/* --- カラーパレット定義 (年代別: レトロ → 最先端) --- */
:root {
    /* 1980s: セピア/アンバー (レトロ) */
    --c-80s-main: #d97706;
    --c-80s-main-dark: #b45309;
    --c-80s-bg: linear-gradient(135deg, #fffbf0 0%, #fff8e7 100%);

    /* 1990s: ティールグリーン (ポップ/初期デジタル) */
    --c-90s-main: #059669;
    --c-90s-main-dark: #047857;
    --c-90s-bg: linear-gradient(135deg, #f0fdf4 0%, #dcfce7 100%);

    /* 2000s: ロイヤルブルー (IT/ソリッド) */
    --c-00s-main: #2563eb;
    --c-00s-main-dark: #1d4ed8;
    --c-00s-bg: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);

    /* 2010s: ビビッドパープル (スマホ/SNS/高解像度) */
    --c-10s-main: #9333ea;
    --c-10s-main-dark: #7e22ce;
    --c-10s-bg: linear-gradient(135deg, #faf5ff 0%, #f3e8ff 100%);

    /* 2020s: シルバー/グラデーション (未来/ニューロ) */
    --c-20s-main: #1f2937;
    --c-20s-accent: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --c-20s-bg: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);

    --timeline-width: 4px;
    --text-color: #1f2937;
    --text-color-light: #6b7280;

    /* シャドウ */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.12);
    --shadow-xl: 0 20px 50px rgba(0, 0, 0, 0.15);
}

html {
    scroll-behavior: smooth;
    /* アンカーリンクでスムーズに移動 */
}

body {
    font-family: 'Zen Maru Gothic', sans-serif;
    margin: 0;
    padding: 0;
    padding-top: 80px;
    /* TOPページのヒーローセクションと同じ背景を使用 */
    background-image: url('../images/hero-bg.jpg');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    background-attachment: fixed;
    color: var(--text-color);
    line-height: 1.7;
    position: relative;
}

body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: url('images/history-bg.jpg');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    background-attachment: fixed;
    z-index: -2;
    mask: radial-gradient(ellipse at center,
            transparent 0%,
            transparent 40%,
            rgba(0, 0, 0, 0.1) 50%,
            rgba(0, 0, 0, 0.3) 60%,
            rgba(0, 0, 0, 0.5) 70%,
            rgba(0, 0, 0, 0.7) 80%,
            rgba(0, 0, 0, 0.9) 90%,
            rgba(0, 0, 0, 1) 100%);
    -webkit-mask: radial-gradient(ellipse at center,
            transparent 0%,
            transparent 40%,
            rgba(0, 0, 0, 0.1) 50%,
            rgba(0, 0, 0, 0.3) 60%,
            rgba(0, 0, 0, 0.5) 70%,
            rgba(0, 0, 0, 0.7) 80%,
            rgba(0, 0, 0, 0.9) 90%,
            rgba(0, 0, 0, 1) 100%);
}

body::after {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(ellipse at center,
            rgba(255, 255, 255, 1) 0%,
            rgba(255, 255, 255, 0.95) 15%,
            rgba(255, 255, 255, 0.8) 30%,
            rgba(255, 255, 255, 0.5) 50%,
            rgba(255, 255, 255, 0.2) 70%,
            rgba(255, 255, 255, 0) 100%);
    z-index: -1;
    pointer-events: none;
}

/* ページタイトル */
.page-title-section {
    padding: 100px 20px 40px;
    text-align: center;
    position: relative;
    z-index: 2;
}

.page-title {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 700;
    color: #4682B4;
    margin: 0;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.1);
    position: relative;
    display: inline-block;
}

.page-title::after {
    content: '';
    position: absolute;
    bottom: -15px;
    left: 50%;
    transform: translateX(-50%);
    width: 120px;
    height: 4px;
    background: linear-gradient(90deg, #FFB6C1, #87CEEB);
    border-radius: 2px;
}

