/* ベース設定と変数 */
:root {
    --bg-color: #0a0a0a;
    --bg-light: #181818;
    --text-primary: #f0f0f0;
    --text-secondary: #a0a0a0;
    --accent-gold: #d4af37;
    --accent-red: #c41e3a;
    --font-heading: 'Shippori Mincho', serif;
    --font-body: 'Shippori Mincho', serif;
    /* 和風の統一感を出すために明朝体ベース */
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    padding: 0;
    font-family: var(--font-body);
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.8;
    overflow-x: hidden;
    letter-spacing: 0.05em;
}

h1,
h2,
h3,
h4,
p {
    margin: 0;
}

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

/* ユーティリティクラス */
.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 5%;
}

.section {
    padding: 100px 0;
    position: relative;
}

.dark-bg {
    background-color: var(--bg-light);
}

.section-title {
    font-family: var(--font-heading);
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: 60px;
    color: var(--text-primary);
    position: relative;
    padding-bottom: 20px;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: linear-gradient(90deg, transparent, var(--accent-red), transparent);
}

.title-gold::after {
    background: linear-gradient(90deg, transparent, var(--accent-gold), transparent);
}

.text-center {
    text-align: center;
}

/* アニメーション用クラス */
.fade-up {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 1s cubic-bezier(0.2, 0.8, 0.2, 1), transform 1s cubic-bezier(0.2, 0.8, 0.2, 1);
}

.fade-in {
    opacity: 0;
    transition: opacity 1.5s ease;
}

.is-visible {
    opacity: 1;
    transform: translateY(0);
}

/* ヒーローセクション */
.hero {
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    /* 代替のグラデーション、背景画像がロードされなかった場合用 */
    background: linear-gradient(to bottom, rgba(10, 10, 10, 0.4), rgba(10, 10, 10, 1)), url('images/hero_bg.png') center/cover no-repeat fixed;
    text-align: center;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(circle, transparent 20%, #0a0a0a 120%);
    z-index: 1;
}

.hero-content {
    position: relative;
    z-index: 2;
    padding: 0 20px;
}

.hero-subtitle {
    font-size: 1.2rem;
    color: var(--accent-gold);
    margin-bottom: 20px;
    font-weight: 500;
    letter-spacing: 0.2em;
}

.hero-title {
    font-size: 5rem;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 30px;
    text-shadow: 0 5px 15px rgba(0, 0, 0, 0.8);
}

.hero-title .highlight {
    color: var(--accent-red);
    font-size: 6rem;
    display: block;
}

.hero-desc {
    font-size: 1.2rem;
    color: var(--text-secondary);
}

/* スクロールダウンインジケーター */
.scroll-down {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 2;
    padding-top: 60px;
}

.scroll-down span {
    position: absolute;
    top: 0;
    left: 50%;
    width: 24px;
    height: 24px;
    margin-left: -12px;
    border-left: 2px solid #fff;
    border-bottom: 2px solid #fff;
    transform: rotate(-45deg);
    animation: sdb 2s infinite;
    box-sizing: border-box;
}

@keyframes sdb {
    0% {
        transform: rotate(-45deg) translate(0, 0);
        opacity: 0;
    }

    50% {
        opacity: 1;
    }

    100% {
        transform: rotate(-45deg) translate(-20px, 20px);
        opacity: 0;
    }
}

/* コンテンツボックス */
.content-box {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.1);
    padding: 60px;
    border-radius: 4px;
    text-align: center;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(10px);
}

.content-box p {
    font-size: 1.2rem;
    margin-bottom: 20px;
}

.content-box p:last-child {
    margin-bottom: 0;
}

/* 和仁三兄弟カード */
.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.card {
    background: linear-gradient(145deg, #1a1a1a, #121212);
    border: 1px solid #333;
    padding: 40px 30px;
    border-radius: 8px;
    transition: transform 0.4s ease, border-color 0.4s ease, box-shadow 0.4s ease;
    position: relative;
    overflow: hidden;
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: var(--accent-gold);
    transform: scaleY(0);
    transform-origin: top;
    transition: transform 0.4s ease;
}

.card:hover {
    transform: translateY(-10px);
    border-color: rgba(212, 175, 55, 0.3);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.6);
}

.card:hover::before {
    transform: scaleY(1);
}

.card h3 {
    font-size: 1.8rem;
    margin-bottom: 20px;
    color: var(--accent-gold);
}

.card .rank {
    font-size: 1rem;
    color: var(--text-secondary);
    display: block;
    margin-bottom: 5px;
}

