:root {
    --primary: #4361ee;
    --primary-dark: #3a56d4;
    --secondary: #7209b7;
    --accent: #f72585;
    --light: #f8f9fa;
    --dark: #212529;
    --gray: #6c757d;
    --success: #4cc9f0;
    --card-shadow: 0 10px 20px rgba(0,0,0,0.1);
    --transition: all 0.3s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: #f5f7ff;
    color: var(--dark);
    line-height: 1.6;
}

html {
    scroll-behavior: smooth;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header Styles */
header {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    padding: 1rem 0;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

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

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.8rem;
    font-weight: 700;
}

.logo i {
    color: var(--accent);
}

nav ul {
    display: flex;
    list-style: none;
    gap: 2rem;
}

nav a {
    color: white;
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    padding: 0.5rem 1rem;
    border-radius: 4px;
}

nav a:hover, nav a.active {
    background-color: rgba(255,255,255,0.15);
}

.auth-buttons {
    display: flex;
    gap: 1rem;
}

.btn {
    padding: 0.6rem 1.5rem;
    border-radius: 30px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    font-size: 0.9rem;
}

.btn-outline {
    background: transparent;
    border: 2px solid white;
    color: white;
}

.btn-outline:hover {
    background: white;
    color: var(--primary);
}

.btn-primary {
    background: var(--accent);
    color: white;
}

.btn-primary:hover {
    background: #e51778;
    transform: translateY(-2px);
}

.btn-outline-dark {
    background: transparent;
    border: 2px solid var(--dark);
    color: var(--dark);
}

.btn-outline-dark:hover {
    background: var(--dark);
    color: white;
}

.btn-outline-light {
    background: transparent;
    border: 2px solid white;
    color: white;
}

.btn-outline-light:hover {
    background: white;
    color: var(--primary);
}

.btn-full {
    width: 100%;
    padding: 0.8rem;
}

.btn-convert {
    margin-right: 10px;
}

.button-group {
    display: flex;
    gap: 1rem;
}

/* Hero Section */
.hero {
    padding: 5rem 0;
    background: linear-gradient(135deg, #f5f7ff 0%, #e6e9ff 100%);
    text-align: center;
}

.hero h1 {
    font-size: 3.5rem;
    margin-bottom: 1rem;
    background: linear-gradient(to right, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

.hero p {
    font-size: 1.2rem;
    color: var(--gray);
    max-width: 700px;
    margin: 0 auto 2rem;
}

.cta-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
}

/* Tool Section */
.tool-section {
    padding: 4rem 0;
    background: white;
    border-radius: 20px;
    margin: -3rem auto 3rem;
    box-shadow: var(--card-shadow);
    max-width: 900px;
}

.tool-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    padding: 0 2rem;
}

.converter-box {
    background: var(--light);
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
}

.converter-box h2 {
    margin-bottom: 1.5rem;
    color: var(--primary);
    display: flex;
    align-items: center;
    gap: 10px;
}

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

.input-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--dark);
}

.input-group input, .input-group select {
    width: 100%;
    padding: 0.8rem 1rem;
    border: 1px solid #ddd;
    border-radius: 8px;
    font-size: 1rem;
    transition: var(--transition);
}

.input-group input:focus, .input-group select:focus {
    border-color: var(--primary);
    outline: none;
    box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.2);
}

.result-box {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    padding: 2rem;
    border-radius: 15px;
    text-align: center;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.result-box h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.percentage-value {
    font-size: 3.5rem;
    font-weight: 700;
    margin: 1rem 0;
}

.grade-text {
    font-size: 1.2rem;
    font-weight: 500;
    margin-bottom: 1rem;
}

.result-details {
    margin: 1.5rem 0;
    text-align: left;
}

.detail-item {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.5rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid rgba(255,255,255,0.2);
}

.save-result {
    margin-top: 1rem;
}

/* Features Section */
.features {
    padding: 5rem 0;
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
}

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

.section-title h2 {
    font-size: 2.5rem;
    color: var(--dark);
    margin-bottom: 1rem;
}

.section-title p {
    color: var(--gray);
    max-width: 600px;
    margin: 0 auto;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.feature-card {
    background: white;
    padding: 2rem;
    border-radius: 15px;
    box-shadow: var(--card-shadow);
    transition: var(--transition);
    text-align: center;
}

.feature-card:hover {
    transform: translateY(-10px);
}

.feature-icon {
    width: 70px;
    height: 70px;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    color: white;
    font-size: 1.8rem;
}

.feature-card h3 {
    margin-bottom: 1rem;
    color: var(--dark);
}

.feature-card p {
    color: var(--gray);
}

/* About Section */
.about {
    padding: 5rem 0;
    background: white;
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.about-text h2 {
    font-size: 2.5rem;
    margin-bottom: 1.5rem;
    color: var(--dark);
}