/* --- ナビゲーション (アンカーリンク) --- */
.nav-sticky {
    position: fixed;
    left: 20px;
    top: 50%;
    transform: translateY(-50%);
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    z-index: 999;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
    padding: 20px 12px;
    display: flex;
    flex-direction: column;
    gap: 10px;
    border-radius: 20px;
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.nav-btn {
    text-decoration: none;
    font-family: 'Zen Maru Gothic', sans-serif;
    font-weight: 700;
    padding: 10px 20px;
    border-radius: 25px;
    font-size: 0.9rem;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    border: 2px solid transparent;
    position: relative;
    overflow: hidden;
    letter-spacing: 0.5px;
}

.nav-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    transition: left 0.5s;
}

.nav-btn:hover::before {
    left: 100%;
}

/* 各年代ボタンの色 */
.nav-btn.n80s {
    color: var(--c-80s-main);
    border-color: var(--c-80s-main);
    background: rgba(217, 119, 6, 0.05);
}

.nav-btn.n80s:hover {
    background: linear-gradient(135deg, var(--c-80s-main) 0%, var(--c-80s-main-dark) 100%);
    color: #fff;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(217, 119, 6, 0.4);
}

.nav-btn.n90s {
    color: var(--c-90s-main);
    border-color: var(--c-90s-main);
    background: rgba(5, 150, 105, 0.05);
}

.nav-btn.n90s:hover {
    background: linear-gradient(135deg, var(--c-90s-main) 0%, var(--c-90s-main-dark) 100%);
    color: #fff;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(5, 150, 105, 0.4);
}

.nav-btn.n00s {
    color: var(--c-00s-main);
    border-color: var(--c-00s-main);
    background: rgba(37, 99, 235, 0.05);
}

.nav-btn.n00s:hover {
    background: linear-gradient(135deg, var(--c-00s-main) 0%, var(--c-00s-main-dark) 100%);
    color: #fff;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(37, 99, 235, 0.4);
}

.nav-btn.n10s {
    color: var(--c-10s-main);
    border-color: var(--c-10s-main);
    background: rgba(147, 51, 234, 0.05);
}

.nav-btn.n10s:hover {
    background: linear-gradient(135deg, var(--c-10s-main) 0%, var(--c-10s-main-dark) 100%);
    color: #fff;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(147, 51, 234, 0.4);
}

.nav-btn.n20s {
    color: var(--c-20s-main);
    border-color: var(--c-20s-main);
    background: rgba(31, 41, 55, 0.05);
}

.nav-btn.n20s:hover {
    background: linear-gradient(135deg, #1f2937 0%, #111827 100%);
    color: #fff;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(31, 41, 55, 0.4);
}


/* --- タイムライン全体 --- */
.timeline-container {
    position: relative;
    z-index: 2;
    max-width: 1200px;
    margin: 0 auto;
    padding-bottom: 100px;
    overflow: hidden;
    /* 横スクロール防止 */
    box-sizing: border-box;
}

/* 中央の線 */
.timeline-spine {
    position: absolute;
    left: 20px;
    top: 0;
    bottom: 0;
    width: var(--timeline-width);
    background: #d1d5db;
    transform: none;
    z-index: 0;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.05);
}

.timeline-spine::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 8px;
    height: 8px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 50%;
    box-shadow: 0 0 15px rgba(102, 126, 234, 0.5);
}

/* --- 年代セクション --- */
.decade-section {
    position: relative;
    padding: 60px 0;
    margin: 10px 0;
    border-radius: 24px;
    transition: all 0.4s ease;
    z-index: 2;
}

/* 年代タイトル */
.decade-title {
    text-align: center;
    font-size: clamp(2rem, 4vw, 3.5rem);
    font-weight: 700;
    color: #4682B4;
    margin: 10px 0 60px;
    padding: 20px 0;
    position: relative;
    z-index: 1;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.1);
    opacity: 0;
    transform: translateY(-20px);
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

.decade-title.animate {
    opacity: 1;
    transform: translateY(0);
}

.decade-title::after {
    content: '';
    position: absolute;
    bottom: 10px;
    left: 50%;
    transform: translateX(-50%);
    width: 100px;
    height: 4px;
    background: linear-gradient(90deg, #FFB6C1, #87CEEB);
    border-radius: 2px;
}

