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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #333;
}

.container {
    width: 100%;
    max-width: 600px;
    padding: 20px;
}

.screen {
    display: none;
}

.screen.active {
    display: block;
}

.card {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 20px;
    padding: 40px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
    backdrop-filter: blur(10px);
    text-align: center;
    position: relative;
}

h1 {
    font-size: 2.5rem;
    margin-bottom: 20px;
    background: linear-gradient(135deg, #667eea, #764ba2);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

h2 {
    font-size: 2rem;
    margin-bottom: 10px;
    color: #333;
}

p {
    font-size: 1.1rem;
    margin-bottom: 30px;
    color: #666;
}

.btn {
    padding: 15px 30px;
    border: none;
    border-radius: 50px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: white;
    box-shadow: 0 10px 20px rgba(102, 126, 234, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 15px 30px rgba(102, 126, 234, 0.4);
}

.mode-toggle {
    margin: 30px 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 15px;
}

.toggle-label {
    font-size: 1.2rem;
    font-weight: 600;
    color: #555;
}

.toggle-buttons {
    display: flex;
    gap: 0;
    border-radius: 25px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    width: 240px;
}

.btn-mode {
    background: white;
    color: #666;
    border: 2px solid #e0e0e0;
    padding: 12px 25px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    border-radius: 0;
    flex: 1;
    width: 50%;
    text-align: center;
    display: flex;
    align-items: center;
    justify-content: center;
}

.btn-mode:first-child {
    border-right: 1px solid #e0e0e0;
}

.btn-mode:last-child {
    border-left: 1px solid #e0e0e0;
}

.btn-mode.active {
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: white;
    border-color: #667eea;
}

.btn-mode:hover:not(.active) {
    background: #f8f9fa;
    color: #333;
}

.btn-twitter {
    background: black;
    color: white;
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.3);
}

.btn-twitter:hover {
    transform: translateY(-2px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.4);
}

.action-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
    flex-wrap: wrap;
}

.btn-quit {
    background: rgba(108, 117, 125, 0.8);
    color: white;
    font-size: 0.9rem;
    padding: 10px 20px;
    margin-top: 30px;
    border: none;
    border-radius: 25px;
    cursor: pointer;
    transition: all 0.3s ease;
    position: absolute;
    bottom: 20px;
    right: 20px;
}

.btn-quit:hover {
    background: rgba(108, 117, 125, 1);
    transform: translateY(-1px);
}

.btn-answer {
    background: white;
    color: #333;
    border: 2px solid #e0e0e0;
    margin: 10px;
    min-width: 120px;
}

.btn-answer:hover {
    background: #f8f9fa;
    /* border-color: #667eea; */
    transform: translateY(-2px);
}

.quiz-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    background: rgba(255, 255, 255, 0.9);
    padding: 20px;
    border-radius: 15px;
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

.timer {
    font-size: 1.5rem;
    font-weight: 700;
    color: #667eea;
}

.progress {
    font-size: 1.2rem;
    color: #666;
}

.answer-buttons {
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
}

.score-summary {
    background: #f8f9fa;
    border-radius: 15px;
    padding: 25px;
    margin: 30px 0;
}

.score-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin: 10px 0;
    font-size: 1.2rem;
}

.label {
    font-weight: 600;
    color: #555;
}

.answer-review {
    margin: 30px 0;
    text-align: left;
}

.review-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px;
    margin: 10px 0;
    border-radius: 10px;
    font-size: 1.1rem;
}

.review-item.correct {
    background: linear-gradient(135deg, #d4edda, #c3e6cb);
    border-left: 5px solid #28a745;
}

.review-item.incorrect {
    background: linear-gradient(135deg, #f8d7da, #f5c6cb);
    border-left: 5px solid #dc3545;
}

.service-name {
    font-weight: 600;
}

.answer-info {
    display: flex;
    gap: 15px;
    align-items: center;
}

.user-answer {
    padding: 5px 10px;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 600;
}

.user-answer.correct {
    background: #28a745;
    color: white;
}

.user-answer.incorrect {
    background: #dc3545;
    color: white;
}

.correct-answer {
    font-size: 0.9rem;
    color: #666;
}

@media (max-width: 768px) {
    .container {
        padding: 10px;
    }

    .card {
        padding: 30px 20px;
    }

    h1 {
        font-size: 2rem;
    }

    h2 {
        font-size: 1.5rem;
    }

    .quiz-header {
        flex-direction: column;
        gap: 15px;
        text-align: center;
    }

    .answer-buttons {
        flex-direction: column;
        align-items: center;
    }

    .btn-answer {
        width: 100%;
        max-width: 200px;
    }

    .review-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }

    .answer-info {
        width: 100%;
        justify-content: space-between;
    }

    .action-buttons {
        flex-direction: column;
        align-items: center;
        gap: 15px;
    }

    .btn-twitter {
        width: 100%;
        max-width: 200px;
    }

    .btn-quit {
        position: static;
        margin-top: 20px;
        width: 100%;
        max-width: 120px;
    }

    .mode-toggle {
        margin: 20px 0;
    }

    .toggle-buttons {
        width: 100%;
        max-width: 250px;
    }

    .btn-mode {
        flex: 1;
        min-width: auto;
    }
}