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

:root {
    --primary-color: #4a90e2;
    --secondary-color: #2c3e50;
    --accent-color: #e74c3c;
    --success-color: #27ae60;
    --text-color: #333;
    --light-bg: #f8f9fa;
    --white: #ffffff;
    --border-color: #e0e0e0;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 4px 20px rgba(0, 0, 0, 0.15);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--light-bg);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
header {
    background: linear-gradient(135deg, var(--primary-color), #357abd);
    color: var(--white);
    padding: 1rem 0;
    box-shadow: var(--shadow);
}

header nav .container {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.header-logo {
    width: 50px !important;
    height: 50px !important;
    max-width: 50px !important;
    max-height: 50px !important;
    min-width: 50px;
    min-height: 50px;
    object-fit: contain;
    border-radius: 6px;
    flex-shrink: 0;
    display: block;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.logo {
    font-size: 1.8rem;
    font-weight: 700;
    letter-spacing: 1px;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--primary-color), #357abd);
    color: var(--white);
    padding: 4rem 0 3rem;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(circle at 30% 50%, rgba(255, 255, 255, 0.1) 0%, transparent 50%);
    pointer-events: none;
}

.hero .container {
    position: relative;
    z-index: 1;
}


.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    font-weight: 700;
}

.subtitle {
    font-size: 1.2rem;
    opacity: 0.95;
    max-width: 800px;
    margin: 0 auto;
}

/* IQ Test Section */
.iq-test-section {
    padding: 3rem 0;
    background: var(--white);
}

#test-container {
    max-width: 800px;
    margin: 0 auto;
    background: var(--white);
    border-radius: 16px;
    box-shadow: 0 4px 24px rgba(0, 0, 0, 0.12);
    padding: 2.5rem;
    min-height: 500px;
    border: 1px solid rgba(74, 144, 226, 0.1);
}

.screen {
    display: none;
}

.screen.active {
    display: block;
}

#welcome-screen {
    text-align: center;
}

.test-image {
    max-width: 150px;
    height: auto;
    margin: 0 auto 1.5rem;
    display: block;
    border-radius: 8px;
}

#welcome-screen h2 {
    color: var(--secondary-color);
    margin-bottom: 1.5rem;
    font-size: 2rem;
}

#welcome-screen p {
    margin-bottom: 1rem;
    color: #666;
    font-size: 1.1rem;
}

#welcome-screen ul {
    text-align: left;
    max-width: 600px;
    margin: 1.5rem auto;
    padding-left: 2rem;
}

#welcome-screen li {
    margin-bottom: 0.8rem;
    color: #555;
}

/* Progress Bar */
.progress-bar {
    width: 100%;
    height: 8px;
    background: var(--light-bg);
    border-radius: 4px;
    margin-bottom: 2rem;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), #357abd);
    width: 0%;
    transition: width 0.3s ease;
    border-radius: 4px;
}

.question-counter {
    text-align: center;
    margin-bottom: 2rem;
    font-size: 1.1rem;
    color: #666;
    font-weight: 600;
}

/* Question Container */
#question-container {
    margin-top: 2rem;
}

#question-text {
    font-size: 1.4rem;
    color: var(--secondary-color);
    margin-bottom: 2rem;
    line-height: 1.8;
}

#options-container {
    margin-bottom: 2rem;
}

.option {
    display: block;
    width: 100%;
    padding: 1.2rem 1.5rem;
    margin-bottom: 1rem;
    background: var(--white);
    border: 2px solid var(--border-color);
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 1rem;
    text-align: left;
    color: var(--text-color);
    font-weight: 500;
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.option:hover {
    background: linear-gradient(90deg, #e8f4f8 0%, #f0f8ff 100%);
    border-color: var(--primary-color);
    transform: translateX(8px);
    color: var(--text-color);
    box-shadow: 0 4px 12px rgba(74, 144, 226, 0.15);
}

.option.selected {
    background: var(--primary-color);
    color: var(--white);
    border-color: var(--primary-color);
}

.option:disabled {
    cursor: not-allowed;
    opacity: 0.7;
    color: var(--text-color);
}

/* Buttons */
.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), #357abd);
    color: var(--white);
    border: none;
    padding: 1rem 2.5rem;
    font-size: 1.1rem;
    font-weight: 600;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(74, 144, 226, 0.3);
    display: block;
    margin: 2rem auto 0;
    position: relative;
    overflow: hidden;
}

.btn-primary::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 0.5s;
}

.btn-primary:hover::before {
    left: 100%;
}

.btn-primary:hover:not(:disabled) {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(74, 144, 226, 0.4);
}

.btn-primary:active:not(:disabled) {
    transform: translateY(0);
}

.btn-primary:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* Results Screen */
#results-screen {
    text-align: center;
}

#results-screen h2 {
    color: var(--secondary-color);
    margin-bottom: 2rem;
    font-size: 2rem;
}

.results-container {
    max-width: 600px;
    margin: 0 auto;
}

.iq-score {
    margin-bottom: 2rem;
}

.score-circle {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-color), #357abd);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1rem;
    box-shadow: var(--shadow-lg);
    position: relative;
}

.score-circle::before {
    content: '';
    position: absolute;
    width: 180px;
    height: 180px;
    border-radius: 50%;
    background: var(--white);
}