/* --- イベントカード --- */
.event-item {
    position: relative;
    width: calc(100% - 40px);
    max-width: none;
    margin: 0 20px 30px 20px;
    padding-left: 45px;
    padding-right: 20px;
    z-index: 3;
    opacity: 0;
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

/* スクロールアニメーション */
.event-item.animate {
    opacity: 1;
}

/* 左側（会社）は右からスライド */
.event-item.company {
    transform: translateX(30px) translateY(30px);
}

.event-item.company.animate {
    opacity: 1;
    transform: translateX(0) translateY(0);
}

/* 右側（福島）は左からスライド */
.event-item.fukushima {
    transform: translateX(-30px) translateY(30px);
}

.event-item.fukushima.animate {
    opacity: 1;
    transform: translateX(0) translateY(0);
}

@keyframes slideInFromRight {
    from {
        opacity: 0;
        transform: translateX(50px);
    }

    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes slideInFromLeft {
    from {
        opacity: 0;
        transform: translateX(-50px);
    }

    to {
        opacity: 1;
        transform: translateX(0);
    }
}

/* 会社 (左側) */
.event-item.company {
    margin-left: 20px;
    margin-right: 20px;
    text-align: left;
    padding-left: 20px;
    right: 0;
}

.event-item.company .card {
    text-align: left;
}

.event-item.company .event-year,
.event-item.company .event-title,
.event-item.company .event-desc {
    text-align: left;
}

/* 福島 (右側) */
.event-item.fukushima {
    margin-left: 20px;
    margin-right: 20px;
    text-align: left;
    padding-left: 20px;
    right: 0;
}

/* カードデザイン（PCでは写真左・テキスト右の横並びレイアウト） */
.card {
    background: #fff;
    padding: 24px 28px 24px 28px;
    padding-top: 56px;
    border-radius: 16px;
    box-shadow: var(--shadow-md);
    width: 100%;
    box-sizing: border-box;
    position: relative;
    border-top: 4px solid transparent;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    overflow: visible;
    /* リボンがはみ出るように */
}

@media (min-width: 769px) {

    /* 画像を持つKFB年表カードのみ横並びグリッドにする（基本は画像左・テキスト右） */
    .event-item.company .card:has(.event-image) {
        display: grid;
        grid-template-columns: minmax(0, 480px) minmax(0, 1fr);
        column-gap: 28px;
        align-items: flex-start;
    }

    /* 画像（単枚・複数どちらも）を左カラムに固定＆大きめ表示 */
    .event-item.company .card:has(.event-image)>img.event-image,
    .event-item.company .card:has(.event-image)>.event-images-slider {
        grid-column: 1;
        grid-row: 1 / span 3;
    }

    .event-item.company .card:has(.event-image) img.event-image {
        height: 300px;
        object-fit: cover;
    }

    /* テキスト要素は右カラムに固定（デフォルト：画像左・テキスト右） */
    .event-item.company .card:has(.event-image)>.event-year,
    .event-item.company .card:has(.event-image)>.event-title,
    .event-item.company .card:has(.event-image)>.event-desc {
        grid-column: 2;
    }

    /* 偶数番目のKFB年表カードはレイアウトを反転（画像右・テキスト左） */
    .decade-section .event-item.company:nth-of-type(even) .card:has(.event-image) {
        grid-template-columns: minmax(0, 1fr) minmax(0, 480px);
    }

    .decade-section .event-item.company:nth-of-type(even) .card:has(.event-image)>img.event-image,
    .decade-section .event-item.company:nth-of-type(even) .card:has(.event-image)>.event-images-slider {
        grid-column: 2;
    }

    .decade-section .event-item.company:nth-of-type(even) .card:has(.event-image)>.event-year,
    .decade-section .event-item.company:nth-of-type(even) .card:has(.event-image)>.event-title,
    .decade-section .event-item.company:nth-of-type(even) .card:has(.event-image)>.event-desc {
        grid-column: 1;
    }
}

/* 「主な出来事」と画像なしのKFB年表カードは1列表示（縦レイアウト） */
.fukushima .card,
.event-item.company .card:not(:has(.event-image)) {
    display: block;
}

