body {
    font-family: Vazirmatn, Tahoma, Arial, sans-serif;
    background: #f1f5f9;
    color: #0f172a;
}
.navbar-brand { font-weight: 700; }
.card { border: none; border-radius: 14px; box-shadow: 0 4px 18px rgba(15,23,42,.06); }
.btn { border-radius: 10px; }
.stat-box {
    background: #fff;
    border-radius: 14px;
    padding: 20px;
    text-align: center;
    box-shadow: 0 4px 18px rgba(15,23,42,.06);
}
.stat-box h3 { font-size: 28px; margin: 0; color: #0f766e; }
.login-wrap {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}
.login-card {
    width: 100%;
    max-width: 420px;
    background: #fff;
    border-radius: 16px;
    padding: 32px;
    box-shadow: 0 10px 30px rgba(15,23,42,.08);
}
.lesson-title {
    background: #ecfeff;
    border-right: 4px solid #0f766e;
    padding: 10px 14px;
    border-radius: 10px;
    font-weight: 700;
    color: #115e59;
    margin: 20px 0 12px;
}
.question-card {
    background: #fff;
    border: 1px solid #e2e8f0;
    border-radius: 12px;
    padding: 18px;
    margin-bottom: 14px;
}
.option-label {
    display: block;
    border: 1px solid #e2e8f0;
    border-radius: 10px;
    padding: 10px 14px;
    margin: 6px 0;
    cursor: pointer;
}
.option-label.selected, .option-label:hover {
    background: #f0fdfa;
    border-color: #0f766e;
}
.review-btn {
    width: 42px; height: 42px;
    border: none; border-radius: 8px;
    font-weight: 700; margin: 3px;
}
.review-answered { background: #dcfce7; color: #166534; }
.review-unanswered { background: #fee2e2; color: #991b1b; }