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

:root {
    --primary: #667eea;
    --primary-dark: #5a67d8;
    --secondary: #764ba2;
    --accent: #f093fb;
    --text: #1a202c;
    --text-light: #4a5568;
    --text-muted: #718096;
    --bg: #f7fafc;
    --surface: #ffffff;
    --border: #e2e8f0;
    --success: #48bb78;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --radius: 12px;
    --radius-lg: 16px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: var(--text);
    line-height: 1.6;
}

.app {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Screen Management */
.screen {
    display: none;
    animation: fadeIn 0.3s ease-out;
}

.screen.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 40px 20px;
}

.hero-content {
    max-width: 600px;
    text-align: center;
    color: white;
}

.hero h1 {
    font-size: 3em;
    font-weight: 800;
    margin-bottom: 12px;
    text-shadow: 0 2px 8px rgba(0,0,0,0.2);
    letter-spacing: -0.5px;
}

.hero-subtitle {
    font-size: 1.3em;
    opacity: 0.95;
    margin-bottom: 40px;
    font-weight: 300;
}

/* Features */
.features {
    display: grid;
    gap: 20px;
    margin-bottom: 40px;
}

.feature {
    background: rgba(255, 255, 255, 0.15);
    backdrop-filter: blur(10px);
    border-radius: var(--radius);
    padding: 20px;
    display: flex;
    align-items: center;
    gap: 16px;
    text-align: left;
    border: 1px solid rgba(255, 255, 255, 0.2);
    transition: transform 0.2s, background 0.2s;
}

.feature:hover {
    transform: translateY(-2px);
    background: rgba(255, 255, 255, 0.2);
}

.feature-icon {
    font-size: 2em;
    flex-shrink: 0;
}

.feature-text {
    display: flex;
    flex-direction: column;
}

.feature-text strong {
    font-size: 1.1em;
    font-weight: 600;
}

.feature-text span {
    font-size: 0.9em;
    opacity: 0.9;
}

/* Buttons */
.btn-primary, .btn-secondary, .btn-outline {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 16px 32px;
    font-size: 1.1em;
    font-weight: 600;
    border: none;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all 0.2s;
    text-decoration: none;
}

.btn-primary {
    background: white;
    color: var(--primary);
    box-shadow: var(--shadow-lg);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 15px 20px -3px rgba(0, 0, 0, 0.15);
}

.btn-primary:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

.btn-large {
    padding: 18px 48px;
    font-size: 1.2em;
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.3);
}

.btn-outline {
    background: transparent;
    color: white;
    border: 2px solid rgba(255, 255, 255, 0.5);
}

.btn-outline:hover {
    background: rgba(255, 255, 255, 0.1);
}

/* Test Section */
.test-wrap {
    max-width: 800px;
    margin: 0 auto;
    padding: 40px 20px;
}

.progress-header {
    margin-bottom: 30px;
}

.progress-info {
    display: flex;
    justify-content: space-between;
    margin-bottom: 10px;
    color: white;
    font-weight: 600;
}

.progress-bar {
    height: 8px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 4px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: white;
    border-radius: 4px;
    transition: width 0.3s ease;
    width: 0%;
}

/* Question List */
.question-list {
    display: flex;
    flex-direction: column;
    gap: 20px;
    margin-bottom: 30px;
}

.question {
    background: var(--surface);
    border-radius: var(--radius-lg);
    padding: 24px;
    box-shadow: var(--shadow-lg);
    animation: slideIn 0.3s ease-out;
}

@keyframes slideIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.question-meta {
    display: flex;
    gap: 10px;
    margin-bottom: 12px;
    font-size: 0.9em;
}

.badge {
    background: var(--primary);
    color: white;
    padding: 4px 12px;
    border-radius: 20px;
    font-weight: 600;
    font-size: 0.85em;
}

.question-title {
    font-size: 1.2em;
    font-weight: 600;
    margin-bottom: 20px;
    color: var(--text);
    line-height: 1.5;
}

.options {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.option {
    display: flex;
    align-items: center;
    padding: 16px;
    background: var(--bg);
    border-radius: var(--radius);
    cursor: pointer;
    transition: all 0.2s;
    border: 2px solid transparent;
}

.option:hover {
    background: #edf2f7;
}

.option input[type="radio"] {
    display: none;
}

.option input[type="radio"]:checked + .option-code {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
}

.option:has(input:checked) {
    background: rgba(102, 126, 234, 0.1);
    border-color: var(--primary);
}

.option-code {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: white;
    border: 2px solid var(--border);
    font-weight: 700;
    margin-right: 16px;
    flex-shrink: 0;
    transition: all 0.2s;
}

.option > div:last-child {
    flex: 1;
    color: var(--text-light);
    font-size: 1em;
}

/* Test Actions */
.test-actions {
    display: flex;
    justify-content: center;
    padding-top: 20px;
}

/* Result Section */
.result-wrap {
    max-width: 800px;
    margin: 0 auto;
    padding: 40px 20px;
}

.result-header {
    text-align: center;
    color: white;
    margin-bottom: 40px;
}

.result-badge {
    display: inline-block;
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    padding: 8px 20px;
    border-radius: 20px;
    font-size: 0.9em;
    font-weight: 600;
    margin-bottom: 16px;
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.result-header h1 {
    font-size: 4em;
    font-weight: 800;
    margin-bottom: 12px;
    letter-spacing: 2px;
    text-shadow: 0 2px 8px rgba(0,0,0,0.2);
}

.result-subtitle {
    font-size: 1.4em;
    opacity: 0.95;
    font-weight: 300;
}

.result-content {
    background: var(--surface);
    border-radius: var(--radius-lg);
    padding: 32px;
    box-shadow: var(--shadow-lg);
    margin-bottom: 30px;
}

.result-content h2 {
    color: var(--primary);
    font-size: 1.5em;
    margin-bottom: 16px;
}

.result-content p {
    color: var(--text-light);
    margin-bottom: 16px;
    line-height: 1.7;
}

.result-content ul {
    margin-left: 20px;
    margin-bottom: 16px;
    color: var(--text-light);
}

.result-content li {
    margin-bottom: 8px;
}

/* Result Actions */
.result-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

/* Responsive */
@media (max-width: 640px) {
    .hero h1 {
        font-size: 2.2em;
    }
    
    .hero-subtitle {
        font-size: 1.1em;
    }
    
    .feature {
        padding: 16px;
    }
    
    .btn-large {
        padding: 16px 36px;
        font-size: 1.1em;
    }
    
    .question {
        padding: 20px;
    }
    
    .question-title {
        font-size: 1.1em;
    }
    
    .result-header h1 {
        font-size: 2.5em;
    }
    
    .result-subtitle {
        font-size: 1.2em;
    }
    
    .result-content {
        padding: 24px;
    }
}