body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f4f7f9;
    color: #333;
    display: flex;
    justify-content: center;
    padding: 20px;
}

.container {
    background: linear-gradient(to right, #ccccff,#0000ee);
    max-width: 800px;
    width: 100%;
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
}

h1 { color: #ffffff; text-align: center; }
.subtitle { text-align: center; color: #ffffff; margin-bottom: 30px; }

.question-block {
    margin-bottom: 25px;
    padding: 15px;
    border-left: 5px solid #3498db;
    background: #f9f9f9;
}

.options-list { list-style: none; padding: 0; }
.options-list li { margin: 10px 0; }

label { cursor: pointer; display: block; padding: 5px; }
label:hover { background: #eef2f3; }

#submit-btn {
    display: block;
    width: 100%;
    padding: 15px;
    background-color: #27ae60;
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 18px;
    cursor: pointer;
    transition: background 0.3s;
}

#submit-btn:hover { background-color: #219150; }

.hidden { display: none; }
#results {
    margin-top: 20px;
    padding: 20px;
    background: #ecf0f1;
    border-radius: 8px;
    text-align: center;
}

.correct { color: #27ae60; font-weight: bold; }
.wrong { color: #e74c3c; font-weight: bold; }

#detailed-correction {
    margin-top: 20px;
    max-height: 400px;
    overflow-y: auto;
    background: #fff;
    padding: 15px;
    border-radius: 5px;
}