.card::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, transparent, currentColor, transparent);
    opacity: 0;
    transition: opacity 0.4s;
}

.card:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: var(--shadow-xl);
}

.card:hover::after {
    opacity: 1;
}

.event-year {
    font-family: 'Zen Maru Gothic', sans-serif;
    font-weight: 700;
    font-size: 1.6rem;
    display: block;
    margin-bottom: 8px;
    line-height: 1.2;
    letter-spacing: -0.5px;
}

.event-title {
    font-weight: 700;
    font-size: 1.15rem;
    margin: 0 0 12px 0;
    line-height: 1.4;
    color: var(--text-color);
}

.event-desc {
    font-size: 0.95rem;
    color: var(--text-color-light);
    margin: 0;
    line-height: 1.7;
}



/* イベント画像 */
.event-image {
    width: 100%;
    height: 220px;
    object-fit: cover;
    border-radius: 12px;
    grid-column: 1;
    grid-row: 1 / 4;
}

/* 複数画像スライダー（カード一覧） */
.event-images-slider {
    position: relative;
    margin-bottom: 18px;
}

.event-images-slider .event-image {
    display: none;
}

.event-images-slider .event-image.active {
    display: block;
}

.event-slider-prev,
.event-slider-next {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: 32px;
    height: 32px;
    border: none;
    background: rgba(0, 0, 0, 0.4);
    color: #fff;
    font-size: 1.2rem;
    line-height: 1;
    cursor: pointer;
    z-index: 2;
    border-radius: 50%;
    transition: background 0.2s;
}

.event-slider-prev:hover,
.event-slider-next:hover {
    background: rgba(0, 0, 0, 0.6);
}

.event-slider-prev {
    left: 8px;
}

.event-slider-next {
    right: 8px;
}

border-radius: 12px;
margin-bottom: 18px;
display: block;
background: linear-gradient(135deg, #f5f5f5 0%, #e5e5e5 100%);
box-shadow: var(--shadow-sm);
transition: transform 0.4s,
box-shadow 0.4s;
}

.card:hover .event-image {
    transform: scale(1.05);
    box-shadow: var(--shadow-md);
}

/* カテゴリラベル - モダンなリボン風デザイン */
.cat-label {
    position: absolute;
    top: 3px;
    font-size: 0.7rem;
    padding: 10px 24px;
    font-weight: 700;
    color: #fff;
    text-transform: uppercase;
    letter-spacing: 1.2px;
    z-index: 10;
    transform-origin: center;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
    white-space: nowrap;
}

/* ラベルリボン（KFB年表・主な出来事 共通で左側に表示） */
.company .cat-label {
    left: -8px;
    background: linear-gradient(135deg, #1f2937 0%, #374151 50%, #1f2937 100%);
    clip-path: polygon(12px 0, 100% 0, 100% 100%, 12px 100%, 0 50%);
    padding-left: 32px;
    transform: rotate(0deg);
}

.fukushima .cat-label {
    left: -8px;
    background: linear-gradient(135deg, #dc2626 0%, #b91c1c 50%, #dc2626 100%);
    clip-path: polygon(12px 0, 100% 0, 100% 100%, 12px 100%, 0 50%);
    padding-left: 32px;
    transform: rotate(0deg);
}

.company .cat-label::before {
    content: '📺';
    position: absolute;
    left: 10px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 1rem;
    opacity: 0.95;
    filter: drop-shadow(0 1px 2px rgba(0, 0, 0, 0.3));
    z-index: 1;
}

.fukushima .cat-label {
    padding-right: 32px;
}

.fukushima .cat-label::before {
    content: '📍';
    position: absolute;
    right: 10px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 1rem;
    opacity: 0.95;
    filter: drop-shadow(0 1px 2px rgba(0, 0, 0, 0.3));
    z-index: 1;
}

/* リボンの光沢効果 */
.cat-label::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 50%;
    background: linear-gradient(180deg, rgba(255, 255, 255, 0.25) 0%, transparent 100%);
    pointer-events: none;
    border-radius: inherit;
    z-index: 2;
}

