:root {
    --primary-color: #0056b3;
    --secondary-color: #007bff;
    --text-color: #333;
    --bg-color: #f8f9fa;
}

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

body {
    font-family: 'Helvetica Neue', Arial, 'Hiragino Kaku Gothic ProN', 'Hiragino Sans', Meiryo, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 20px;
}

header {
    background-color: #fff;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 100;
}

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

header h1 {
    color: var(--primary-color);
    font-size: 1.5rem;
}

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

nav a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: bold;
    transition: color 0.3s;
}

nav a:hover {
    color: var(--secondary-color);
}

.hero {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: #fff;
    text-align: center;
    padding: 80px 20px;
}

.hero h2 {
    font-size: 2.5rem;
    margin-bottom: 20px;
}

.hero p {
    font-size: 1.2rem;
    margin-bottom: 40px;
}

.btn-download {
    display: inline-block;
    background-color: #fff;
    color: var(--primary-color);
    padding: 15px 30px;
    border-radius: 30px;
    text-decoration: none;
    font-weight: bold;
    font-size: 1.2rem;
    transition: transform 0.3s, box-shadow 0.3s;
}

.btn-download:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 10px rgba(0,0,0,0.2);
}

.features {
    padding: 60px 0;
}

.features h2 {
    text-align: center;
    margin-bottom: 40px;
    color: var(--primary-color);
}

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

.feature-card {
    background: #fff;
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    text-align: center;
}

.feature-card h3 {
    margin-bottom: 15px;
    color: var(--secondary-color);
}

.content {
    padding: 60px 0;
    background: #fff;
    flex: 1;
}

.content h2 {
    margin-bottom: 30px;
    color: var(--primary-color);
    border-bottom: 2px solid var(--primary-color);
    padding-bottom: 10px;
}

.content h3 {
    margin: 30px 0 15px;
    color: var(--secondary-color);
}

.content p, .content ul {
    margin-bottom: 15px;
}

.content ul {
    padding-left: 25px;
}

.official-sites {
    padding: 60px 0;
}

.official-sites h2 {
    text-align: center;
    margin-bottom: 40px;
    color: var(--primary-color);
}

.site-links {
    list-style: none;
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
}

.site-links li a {
    display: block;
    padding: 15px 30px;
    background-color: #fff;
    color: var(--primary-color);
    text-decoration: none;
    font-weight: bold;
    border-radius: 5px;
    transition: background-color 0.3s, color 0.3s;
    border: 1px solid var(--primary-color);
}

.site-links li a:hover {
    background-color: var(--primary-color);
    color: #fff;
}

footer {
    background-color: #333;
    color: #fff;
    text-align: center;
    padding: 20px 0;
    margin-top: auto;
}