:root {
    --primary: #4A5568;
    --secondary: #2D3748;
    --accent: #3182CE;
    --bg: #F7FAFC;
    --text-primary: #1A202C;
    --text-secondary: #718096;
    --white: #FFFFFF;
    --border: #E2E8F0;
    --shadow: rgba(0, 0, 0, 0.1);
    --max-width: 1200px;
    --spacing: 80px;
    --spacing-mobile: 48px;
    --padding: 24px;
    --padding-mobile: 16px;
}

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

html {
    scroll-behavior: smooth;
}

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

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

img {
    max-width: 100%;
    height: auto;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--padding);
}

.section {
    padding: var(--spacing) 0;
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
    color: var(--secondary);
    text-align: center;
    margin-bottom: 1rem;
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--text-secondary);
    text-align: center;
    margin-bottom: 3rem;
}

.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--white);
    box-shadow: 0 2px 10px var(--shadow);
    z-index: 1000;
    transition: all 0.3s ease;
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem var(--padding);
    max-width: var(--max-width);
    margin: 0 auto;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--secondary);
}

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

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

.nav-link {
    font-size: 1rem;
    color: var(--text-secondary);
    font-weight: 500;
    padding: 1rem 1.25rem;
    border-bottom: 3px solid transparent;
    transition: all 0.3s ease;
    cursor: pointer;
}

.nav-link:hover,
.nav-link.active {
    color: var(--accent);
    border-bottom-color: var(--accent);
}

.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    padding: 5px;
}

.menu-toggle span {
    width: 25px;
    height: 3px;
    background: var(--secondary);
    border-radius: 2px;
    transition: all 0.3s ease;
}

.mobile-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--white);
    box-shadow: 0 4px 10px var(--shadow);
    padding: 1rem;
}

.mobile-menu.active {
    display: block;
}

.mobile-menu .nav-link {
    display: block;
    padding: 0.75rem 1rem;
    border-bottom: none;
}

.mobile-menu .nav-link.active {
    background: rgba(49, 130, 206, 0.1);
}

.tab-content {
    display: none;
    animation: fadeIn 0.5s ease;
}

.tab-content.active {
    display: block;
}

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

.hero {
    background: linear-gradient(135deg, var(--secondary) 0%, var(--primary) 100%);
    color: var(--white);
    padding: 5rem 0 4rem;
    margin-top: 60px;
    text-align: center;
}

.hero-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.3;
}

.hero-subtitle {
    font-size: 1.25rem;
    opacity: 0.9;
    margin-bottom: 2rem;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.btn {
    display: inline-block;
    padding: 0.875rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.3s ease;
    border: none;
}

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

.btn-primary:hover {
    background: #2c6cb0;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(49, 130, 206, 0.3);
}

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

.card {
    background: var(--white);
    border-radius: 8px;
    padding: 2rem;
    box-shadow: 0 2px 10px var(--shadow);
    transition: all 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px var(--shadow);
}

.card-icon {
    width: 60px;
    height: 60px;
    background: var(--accent);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
    font-size: 1.75rem;
    color: var(--white);
}

.card-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--secondary);
    margin-bottom: 0.75rem;
}

.card-desc {
    color: var(--text-secondary);
    font-size: 0.9375rem;
}

.feature-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.feature-item {
    display: flex;
    gap: 1rem;
    padding: 1.5rem;
    background: var(--white);
    border-radius: 8px;
    box-shadow: 0 2px 8px var(--shadow);
}

.feature-icon {
    width: 48px;
    height: 48px;
    background: var(--accent);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-weight: 700;
    flex-shrink: 0;
}

.feature-content h4 {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--secondary);
    margin-bottom: 0.5rem;
}

.feature-content p {
    color: var(--text-secondary);
    font-size: 0.9375rem;
}

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

.advantage-item {
    text-align: center;
    padding: 2rem;
    background: var(--white);
    border-radius: 8px;
    box-shadow: 0 2px 10px var(--shadow);
}

.advantage-icon {
    width: 70px;
    height: 70px;
    background: linear-gradient(135deg, var(--accent) 0%, var(--primary) 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    font-size: 1.75rem;
    color: var(--white);
}

.advantage-title {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--secondary);
    margin-bottom: 0.75rem;
}

.advantage-desc {
    color: var(--text-secondary);
    font-size: 0.9375rem;
}

.contact-info {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin: 2rem 0;
}

.contact-item {
    background: var(--white);
    padding: 1.5rem;
    border-radius: 8px;
    text-align: center;
    box-shadow: 0 2px 10px var(--shadow);
}

.contact-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.contact-value {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--secondary);
}

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

.form-label {
    display: block;
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.form-input,
.form-select,
.form-textarea {
    width: 100%;
    padding: 0.75rem 1rem;
    font-size: 1rem;
    border: 1px solid var(--border);
    border-radius: 6px;
    background: var(--white);
    transition: all 0.3s ease;
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(49, 130, 206, 0.1);
}

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

.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
}

.footer {
    background: var(--secondary);
    color: var(--white);
    padding: 2rem 0;
    text-align: center;
}

.footer-content {
    margin-bottom: 1rem;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    margin-bottom: 1rem;
}

.footer-link {
    color: rgba(255, 255, 255, 0.8);
    font-size: 0.875rem;
    transition: color 0.3s ease;
}

.footer-link:hover {
    color: var(--white);
}

.footer-copy {
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.6);
}

.footer-slogan {
    margin-top: 1rem;
    font-size: 0.9375rem;
    color: rgba(255, 255, 255, 0.7);
}

.scroll-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 48px;
    height: 48px;
    background: var(--accent);
    color: var(--white);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    font-size: 1.25rem;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    box-shadow: 0 4px 12px rgba(49, 130, 206, 0.3);
}

.scroll-top.visible {
    opacity: 1;
    visibility: visible;
}

.scroll-top:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 16px rgba(49, 130, 206, 0.4);
}

@media (max-width: 768px) {
    .section {
        padding: var(--spacing-mobile) 0;
    }

    .hero {
        padding: 5rem 0 3rem;
    }

    .hero-title {
        font-size: 1.75rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .nav-links {
        display: none;
    }

    .menu-toggle {
        display: flex;
    }

    .section-title {
        font-size: 1.5rem;
    }

    .section-subtitle {
        font-size: 1rem;
    }

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

    .feature-list {
        grid-template-columns: 1fr;
    }

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

    .contact-info {
        grid-template-columns: 1fr;
    }

    .form-row {
        grid-template-columns: 1fr;
    }

    .footer-links {
        flex-direction: column;
        gap: 0.75rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 var(--padding-mobile);
    }

    .hero-title {
        font-size: 1.5rem;
    }

    .btn {
        padding: 0.75rem 1.5rem;
        font-size: 0.9375rem;
    }
}