/* ホバー時のアニメーション */
.card:hover .cat-label {
    transform: rotate(0deg) translateY(-4px) scale(1.05);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3);
}


/* タイムライン上のドット */
.event-dot {
    position: absolute;
    top: 20px;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: #fff;
    border: 4px solid #ccc;
    z-index: 2;
    box-shadow: 0 0 0 4px rgba(255, 255, 255, 0.8), var(--shadow-md);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.event-dot::before {
    content: '';
    position: absolute;
    inset: -2px;
    border-radius: 50%;
    opacity: 0;
    transition: opacity 0.4s;
}

.event-item:hover .event-dot {
    transform: scale(1.2);
    box-shadow: 0 0 0 6px rgba(255, 255, 255, 0.9), var(--shadow-lg);
}

.event-item:hover .event-dot::before {
    opacity: 1;
}

.company .event-dot {
    left: -48px;
}

/* 線の上に配置するための調整 */
.fukushima .event-dot {
    left: -48px;
}

/* --- 年代別スタイル適用 --- */

/* 1980s Style */
.style-80s {
    background: transparent;
    padding: 5px 40px;
}



.style-80s .card {
    border-color: var(--c-80s-main);
    background: rgba(255, 255, 255, 0.95);
}

.style-80s .card:hover {
    box-shadow: 0 20px 50px rgba(217, 119, 6, 0.15);
    background: #fff;
}

.style-80s .event-year {
    color: var(--c-80s-main);
}

.style-80s .event-title {
    color: var(--text-color);
}

.style-80s .event-desc {
    color: var(--text-color-light);
}

.style-80s .event-dot {
    border-color: var(--c-80s-main);
    background: linear-gradient(135deg, #fff 0%, #fffbf0 100%);
}

.style-80s .event-dot::before {
    background: var(--c-80s-main);
    filter: blur(8px);
}


.style-80s .event-year,
.style-80s .event-title,
.style-80s .event-desc {
    color: var(--text-color);
}

.style-80s .card .event-year,
.style-80s .card .event-title,
.style-80s .card .event-desc {
    color: var(--text-color);
}

/* 1990s Style */
.style-90s {
    background: transparent;
    padding: 5px 40px;
}

.style-90s .card {
    border-color: var(--c-90s-main);
    background: rgba(255, 255, 255, 0.95);
}

.style-90s .card:hover {
    box-shadow: 0 20px 50px rgba(5, 150, 105, 0.15);
    background: #fff;
}

.style-90s .event-year {
    color: var(--c-90s-main);
}

.style-90s .event-title {
    color: var(--text-color);
}

.style-90s .event-desc {
    color: var(--text-color-light);
}

.style-90s .event-dot {
    border-color: var(--c-90s-main);
    background: linear-gradient(135deg, #fff 0%, #f0fdf4 100%);
}

.style-90s .event-dot::before {
    background: var(--c-90s-main);
    filter: blur(8px);
}


.style-90s .event-year,
.style-90s .event-title,
.style-90s .event-desc {
    color: var(--text-color);
}

.style-90s .card .event-year,
.style-90s .card .event-title,
.style-90s .card .event-desc {
    color: var(--text-color);
}

/* 2000s Style */
.style-00s {
    background: transparent;
    padding: 5px 40px;
}

.style-00s .card {
    border-color: var(--c-00s-main);
    background: rgba(255, 255, 255, 0.95);
}

.style-00s .card:hover {
    box-shadow: 0 20px 50px rgba(37, 99, 235, 0.15);
    background: #fff;
}

.style-00s .event-year {
    color: var(--c-00s-main);
}

.style-00s .event-title {
    color: var(--text-color);
}

.style-00s .event-desc {
    color: var(--text-color-light);
}

.style-00s .event-dot {
    border-color: var(--c-00s-main);
    background: linear-gradient(135deg, #fff 0%, #eff6ff 100%);
}

.style-00s .event-dot::before {
    background: var(--c-00s-main);
    filter: blur(8px);
}


.style-00s .event-year,
.style-00s .event-title,
.style-00s .event-desc {
    color: var(--text-color);
}

