/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: #333;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    padding: 1rem 0;
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: 700;
    color: #667eea;
}

.nav-brand i {
    font-size: 2rem;
}

.nav-menu {
    display: flex;
    gap: 2rem;
}

.nav-link {
    text-decoration: none;
    color: #333;
    font-weight: 500;
    transition: color 0.3s ease;
    cursor: pointer;
}

.nav-link:hover {
    color: #667eea;
}

/* Main Container */
.main-container {
    margin-top: 80px;
    min-height: calc(100vh - 80px);
}

/* Sections */
.section {
    display: none;
    padding: 4rem 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.section.active {
    display: block;
}

.section-header {
    text-align: center;
    margin-bottom: 3rem;
}

.section-header h2 {
    font-size: 2.5rem;
    font-weight: 700;
    color: white;
    margin-bottom: 1rem;
}

.section-header p {
    font-size: 1.2rem;
    color: rgba(255, 255, 255, 0.8);
}

/* Hero Section */
.hero {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
    min-height: 70vh;
}

.hero-content {
    color: white;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1.5rem;
}

.gradient-text {
    background: linear-gradient(45deg, #ffd700, #ff6b6b);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.3rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.hero-stats {
    display: flex;
    gap: 2rem;
    margin-bottom: 2rem;
}

.stat {
    text-align: center;
}

.stat-number {
    font-size: 2rem;
    font-weight: 700;
    color: #ffd700;
}

.stat-label {
    font-size: 0.9rem;
    opacity: 0.8;
}

.cta-button {
    background: linear-gradient(45deg, #ff6b6b, #ffd700);
    color: white;
    border: none;
    padding: 1rem 2rem;
    font-size: 1.1rem;
    font-weight: 600;
    border-radius: 50px;
    cursor: pointer;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.cta-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 30px rgba(255, 107, 107, 0.3);
}

.hero-visual {
    display: flex;
    justify-content: center;
    align-items: center;
}

.brain-animation {
    font-size: 8rem;
    color: rgba(255, 255, 255, 0.2);
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.1); }
}

/* Test Cards */
.test-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.test-card {
    background: white;
    border-radius: 20px;
    padding: 2rem;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    cursor: pointer;
}

.test-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.15);
}

.test-card-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.test-icon {
    width: 60px;
    height: 60px;
    border-radius: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: white;
}

.test-icon.basic { background: linear-gradient(45deg, #4CAF50, #8BC34A); }
.test-icon.intermediate { background: linear-gradient(45deg, #FF9800, #FFC107); }
.test-icon.advanced { background: linear-gradient(45deg, #F44336, #E91E63); }

.test-info h3 {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.test-info .difficulty {
    font-size: 0.9rem;
    color: #666;
    text-transform: uppercase;
    font-weight: 500;
}

.test-description {
    color: #666;
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.test-details {
    display: flex;
    justify-content: space-between;
    margin-bottom: 1.5rem;
    font-size: 0.9rem;
    color: #888;
}

.test-card-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

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

.btn-start {
    background: #667eea;
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 10px;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.3s ease;
}

.btn-start:hover {
    background: #5a6fd8;
}

/* Modal Styles */
.modal {
    display: none;
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(5px);
}

.modal-content {
    background-color: white;
    margin: 10% auto;
    padding: 0;
    border-radius: 20px;
    width: 90%;
    max-width: 500px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    animation: modalSlideIn 0.3s ease;
}

@keyframes modalSlideIn {
    from { transform: translateY(-50px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

.modal-header {
    padding: 2rem 2rem 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid #eee;
}

.modal-header h3 {
    font-size: 1.5rem;
    font-weight: 600;
}

.close {
    color: #aaa;
    font-size: 2rem;
    font-weight: bold;
    cursor: pointer;
    transition: color 0.3s ease;
}

.close:hover {
    color: #333;
}

.user-form {
    padding: 2rem;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: #333;
}

.form-group input {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid #eee;
    border-radius: 10px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.form-group input:focus {
    outline: none;
    border-color: #667eea;
}

.form-actions {
    display: flex;
    gap: 1rem;
    justify-content: flex-end;
}

/* Buttons */
.btn-primary, .btn-secondary, .btn-success {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 10px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.btn-primary {
    background: #667eea;
    color: white;
}

.btn-primary:hover {
    background: #5a6fd8;
    transform: translateY(-1px);
}

.btn-secondary {
    background: #f8f9fa;
    color: #333;
    border: 2px solid #eee;
}

