@charset "UTF-8";

/* ===================================================================
   基本設定 (Common)
   =================================================================== */
:root {
    --text-color: #222;
    --bg-color: #fff;
    --border-color: #eee;
    --accent-color: #333;
    --spacing-section: 140px;
    --font-main: "Helvetica Neue", Helvetica, Arial, "Noto Sans JP", sans-serif;
}

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

body {
    font-family: var(--font-main);
    color: var(--text-color);
    background-color: var(--bg-color);
    line-height: 2.0;
    letter-spacing: 0.06em;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    /* フッターを最下部に固定するためのFlex設定 */
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

a {
    text-decoration: none;
    color: inherit;
    transition: opacity 0.3s;
}

ul { list-style: none; }

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ===================================================================
   共通パーツ：見出し・ボタン
   =================================================================== */
.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-title {
    font-size: 24px;
    font-weight: 700;
    letter-spacing: 0.1em;
    margin-bottom: 15px;
    text-transform: uppercase;
    color: var(--text-color);
}

.section-subtitle {
    font-size: 12px;
    color: #888;
    font-weight: 400;
}

.btn {
    display: inline-block;
    padding: 14px 60px;
    border: 1px solid var(--text-color);
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 0.1em;
    margin-top: 40px;
    background: #fff;
    transition: all 0.3s ease;
    text-transform: uppercase;
    color: var(--text-color);
    cursor: pointer;
}

.btn:hover {
    background-color: var(--text-color);
    color: #fff;
}

/* フェードアニメーション */
.js-fade {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 1.2s, transform 1.2s;
}
.js-fade.is-shown {
    opacity: 1;
    transform: translateY(0);
}

/* ===================================================================
   共通ヘッダー
   =================================================================== */
header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 90px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 40px;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(5px);
    z-index: 1000;
}

.logo {
    font-size: 18px;
    letter-spacing: 0.15em;
    font-weight: 700;
    color: var(--text-color);
}

.back-link { /* 詳細ページ用 */
    font-size: 12px;
    margin-top: 5px;
    display: block;
    color: #888;
}

/* ハンバーガーメニューボタン */
.menu-trigger {
    cursor: pointer;
    z-index: 1001;
    width: 30px;
    height: 20px;
    position: relative;
}
.menu-trigger span {
    display: block;
    position: absolute;
    width: 100%;
    height: 2px;
    background-color: var(--text-color);
    transition: all 0.4s;
    left: 0;
}
.menu-trigger span:nth-child(1) { top: 0; }
.menu-trigger span:nth-child(2) { top: 9px; }
.menu-trigger span:nth-child(3) { bottom: 0; }

.menu-trigger.active span:nth-child(1) { transform: translateY(9px) rotate(45deg); }
.menu-trigger.active span:nth-child(2) { opacity: 0; }
.menu-trigger.active span:nth-child(3) { transform: translateY(-9px) rotate(-45deg); }

/* モバイルメニュー */
.mobile-menu {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background-color: #fff;
    z-index: 999;
    opacity: 0;
    visibility: hidden;
    transition: 0.5s;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}
.mobile-menu.active { opacity: 1; visibility: visible; }

.mobile-menu ul li {
    margin: 20px 0;
    text-align: center;
    opacity: 0;
    transform: translateY(20px);
    transition: 0.5s;
}
.mobile-menu.active ul li { opacity: 1; transform: translateY(0); }
.mobile-menu.active ul li:nth-child(1) { transition-delay: 0.1s; }
.mobile-menu.active ul li:nth-child(2) { transition-delay: 0.2s; }
.mobile-menu.active ul li:nth-child(3) { transition-delay: 0.3s; }
.mobile-menu.active ul li:nth-child(4) { transition-delay: 0.4s; }
.mobile-menu.active ul li:nth-child(5) { transition-delay: 0.5s; }
.mobile-menu.active ul li:nth-child(6) { transition-delay: 0.6s; }

.mobile-menu a {
    font-size: 24px;
    font-weight: 700;
    letter-spacing: 0.1em;
    display: block;
    color: var(--text-color);
}
.external-link-mark { font-size: 10px; vertical-align: top; margin-left: 5px; }

/* ソーシャルアイコン（メニュー内） */
.social-icons-menu {
    margin-top: 40px;
    display: flex;
    gap: 30px;
    opacity: 0;
    transform: translateY(20px);
    transition: 0.5s;
}
.mobile-menu.active .social-icons-menu { opacity: 1; transform: translateY(0); transition-delay: 0.7s; }
.social-icon { font-size: 24px; color: var(--text-color); transition: opacity 0.3s; }
.social-icon:hover { opacity: 0.6; }

/* ===================================================================
   共通フッター
   =================================================================== */
footer {
    padding: 60px 0;
    text-align: center;
    font-size: 11px;
    font-weight: 500;
    color: #aaa;
    letter-spacing: 0.1em;
    margin-top: auto;
}
.footer-social {
    margin-bottom: 30px;
    display: flex;
    justify-content: center;
    gap: 25px;
}
.footer-social a { font-size: 18px; color: var(--text-color); transition: opacity 0.3s; }
.footer-social a:hover { opacity: 0.6; }

/* ===================================================================
   old_blog.html / 準備中ページ専用スタイル
   =================================================================== */
.main-content {
    flex-grow: 1; 
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding-top: 90px; /* ヘッダーの高さ分 */
}

.message-box {
    border: 1px solid var(--border-color);
    padding: 60px 40px;
    max-width: 600px;
    text-align: center;
    margin: 40px 20px;
}

.message-box h1 {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 30px;
    color: var(--text-color);
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.message-box p {
    font-size: 14px;
    color: #555;
    line-height: 1.8;
    margin-bottom: 10px;
}

.btn-home {
    display: inline-block;
    padding: 14px 60px;
    border: 1px solid var(--text-color);
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 0.1em;
    margin-top: 40px;
    background: #fff;
    transition: all 0.3s ease;
    text-transform: uppercase;
    color: var(--text-color);
}

.btn-home:hover {
    background-color: var(--text-color);
    color: #fff;
}

/* 汎用クラス：テキストセンター寄せ */
.text-center {
    text-align: center;
}

/* ===================================================================
   モバイル対応共通設定
   =================================================================== */
@media (max-width: 768px) {
    :root { --spacing-section: 80px; }
    
    header { padding: 0 20px; height: 70px; }
    
    .logo { font-size: 14px; } /* スマホ用ロゴサイズ */
    
    /* old_blog.html用 */
    .message-box { padding: 40px 20px; }
}