.about-text p {
    margin-bottom: 1.5rem;
    color: var(--gray);
}

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

.stat {
    text-align: center;
}

.stat-number {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary);
}

.stat-label {
    color: var(--gray);
    font-size: 0.9rem;
}

.about-image {
    display: flex;
    justify-content: center;
}

.image-placeholder {
    width: 300px;
    height: 300px;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 5rem;
    box-shadow: var(--card-shadow);
}

/* Contact Section */
.contact {
    padding: 5rem 0;
    background: var(--light);
}

.contact-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
}

.contact-info {
    padding: 2rem;
}

.contact-info h3 {
    font-size: 1.8rem;
    margin-bottom: 1.5rem;
    color: var(--primary);
}

.contact-info > p {
    color: var(--gray);
    margin-bottom: 2rem;
}

.contact-method {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    margin-bottom: 2rem;
}

.contact-icon {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.2rem;
}

.contact-details h4 {
    margin-bottom: 0.5rem;
    color: var(--dark);
}

.contact-details p {
    color: var(--gray);
}

.contact-form {
    background: white;
    padding: 2.5rem;
    border-radius: 15px;
    box-shadow: var(--card-shadow);
}

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

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--dark);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.8rem 1rem;
    border: 1px solid #ddd;
    border-radius: 8px;
    font-size: 1rem;
    transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
    border-color: var(--primary);
    outline: none;
    box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.2);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

/* Footer */
footer {
    background: var(--dark);
    color: white;
    padding: 4rem 0 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3 {
    margin-bottom: 1.5rem;
    font-size: 1.2rem;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.8rem;
}

.footer-section a {
    color: #ddd;
    text-decoration: none;
    transition: var(--transition);
}

.footer-section a:hover {
    color: white;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255,255,255,0.1);
    color: #aaa;
    font-size: 0.9rem;
}

/* Modal Styles */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.5);
    z-index: 2000;
    align-items: center;
    justify-content: center;
}

.modal-content {
    background: white;
    border-radius: 15px;
    width: 100%;
    max-width: 500px;
    box-shadow: 0 15px 30px rgba(0,0,0,0.2);
    overflow: hidden;
}

.modal-header {
    padding: 1.5rem 2rem;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-header h2 {
    font-size: 1.5rem;
}

.close {
    font-size: 1.8rem;
    cursor: pointer;
    transition: var(--transition);
}

.close:hover {
    color: var(--accent);
}

.modal-body {
    padding: 2rem;
}

.auth-switch {
    text-align: center;
    margin-top: 1.5rem;
    font-size: 0.9rem;
}

.auth-switch a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 600;
}

/* Responsive Styles */
@media (max-width: 992px) {
    .tool-container {
        grid-template-columns: 1fr;
    }
    
    .about-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .contact-container {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr 1fr;
    }
    
    .hero h1 {
        font-size: 2.8rem;
    }
}

@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        gap: 1rem;
    }
    
    nav ul {
        gap: 1rem;
    }
    
    .hero h1 {
        font-size: 2.2rem;
    }
    
    .cta-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .stats {
        flex-direction: column;
        gap: 1rem;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }
    
    .button-group {
        flex-direction: column;
    }
}

@media (max-width: 576px) {
    .tool-container {
        padding: 0 1rem;
    }
    
    .converter-box, .result-box {
        padding: 1.5rem;
    }
    
    .percentage-value {
        font-size: 2.5rem;
    }
    
    .modal-content {
        margin: 1rem;
    }
    
    .modal-body {
        padding: 1.5rem;
    }
    
    .contact-form {
        padding: 1.5rem;
    }
    
    .contact-info {
        padding: 1rem;
    }
    /* Ad Container Styles */
.ad-container {
    margin: 2rem auto;
    text-align: center;
    max-width: 1200px;
    padding: 0 20px;
}

.ad-container ins {
    border-radius: 8px;
    overflow: hidden;
}

/* Responsive ads */
@media (max-width: 768px) {
    .ad-container {
        margin: 1rem auto;
    }
}
/* SEO Content Styles */
.seo-content {
    padding: 60px 0;
    background: #f8f9fa;
    line-height: 1.7;
}

.seo-content h1 {
    text-align: center;
    margin-bottom: 30px;
    color: var(--dark);
    font-size: 2.2rem;
}

.seo-content h2 {
    color: var(--primary);
    margin: 25px 0 15px 0;
    font-size: 1.4rem;
}

.seo-content h3 {
    color: var(--secondary);
    margin: 20px 0 10px 0;
    font-size: 1.2rem;
}

.seo-content p {
    color: var(--gray);
    margin-bottom: 15px;
    font-size: 1.1rem;
}

.content-grid {
    display: grid;
    gap: 30px;
    margin-bottom: 40px;
}

.content-block {
    background: white;
    padding: 25px;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.faq-section {
    background: white;
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.faq-item {
    margin-bottom: 20px;
    padding-bottom: 20px;
    border-bottom: 1px solid #eee;
}

.faq-item:last-child {
    border-bottom: none;
    margin-bottom: 0;
}
}