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

body {
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    color: #333;
    overflow-x: hidden;
}

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

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 100px 0;
    min-height: 100vh;
    display: flex;
    align-items: center;
}

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 20px;
}

.hero-subtitle {
    font-size: 1.25rem;
    opacity: 0.9;
    margin-bottom: 40px;
    line-height: 1.6;
}

.hero-buttons {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
}

.btn {
    padding: 15px 30px;
    border: none;
    border-radius: 50px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
}

.btn-primary {
    background: #ff6b6b;
    color: white;
}

.btn-primary:hover {
    background: #ff5252;
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(255, 107, 107, 0.3);
}

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

.btn-secondary:hover {
    background: white;
    color: #667eea;
    transform: translateY(-2px);
}

.btn-large {
    padding: 20px 40px;
    font-size: 1.1rem;
}

/* Phone Mockup */
.phone-mockup {
    width: 300px;
    height: 600px;
    background: #1a1a1a;
    border-radius: 30px;
    padding: 20px;
    margin: 0 auto;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
}

.screen {
    width: 100%;
    height: 100%;
    background: white;
    border-radius: 20px;
    overflow: hidden;
}

.app-preview {
    padding: 20px;
    height: 100%;
}

.header {
    font-size: 1.5rem;
    font-weight: 700;
    color: #667eea;
    text-align: center;
    margin-bottom: 30px;
    padding-bottom: 15px;
    border-bottom: 2px solid #f0f0f0;
}

.student-list {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.student-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px;
    background: #f8f9fa;
    border-radius: 10px;
    border-left: 4px solid #667eea;
}

.student-item .name {
    font-weight: 600;
    color: #333;
}

.status {
    padding: 5px 12px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
}

.status.paid {
    background: #d4edda;
    color: #155724;
}

.status.pending {
    background: #f8d7da;
    color: #721c24;
}

/* Features Section */
.features {
    padding: 100px 0;
    background: #f8f9fa;
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 60px;
    color: #333;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 40px;
}

.feature-card {
    background: white;
    padding: 40px 30px;
    border-radius: 15px;
    text-align: center;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-5px);
}

.feature-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, #667eea, #764ba2);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 25px;
    color: white;
    font-size: 2rem;
}

.feature-card h3 {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 15px;
    color: #333;
}

.feature-card p {
    color: #666;
    line-height: 1.6;
}

/* How It Works Section */
.how-it-works {
    padding: 100px 0;
    background: white;
}

.steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 40px;
    margin-top: 60px;
}

.step {
    display: flex;
    align-items: flex-start;
    gap: 25px;
}

.step-number {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, #ff6b6b, #ff8e8e);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 700;
    flex-shrink: 0;
}

.step-content h3 {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 10px;
    color: #333;
}

.step-content p {
    color: #666;
    line-height: 1.6;
}

/* Testimonials Section */
.testimonials {
    padding: 100px 0;
    background: #f8f9fa;
}

.testimonial-card {
    background: white;
    padding: 50px;
    border-radius: 20px;
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    position: relative;
}

/* Testimonials Slider */
.testimonial-slider {
    position: relative;
    max-width: 900px;
    margin: 0 auto;
}

.ts-viewport {
    overflow: hidden;
}

.ts-slides {
    display: flex;
    transition: transform 0.5s ease;
    will-change: transform;
}

.ts-slide {
    min-width: 100%;
    flex-shrink: 0;
    opacity: 0.6;
    transition: opacity 0.4s ease;
}

.ts-slide.is-active {
    opacity: 1;
}

.ts-nav {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: 44px;
    height: 44px;
    border-radius: 50%;
    border: 0;
    background: rgba(102, 126, 234, 0.15);
    color: #667eea;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: background 0.3s ease, transform 0.2s ease;
}

.ts-nav:hover {
    background: rgba(102, 126, 234, 0.3);
    transform: translateY(-50%) scale(1.05);
}

.ts-prev { left: -10px; }
.ts-next { right: -10px; }

@media (max-width: 768px) {
    .ts-prev { left: 0; }
    .ts-next { right: 0; }
}

.ts-dots {
    display: flex;
    gap: 10px;
    justify-content: center;
    margin-top: 20px;
}

.ts-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    border: 0;
    background: #d8dcff;
    cursor: pointer;
    transition: background 0.3s ease, transform 0.2s ease;
}

.ts-dot.is-active {
    background: #667eea;
    transform: scale(1.2);
}

.quote-icon {
    font-size: 3rem;
    color: #667eea;
    margin-bottom: 20px;
}

.testimonial-card blockquote {
    font-size: 1.5rem;
    font-style: italic;
    color: #333;
    margin-bottom: 30px;
    line-height: 1.6;
}

.testimonial-author h4 {
    font-size: 1.2rem;
    font-weight: 600;
    color: #333;
    margin-bottom: 5px;
}

.testimonial-author p {
    color: #666;
}

/* Call to Action Section */
.cta {
    padding: 100px 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
}

.cta h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 20px;
}

.cta p {
    font-size: 1.2rem;
    opacity: 0.9;
    margin-bottom: 40px;
}

.cta-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
    flex-wrap: wrap;
}

/* Footer */
.footer {
    background: #1a1a1a;
    color: white;
    padding: 40px 0;
    text-align: center;
}

.footer-content p {
    opacity: 0.8;
}

.footer-content a {
    color: #667eea;
    text-decoration: none;
}

.footer-content a:hover {
    text-decoration: underline;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
}

.modal-content {
    background-color: white;
    margin: 10% auto;
    padding: 40px;
    border-radius: 15px;
    width: 90%;
    max-width: 600px;
    position: relative;
    animation: modalSlideIn 0.3s ease;
}

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

.close {
    color: #aaa;
    float: right;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
    position: absolute;
    top: 15px;
    right: 20px;
}

.close:hover {
    color: #333;
}

.demo-features {
    margin: 20px 0;
    text-align: left;
}

.demo-features h4 {
    margin-bottom: 15px;
    color: #333;
}

.demo-features ul {
    list-style: none;
    padding-left: 0;
}

.demo-features li {
    padding: 8px 0;
    padding-left: 25px;
    position: relative;
    color: #666;
}

.demo-features li:before {
    content: "✓";
    position: absolute;
    left: 0;
    color: #667eea;
    font-weight: bold;
}

/* Responsive Design */
@media (max-width: 768px) {
    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 40px;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-subtitle {
        font-size: 1.1rem;
    }
    
    .hero-buttons {
        justify-content: center;
    }
    
    .phone-mockup {
        width: 250px;
        height: 500px;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .steps {
        grid-template-columns: 1fr;
    }
    
    .step {
        flex-direction: column;
        text-align: center;
    }
    
    .cta h2 {
        font-size: 2rem;
    }
    
    .cta-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .testimonial-card {
        padding: 30px 20px;
    }
    
    .testimonial-card blockquote {
        font-size: 1.2rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }
    
    .hero {
        padding: 60px 0;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .btn {
        padding: 12px 24px;
        font-size: 0.9rem;
    }
    
    .phone-mockup {
        width: 200px;
        height: 400px;
    }
    
    .features, .how-it-works, .testimonials, .cta {
        padding: 60px 0;
    }
    
    .feature-card {
        padding: 30px 20px;
    }
    
    .modal-content {
        margin: 5% auto;
        padding: 30px 20px;
    }
}