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

:root {
    --primary: #0ea5e9;
    --primary-dark: #0284c7;
    --primary-light: #38bdf8;
    --secondary: #8b5cf6;
    --accent: #f43f5e;
    --dark: #0f172a;
    --dark-light: #475569;
    --bg: #0f172a;
    --bg-white: #1e293b;
    --border: #334155;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.5);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.6);
    --gradient-1: linear-gradient(135deg, #0ea5e9 0%, #3b82f6 100%);
    --gradient-2: linear-gradient(135deg, #8b5cf6 0%, #a855f7 100%);
    --gradient-3: linear-gradient(135deg, #f43f5e 0%, #ec4899 100%);
    --gradient-4: linear-gradient(135deg, #10b981 0%, #059669 100%);
    --gradient-5: linear-gradient(135deg, #f59e0b 0%, #d97706 100%);
    --gradient-dark: linear-gradient(180deg, #0f172a 0%, #1e293b 100%);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: #e2e8f0;
    background: var(--bg);
    overflow-x: hidden;
}

.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 28px;
}

/* ===== Header ===== */
.header {
    background: rgba(15, 23, 42, 0.95);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    transition: all 0.3s ease;
}

.header.scrolled {
    background: rgba(15, 23, 42, 0.98);
    box-shadow: var(--shadow-lg);
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 80px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 14px;
    font-size: 26px;
    font-weight: 800;
    color: #fff;
    text-decoration: none;
    letter-spacing: -1px;
    background: var(--gradient-1);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.logo svg {
    width: 40px;
    height: 40px;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 8px;
}

.nav-menu a {
    text-decoration: none;
    color: #94a3b8;
    font-weight: 600;
    font-size: 15px;
    padding: 12px 24px;
    border-radius: 10px;
    transition: all 0.3s ease;
}

.nav-menu a:hover,
.nav-menu a.active {
    color: #fff;
    background: rgba(14, 165, 233, 0.15);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 16px 36px;
    border: none;
    border-radius: 12px;
    font-size: 15px;
    font-weight: 700;
    text-decoration: none;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    letter-spacing: 0.3px;
}

.btn-primary {
    background: var(--gradient-1);
    color: #fff;
    box-shadow: 0 4px 20px rgba(14, 165, 233, 0.4);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 30px rgba(14, 165, 233, 0.6);
}

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

.btn-secondary:hover {
    background: var(--primary-light);
    color: #fff;
    transform: translateY(-3px);
    box-shadow: 0 8px 30px rgba(14, 165, 233, 0.4);
}

.btn-large {
    padding: 18px 44px;
    font-size: 17px;
}

main {
    margin-top: 80px;
}

/* ===== Hero Section ===== */
.hero {
    padding: 180px 0 120px;
    background: var(--gradient-dark);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 900px;
    height: 900px;
    background: radial-gradient(circle, rgba(14, 165, 233, 0.15) 0%, transparent 70%);
    border-radius: 50%;
}

.hero::after {
    content: '';
    position: absolute;
    bottom: -40%;
    left: -15%;
    width: 700px;
    height: 700px;
    background: radial-gradient(circle, rgba(139, 92, 246, 0.1) 0%, transparent 70%);
    border-radius: 50%;
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 120px;
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-text {
    max-width: 720px;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    background: rgba(14, 165, 233, 0.15);
    color: var(--primary-light);
    padding: 12px 24px;
    border-radius: 50px;
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 36px;
    border: 1px solid rgba(14, 165, 233, 0.3);
}

.hero-title {
    font-size: 76px;
    font-weight: 900;
    margin-bottom: 28px;
    line-height: 1.1;
    color: #fff;
    letter-spacing: -3px;
}

.hero-title span {
    background: var(--gradient-1);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 26px;
    margin-bottom: 28px;
    color: #94a3b8;
    font-weight: 500;
    line-height: 1.4;
}

.hero-description {
    font-size: 19px;
    margin-bottom: 48px;
    color: #64748b;
    line-height: 1.8;
    max-width: 640px;
}