.card .kana {
    font-size: 1rem;
    color: #888;
}

/* 歴史セクション */
.history-content {
    background: url('data:image/svg+xml;utf8,<svg width="20" height="20" viewBox="0 0 20 20" xmlns="http://www.w3.org/2000/svg"><circle cx="2" cy="2" r="1" fill="rgba(255,255,255,0.05)"/></svg>') repeat;
    padding: 60px;
    border: 1px solid #222;
    border-left: 4px solid var(--accent-red);
}

.history-text h3 {
    font-size: 1.8rem;
    margin: 40px 0 20px;
    color: #fff;
}

.history-text h3:first-child {
    margin-top: 0;
}

/* ゲームセクション */
.game-section {
    background: linear-gradient(135deg, rgba(20, 20, 20, 0.95), rgba(0, 0, 0, 0.98));
    border-top: 1px solid #333;
    border-bottom: 1px solid #333;
}

.section-tag {
    display: inline-block;
    padding: 5px 15px;
    background-color: rgba(212, 175, 55, 0.1);
    color: var(--accent-gold);
    font-size: 0.9rem;
    letter-spacing: 0.1em;
    border-radius: 50px;
    margin-bottom: 20px;
    border: 1px solid rgba(212, 175, 55, 0.3);
}

.game-showcase {
    max-width: 700px;
    margin: 0 auto;
}

.game-desc {
    font-size: 1.3rem;
    line-height: 2;
    margin-bottom: 50px;
    color: #ddd;
}

.btn-wrap {
    display: flex;
    justify-content: center;
}

.game-btn {
    display: inline-flex;
    align-items: center;
    background: linear-gradient(45deg, #8B0000, var(--accent-red));
    color: #fff;
    padding: 20px 50px;
    font-size: 1.5rem;
    font-weight: 600;
    border-radius: 4px;
    border: 1px solid #ff4d6d;
    box-shadow: 0 0 20px rgba(196, 30, 58, 0.4);
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    position: relative;
    overflow: hidden;
}

.game-btn::after {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 50%;
    height: 100%;
    background: linear-gradient(to right, transparent, rgba(255, 255, 255, 0.3), transparent);
    transform: skewX(-20deg);
    transition: left 0.5s ease;
}

.game-btn:hover {
    box-shadow: 0 0 40px rgba(196, 30, 58, 0.8);
    transform: scale(1.05);
}

.game-btn:hover::after {
    left: 200%;
}

.btn-icon {
    font-size: 1.2em;
    margin-right: 15px;
}

/* 動画埋め込み・サムネイルリンク */
.video-container {
    position: relative;
    padding-bottom: 56.25%;
    /* 16:9 ratio */
    height: 0;
    overflow: hidden;
    border-radius: 8px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.6);
    border: 1px solid #333;
    background: #000;
}

.video-container iframe,
.video-container img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.thumbnail-link a:hover img {
    transform: scale(1.05);
}

.play-overlay {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 80px;
    height: 80px;
    background: rgba(196, 30, 58, 0.8);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.5);
    transition: all 0.3s ease;
}

.thumbnail-link a:hover .play-overlay {
    background: rgba(212, 175, 55, 0.9);
    transform: translate(-50%, -50%) scale(1.1);
}

.play-overlay span {
    color: #fff;
    font-size: 2rem;
    margin-left: 5px;
    /* 再生マークの中央寄せ調整 */
}

/* リソースリンク */
.resource-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.resource-list li {
    margin-bottom: 20px;
}

.resource-list a {
    display: block;
    background: #111;
    padding: 30px;
    border-radius: 4px;
    border: 1px solid #222;
    transition: all 0.3s ease;
    position: relative;
}

.resource-list a::after {
    content: '→';
    position: absolute;
    right: 30px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--accent-gold);
    font-size: 1.5rem;
    opacity: 0;
    transition: all 0.3s ease;
}

.resource-list a:hover {
    background: #1a1a1a;
    border-color: var(--accent-gold);
}

.resource-list a:hover::after {
    opacity: 1;
    right: 20px;
}

.link-title {
    display: block;
    font-size: 1.3rem;
    color: var(--accent-gold);
    margin-bottom: 10px;
}

.link-desc {
    color: var(--text-secondary);
    font-size: 1rem;
}

/* フッター */
.footer {
    background-color: #050505;
    text-align: center;
    padding: 40px 20px;
    font-size: 0.9rem;
    color: #666;
    border-top: 1px solid #1a1a1a;
}

/* レスポンシブ */
@media (max-width: 768px) {
    .hero-title {
        font-size: 3rem;
    }

    .hero-title .highlight {
        font-size: 3.5rem;
    }

    .section {
        padding: 60px 0;
    }

    .content-box,
    .history-content {
        padding: 30px;
    }

    .game-btn {
        padding: 15px 30px;
        font-size: 1.2rem;
    }
}