:root {
    --primary-color: #2563eb;
    --text-color: #1f2937;
    --bg-color: #ffffff;
    --secondary-bg: #f3f4f6;
    --border-color: #e5e7eb;
    --max-width: 900px;
}

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

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

nav {
    border-bottom: 1px solid var(--border-color);
    padding: 1.5rem 0;
    position: sticky;
    top: 0;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    z-index: 100;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 2rem;
}

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

.logo {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
}

.nav-links a {
    margin-left: 2rem;
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: color 0.2s;
}

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

header {
    padding: 6rem 0 4rem;
    text-align: center;
}

h1 {
    font-size: 3rem;
    line-height: 1.2;
    margin-bottom: 1.5rem;
    color: #111827;
}

.subtitle {
    font-size: 1.25rem;
    color: #4b5563;
    max-width: 600px;
    margin: 0 auto 2.5rem;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
    padding: 0.875rem 2rem;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    display: inline-block;
    transition: transform 0.2s, background-color 0.2s;
}

.btn-primary:hover {
    background-color: #1d4ed8;
    transform: translateY(-1px);
}

main {
    padding: 4rem 0;
}

.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2.5rem;
    margin-top: 2rem;
}

.feature-card {
    padding: 2rem;
    border: 1px solid var(--border-color);
    border-radius: 12px;
    background: var(--secondary-bg);
}

.feature-card h3 {
    margin-bottom: 1rem;
    color: #111827;
    font-size: 1.5rem;
}

.privacy-content {
    background: var(--secondary-bg);
    padding: 3rem;
    border-radius: 16px;
    margin-top: 2rem;
}

.privacy-content h2 {
    margin-bottom: 1.5rem;
    font-size: 2rem;
}

.privacy-content ul {
    list-style-type: none;
    margin: 1.5rem 0;
}

.privacy-content li {
    position: relative;
    padding-left: 1.5rem;
    margin-bottom: 1rem;
}

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

footer {
    padding: 4rem 0;
    border-top: 1px solid var(--border-color);
    text-align: center;
    color: #6b7280;
    font-size: 0.875rem;
}

@media (max-width: 640px) {
    h1 { font-size: 2.25rem; }
    header { padding: 4rem 0 2rem; }
}