.hero-buttons {
    display: flex;
    gap: 24px;
}

.hero-card {
    background: var(--bg-white);
    border-radius: 32px;
    padding: 56px;
    box-shadow: var(--shadow-xl);
    border: 1px solid var(--border);
    position: relative;
    overflow: hidden;
}

.hero-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient-1);
}

.hero-card svg {
    width: 100%;
    height: auto;
}

/* ===== Features Section ===== */
.features {
    padding: 160px 0;
    background: var(--bg);
}

.section-header {
    text-align: center;
    margin-bottom: 120px;
}

.section-title {
    font-size: 60px;
    font-weight: 800;
    margin-bottom: 24px;
    color: #fff;
    letter-spacing: -2px;
}

.section-subtitle {
    font-size: 22px;
    color: #94a3b8;
    max-width: 640px;
    margin: 0 auto;
    line-height: 1.6;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 36px;
}

.feature-card {
    background: var(--bg-white);
    border: 1px solid var(--border);
    border-radius: 28px;
    padding: 56px 40px;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
}

.feature-card::before {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: 28px;
    padding: 2px;
    background: transparent;
    -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    -webkit-mask-composite: xor;
    mask-composite: exclude;
    transition: background 0.4s ease;
}

.feature-card:hover::before {
    background: var(--gradient-1);
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-xl);
    border-color: transparent;
    background: #1e293b;
}

.feature-icon {
    width: 80px;
    height: 80px;
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 36px;
    background: var(--gradient-1);
    box-shadow: 0 10px 30px rgba(14, 165, 233, 0.4);
}

.feature-icon svg {
    width: 40px;
    height: 40px;
    color: #fff;
}

.feature-card:nth-child(2) .feature-icon {
    background: var(--gradient-2);
    box-shadow: 0 10px 30px rgba(139, 92, 246, 0.4);
}

.feature-card:nth-child(3) .feature-icon {
    background: var(--gradient-3);
    box-shadow: 0 10px 30px rgba(244, 63, 94, 0.4);
}

.feature-card:nth-child(4) .feature-icon {
    background: var(--gradient-4);
    box-shadow: 0 10px 30px rgba(16, 185, 129, 0.4);
}

.feature-card:nth-child(5) .feature-icon {
    background: var(--gradient-5);
    box-shadow: 0 10px 30px rgba(245, 158, 11, 0.4);
}

.feature-card:nth-child(6) .feature-icon {
    background: linear-gradient(135deg, #06b6d4 0%, #0891b2 100%);
}

.feature-card h3 {
    font-size: 28px;
    margin-bottom: 18px;
    color: #fff;
    font-weight: 700;
}

.feature-card p {
    font-size: 18px;
    color: #94a3b8;
    line-height: 1.7;
}

/* ===== Stats Section ===== */
.stats {
    padding: 140px 0;
    background: var(--gradient-1);
    color: #fff;
    position: relative;
    overflow: hidden;
}

.stats::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url("data:image/svg+xml,%3Csvg width='100' height='100' viewBox='0 0 100 100' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.08'%3E%3Cpath d='M0 0h50v50H0V0zm50 50h50v50H50V50zm0-50h2l-2 2V0zm0 4l4-4h2L50 10V8zm0 4L58 4h2L50 14v-2zm0 4L62 0h2L50 18v-2zm0 4L66 0h2L50 22v-2zm0 4L70 0h2L50 26v-2zm0 4L74 0h2L50 30v-2zm0 4L78 0h2L50 34v-2zm0 4L82 0h2L50 38v-2zm0 4L86 0h2L50 42v-2zm0 4L90 0v2L54 50h-2zm4 0L92 4v2L56 50h-2zm4 0L96 8v2L60 50h-2zm4 0l20-20v2L64 50h-2zm4 0l16-16v2L68 50h-2zm4 0l12-12v2L72 50h-2zm4 0l8-8v2l-6 6h-2zm4 0l4-4v2l-2 2h-2z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 56px;
    text-align: center;
    position: relative;
    z-index: 1;
}

