/* --- 基本設定 & 変数 --- */
:root {
    --primary-blue: #29B6F6; /* ライトブルー */
    --primary-orange: #FFA726; /* オレンジ */
    --primary-green: #66BB6A; /* ライムグリーン */
    --text-dark: #333;
    --text-light: #f4f4f4;
    --bg-white: rgba(255, 255, 255, 0.9);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans JP', sans-serif;
    margin: 0;
    color: var(--text-dark);
    overflow-x: hidden;
    background-color: #333; /* 背景画像読み込みまでの色 */
    transition: background-image 1s ease-in-out;
}

/* --- 背景画像スタイル --- */
.background-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    background-size: cover;
    background-position: center center;
    background-repeat: no-repeat;
    transition: opacity 1s ease-in-out;
    opacity: 0;
}
.background-container.visible {
    opacity: 1;
}

/* --- 共通レイアウト --- */
.full-screen {
    min-height: 100vh; /* 高さを「最低でも画面100%」とし、コンテンツに合わせて伸びるように変更 */
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 5rem 2rem; /* 全てのセクションに十分な上下の余白を確保 */
    box-sizing: border-box;
    position: relative;
    color: var(--text-light);
    text-shadow: 0 2px 4px rgba(0,0,0,0.5);
}

.section-content {
    background: rgba(0, 0, 0, 0.5);
    padding: 2rem 4rem; /* paddingを元のシンプルな状態に戻す */
    border-radius: 20px;
    width: 100%;
    max-width: 1200px;
    text-align: center;
    backdrop-filter: blur(5px);
}

h1, h2, h3 {
    font-family: 'Roboto', sans-serif;
    font-weight: 700;
}

h2 {
    font-size: 2.8rem;
    margin-bottom: 2rem;
    color: var(--text-light);
}

p {
    line-height: 1.8;
}

/* --- Section 1: イントロダクション --- */
#intro h1 {
    font-size: 3.5rem;
    color: #fff;
    margin-bottom: 2rem;
    min-height: 110px; /* タイプライター表示中のガタツキ防止 */
}

.info-cards-container {
    display: flex;
    flex-wrap: wrap;
    gap: 1.5rem;
    justify-content: center;
}

.info-card {
    background-color: var(--bg-white);
    color: var(--text-dark);
    text-shadow: none;
    padding: 1.5rem;
    border-radius: 15px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
    width: 200px;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.info-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.15);
}

.info-card.wide {
    width: 100%;
    max-width: 860px;
}

.info-card .icon {
    font-size: 2rem;
    margin-bottom: 1rem;
    color: var(--primary-green);
}

.info-card h3 {
    margin: 0 0 0.5rem 0;
    color: #333;
}

.info-card p {
    margin: 0;
    font-size: 0.95rem;
}

/* --- Section 2: 活動紹介 --- */
.subsection-title {
    margin-top: 3rem;
    margin-bottom: 1rem;
}
.activities-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    grid-auto-rows: 350px; /* タイルの高さを確保 */
}

.activity-tile {
    border-radius: 15px;
    overflow: hidden;
    position: relative;
    box-shadow: 0 5px 20px rgba(0,0,0,0.2);
    text-shadow: none;
    transition: transform 0.3s ease;
}

.activity-tile:hover {
    transform: scale(1.05);
}

.activity-tile img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.activity-tile .tile-content {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 100%; /* 高さをタイル全体に広げる */
     /* 背景グラデーションを濃く、範囲を広くして視認性を向上 */
    background: linear-gradient(to top, rgba(0,0,0,0.95)20%, rgba(0,0,0,0.7) 60%, transparent 100%);
    padding: 1.5rem;
    color: #fff;

    /* Flexboxでコンテンツを下揃えにする */
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    box-sizing: border-box;
}

.activity-tile h3 {
    margin: 0 0 0.5rem 0;
}

.activity-tile p {
    margin: 0;
    font-size: 0.9rem;
    opacity: 0.9;
}

.achievements {
    background-color: var(--bg-white);
    color: var(--text-dark);
    text-shadow: none;
    padding: 1rem 1.5rem;
    border-radius: 50px;
    display: inline-block;
    font-weight: bold;
}

/* --- Section 3: ビジョンと展望 --- */
.timeline {
    position: relative;
    width: 100%;
    max-width: 800px;
    margin: 2rem auto 0;
    padding: 2rem 0;
}

.timeline::after {
    content: '';
    position: absolute;
    width: 4px;
    background-color: var(--primary-blue);
    top: 0;
    bottom: 0;
    left: 50%;
    margin-left: -2px;
    border-radius: 2px;
}

.timeline-item {
    padding: 1rem 2rem;
    position: relative;
    width: 50%;
    box-sizing: border-box;
}

.timeline-item:nth-child(odd) {
    left: 0;
    padding-right: 40px;
    text-align: right;
}

.timeline-item:nth-child(even) {
    left: 50%;
    padding-left: 40px;
    text-align: left;
}

.timeline-item::after {
    content: '';
    position: absolute;
    width: 20px;
    height: 20px;
    background-color: var(--bg-white);
    border: 4px solid var(--primary-blue);
    border-radius: 50%;
    top: 50%;
    transform: translateY(-50%);
    z-index: 1;
}

.timeline-item:nth-child(odd)::after {
    right: -10px;
}

.timeline-item:nth-child(even)::after {
    left: -10px;
}

.timeline-content {
    padding: 1rem;
    background-color: rgba(255,255,255,0.1);
    border-radius: 10px;
    text-shadow: none;
}
.timeline-content h3 {
    color: var(--primary-orange);
}
.timeline-content p {
    font-size: 0.95rem;
}


/* --- レスポンシブ対応 --- */
@media (max-width: 768px) {
    .section-content {
        padding: 2rem 1.5rem;
        backdrop-filter: blur(3px);
    }
    h1 {
        font-size: 2.5rem !important;
        min-height: 80px !important;
    }
    h2 {
        font-size: 2rem;
    }
    .info-card {
        width: calc(50% - 2rem);
    }
    .info-card.wide {
        width: calc(100% - 2rem);
    }
    
    /* Timeline for mobile */
    .timeline::after {
        left: 20px;
    }
    .timeline-item {
        width: 100%;
        padding-left: 50px;
        padding-right: 1rem;
        left: 0 !important;
        text-align: left !important;
    }
    .timeline-item::after {
        left: 10px;
    }
}

@media (max-width: 480px) {
    .info-card {
        width: 100%;
    }
    .achievements {
        font-size: 0.8rem;
        padding: 0.8rem 1rem;
        display: flex;
        flex-direction: column;
        gap: 0.5rem;
        align-items: center;
        border-radius: 15px;
    }
    .achievements span {
        display: block;
    }
}