.style-00s .card .event-year,
.style-00s .card .event-title,
.style-00s .card .event-desc {
    color: var(--text-color);
}

/* 2010s Style */
.style-10s {
    background: transparent;
    padding: 5px 40px;
}

.style-10s .card {
    border-color: var(--c-10s-main);
    background: rgba(255, 255, 255, 0.95);
}

.style-10s .card:hover {
    box-shadow: 0 20px 50px rgba(147, 51, 234, 0.15);
    background: #fff;
}

.style-10s .event-year {
    color: var(--c-10s-main);
}

.style-10s .event-title {
    color: var(--text-color);
}

.style-10s .event-desc {
    color: var(--text-color-light);
}

.style-10s .event-dot {
    border-color: var(--c-10s-main);
    background: linear-gradient(135deg, #fff 0%, #faf5ff 100%);
}

.style-10s .event-dot::before {
    background: var(--c-10s-main);
    filter: blur(8px);
}


.style-10s .event-year,
.style-10s .event-title,
.style-10s .event-desc {
    color: var(--text-color);
}

.style-10s .card .event-year,
.style-10s .card .event-title,
.style-10s .card .event-desc {
    color: var(--text-color);
}

/* 2020s Style (Special) */
.style-20s {
    background: transparent;
    padding: 5px 40px;
}

.style-20s .card {
    background: rgba(255, 255, 255, 0.95);
    border-top: 4px solid var(--c-20s-main);
    box-shadow: var(--shadow-lg);
}

.style-20s .card:hover {
    box-shadow: 0 20px 50px rgba(31, 41, 55, 0.2);
    background: #fff;
}

.style-20s .event-year {
    background: var(--c-20s-accent);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.style-20s .event-title {
    color: var(--text-color);
}

.style-20s .event-desc {
    color: var(--text-color-light);
}

.style-20s .event-dot {
    border-color: var(--c-20s-main);
    background: linear-gradient(135deg, var(--c-20s-main) 0%, #111827 100%);
}

.style-20s .event-dot::before {
    background: var(--c-20s-accent);
    filter: blur(10px);
}


.style-20s .event-year,
.style-20s .event-title,
.style-20s .event-desc {
    color: var(--text-color);
}

.style-20s .card .event-year {
    background: var(--c-20s-accent);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.style-20s .card .event-title,
.style-20s .card .event-desc {
    color: var(--text-color);
}


/* --- レスポンシブ (スマホ表示) --- */
@media (max-width: 768px) {
    body {
        padding-top: 70px;
        padding-bottom: 65px;
    }

    .page-title-section {
        padding: 20px 15px 30px;
    }

    .page-title {
        font-size: clamp(2rem, 6vw, 3rem);
    }

    body::before {
        background-image: url('../images/sp-bg2.jpg');
        mask: linear-gradient(to bottom,
                transparent 0%,
                transparent 40%,
                rgba(0, 0, 0, 0.1) 50%,
                rgba(0, 0, 0, 0.3) 60%,
                rgba(0, 0, 0, 0.5) 70%,
                rgba(0, 0, 0, 0.7) 80%,
                rgba(0, 0, 0, 0.9) 90%,
                rgba(0, 0, 0, 1) 100%);
        -webkit-mask: linear-gradient(to bottom,
                transparent 0%,
                transparent 40%,
                rgba(0, 0, 0, 0.1) 50%,
                rgba(0, 0, 0, 0.3) 60%,
                rgba(0, 0, 0, 0.5) 70%,
                rgba(0, 0, 0, 0.7) 80%,
                rgba(0, 0, 0, 0.9) 90%,
                rgba(0, 0, 0, 1) 100%);
    }

    .nav-sticky {
        position: fixed;
        left: auto;
        right: 0;
        top: auto;
        bottom: 0;
        transform: none;
        flex-direction: row;
        justify-content: center;
        width: 100%;
        padding: 12px 10px;
        border-radius: 20px 20px 0 0;
        border-left: none;
        border-right: none;
        border-bottom: none;
        box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.15);
        gap: 8px;
    }

    .nav-btn {
        font-size: 0.8rem;
        padding: 8px 16px;
        flex: 1;
        text-align: center;
        max-width: 120px;
    }