.stat-item {
    padding: 36px 20px;
}

.stat-number {
    font-size: 72px;
    font-weight: 800;
    margin-bottom: 20px;
    letter-spacing: -2px;
    line-height: 1;
    text-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
}

.stat-label {
    font-size: 18px;
    font-weight: 600;
    opacity: 0.95;
    text-transform: uppercase;
    letter-spacing: 2px;
}

/* ===== CTA Section ===== */
.cta {
    padding: 160px 0;
    background: var(--bg);
}

.cta-box {
    background: linear-gradient(135deg, #1e293b 0%, #0f172a 100%);
    border-radius: 36px;
    padding: 100px 80px;
    text-align: center;
    box-shadow: var(--shadow-xl);
    border: 1px solid var(--border);
    max-width: 1000px;
    margin: 0 auto;
    position: relative;
    overflow: hidden;
}

.cta-box::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient-1);
}

.cta h2 {
    font-size: 56px;
    font-weight: 800;
    margin-bottom: 24px;
    color: #fff;
    letter-spacing: -2px;
}

.cta p {
    font-size: 24px;
    margin-bottom: 56px;
    color: #94a3b8;
    line-height: 1.6;
}

/* ===== Download Page ===== */
.download-hero {
    padding: 180px 0 120px;
    background: var(--gradient-dark);
    text-align: center;
    position: relative;
}

.download-hero::before {
    content: '';
    position: absolute;
    top: -40%;
    left: 50%;
    transform: translateX(-50%);
    width: 800px;
    height: 800px;
    background: radial-gradient(circle, rgba(14, 165, 233, 0.12) 0%, transparent 70%);
    border-radius: 50%;
}

.download-title {
    font-size: 72px;
    font-weight: 800;
    margin-bottom: 28px;
    letter-spacing: -2px;
    color: #fff;
    position: relative;
    z-index: 1;
}

.download-subtitle {
    font-size: 24px;
    margin-bottom: 80px;
    color: #94a3b8;
    position: relative;
    z-index: 1;
}

.download-auto {
    display: inline-flex;
    align-items: center;
    gap: 48px;
    background: var(--bg-white);
    border: 1px solid var(--border);
    border-radius: 28px;
    padding: 64px 72px;
    box-shadow: var(--shadow-lg);
    position: relative;
    z-index: 1;
}

.download-auto svg {
    width: 90px;
    height: 90px;
}

.os-detect {
    font-size: 40px;
    font-weight: 700;
    color: var(--primary-light);
    letter-spacing: -0.5px;
}

.download-platforms {
    padding: 160px 0;
    background: var(--bg);
}

.platforms-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
    gap: 36px;
    margin-top: 120px;
}

.platform-card {
    background: var(--bg-white);
    border: 1px solid var(--border);
    border-radius: 32px;
    padding: 64px 56px;
    text-align: center;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.platform-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary);
    background: #1e293b;
}

.platform-icon {
    width: 100px;
    height: 100px;
    margin: 0 auto 36px;
}

.platform-card h3 {
    font-size: 32px;
    margin-bottom: 18px;
    color: #fff;
    font-weight: 700;
}

.platform-card > p {
    font-size: 18px;
    margin-bottom: 36px;
    color: #94a3b8;
}

.platform-links {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.system-requirements {
    padding: 160px 0;
    background: var(--bg);
}

.requirements-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 36px;
    margin-top: 120px;
}

.requirement-item {
    background: var(--bg-white);
    border: 1px solid var(--border);
    border-radius: 32px;
    padding: 64px 56px;
}

.requirement-item h3 {
    font-size: 30px;
    margin-bottom: 36px;
    color: #fff;
    font-weight: 700;
}

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

.requirement-item li {
    padding: 16px 0;
    padding-left: 40px;
    position: relative;
    color: #94a3b8;
    font-size: 17px;
}

.requirement-item li::before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--primary-light);
    font-weight: 700;
    font-size: 22px;
}

