/* リセットCSS */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Noto Sans JP", sans-serif;
    background-color: #f5f5f5;
    max-width: 100%;
    overflow-x: hidden;
}

/* ヘッダー */
.header {
    background-color: #ffffff;
    border-bottom: 1px solid #e0e0e0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 20px;
    max-width: 100%;
}

.logo {
    font-size: 24px;
    font-weight: bold;
    color: #1e50a2;
}

.logo-number {
    color: #4aa3df;
}

.menu-button {
    width: 40px;
    height: 40px;
    background-color: #1e50a2;
    border: none;
    border-radius: 50%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 5px;
    cursor: pointer;
    padding: 10px;
}

.menu-button span {
    width: 20px;
    height: 2px;
    background-color: #ffffff;
    display: block;
}

/* セクション */
.section {
    width: 100%;
    background-color: #ffffff;
}

.section-image {
    width: 100%;
    height: auto;
    display: block;
}

/* フッター */
.footer {
    background-color: #1e50a2;
    color: #ffffff;
    text-align: center;
    padding: 20px;
    font-size: 12px;
}

/* スマホ最適化 */
@media screen and (max-width: 480px) {
    .header-content {
        padding: 10px 15px;
    }
    
    .logo {
        font-size: 20px;
    }
    
    .menu-button {
        width: 36px;
        height: 36px;
    }
}

/* タブレット・PC（スマホサイズで表示） */
@media screen and (min-width: 481px) {
    body {
        max-width: 480px;
        margin: 0 auto;
        box-shadow: 0 0 20px rgba(0, 0, 0, 0.1);
    }
}