.tf-grader-container {
    margin: 20px 0;
    font-family: sans-serif;
}

.tf-btn {
    background-color: #ff9900;
    color: #fff;
    border: none;
    padding: 12px 24px;
    font-size: 16px;
    font-weight: bold;
    border-radius: 4px;
    cursor: pointer;
    transition: background-color 0.3s;
}

.tf-btn:hover {
    background-color: #e68a00;
}

.tf-btn:disabled {
    background-color: #ccc;
    cursor: not-allowed;
}

#tf-grader-loading {
    margin-top: 10px;
    color: #666;
    font-size: 14px;
    font-weight: bold;
}

#tf-grader-result {
    margin-top: 15px;
    padding: 15px;
    border-radius: 4px;
    font-weight: bold;
    line-height: 1.5;
}

.tf-success {
    background-color: #e6f4ea;
    color: #1e8e3e;
    border: 1px solid #1e8e3e;
}

.tf-hint {
    background-color: #fff3e0;
    color: #e65100;
    border: 1px solid #ff9800;
}

.tf-error {
    background-color: #fce8e6;
    color: #d93025;
    border: 1px solid #d93025;
}

/* ✨ パーソナルベスト通知用のアニメーション装飾 ✨ */
.tf-pb-notification {
    margin-top: 15px;
    padding: 10px;
    background: linear-gradient(45deg, #FFD700, #FFA500);
    color: #fff;
    font-weight: bold;
    text-align: center;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    animation: popIn 0.6s cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards;
}

@keyframes popIn {
    0% { transform: scale(0.5); opacity: 0; }
    100% { transform: scale(1); opacity: 1; }
}

/* --- 追加：レイアウトと終了ボタンのデザイン --- */
.tf-action-buttons {
    display: flex;
    gap: 15px;
    margin-bottom: 10px;
    flex-wrap: wrap;
}

.tf-btn-danger {
    background-color: #d93025;
}

.tf-btn-danger:hover {
    background-color: #b3261e;
}


/* --- 追加：開始ボタンとタイマーのデザイン --- */
.tf-btn-primary {
    background-color: #0073bb; /* AWSブルー */
    width: 100%;
    max-width: 400px;
    padding: 15px;
    font-size: 18px;
}

.tf-btn-primary:hover {
    background-color: #005a93;
}

.tf-timer-display {
    font-size: 20px;
    font-weight: bold;
    color: #333;
    background-color: #f8f9fa;
    padding: 10px 15px;
    border-radius: 4px;
    margin-bottom: 15px;
    display: inline-block;
    border: 1px solid #ddd;
}

#tf-stopwatch {
    font-family: monospace;
    color: #d93025;
}