    .timeline-container {
        padding-left: 0;
    }

    .timeline-spine {
        left: 20px;
        /* 線を左端に寄せる */
    }

    .decade-title {
        font-size: clamp(1.8rem, 5vw, 2.5rem);
        margin: 30px 0 40px;
        padding: 15px 0;
    }

    .event-item {
        width: calc(100% - 40px);
        padding-left: 45px;
        /* 線とドットの分空ける */
        padding-right: 20px;
        margin-left: 20px !important;
        margin-right: 20px !important;
        box-sizing: border-box;
        margin-bottom: 30px;
        text-align: left !important;
        /* 強制的に左揃え */
        left: 0 !important;
        right: 0 !important;
        max-width: none;
        /* キーフレームアニメと二重に効かせない（終了時のかくつき防止） */
        transition: none;
    }

    .event-item.company,
    .event-item.fukushima {
        width: calc(100% - 40px) !important;
        margin-left: 20px !important;
        margin-right: 20px !important;
        padding-right: 0px;
        padding-left: 20px;
        left: 0 !important;
        right: 0 !important;
        max-width: none;
        /* PC用の translateX と keyframes の translateY をぶつけない */
        transform: translateY(30px);
    }

    .event-item.company {
        text-align: left !important;
    }

    .event-item.company .card {
        text-align: left !important;
    }

    .event-item.company .event-year,
    .event-item.company .event-title,
    .event-item.company .event-desc {
        text-align: left !important;
    }

    /* ドットの位置調整 */
    .company .event-dot,
    .fukushima .event-dot {
        left: -10px;
        right: auto;
    }

    .card::before {
        /* スマホで見分けやすくするためのサイドライン */
        content: '';
        position: absolute;
        left: 0;
        top: 0;
        bottom: 0;
        width: 6px;
        border-radius: 4px 0 0 4px;
    }

    /* スマホではリボンを通常のバッジに */
    .cat-label {
        position: relative;
        top: auto;
        right: auto;
        display: inline-block;
        margin-bottom: 12px;
        clip-path: none;
        border-radius: 20px;
        padding: 6px 16px;
        transform: none;
    }

    .company .cat-label::after,
    .fukushima .cat-label::after {
        display: none;
    }

    .card {
        /* スマホでは画像とテキストを縦並びに戻す */
        display: block;
        padding: 20px;
        padding-top: 24px;
        overflow: hidden;
    }

    /* 会社はグレーのタグ */
    .company .card::before {
        background-color: #555;
    }

    /* 福島は赤系のタグ */
    .fukushima .card::before {
        background-color: #de5d5d;
    }

    /* 画像のレスポンシブ調整 */
    .event-image {
        height: 150px;
        object-fit: contain;
    }

    .card:hover {
        transform: translateY(-5px);
    }

    /* 下からの表示は keyframes のみ（デスクトップの .animate の transform/opacity と競合させない） */
    .event-item.company.animate,
    .event-item.fukushima.animate {
        opacity: 0;
        transform: translateY(30px);
        animation: slideInFromBottom 0.55s ease-out forwards;
    }

    @keyframes slideInFromBottom {
        from {
            opacity: 0;
            transform: translateY(30px);
        }

        to {
            opacity: 1;
            transform: translateY(0);
        }
    }

    .style-80s {
        background: transparent;
        padding: 5px 0;
    }

    .style-90s {
        background: transparent;
        padding: 5px 0;
    }

    .style-00s {
        background: transparent;
        padding: 5px 0;
    }

    .style-10s {
        background: transparent;
        padding: 5px 0;
    }

    .style-20s {
        background: transparent;
        padding: 5px 0;
    }
}

/* --- フローティングバナー（ページトップへ） --- */
.floating-banner {
    position: fixed;
    bottom: 30px;
    right: 30px;
    z-index: 999;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, visibility 0.3s ease, transform 0.3s ease;
    transform: translateY(20px);
}

.floating-banner.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.floating-banner-link {
    display: block;
    text-decoration: none;
    transition: transform 0.3s ease;
}

