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

:root {
    --primary-color: #4285F4;
    --secondary-color: #34A853;
    --accent-color: #FBBC04;
    --error-color: #EA4335;
    --dark-color: #202124;
    --text-color: #5f6368;
    --light-bg: #f8f9fa;
    --white: #ffffff;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-hover: 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(--white);
}

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

.header {
    background: var(--white);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.08);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 24px;
    font-weight: bold;
    color: var(--dark-color);
    text-decoration: none;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 30px;
}

.nav-menu a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: color 0.3s;
}

.nav-menu a:hover,
.nav-menu a.active {
    color: var(--primary-color);
}

.btn {
    display: inline-block;
    padding: 12px 24px;
    border: none;
    border-radius: 25px;
    font-size: 16px;
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    transition: all 0.3s;
    text-align: center;
}

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

.btn-primary:hover {
    background: #3367d6;
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

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

.btn-secondary:hover {
    background: var(--primary-color);
    color: var(--white);
    transform: translateY(-2px);
}

.btn-large {
    padding: 16px 32px;
    font-size: 18px;
}

main {
    margin-top: 70px;
}

.hero {
    padding: 100px 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: var(--white);
}

.hero-content {
    max-width: 600px;
}

.hero-title {
    font-size: 56px;
    font-weight: 700;
    margin-bottom: 20px;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 24px;
    margin-bottom: 20px;
    color: rgba(255, 255, 255, 0.9);
}

.hero-description {
    font-size: 18px;
    margin-bottom: 30px;
    color: rgba(255, 255, 255, 0.85);
    line-height: 1.8;
}

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

.hero-image {
    display: flex;
    justify-content: center;
    align-items: center;
    margin-top: 50px;
}

.browser-mockup {
    width: 100%;
    max-width: 500px;
    height: auto;
}

.section-title {
    font-size: 42px;
    font-weight: 700;
    text-align: center;
    margin-bottom: 15px;
    color: var(--dark-color);
}

.section-subtitle {
    font-size: 18px;
    text-align: center;
    margin-bottom: 60px;
    color: var(--text-color);
}

.features {
    padding: 100px 0;
    background: var(--light-bg);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.feature-card {
    background: var(--white);
    padding: 40px 30px;
    border-radius: 12px;
    box-shadow: var(--shadow);
    transition: transform 0.3s, box-shadow 0.3s;
}

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

.feature-icon {
    margin-bottom: 20px;
}

.feature-card h3 {
    font-size: 24px;
    margin-bottom: 15px;
    color: var(--dark-color);
}

.feature-card p {
    font-size: 16px;
    color: var(--text-color);
    line-height: 1.8;
}

.stats {
    padding: 80px 0;
    background: var(--primary-color);
    color: var(--white);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 40px;
    text-align: center;
}

.stat-item {
    padding: 20px;
}

.stat-number {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 10px;
}

.stat-label {
    font-size: 18px;
    opacity: 0.9;
}

.cta {
    padding: 100px 0;
    background: var(--white);
    text-align: center;
}

.cta h2 {
    font-size: 42px;
    margin-bottom: 20px;
    color: var(--dark-color);
}

.cta p {
    font-size: 18px;
    margin-bottom: 40px;
    color: var(--text-color);
}

.download-hero {
    padding: 100px 0;
    background: linear-gradient(135deg, #4285F4 0%, #34A853 100%);
    color: var(--white);
    text-align: center;
}

.download-title {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 15px;
}

.download-subtitle {
    font-size: 20px;
    margin-bottom: 50px;
    opacity: 0.9;
}

.download-auto {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 30px;
    background: rgba(255, 255, 255, 0.1);
    padding: 40px;
    border-radius: 16px;
    backdrop-filter: blur(10px);
}

.download-auto svg {
    flex-shrink: 0;
}

.download-auto p {
    text-align: left;
}

.os-detect {
    font-weight: 600;
    margin-top: 5px;
}

.download-platforms {
    padding: 100px 0;
    background: #f5f5f5;
}

.platforms-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
    margin-top: 50px;
}

.platform-card {
    background: #ffffff;
    padding: 40px 30px;
    border-radius: 12px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    text-align: center;
    transition: transform 0.3s, box-shadow 0.3s;
    border: 1px solid #e0e0e0;
}

.platform-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
}

.platform-icon {
    margin-bottom: 20px;
}

.platform-card h3 {
    font-size: 28px;
    margin-bottom: 10px;
    color: var(--dark-color);
}

.platform-card > p {
    font-size: 16px;
    margin-bottom: 25px;
    color: var(--text-color);
}

