/* Base Styles */
:root {
    --primary-color: #1a73e8;
    --primary-hover: #1765cc;
    --text-main: #202124;
    --text-muted: #5f6368;
    --bg-light: #f8f9fa;
    --border-color: #dadce0;
    --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
}

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

body {
    font-family: var(--font-family);
    color: var(--text-main);
    line-height: 1.6;
    background-color: #fff;
}

.container {
    max-width: 1140px;
    margin: 0 auto;
    padding: 0 20px;
}

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

/* Header */
header {
    background-color: #fff;
    border-bottom: 1px solid var(--border-color);
    padding: 15px 0;
    position: sticky;
    top: 0;
    z-index: 1000;
}

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

.logo a {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.2rem;
    font-weight: bold;
    color: var(--text-main);
    text-decoration: none;
}

nav ul {
    list-style: none;
    display: flex;
    gap: 20px;
}

nav a {
    color: var(--text-muted);
    font-weight: 500;
    padding: 5px 10px;
    border-radius: 4px;
}

nav a:hover, nav a.active {
    color: var(--primary-color);
    text-decoration: none;
    background-color: var(--bg-light);
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #e8f0fe 0%, #fff 100%);
    padding: 80px 0;
    text-align: center;
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 20px;
    color: #202124;
}

.subtitle {
    font-size: 1.2rem;
    color: var(--text-muted);
    max-width: 700px;
    margin: 0 auto 40px;
}

.download-box {
    background: #fff;
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    max-width: 500px;
    margin: 0 auto;
}

.version-info {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-bottom: 20px;
}

.btn {
    display: inline-block;
    padding: 12px 24px;
    border-radius: 24px;
    font-weight: bold;
    text-align: center;
    cursor: pointer;
    transition: background-color 0.2s;
}

.btn-primary {
    background-color: var(--primary-color);
    color: #fff;
    border: none;
}

.btn-primary:hover {
    background-color: var(--primary-hover);
    text-decoration: none;
    color: #fff;
}

.btn-large {
    font-size: 1.1rem;
    padding: 15px 40px;
    width: 100%;
}

.security-badge {
    margin-top: 15px;
    font-size: 0.85rem;
    color: #0d652d;
    font-weight: 500;
}

/* Features */
.features-summary {
    padding: 60px 20px;
    text-align: center;
}

.features-summary h2 {
    font-size: 2rem;
    margin-bottom: 40px;
}

.grid-3 {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.card {
    background: var(--bg-light);
    padding: 30px;
    border-radius: 8px;
    text-align: left;
    border: 1px solid var(--border-color);
}

.card h3 {
    margin-bottom: 15px;
    color: var(--text-main);
    font-size: 1.25rem;
}

.card p {
    color: var(--text-muted);
}

/* SEO Content */
.seo-content {
    padding: 40px 20px 80px;
    border-top: 1px solid var(--border-color);
}

.seo-content h2, .seo-content h3 {
    margin: 25px 0 15px;
    color: var(--text-main);
}

.seo-content p {
    margin-bottom: 15px;
    color: var(--text-muted);
}

.seo-content ol {
    margin-left: 20px;
    margin-bottom: 20px;
    color: var(--text-muted);
}

.seo-content ol li {
    margin-bottom: 10px;
}

/* Footer */
footer {
    background-color: var(--bg-light);
    border-top: 1px solid var(--border-color);
    padding: 40px 0 20px;
    text-align: center;
    font-size: 0.9rem;
    color: var(--text-muted);
}

.footer-links {
    margin-bottom: 20px;
}

.footer-links a {
    margin: 0 10px;
    color: var(--text-muted);
}

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

footer p {
    margin-bottom: 10px;
}