.floating-banner-link:hover {
    transform: scale(1.1);
}

.floating-banner-img {
    width: 60px;
    height: auto;
    display: block;
    filter: drop-shadow(0 4px 8px rgba(0, 0, 0, 0.2));
}

/* モバイル表示時のフローティングバナー */
@media (max-width: 768px) {
    .floating-banner {
        bottom: 20px;
        right: 20px;
    }

    .floating-banner-img {
        width: 50px;
    }
}

/* イベント写真拡大モーダル */
.history-modal-overlay {
    position: fixed;
    inset: 0;
    z-index: 10000;
    background: rgba(0, 0, 0, 0.6);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s, visibility 0.3s;
}

.history-modal-overlay.is-open {
    opacity: 1;
    visibility: visible;
}

.history-modal {
    position: relative;
    background: #fff;
    border-radius: 16px;
    max-width: 720px;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    padding: 24px 24px 40px;
    transform: scale(0.95);
    transition: transform 0.3s;
}

.history-modal-overlay.is-open .history-modal {
    transform: scale(1);
}

.history-modal-close {
    position: absolute;
    top: 16px;
    right: 16px;
    width: 36px;
    height: 36px;
    border: none;
    background: rgba(0, 0, 0, 0.06);
    border-radius: 50%;
    font-size: 1.5rem;
    line-height: 1;
    cursor: pointer;
    color: #333;
    transition: background 0.2s;
}

.history-modal-close:hover {
    background: rgba(0, 0, 0, 0.12);
}

.history-modal-content {
    padding-top: 8px;
}

.history-modal-cat {
    display: inline-block;
    font-size: 0.7rem;
    padding: 6px 16px;
    font-weight: 700;
    color: #fff;
    background: #1f2937;
    border-radius: 4px;
    margin-bottom: 12px;
}

.history-modal-year {
    display: block;
    font-weight: 700;
    font-size: 1.4rem;
    margin-bottom: 12px;
    color: var(--text-color);
}

.history-modal-image {
    width: 100%;
    max-height: 65vh;
    object-fit: contain;
    border-radius: 12px;
    margin-bottom: 16px;
    background: linear-gradient(135deg, #f5f5f5 0%, #e5e5e5 100%);
}

.history-modal-slider {
    position: relative;
    margin-bottom: 16px;
}

.history-modal-slider-track {
    position: relative;
    overflow: hidden;
}

.history-modal-slider .history-modal-image {
    display: none;
    margin-bottom: 0;
}

.history-modal-slider .history-modal-image.active {
    display: block;
}

.history-modal-slider-prev,
.history-modal-slider-next {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: 44px;
    height: 44px;
    border: none;
    background: rgba(0, 0, 0, 0.5);
    color: #fff;
    font-size: 1.5rem;
    line-height: 1;
    cursor: pointer;
    z-index: 2;
    border-radius: 50%;
    transition: background 0.2s;
}

.history-modal-slider-prev:hover,
.history-modal-slider-next:hover {
    background: rgba(0, 0, 0, 0.7);
}

.history-modal-slider-prev {
    left: 10px;
}

.history-modal-slider-next {
    right: 10px;
}

.history-modal-slider-dots {
    display: flex;
    justify-content: center;
    gap: 8px;
    margin-top: 12px;
}

.history-modal-slider-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    border: none;
    background: #ccc;
    cursor: pointer;
    padding: 0;
    transition: background 0.2s;
}

.history-modal-slider-dot.active {
    background: #1f2937;
}

.history-modal-title {
    font-size: 1.2rem;
    font-weight: 700;
    margin: 0 0 16px;
    line-height: 1.4;
    color: var(--text-color);
}

.history-modal-desc {
    font-size: 0.95rem;
    color: var(--text-color-light);
    line-height: 1.7;
    margin: 0;
}

.history-modal-overlay.modal-fukushima .history-modal-cat {
    background: linear-gradient(135deg, #dc2626 0%, #b91c1c 100%);
}

.card {
    cursor: pointer;
}

@media (max-width: 480px) {
    .floating-banner {
        bottom: 55px;
        right: 15px;
    }

    .floating-banner-img {
        width: 45px;
    }
}