/* --- リセットCSSと共通設定 --- */
* {
    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: #333;
    background-color: #f9f9f9;
}

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

/* 共通パーツ：幅の制限 */
.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
}

/* --- ヘッダー --- */
header {
    background-color: #ffffff;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 0;
}

.nav-links {
    display: flex;
    gap: 20px;
}

.nav-links a:hover {
    color: #007bff;
    transition: color 0.3s;
}

/* --- ヒーローセクション --- */
.hero {
    background: linear-gradient(rgba(0, 0, 0, 0.5), rgba(0, 0, 0, 0.5)), url('https://via.placeholder.com/1200x600') no-repeat center center/cover;
    height: 60vh;
    display: flex;
    justify-content: center;
    align-items: center;
    text-align: center;
    color: #fff;
}

.hero-content h2 {
    font-size: 2.5rem;
    margin-bottom: 15px;
}

.hero-content p {
    font-size: 1.2rem;
    margin-bottom: 25px;
}

/* ボタン */
.btn {
    display: inline-block;
    background-color: #007bff;
    color: #fff;
    padding: 10px 25px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1rem;
    transition: background 0.3s;
}

.btn:hover {
    background-color: #0056b3;
}

/* --- 一般セクション --- */
.section {
    padding: 60px 0;
}

.section h2 {
    font-size: 2rem;
    margin-bottom: 20px;
    border-left: 5px solid #007bff;
    padding-left: 10px;
}

/* --- フッター --- */
footer {
    background-color: #333;
    color: #fff;
    text-align: center;
    padding: 20px 0;
    margin-top: 40px;
}

/* --- レスポンシブ対応（スマホ向け） --- */
@media (max-width: 768px) {
    .header-container {
        flex-direction: column;
        gap: 10px;
    }
    
    .hero-content h2 {
        font-size: 1.8rem;
    }
}