/* === 基本設定 === */
:root {
    --base-bg: #fdfdfd;
    --main-text: #333;
    --accent-color: #1E3A8A; /* ← ここだけ変更（元: #3A506B） */
    --light-gray: #f4f4f4;
    --font-body: 'Noto Sans JP', sans-serif;
    --font-heading: 'Shippori Mincho', serif;
    --header-h: 100px; /* 追加: 固定ヘッダーの高さ */
}

*, *::before, *::after {
    box-sizing: border-box;
}

body {
    font-family: var(--font-body);
    color: var(--main-text);
    background-color: var(--base-bg);
    margin: 0;
    line-height: 1.8;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.container {
    width: 90%;
    max-width: 1120px;
    margin: 0 auto;
}

/* === ヘッダー === */
.site-header {
    padding: 30px 0;
    position: fixed;
    top: 0; left: 0; right: 0;
    width: 100%;
    z-index: 1000;
    background: rgba(34,34,34,0.55);
    backdrop-filter: saturate(150%) blur(6px);
    -webkit-backdrop-filter: saturate(150%) blur(6px);
    border-bottom: 1px solid rgba(255,255,255,0.08);
}
.site-header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.site-logo a {
    font-family: var(--font-heading);
    font-size: 24px;
    font-weight: 500;
    color: #fff;
    text-decoration: none;
    letter-spacing: 1px;
}
.global-nav ul {
    margin: 0;
    padding: 0;
    list-style: none;
    display: flex;
    gap: 30px;
}
.global-nav a {
    color: rgba(255, 255, 255, 0.9);
    text-decoration: none;
    font-size: 15px;
    transition: color 0.3s ease;
}
.global-nav a:hover {
    color: #fff;
}

/* === メインコンテンツの位置調整 === */
main {
    padding-top: var(--header-h);
}
.hero,
.lp-hero {
    margin-top: calc(-1 * var(--header-h));
    padding-top: var(--header-h);
}
[id] { scroll-margin-top: var(--header-h); }

/* === メインビジュアル (Hero) === */
.hero{
  height:100vh;
  min-height:700px;
  background:
    /* ← 左を濃く・右へ行くほど薄く */
    linear-gradient(90deg,
      rgba(0,0,0,.48) 0%,
      rgba(0,0,0,.36) 35%,
      rgba(0,0,0,.20) 65%,
      rgba(0,0,0,.10) 100%
    ),
    url('./img/top.jpg') center/cover no-repeat;
  display:flex;align-items:center;justify-content:center;
  text-align:center;color:#fff;
}
.hero-content {
    animation: fadeIn 2s ease-out;
}
.hero-title {
    font-family: var(--font-heading);
    font-size: 48px;
    font-weight: 600;
    margin: 0 0 20px;
    letter-spacing: 2px;
}
.hero-motto {
    font-family: 'Times New Roman', Times, serif;
    font-style: italic;
    font-size: 22px;
    margin: 0;
    opacity: 0.9;
}

/* === セクション共通 === */
.content-section {
    padding: 100px 0;
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}
.content-section.is-visible {
    opacity: 1;
    transform: translateY(0);
}
.section-title {
    font-family: var(--font-heading);
    font-size: 36px;
    text-align: center;
    margin: 0 0 60px;
    font-weight: 500;
}

/* === 探究所について (About) === */
.about-text {
    max-width: 720px;
    margin: 0 auto;
    text-align: center;
    font-size: 18px;
    font-weight: 300;
}

/* === 活動内容 (Activities) === */
.activities-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 40px;
}
.activity-card {
    background: #fff;
    padding: 40px;
    border: 1px solid #eee;
    border-radius: 5px;
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    height: 100%;
}
.activity-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0,0,0,0.08);
}
.activity-icon {
    color: var(--accent-color);
    margin-bottom: 20px;
}
.activity-title {
    font-family: var(--font-heading);
    font-size: 22px;
    margin: 0 0 15px;
    color: var(--accent-color);
}
.activity-subtitle {
    font-size: 14px;
    color: #888;
    margin-bottom: 15px;
}
.activity-description {
    font-size: 15px;
    font-weight: 300;
}

/* === カードリンクのスタイル === */
.card-link {
    text-decoration: none;
    color: inherit;
    display: block;
}

/* === 主宰者 (Founder) === */
.founder-content {
    display: flex;
    align-items: center;
    gap: 60px;
    max-width: 960px;
    margin: 0 auto;
}
.founder-image img {
    width: 250px;
    height: 250px;
    border-radius: 50%;
    object-fit: cover;
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
}
.founder-text {
    flex: 1;
}
.founder-name {
    font-family: var(--font-heading);
    font-size: 28px;
    margin: 0 0 5px;
}
.founder-title {
    font-size: 16px;
    color: var(--accent-color);
    margin: 0 0 20px;
    font-family: 'Times New Roman', Times, serif;
    font-style: italic;
}
.founder-bio {
    font-weight: 300;
}

/* === フッター === */
.site-footer {
    background: #222;
    color: rgba(255, 255, 255, 0.7);
    padding: 60px 0;
    text-align: center;
}
.footer-logo {
    font-family: var(--font-heading);
    font-size: 20px;
    margin-bottom: 20px;
}
.footer-nav ul {
    margin: 0 0 30px;
    padding: 0;
    list-style: none;
    display: flex;
    justify-content: center;
    gap: 25px;
}
.footer-nav a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    font-size: 14px;
}
.footer-nav a:hover {
    color: #fff;
}
.copyright {
    font-size: 12px;
    opacity: 0.5;
}

/* === アニメーション === */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

/* === レスポンシブ対応 === */
@media (max-width: 768px) {
    .site-header { padding: 20px 0; }

    /* ▼▼ ここが修正点：スマホでもメニューを表示する ▼▼ */
    .site-header .container { 
        flex-wrap: wrap; 
        gap: 8px 16px;
    }
    .global-nav ul {
        gap: 16px;
        flex-wrap: wrap;
        justify-content: center;
    }
    .global-nav {
        display: block;            /* ← 以前の display:none を撤回 */
        width: 100%;
        text-align: center;
        margin-top: 8px;
    }
    /* ▲▲ 修正ここまで ▲▲ */

  .site-logo a{ text-shadow:0 1px 4px rgba(0,0,0,.45); }
    .hero { min-height: 500px; }
    .hero-title { font-size: 32px; }
    .hero-motto { font-size: 18px; }

    .content-section { padding: 80px 0; }
    .section-title { font-size: 28px; }

    .activities-grid { grid-template-columns: 1fr; }
    .founder-content { flex-direction: column; text-align: center; }
}