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

:root {
    --primary: #2563EB;
    --primary-light: #3B82F6;
    --secondary: #7C3AED;
    --accent: #EC4899;
    --bg-light: #FAFAFA;
    --bg-white: #FFFFFF;
    --text-dark: #1F2937;
    --text-gray: #6B7280;
    --text-light: #9CA3AF;
    --border-light: #E5E7EB;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.15);
    --gradient-main: linear-gradient(135deg, #2563EB 0%, #7C3AED 100%);
    --gradient-secondary: linear-gradient(135deg, #EC4899 0%, #8B5CF6 100%);
    --gradient-tertiary: linear-gradient(135deg, #10B981 0%, #3B82F6 100%);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background: var(--bg-light);
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ===== Header ===== */
.header {
    background: var(--bg-white);
    border-bottom: 1px solid var(--border-light);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    transition: all 0.3s ease;
}

.header.scrolled {
    box-shadow: var(--shadow-md);
}

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

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 20px;
    font-weight: 700;
    color: var(--text-dark);
    text-decoration: none;
}

.logo svg {
    width: 32px;
    height: 32px;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 32px;
}

.nav-menu a {
    text-decoration: none;
    color: var(--text-gray);
    font-weight: 500;
    font-size: 14px;
    transition: all 0.3s ease;
    position: relative;
}

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

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: -24px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient-main);
    transition: width 0.3s ease;
}

.nav-menu a:hover::after,
.nav-menu a.active::after {
    width: 100%;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-primary {
    background: var(--gradient-main);
    color: var(--bg-white);
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

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

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

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

main {
    margin-top: 70px;
}

/* ===== Hero Section ===== */
.hero {
    padding: 120px 0 80px;
    background: linear-gradient(180deg, var(--bg-white) 0%, var(--bg-light) 100%);
    position: relative;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    width: 50%;
    height: 100%;
    background: radial-gradient(circle at 80% 50%, rgba(37, 99, 235, 0.08) 0%, transparent 50%);
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
}

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

.hero-badge {
    display: inline-block;
    background: linear-gradient(135deg, rgba(37, 99, 235, 0.1) 0%, rgba(124, 58, 237, 0.1) 100%);
    color: var(--primary);
    padding: 6px 16px;
    border-radius: 20px;
    font-size: 13px;
    font-weight: 600;
    margin-bottom: 24px;
}

.hero-title {
    font-size: 56px;
    font-weight: 800;
    margin-bottom: 24px;
    line-height: 1.1;
    color: var(--text-dark);
    letter-spacing: -1px;
}

.hero-subtitle {
    font-size: 20px;
    margin-bottom: 20px;
    color: var(--text-gray);
    font-weight: 500;
}

.hero-description {
    font-size: 16px;
    margin-bottom: 40px;
    color: var(--text-light);
    line-height: 1.8;
}

.hero-buttons {
    display: flex;
    gap: 16px;
}

.hero-image {
    position: relative;
}

.hero-image svg {
    width: 100%;
    height: auto;
    max-width: 500px;
}

/* ===== Features Section ===== */
.features {
    padding: 100px 0;
    background: var(--bg-white);
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-title {
    font-size: 42px;
    font-weight: 800;
    margin-bottom: 16px;
    color: var(--text-dark);
    letter-spacing: -0.5px;
}

.section-subtitle {
    font-size: 18px;
    color: var(--text-gray);
    max-width: 600px;
    margin: 0 auto;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.feature-card {
    background: var(--bg-white);
    border: 1px solid var(--border-light);
    border-radius: 16px;
    padding: 40px;
    transition: all 0.4s ease;
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: var(--gradient-main);
    transform: scaleX(0);
    transition: transform 0.4s ease;
}

.feature-card:hover::before {
    transform: scaleX(1);
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
    border-color: rgba(37, 99, 235, 0.2);
}

.feature-icon {
    width: 56px;
    height: 56px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 24px;
    background: var(--gradient-main);
}

