #5568d3;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

.btn-secondary {
    background: #6c757d;
}

.btn-secondary:hover {
    background: #5a6268;
    box-shadow: 0 4px 12px rgba(108, 117, 125, 0.4);
}

/* メインコンテンツ */
.main-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0;
    min-height: 600px;
}

.editor-section,
.preview-section {
    padding: 30px;
    display: flex;
    flex-direction: column;
}

.editor-section {
    border-right: 2px solid #e9ecef;
}

.editor-section h2,
.preview-section h2 {
    font-size: 1.3rem;
    margin-bottom: 15px;
    color: #667eea;
}

/* テキストエリア */
#htmlInput {
    flex: 1;
    width: 100%;
    padding: 15px;
    border: 2px solid #e9ecef;
    border-radius: 8px;
    font-family: 'Courier New', Courier, monospace;
    font-size: 14px;
    line-height: 1.6;
    resize: none;
    transition: border-color 0.3s ease;
}

#htmlInput:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

/* プレビューエリア */
#preview {
    flex: 1;
    width: 100%;
    border: 2px solid #e9ecef;
    border-radius: 8px;
    background: white;
}

/* フッター */
footer {
    padding: 20px 30px;
    background: #f8f9fa;
    border-top: 2px solid #e9ecef;
    text-align: center;
    color: #6c757d;
    font-size: 0.9rem;
}

/* レスポンシブデザイン */
@media (max-width: 768px) {
    body {
        padding: 10px;
    }

    header h1 {
        font-size: 1.8rem;
    }

    .subtitle {
        font-size: 1rem;
    }

    .main-content {
        grid-template-columns: 1fr;
        min-height: auto;
    }

    .editor-section {
        border-right: none;
        border-bottom: 2px solid #e9ecef;
        min-height: 300px;
    }

    .preview-section {
        min-height: 400px;
    }

    .controls {
        flex-wrap: wrap;
    }
}

/* プレビューヘッダー */
.preview-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
}

.preview-header h2 {
    margin-bottom: 0;
}

/* アイコンボタン */
.btn-icon {
    background: transparent;
    border: 2px solid #667eea;
    border-radius: 6px;
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: #667eea;
    transition: all 0.3s ease;
}

.btn-icon:hover {
    background: #667eea;
    color: white;
    transform: scale(1.1);
}

/* 最大化オーバーレイ */
.maximized-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(0, 0, 0, 0.95);
    z-index: 9999;
    display: flex;
    flex-direction: column;
    animation: fadeIn 0.3s ease;
}

.maximized-overlay.hidden {
    display: none;
}

.maximized-header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 20px 30px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
}

.maximized-header h2 {
    margin: 0;
    font-size: 1.5rem;
}

.btn-close {
    background: rgba(255, 255, 255, 0.2);
    border: 2px solid white;
    border-radius: 6px;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: white;
    transition: all 0.3s ease;
}

.btn-close:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: scale(1.1);
}

#previewMaximized {
    flex: 1;
    width: 100%;
    border: none;
    background: white;
}

/* アニメーション */
@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

/* スクロールバーのカスタマイズ */
#htmlInput::-webkit-scrollbar {
    width: 10px;
}

#htmlInput::-webkit-scrollbar-track {
    background: #f1f1f1;
    border-radius: 10px;
}

#htmlInput::-webkit-scrollbar-thumb {
    background: #667eea;
    border-radius: 10px;
}

#htmlInput::-webkit-scrollbar-thumb:hover {
    background: #5568d3;
}

/* 履歴ボタンスタイル */
.btn-primary {
    background: #28a745;
}

.btn-primary:hover {
    background: #218838;
    box-shadow: 0 4px 12px rgba(40, 167, 69, 0.4);
}

.btn-danger {
    background: #dc3545;
    color: white;
}

.btn-danger:hover {
    background: #c82333;
    box-shadow: 0 4px 12px rgba(220, 53, 69, 0.4);
}

/* 履歴モーダルオーバーレイ */
.history-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(0, 0, 0, 0.8);
    z-index: 9999;
    display: flex;
    align-items: center;
    justify-content: center;
    animation: fadeIn 0.3s ease;
    padding: 20px;
}

.history-overlay.hidden {
    display: none;
}

.history-modal {
    background: white;
    border-radius: 12px;
    max-width: 1200px;
    width: 100%;
    max-height: 90vh;
    display: flex;
    flex-direction: column;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
    animation: slideIn 0.3s ease;
}

@keyframes slideIn {
    from {
        transform: translateY(-50px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.history-header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 20px 30px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-radius: 12px 12px 0 0;
}

.history-header h2 {
    margin: 0;
    font-size: 1.5rem;
    color: white;
}

.history-controls {
    padding: 20px 30px;
    background: #f8f9fa;
    border-bottom: 2px solid #e9ecef;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.history-count {
    margin: 0;
    font-size: 1rem;
    color: #6c757d;
    font-weight: 600;
}

.history-count span {
    color: #667eea;
    font-size: 1.2rem;
}

.history-content {
    flex: 1;
    padding: 30px;
    overflow-y: auto;
    min-height: 300px;
}

.history-empty {
    text-align: center;
    color: #6c757d;
    font-size: 1.1rem;
    padding: 60px 20px;
}

/* 履歴グリッド */
.history-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
}

.history-item {
    background: #f8f9fa;
    border: 2px solid #e9ecef;
    border-radius: 8px;
    padding: 20px;
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.history-item:hover {
    border-color: #667eea;
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.2);
    transform: translateY(-2px);
}

.history-item-title {
    font-size: 1.1rem;
    font-weight: 600;
    color: #333;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.history-item-date {
    font-size: 0.9rem;
    color: #6c757d;
}

.history-item-preview {
    font-size: 0.85rem;
    color: #6c757d;
    background: white;
    padding: 10px;
    border-radius: 4px;
    max-height: 60px;
    overflow: hidden;
    text-overflow: ellipsis;
    font-family: 'Courier New', monospace;
    white-space: pre-wrap;
    word-break: break-all;
}

.history-item-actions {
    display: flex;
    gap: 10px;
    margin-top: auto;
}

.history-item-actions .btn {
    flex: 1;
    padding: 8px 12px;
    font-size: 0.9rem;
}

/* 履歴コンテンツのスクロールバー */
.history-content::-webkit-scrollbar {
    width: 10px;
}

.history-content::-webkit-scrollbar-track {
    background: #f1f1f1;
    border-radius: 10px;
}

.history-content::-webkit-scrollbar-thumb {
    background: #667eea;
    border-radius: 10px;
}

.history-content::-webkit-scrollbar-thumb:hover {
    background: #5568d3;
}

/* レスポンシブ対応 */
@media (max-width: 768px) {
    .history-grid {
        grid-template-columns: 1fr;
    }

    .history-controls {
        flex-direction: column;
        gap: 15px;
        align-items: stretch;
    }

    .history-count {
        text-align: center;
    }
}