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

:root {
    --primary-color: #0f172a;
    --secondary-color: #1e293b;
    --accent-color: #3b82f6;
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --border-color: #334155;
    --success-color: #10b981;
    --error-color: #ef4444;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background-color: var(--primary-color);
    color: var(--text-primary);
    line-height: 1.6;
}

a {
    color: var(--accent-color);
    text-decoration: none;
    transition: color 0.3s ease;
}

a:hover {
    color: #60a5fa;
}

.header {
    background-color: var(--secondary-color);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo-section h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--accent-color);
    margin-bottom: 0.25rem;
}

.logo-section .tagline {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.nav {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.nav-link {
    color: var(--text-secondary);
    font-weight: 500;
    transition: color 0.3s ease;
}

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

.hero {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    padding: 6rem 2rem;
    text-align: center;
    border-bottom: 1px solid var(--border-color);
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.hero-content h1 {
    font-size: 3rem;
    margin-bottom: 1.5rem;
    line-height: 1.2;
    color: var(--text-primary);
}

.hero-content p {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.cta-button {
    background-color: var(--accent-color);
    color: white;
    padding: 0.75rem 2rem;
    border: none;
    border-radius: 0.5rem;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.3s ease, transform 0.2s ease;
}

.cta-button:hover {
    background-color: #2563eb;
    transform: translateY(-2px);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

.features-section,
.approach-section {
    margin: 4rem 0;
}

.features-section h2,
.demo-section h2,
.approach-section h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    text-align: center;
    color: var(--text-primary);
}

.features-section > p,
.demo-section > p {
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: 3rem;
    font-size: 1.1rem;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin: 2rem 0;
}

.feature-card {
    background-color: var(--secondary-color);
    border: 1px solid var(--border-color);
    padding: 2rem;
    border-radius: 0.75rem;
    transition: transform 0.3s ease, border-color 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-4px);
    border-color: var(--accent-color);
}

.feature-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    display: block;
}

.feature-card h3 {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

.feature-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.demo-section {
    background-color: var(--secondary-color);
    padding: 3rem;
    border-radius: 0.75rem;
    border: 1px solid var(--border-color);
    text-align: center;
    margin: 4rem 0;
}

.approach-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin: 2rem 0;
}

.approach-item {
    padding: 2rem;
    border: 1px solid var(--border-color);
    border-radius: 0.75rem;
    position: relative;
    background-color: rgba(59, 130, 246, 0.05);
}

.approach-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--accent-color);
    margin-bottom: 1rem;
}

.approach-item h3 {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

.approach-item p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.modal-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.7);
    z-index: 1000;
    align-items: center;
    justify-content: center;
}

.modal-overlay.active {
    display: flex;
}

.modal {
    background-color: var(--secondary-color);
    border: 1px solid var(--border-color);
    border-radius: 0.75rem;
    max-width: 500px;
    width: 90%;
    max-height: 80vh;
    overflow-y: auto;
}

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

.modal-header h2 {
    color: var(--text-primary);
    margin: 0;
}

.modal-close {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 2rem;
    cursor: pointer;
    transition: color 0.2s ease;
}

.modal-close:hover {
    color: var(--text-primary);
}

.modal-body {
    padding: 2rem;
}

.form-step {
    display: none;
}

.form-step.active {
    display: block;
    animation: slideIn 0.3s ease;
}

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

.form-step h3 {
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.availability-section {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.day-availability {
    border: 1px solid var(--border-color);
    padding: 1rem;
    border-radius: 0.5rem;
    background-color: rgba(59, 130, 246, 0.03);
}

.day-label {
    display: block;
    font-weight: 600;
    margin-bottom: 0.75rem;
    color: var(--accent-color);
}

.time-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 0.75rem;
}

.time-slot {
    display: flex;
    align-items: center;
    cursor: pointer;
    color: var(--text-secondary);
    font-size: 0.9rem;
    transition: color 0.2s ease;
}

.time-slot input {
    margin-right: 0.5rem;
    cursor: pointer;
    accent-color: var(--accent-color);
}

.time-slot:hover {
    color: var(--text-primary);
}

.form-group {
    margin-bottom: 1.25rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text-primary);
    font-size: 0.95rem;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.75rem;
    background-color: var(--primary-color);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    color: var(--text-primary);
    font-family: inherit;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.form-group textarea {
    resize: vertical;
    font-family: inherit;
}

.form-actions {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
}

.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 0.5rem;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    flex: 1;
}

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

.btn-primary:hover {
    background-color: #2563eb;
    transform: translateY(-1px);
}

.btn-secondary {
    background-color: var(--border-color);
    color: var(--text-primary);
}

.btn-secondary:hover {
    background-color: #475569;
    transform: translateY(-1px);
}

.footer {
    background-color: var(--secondary-color);
    border-top: 1px solid var(--border-color);
    padding: 3rem 2rem 2rem;
    margin-top: 4rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h4 {
    color: var(--accent-color);
    margin-bottom: 1rem;
    font-size: 1.1rem;
}

.footer-section p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

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

.footer-section li {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    font-size: 0.95rem;
}

.footer-section a {
    color: var(--text-secondary);
    transition: color 0.3s ease;
}

.footer-section a:hover {
    color: var(--accent-color);
}

.footer-bottom {
    border-top: 1px solid var(--border-color);
    padding-top: 2rem;
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

@media (max-width: 768px) {
    .header-container {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }

    .nav {
        width: 100%;
        justify-content: space-around;
        gap: 1rem;
    }

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

    .hero-content p {
        font-size: 1rem;
    }

    .features-section h2,
    .demo-section h2,
    .approach-section h2 {
        font-size: 1.75rem;
    }

    .time-grid {
        grid-template-columns: 1fr;
    }

    .form-actions {
        flex-direction: column;
    }

    .btn {
        width: 100%;
    }
}