.feature-icon svg {
    width: 28px;
    height: 28px;
    color: var(--bg-white);
}

.feature-card:nth-child(2) .feature-icon {
    background: var(--gradient-secondary);
}

.feature-card:nth-child(3) .feature-icon {
    background: var(--gradient-tertiary);
}

.feature-card h3 {
    font-size: 22px;
    margin-bottom: 12px;
    color: var(--text-dark);
    font-weight: 700;
}

.feature-card p {
    font-size: 15px;
    color: var(--text-gray);
    line-height: 1.7;
}

/* ===== Stats Section ===== */
.stats {
    padding: 80px 0;
    background: var(--gradient-main);
    color: var(--bg-white);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 40px;
    text-align: center;
}

.stat-item {
    padding: 20px;
}

.stat-number {
    font-size: 56px;
    font-weight: 800;
    margin-bottom: 8px;
    letter-spacing: -1px;
}

.stat-label {
    font-size: 15px;
    font-weight: 500;
    opacity: 0.9;
}

/* ===== CTA Section ===== */
.cta {
    padding: 100px 0;
    background: var(--bg-light);
    text-align: center;
}

.cta-content {
    max-width: 700px;
    margin: 0 auto;
    background: var(--bg-white);
    border-radius: 24px;
    padding: 60px;
    box-shadow: var(--shadow-xl);
    border: 1px solid var(--border-light);
}

.cta h2 {
    font-size: 40px;
    font-weight: 800;
    margin-bottom: 16px;
    color: var(--text-dark);
    letter-spacing: -0.5px;
}

.cta p {
    font-size: 18px;
    margin-bottom: 32px;
    color: var(--text-gray);
}

/* ===== Download Page ===== */
.download-hero {
    padding: 100px 0 80px;
    background: linear-gradient(180deg, var(--bg-white) 0%, var(--bg-light) 100%);
    text-align: center;
}

.download-title {
    font-size: 48px;
    font-weight: 800;
    margin-bottom: 16px;
    letter-spacing: -1px;
    color: var(--text-dark);
}

.download-subtitle {
    font-size: 18px;
    margin-bottom: 48px;
    color: var(--text-gray);
}

.download-auto {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 32px;
    background: var(--bg-white);
    border: 1px solid var(--border-light);
    border-radius: 16px;
    padding: 40px;
    max-width: 600px;
    margin: 0 auto;
    box-shadow: var(--shadow-lg);
}

.download-auto svg {
    width: 56px;
    height: 56px;
}

.os-detect {
    font-size: 28px;
    font-weight: 700;
    color: var(--primary);
}

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

.platforms-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
    margin-top: 60px;
}

.platform-card {
    background: var(--bg-white);
    border: 1px solid var(--border-light);
    border-radius: 16px;
    padding: 40px 32px;
    text-align: center;
    transition: all 0.4s ease;
}

.platform-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
    border-color: rgba(37, 99, 235, 0.3);
}

.platform-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto 20px;
}

.platform-card h3 {
    font-size: 24px;
    margin-bottom: 12px;
    color: var(--text-dark);
    font-weight: 700;
}

.platform-card > p {
    font-size: 14px;
    margin-bottom: 24px;
    color: var(--text-gray);
}

.platform-links {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

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

.requirements-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin-top: 60px;
}

.requirement-item {
    background: var(--bg-white);
    border: 1px solid var(--border-light);
    border-radius: 16px;
    padding: 40px 32px;
}

.requirement-item h3 {
    font-size: 24px;
    margin-bottom: 24px;
    color: var(--text-dark);
    font-weight: 700;
}

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

.requirement-item li {
    padding: 10px 0;
    padding-left: 28px;
    position: relative;
    color: var(--text-gray);
    font-size: 14px;
}

.requirement-item li::before {
    content: "✓";
    position: absolute;
    left: 0;
    color: #10B981;
    font-weight: bold;
}