.download-info {
    padding: 160px 0;
    background: var(--bg);
}

.info-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 36px;
    margin-top: 120px;
}

.info-item {
    text-align: center;
    padding: 64px 44px;
    background: var(--bg-white);
    border-radius: 32px;
    transition: all 0.3s ease;
    border: 1px solid transparent;
}

.info-item:hover {
    transform: translateY(-8px);
    background: #1e293b;
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border);
}

.info-icon {
    font-size: 72px;
    margin-bottom: 32px;
}

.info-item h3 {
    font-size: 26px;
    margin-bottom: 18px;
    color: #fff;
    font-weight: 700;
}

.info-item p {
    color: #94a3b8;
    line-height: 1.7;
    font-size: 17px;
}

/* ===== Footer ===== */
.footer {
    background: var(--bg);
    color: #94a3b8;
    padding: 140px 0 60px;
    border-top: 1px solid var(--border);
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 72px;
    margin-bottom: 80px;
}

.footer-section h4 {
    font-size: 17px;
    margin-bottom: 36px;
    color: #fff;
    font-weight: 700;
    letter-spacing: 0.3px;
}

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

.footer-section li {
    margin-bottom: 18px;
}

.footer-section a {
    color: #94a3b8;
    text-decoration: none;
    transition: all 0.3s;
    font-size: 16px;
}

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

.footer-bottom {
    text-align: center;
    padding-top: 56px;
    border-top: 1px solid var(--border);
    color: #64748b;
    font-size: 15px;
}

/* ===== 404 Page ===== */
.page-404 .error-main {
    min-height: calc(100vh - 80px);
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient-dark);
}

.error-content {
    text-align: center;
    padding: 140px 28px;
    max-width: 640px;
}

.error-illustration {
    margin-bottom: 64px;
}

.error-title {
    font-size: 140px;
    font-weight: 800;
    margin-bottom: 36px;
    background: var(--gradient-1);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -4px;
}

.error-description {
    font-size: 22px;
    color: #94a3b8;
    margin-bottom: 64px;
    line-height: 1.8;
}

.error-actions {
    display: flex;
    gap: 24px;
    justify-content: center;
    margin-bottom: 80px;
}

.error-help {
    background: var(--bg-white);
    border: 1px solid var(--border);
    padding: 64px;
    border-radius: 32px;
    text-align: left;
}

.error-help h3 {
    font-size: 26px;
    margin-bottom: 32px;
    color: #fff;
    font-weight: 700;
}

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

.error-help li {
    margin-bottom: 20px;
    font-size: 17px;
}

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

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

/* ===== Mobile Menu ===== */
.mobile-menu {
    display: none;
    position: absolute;
    top: 80px;
    left: 0;
    right: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow-xl);
    padding: 28px;
    z-index: 999;
}

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

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

.mobile-menu a {
    display: block;
    padding: 18px 28px;
    color: #94a3b8;
    text-decoration: none;
    font-size: 17px;
    font-weight: 600;
    border-radius: 12px;
    transition: all 0.3s ease;
}

.mobile-menu a:hover {
    background: rgba(14, 165, 233, 0.15);
    color: #fff;
}

.menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 32px;
    cursor: pointer;
    color: #fff;
    padding: 8px;
}

/* ===== Responsive ===== */
@media (max-width: 1024px) {
    .hero-content {
        grid-template-columns: 1fr;
        gap: 80px;
        text-align: center;
    }

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

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

    .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: 52px;
    }

    .section-title {
        font-size: 44px;
    }

    .download-title {
        font-size: 48px;
    }

    .error-title {
        font-size: 80px;
    }

    .download-auto {
        flex-direction: column;
        padding: 48px 40px;
    }

    .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-box {
        padding: 64px 40px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 24px;
    }

    .hero {
        padding: 120px 0 100px;
    }

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

    .stat-number {
        font-size: 56px;
    }

    .cta h2 {
        font-size: 36px;
    }
}

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