.btn-secondary:hover {
    background: #e9ecef;
}

.btn-success {
    background: #28a745;
    color: white;
}

.btn-success:hover {
    background: #218838;
}

/* Test Interface */
.test-container {
    background: white;
    border-radius: 20px;
    padding: 2rem;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
    max-width: 800px;
    margin: 0 auto;
}

.test-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 2px solid #f8f9fa;
}

.test-progress {
    flex: 1;
}

.progress-bar {
    width: 100%;
    height: 8px;
    background: #f8f9fa;
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 0.5rem;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(45deg, #667eea, #764ba2);
    transition: width 0.3s ease;
    width: 0%;
}

.progress-text {
    font-size: 0.9rem;
    color: #666;
}

.test-timer {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.1rem;
    font-weight: 600;
    color: #667eea;
}

.question-container {
    margin-bottom: 2rem;
}

.question-card {
    background: #f8f9fa;
    border-radius: 15px;
    padding: 2rem;
}

.question-card h3 {
    font-size: 1.3rem;
    margin-bottom: 1.5rem;
    line-height: 1.5;
}

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

.option {
    background: white;
    border: 2px solid #eee;
    border-radius: 10px;
    padding: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 1rem;
}

.option:hover {
    border-color: #667eea;
    background: #f0f4ff;
}

.option.selected {
    border-color: #667eea;
    background: #667eea;
    color: white;
}

.option-letter {
    width: 30px;
    height: 30px;
    border-radius: 50%;
    background: #f8f9fa;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    flex-shrink: 0;
}

.option.selected .option-letter {
    background: white;
    color: #667eea;
}

.test-controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

/* Results */
.results-container {
    background: white;
    border-radius: 20px;
    padding: 3rem;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
    max-width: 600px;
    margin: 0 auto;
    text-align: center;
}

.results-header {
    margin-bottom: 2rem;
}

.results-icon {
    font-size: 4rem;
    color: #ffd700;
    margin-bottom: 1rem;
}

.results-header h2 {
    font-size: 2rem;
    color: #333;
    margin-bottom: 1rem;
}

.results-content {
    margin-bottom: 2rem;
}

.result-score {
    font-size: 4rem;
    font-weight: 700;
    color: #667eea;
    margin-bottom: 1rem;
}

.result-level {
    font-size: 1.5rem;
    color: #28a745;
    margin-bottom: 2rem;
    text-transform: capitalize;
}

.result-details {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.result-detail {
    background: #f8f9fa;
    padding: 1rem;
    border-radius: 10px;
}

.result-detail-value {
    font-size: 1.5rem;
    font-weight: 600;
    color: #667eea;
}

.result-detail-label {
    font-size: 0.9rem;
    color: #666;
}

.results-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

/* History */
.history-search {
    background: white;
    border-radius: 15px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
}

.search-form {
    display: flex;
    gap: 1rem;
    max-width: 500px;
    margin: 0 auto;
}

.search-form input {
    flex: 1;
    padding: 0.75rem;
    border: 2px solid #eee;
    border-radius: 10px;
    font-size: 1rem;
}

.history-content {
    background: white;
    border-radius: 15px;
    padding: 2rem;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
}

.history-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    border-bottom: 1px solid #eee;
}

.history-item:last-child {
    border-bottom: none;
}

.history-info h4 {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
}

.history-info p {
    font-size: 0.9rem;
    color: #666;
}

.history-score {
    text-align: right;
}

.history-iq {
    font-size: 1.5rem;
    font-weight: 600;
    color: #667eea;
}

.history-level {
    font-size: 0.9rem;
    color: #28a745;
    text-transform: capitalize;
}

/* Loading */
.loading-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    z-index: 3000;
    backdrop-filter: blur(5px);
}

.loading-spinner {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    text-align: center;
    color: white;
}

.loading-spinner i {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.loading-spinner p {
    font-size: 1.2rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-container {
        padding: 0 1rem;
    }
    
    .nav-menu {
        gap: 1rem;
    }
    
    .hero {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 2rem;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-stats {
        justify-content: center;
    }
    
    .test-cards {
        grid-template-columns: 1fr;
    }
    
    .test-header {
        flex-direction: column;
        gap: 1rem;
        align-items: stretch;
    }
    
    .test-controls {
        flex-direction: column;
        gap: 1rem;
    }
    
    .results-actions {
        flex-direction: column;
    }
    
    .search-form {
        flex-direction: column;
    }
    
    .history-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }
    
    .section {
        padding: 2rem 1rem;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .section-header h2 {
        font-size: 2rem;
    }
    
    .test-container,
    .results-container {
        padding: 1.5rem;
    }
    
    .modal-content {
        margin: 5% auto;
        width: 95%;
    }
}