body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    margin: 0;
    padding: 20px;
    color: #333;
    transition: all 0.3s ease;
}

.dark-mode {
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
    color: #ffffff;
}

.quiz-header {
    text-align: center;
    margin-bottom: 2rem;
    position: relative;
}

.hackathon-badge {
    display: inline-block;
    background: linear-gradient(135deg, #ff6b6b, #feca57);
    color: white;
    padding: 0.75rem 2rem;
    border-radius: 50px;
    font-weight: 600;
    font-size: 1rem;
    box-shadow: 0 4px 15px rgba(255, 107, 107, 0.3);
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
        box-shadow: 0 4px 15px rgba(255, 107, 107, 0.3);
    }
    50% {
        transform: scale(1.05);
        box-shadow: 0 6px 20px rgba(255, 107, 107, 0.5);
    }
}

.quiz-title {
    font-size: 2.5rem;
    font-weight: 700;
    color: white;
    margin-bottom: 1rem;
    text-shadow: 0 2px 4px rgba(0,0,0,0.3);
}

.timer-container {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 1rem 2rem;
    display: inline-block;
    margin-bottom: 2rem;
    box-shadow: 0 8px 32px rgba(0,0,0,0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.timer {
    font-size: 1.5rem;
    font-weight: 600;
    color: #e53e3e;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.timer::before {
    content: "⏱️";
    font-size: 1.2rem;
}

.dark-mode .timer-container {
    background: rgba(0, 0, 0, 0.3);
    color: #ff6b6b;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    border-radius: 24px;
    padding: 3rem;
    box-shadow: 0 20px 40px rgba(0,0,0,0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    position: relative;
    overflow: hidden;
}

.container::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, #667eea, #764ba2, #667eea);
    background-size: 200% 100%;
    animation: gradientMove 3s ease infinite;
}

@keyframes gradientMove {
    0%, 100% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
}

.dark-mode .container {
    background: rgba(0, 0, 0, 0.4);
    color: #ffffff;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.question-card {
    background: #f8fafc;
    border-radius: 16px;
    padding: 2rem;
    margin-bottom: 2rem;
    border-left: 5px solid #667eea;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    transition: all 0.3s ease;
    position: relative;
}

.question-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.1);
}

.dark-mode .question-card {
    background: rgba(255, 255, 255, 0.05);
    border-left-color: #9f7aea;
}

.question-text {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    color: #2d3748;
    line-height: 1.6;
}

.dark-mode .question-text {
    color: #e2e8f0;
}

.options-container {
    display: grid;
    gap: 1rem;
}

.option-label {
    display: flex;
    align-items: center;
    padding: 1rem 1.5rem;
    background: white;
    border: 2px solid #e2e8f0;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 500;
    position: relative;
    overflow: hidden;
}

.option-label::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(102, 126, 234, 0.1), transparent);
    transition: left 0.5s ease;
}

.option-label:hover::before {
    left: 100%;
}

.option-label:hover {
    border-color: #667eea;
    background: #f7fafc;
    transform: translateX(4px);
}

.dark-mode .option-label {
    background: rgba(255, 255, 255, 0.05);
    border-color: rgba(255, 255, 255, 0.1);
    color: #e2e8f0;
}

.dark-mode .option-label:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: #9f7aea;
}

input[type="radio"] {
    width: 20px;
    height: 20px;
    margin-right: 1rem;
    accent-color: #667eea;
    cursor: pointer;
}

.submit-button {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    padding: 1rem 3rem;
    font-size: 1.1rem;
    font-weight: 600;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
    display: block;
    margin: 2rem auto;
    position: relative;
    overflow: hidden;
}

.submit-button::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transition: left 0.6s ease;
}

.submit-button:hover::before {
    left: 100%;
}

.submit-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(102, 126, 234, 0.6);
}

.submit-button:active {
    transform: translateY(0);
}

.result {
    text-align: center;
    font-size: 1.8rem;
    font-weight: 700;
    padding: 2rem;
    background: linear-gradient(135deg, #48bb78 0%, #38a169 100%);
    color: white;
    border-radius: 16px;
    margin-top: 2rem;
    box-shadow: 0 8px 25px rgba(72, 187, 120, 0.3);
    animation: slideInUp 0.5s ease;
}

@keyframes slideInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.theme-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    border: none;
    color: #333;
    padding: 1rem;
    border-radius: 50px;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
    z-index: 1000;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.theme-toggle:hover {
    background: white;
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.15);
}

.dark-mode .theme-toggle {
    background: rgba(0, 0, 0, 0.7);
    color: white;
}

.progress-bar {
    position: fixed;
    top: 0;
    left: 0;
    width: 0%;
    height: 4px;
    background: linear-gradient(90deg, #667eea, #764ba2);
    transition: width 0.3s ease;
    z-index: 1001;
}

@media (max-width: 768px) {
    .container {
        margin: 1rem;
        padding: 2rem;
    }
    
    .quiz-title {
        font-size: 2rem;
    }
    
    .question-text {
        font-size: 1.1rem;
    }
    
    .option-label {
        padding: 0.875rem 1rem;
    }
}