#iq-number {
    font-size: 3.5rem;
    font-weight: 700;
    color: var(--primary-color);
    z-index: 1;
    position: relative;
}

.score-label {
    font-size: 1.3rem;
    color: var(--secondary-color);
    font-weight: 600;
}

.score-interpretation {
    background: var(--light-bg);
    padding: 2rem;
    border-radius: 12px;
    margin-bottom: 2rem;
    box-shadow: var(--shadow);
}

.score-interpretation h3 {
    color: var(--secondary-color);
    font-size: 1.8rem;
    margin-bottom: 1rem;
}

.score-interpretation p {
    color: #666;
    font-size: 1.1rem;
    line-height: 1.8;
}

.results-breakdown {
    background: var(--white);
    border: 2px solid var(--border-color);
    border-radius: 12px;
    padding: 1.5rem;
    margin-bottom: 2rem;
}

.results-breakdown h3 {
    color: var(--secondary-color);
    margin-bottom: 1.5rem;
    font-size: 1.5rem;
}

.breakdown-item {
    display: flex;
    justify-content: space-between;
    padding: 1rem 0;
    border-bottom: 1px solid var(--border-color);
    font-size: 1.1rem;
}

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

.breakdown-item span:first-child {
    color: #666;
}

.breakdown-item span:last-child {
    font-weight: 600;
    color: var(--secondary-color);
}

/* SEO Content Section */
.seo-content {
    padding: 4rem 0;
    background: var(--white);
}

.seo-content article {
    max-width: 900px;
    margin: 0 auto;
}

.seo-content h2 {
    color: var(--secondary-color);
    font-size: 2rem;
    margin-top: 3rem;
    margin-bottom: 1.5rem;
    font-weight: 700;
}

.seo-content h2:first-of-type {
    margin-top: 0;
}

.seo-content h3 {
    color: var(--secondary-color);
    font-size: 1.5rem;
    margin-top: 2rem;
    margin-bottom: 1rem;
    font-weight: 600;
}

.seo-content p {
    margin-bottom: 1.5rem;
    color: #555;
    font-size: 1.1rem;
    line-height: 1.8;
}

.content-image {
    max-width: 100%;
    height: auto;
    margin: 2rem auto;
    display: block;
    border-radius: 12px;
    box-shadow: var(--shadow);
}

.seo-content ul {
    margin: 1.5rem 0;
    padding-left: 2rem;
}

.seo-content li {
    margin-bottom: 1rem;
    color: #555;
    font-size: 1.1rem;
    line-height: 1.8;
}

.seo-content li strong {
    color: var(--secondary-color);
}

.faq-section {
    background: var(--light-bg);
    padding: 2rem;
    border-radius: 12px;
    margin: 2rem 0;
}

.faq-section h3 {
    color: var(--primary-color);
    margin-top: 1.5rem;
    margin-bottom: 0.8rem;
    font-size: 1.3rem;
}

.faq-section h3:first-of-type {
    margin-top: 0;
}

.faq-section p {
    margin-bottom: 1rem;
    color: #666;
}

/* Footer */
footer {
    background: var(--secondary-color);
    color: var(--white);
    text-align: center;
    padding: 2rem 0;
    margin-top: 3rem;
}

footer p {
    opacity: 0.9;
}

/* Responsive Design */
@media (max-width: 768px) {
    .header-logo {
        width: 40px !important;
        height: 40px !important;
        max-width: 40px !important;
        max-height: 40px !important;
        min-width: 40px;
        min-height: 40px;
    }

    .logo {
        font-size: 1.5rem;
    }

    .hero h1 {
        font-size: 2rem;
    }

    .subtitle {
        font-size: 1rem;
    }

    #test-container {
        padding: 1.5rem;
        margin: 0 1rem;
    }

    #question-text {
        font-size: 1.2rem;
    }

    .option {
        padding: 0.8rem 1rem;
        font-size: 0.95rem;
    }

    .score-circle {
        width: 150px;
        height: 150px;
    }

    .score-circle::before {
        width: 135px;
        height: 135px;
    }

    #iq-number {
        font-size: 2.5rem;
    }

    .seo-content h2 {
        font-size: 1.6rem;
    }

    .seo-content h3 {
        font-size: 1.3rem;
    }

    .seo-content p,
    .seo-content li {
        font-size: 1rem;
    }
}

@media (max-width: 480px) {
    .header-logo {
        width: 35px !important;
        height: 35px !important;
        max-width: 35px !important;
        max-height: 35px !important;
        min-width: 35px;
        min-height: 35px;
    }

    .logo {
        font-size: 1.3rem;
    }

    header nav .container {
        gap: 0.5rem;
    }

    .hero {
        padding: 2rem 0;
    }

    .hero h1 {
        font-size: 1.6rem;
    }

    #test-container {
        padding: 1rem;
    }

    #question-text {
        font-size: 1.1rem;
    }

    .btn-primary {
        padding: 0.8rem 2rem;
        font-size: 1rem;
    }
}

/* Accessibility */
.option:focus,
.btn-primary:focus {
    outline: 3px solid var(--primary-color);
    outline-offset: 2px;
}

/* Print Styles */
@media print {
    .iq-test-section,
    header,
    footer {
        display: none;
    }

    .seo-content {
        padding: 0;
    }
}