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

.info-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    margin-top: 60px;
}

.info-item {
    text-align: center;
    padding: 40px 24px;
    background: var(--bg-light);
    border-radius: 16px;
    transition: all 0.3s ease;
}

.info-item:hover {
    transform: translateY(-4px);
    background: var(--bg-white);
    box-shadow: var(--shadow-md);
}

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

.info-item h3 {
    font-size: 20px;
    margin-bottom: 12px;
    color: var(--text-dark);
    font-weight: 700;
}

.info-item p {
    color: var(--text-gray);
    line-height: 1.6;
    font-size: 14px;
}

/* ===== Footer ===== */
.footer {
    background: var(--bg-white);
    color: var(--text-gray);
    padding: 80px 0 32px;
    border-top: 1px solid var(--border-light);
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 48px;
    margin-bottom: 48px;
}

.footer-section h4 {
    font-size: 15px;
    margin-bottom: 24px;
    color: var(--text-dark);
    font-weight: 700;
}

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

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

.footer-section a {
    color: var(--text-gray);
    text-decoration: none;
    transition: all 0.3s;
    font-size: 14px;
}

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

.footer-bottom {
    text-align: center;
    padding-top: 32px;
    border-top: 1px solid var(--border-light);
    color: var(--text-light);
    font-size: 13px;
}

/* ===== 404 Page ===== */
.page-404 .error-main {
    min-height: calc(100vh - 70px);
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-light);
}

.error-content {
    text-align: center;
    padding: 80px 20px;
    max-width: 500px;
}

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

.error-title {
    font-size: 80px;
    font-weight: 900;
    margin-bottom: 24px;
    background: var(--gradient-secondary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -2px;
}

.error-description {
    font-size: 18px;
    color: var(--text-gray);
    margin-bottom: 40px;
    line-height: 1.7;
}

.error-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
    margin-bottom: 48px;
}

.error-help {
    background: var(--bg-white);
    border: 1px solid var(--border-light);
    padding: 40px;
    border-radius: 16px;
    text-align: left;
}

.error-help h3 {
    font-size: 20px;
    margin-bottom: 20px;
    color: var(--text-dark);
    font-weight: 700;
}

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

.error-help li {
    margin-bottom: 12px;
    font-size: 14px;
}

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

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

/* ===== Mobile Menu ===== */
.mobile-menu {
    display: none;
    position: absolute;
    top: 70px;
    left: 0;
    right: 0;
    background: var(--bg-white);
    border-bottom: 1px solid var(--border-light);
    box-shadow: var(--shadow-lg);
    padding: 20px;
    z-index: 999;
}

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

.mobile-menu li {
    margin-bottom: 0;
}

.mobile-menu a {
    display: block;
    padding: 14px 20px;
    color: var(--text-gray);
    text-decoration: none;
    font-size: 15px;
    font-weight: 500;
    border-radius: 8px;
    transition: all 0.3s ease;
}

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

.menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: var(--text-dark);
    padding: 8px;
}

/* ===== Responsive ===== */
@media (max-width: 1024px) {
    .hero-content {
        grid-template-columns: 1fr;
        gap: 40px;
        text-align: center;
    }

    .hero-text {
        max-width: 100%;
    }

    .hero-buttons {
        justify-content: center;
    }

    .hero-image {
        max-width: 400px;
        margin: 0 auto;
    }

    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .requirements-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .info-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

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

    .menu-toggle {
        display: block;
    }

    .hero-title {
        font-size: 40px;
    }

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

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

    .error-title {
        font-size: 56px;
    }

    .download-auto {
        flex-direction: column;
        padding: 32px;
    }

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

    .btn {
        width: 100%;
    }

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

    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .cta-content {
        padding: 40px 24px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 20px;
    }

    .hero {
        padding: 80px 0 60px;
    }

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

    .stat-number {
        font-size: 40px;
    }

    .cta h2 {
        font-size: 28px;
    }
}

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