.platform-links {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.system-requirements {
    padding: 100px 0;
    background: var(--white);
}

.requirements-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 50px;
}

.requirement-item {
    background: var(--light-bg);
    padding: 30px;
    border-radius: 12px;
}

.requirement-item h3 {
    font-size: 24px;
    margin-bottom: 20px;
    color: var(--dark-color);
}

.requirement-item ul {
    list-style: none;
}

.requirement-item li {
    padding: 10px 0;
    padding-left: 25px;
    position: relative;
    color: var(--text-color);
}

.requirement-item li::before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--secondary-color);
    font-weight: bold;
}

.download-info {
    padding: 100px 0;
    background: var(--light-bg);
}

.info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin-top: 50px;
}

.info-item {
    text-align: center;
    padding: 30px;
}

.info-icon {
    font-size: 48px;
    margin-bottom: 20px;
}

.info-item h3 {
    font-size: 24px;
    margin-bottom: 15px;
    color: var(--dark-color);
}

.info-item p {
    color: var(--text-color);
    line-height: 1.8;
}

.footer {
    background: var(--dark-color);
    color: var(--white);
    padding: 60px 0 30px;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.footer-section h4 {
    font-size: 18px;
    margin-bottom: 20px;
    color: rgba(255, 255, 255, 0.9);
}

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

.footer-section li {
    margin-bottom: 12px;
}

.footer-section a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: color 0.3s;
}

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

.footer-bottom {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.6);
}

.page-404 .error-main {
    min-height: calc(100vh - 70px);
    display: flex;
    align-items: center;
    justify-content: center;
}

.error-content {
    text-align: center;
    padding: 60px 20px;
}

.error-illustration {
    margin-bottom: 40px;
}

.error-title {
    font-size: 56px;
    font-weight: 700;
    margin-bottom: 20px;
    color: var(--dark-color);
}

.error-description {
    font-size: 18px;
    color: var(--text-color);
    margin-bottom: 40px;
    line-height: 1.8;
}

.error-actions {
    display: flex;
    gap: 20px;
    justify-content: center;
    margin-bottom: 50px;
    flex-wrap: wrap;
}

.error-help {
    background: var(--light-bg);
    padding: 30px;
    border-radius: 12px;
    max-width: 500px;
    margin: 0 auto;
}

.error-help h3 {
    font-size: 20px;
    margin-bottom: 20px;
    color: var(--dark-color);
}

.error-help ul {
    list-style: none;
}

.error-help li {
    margin-bottom: 12px;
}

.error-help a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
}

.error-help a:hover {
    text-decoration: underline;
}

.mobile-menu {
    display: none;
    position: absolute;
    top: 70px;
    left: 0;
    right: 0;
    background: var(--white);
    box-shadow: var(--shadow);
    padding: 20px;
    z-index: 999;
}

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

.mobile-menu li {
    margin-bottom: 15px;
}

.mobile-menu a {
    display: block;
    padding: 10px 0;
    color: var(--text-color);
    text-decoration: none;
    font-size: 16px;
}

.mobile-menu a:hover {
    color: var(--primary-color);
}

.menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 28px;
    cursor: pointer;
    color: var(--dark-color);
    padding: 5px;
}

@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }

    .menu-toggle {
        display: block;
    }

    .hero-title {
        font-size: 36px;
    }

    .hero-subtitle {
        font-size: 18px;
    }

    .section-title {
        font-size: 32px;
    }

    .download-title {
        font-size: 36px;
    }

    .download-auto {
        flex-direction: column;
    }

    .download-auto p {
        text-align: center;
    }

    .error-title {
        font-size: 42px;
    }

    .hero-buttons,
    .error-actions {
        flex-direction: column;
    }

    .btn {
        width: 100%;
    }
}

@media (max-width: 480px) {
    .hero {
        padding: 60px 0;
    }

    .hero-title {
        font-size: 28px;
    }

    .stat-number {
        font-size: 32px;
    }

    .features-grid,
    .platforms-grid,
    .requirements-grid,
    .info-grid {
        grid-template-columns: 1fr;
    }
}

.scroll-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    color: var(--white);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    box-shadow: var(--shadow-hover);
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s;
    z-index: 999;
}

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

.scroll-to-top:hover {
    background: #3367d6;
    transform: translateY(-3px);
}

.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--white);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    transition: opacity 0.5s;
}

.loading-overlay.hidden {
    opacity: 0;
    pointer-events: none;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 4px solid var(--light-bg);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

.fade-in {
    animation: fadeIn 0.6s ease-in;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.smooth-scroll {
    scroll-behavior: smooth;
}