* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: Arial, sans-serif;
    background: #f0f4f8;
    color: #1a1a2e;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

header {
    background: #2d6a4f;
    color: white;
    padding: 24px;
    text-align: center;
}

header h1 {
    font-size: 24px;
    margin-bottom: 4px;
}

.subtitle {
    font-size: 14px;
    opacity: 0.85;
}

main {
    flex: 1;
    padding: 20px;
    display: flex;
    justify-content: center;
    align-items: flex-start;
}

.task-card {
    background: white;
    border-radius: 16px;
    padding: 24px;
    max-width: 500px;
    width: 100%;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    margin-top: 20px;
}

.task-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 16px;
    font-size: 13px;
}

.task-number {
    background: #d8f3dc;
    color: #2d6a4f;
    padding: 4px 10px;
    border-radius: 12px;
    font-weight: bold;
}

.task-subject {
    color: #888;
}

.task-question {
    font-size: 18px;
    line-height: 1.5;
    margin-bottom: 20px;
}

.answers {
    display: grid;
    gap: 10px;
}

.answer {
    background: #f8f9fa;
    border: 2px solid #e9ecef;
    border-radius: 10px;
    padding: 14px;
    font-size: 16px;
    cursor: pointer;
    transition: all 0.2s;
    text-align: left;
    font-family: inherit;
}

.answer:active {
    transform: scale(0.98);
}

.answer.correct {
    background: #d8f3dc;
    border-color: #52b788;
    color: #1b4332;
}

.answer.wrong {
    background: #ffe5e5;
    border-color: #e63946;
    color: #7d1128;
}

.answer.disabled {
    pointer-events: none;
    opacity: 0.7;
}

.result {
    margin-top: 16px;
    font-size: 16px;
    font-weight: bold;
    text-align: center;
    min-height: 24px;
}

.result.success {
    color: #2d6a4f;
}

.result.error {
    color: #e63946;
}

footer {
    text-align: center;
    padding: 16px;
    font-size: 12px;
    color: #888;
}