:root {
    --primary: #1a73e8;
    --primary-dark: #1557b0;
    --primary-light: #e8f0fe;
    --accent: #00c853;
    --accent-dark: #00a844;
    --text: #202124;
    --text-secondary: #5f6368;
    --bg: #ffffff;
    --bg-alt: #f8f9fa;
    --border: #dadce0;
    --shadow: 0 1px 3px rgba(0,0,0,0.12), 0 1px 2px rgba(0,0,0,0.08);
    --shadow-lg: 0 10px 40px rgba(0,0,0,0.1);
    --radius: 12px;
    --radius-sm: 8px;
    --max-width: 1200px;
    --transition: 0.2s ease;
}

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

html { scroll-behavior: smooth; }

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Noto Sans SC', sans-serif;
    color: var(--text);
    background: var(--bg);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

a { color: var(--primary); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--primary-dark); }

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}

nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: rgba(255,255,255,0.95);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    transition: box-shadow var(--transition);
}

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

nav .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

nav .logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text);
}

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

nav .nav-links {
    display: flex;
    align-items: center;
    gap: 32px;
    list-style: none;
}

nav .nav-links a {
    color: var(--text-secondary);
    font-size: 0.9375rem;
    font-weight: 500;
    transition: color var(--transition);
}

nav .nav-links a:hover { color: var(--primary); }

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 28px;
    border-radius: var(--radius-sm);
    font-size: 1rem;
    font-weight: 600;
    border: none;
    cursor: pointer;
    transition: all var(--transition);
    text-decoration: none;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    color: white;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(26,115,232,0.4);
}

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

.btn-accent:hover {
    background: var(--accent-dark);
    color: white;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(0,200,83,0.4);
}

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

.btn-outline:hover {
    background: var(--primary-light);
    color: var(--primary-dark);
}

.btn-lg { padding: 16px 36px; font-size: 1.125rem; }

.hero {
    padding: 140px 0 80px;
    text-align: center;
    background: linear-gradient(180deg, var(--primary-light) 0%, var(--bg) 100%);
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 800;
    line-height: 1.15;
    margin-bottom: 20px;
    letter-spacing: -0.02em;
}

.hero h1 .highlight {
    background: linear-gradient(135deg, var(--primary), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero p {
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto 36px;
}

.hero .cta-group {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
    flex-wrap: wrap;
}

.hero .badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 14px;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 20px;
    font-size: 0.8125rem;
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.hero .badge svg { width: 16px; height: 16px; color: var(--accent); }

section { padding: 80px 0; }

section.alt { background: var(--bg-alt); }

section h2 {
    font-size: 2.25rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 16px;
    letter-spacing: -0.01em;
}

section .subtitle {
    text-align: center;
    color: var(--text-secondary);
    font-size: 1.125rem;
    max-width: 600px;
    margin: 0 auto 48px;
}

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

.feature-card {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 32px;
    transition: all var(--transition);
}

.feature-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-2px);
    border-color: var(--primary);
}

.feature-card .icon {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 16px;
    font-size: 1.5rem;
}

.feature-card .icon.blue { background: #e8f0fe; color: var(--primary); }
.feature-card .icon.green { background: #e6f4ea; color: var(--accent); }
.feature-card .icon.orange { background: #fef3e0; color: #f9ab00; }
.feature-card .icon.red { background: #fce8e6; color: #d93025; }
.feature-card .icon.purple { background: #f3e8fd; color: #9334e6; }
.feature-card .icon.teal { background: #e0f7fa; color: #00838f; }

.feature-card h3 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 8px;
}

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

.download-section {
    padding: 80px 0;
    text-align: center;
}

.download-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
    max-width: 900px;
    margin: 0 auto;
}

.download-card {
    background: var(--bg);
    border: 2px solid var(--border);
    border-radius: var(--radius);
    padding: 36px;
    text-align: center;
    transition: all var(--transition);
    position: relative;
}

.download-card:hover {
    border-color: var(--primary);
    box-shadow: var(--shadow-lg);
}

.download-card.recommended {
    border-color: var(--primary);
    background: linear-gradient(180deg, var(--primary-light), var(--bg));
}

.download-card .tag {
    position: absolute;
    top: -12px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--primary);
    color: white;
    padding: 4px 16px;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.download-card h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.download-card .desc {
    color: var(--text-secondary);
    font-size: 0.9375rem;
    margin-bottom: 8px;
}

.download-card .size {
    color: var(--text-secondary);
    font-size: 0.8125rem;
    margin-bottom: 20px;
}

.download-card .btn { width: 100%; }

.privacy-features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 24px;
    margin-top: 48px;
}

.privacy-item {
    text-align: center;
    padding: 24px;
}

.privacy-item .icon-circle {
    width: 64px;
    height: 64px;
    border-radius: 50%;
    background: var(--primary-light);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 16px;
    font-size: 1.5rem;
}

.privacy-item h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 6px;
}

.privacy-item p {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

footer {
    background: var(--bg-alt);
    border-top: 1px solid var(--border);
    padding: 48px 0 24px;
}

footer .container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 24px;
}

footer .footer-links {
    display: flex;
    gap: 32px;
    list-style: none;
}

footer .footer-links a {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

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

footer .copyright {
    color: var(--text-secondary);
    font-size: 0.8125rem;
}

@media (max-width: 768px) {
    .hero h1 { font-size: 2.25rem; }
    .hero p { font-size: 1.0625rem; }
    section h2 { font-size: 1.75rem; }
    nav .nav-links { gap: 16px; }
    nav .nav-links a { font-size: 0.8125rem; }
    .btn-lg { padding: 14px 28px; font-size: 1rem; }
    .download-cards { grid-template-columns: 1fr; }
}