/* --- 基本設定 --- */
:root {
    --bg-color: #2E3439;
    --main-color: #FFFFFF;
    --accent-color: #00AEEF;
    --font-family-sans: 'Noto Sans JP', sans-serif;
    --font-family-orbitron: 'Orbitron', sans-serif;
}

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

html {
    scroll-behavior: smooth;
}

body {
    background-color: var(--bg-color);
    color: var(--main-color);
    font-family: var(--font-family-sans);
    line-height: 1.8;
}

img {
    max-width: 100%;
    height: auto;
    vertical-align: middle;
}

a {
    color: var(--accent-color);
    text-decoration: none;
}

/* --- ヘッダー --- */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    background-color: rgba(46, 52, 57, 0.8);
    backdrop-filter: blur(10px);
    z-index: 1000;
}

.logo {
    height: 40px;
}

.nav-list {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-list a {
    color: var(--main-color);
    font-weight: bold;
    transition: color 0.3s;
}

.nav-list a:hover {
    color: var(--accent-color);
}

.header-sns {
    display: flex;
    gap: 1rem;
}

.header-sns img {
    width: 40px;
    height: 40px;
    transition: transform 0.2s;
}

/* Only apply transform if user does NOT prefer reduced motion */
@media (prefers-reduced-motion: no-preference) {
    .header-sns img:hover {
        transform: scale(1.15);
    }
}

/* If user prefers reduced motion, disable transform */
@media (prefers-reduced-motion: reduce) {
    .header-sns img:hover {
        transform: none;
    }
}

.hamburger {
    display: none; /* Default: hidden (desktop) */
    background: none;
    border: none;
    cursor: pointer;
    z-index: 1001;
}
.hamburger span {
    display: block;
    width: 25px;
    height: 3px;
    background-color: var(--main-color);
    margin: 5px 0;
    transition: all 0.3s;
}


/* --- 共通セクションスタイル --- */
.content-section {
    padding: 100px 5%;
    max-width: 1200px;
    margin: 0 auto;
    opacity: 0; /* アニメーション用 */
    transform: translateY(30px); /* アニメーション用 */
    transition: opacity 0.8s, transform 0.8s;
}
.content-section.is-visible {
    opacity: 1;
    transform: translateY(0);
}

.section-title-container {
    text-align: center;
    margin-bottom: 4rem;
}
.section-title {
    font-family: var(--font-family-orbitron);
    font-size: 1.5rem;
    position: relative;
    display: inline-block;
}
.section-title::before {
    content: attr(data-bg-text);
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 6rem;
    color: rgba(255, 255, 255, 0.05);
    z-index: -1;
    white-space: nowrap;
}

.btn {
    display: inline-block;
    border: 1px solid var(--accent-color);
    padding: 0.5rem 1.5rem;
    margin-top: 1rem;
    color: var(--accent-color);
    transition: background-color 0.3s, color 0.3s;
}
.btn:hover {
    background-color: var(--accent-color);
    color: var(--bg-color);
}


/* --- トップビュー --- */
.hero {
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding-top: 80px; /* 固定ヘッダーの高さ分の余白 */
}
.hero-content {
    position: relative;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}
.hero-logo {
    max-width: 400px;
    width: 60vw;
    position: absolute;
    top: 18%;
    left: 50%;
    transform: translate(-50%, 0);
    z-index: 1;
    opacity: 0.85;
}
.hero-miku {
    max-height: 70vh;
    max-width: 90%;
    position: relative;
    z-index: 1;
}
.hero-subtitle, .hero-year {
    font-family: var(--font-family-orbitron);
    border: 1px solid var(--main-color);
    padding: 0.75rem 2rem;
    display: block;
    position: absolute;
    background-color: rgba(46, 52, 57, 0.7);
    font-size: 1.7rem;
    letter-spacing: 0.05em;
    box-shadow: 0 4px 24px 0 rgba(0,0,0,0.12);
    z-index: 2;
    width: 70vw;
    max-width: 700px;
    text-align: center;
}
.hero-subtitle {
    top: 60%;
    left: -5%;
}
.hero-subtitle span { color: var(--accent-color); }
.hero-year {
    bottom: 5%;
    right: -5%;
}

/* --- ヒーローセクション開催情報 --- */
.hero-event-info {
    margin-top: 2.5rem;
    background: rgba(0, 174, 239, 0.15);
    border: 2px solid var(--accent-color);
    border-radius: 1.5rem;
    padding: 1.2rem 2.5rem;
    display: inline-block;
    box-shadow: 0 4px 24px 0 rgba(0,174,239,0.10);
    z-index: 3;
    font-family: var(--font-family-orbitron);
}
.hero-date, .hero-venue {
    margin: 0.2em 0;
}
.hero-date {
    font-size: 2.1rem;
    font-weight: bold;
    color: var(--accent-color);
    text-shadow: 0 2px 8px rgba(0,174,239,0.15);
}
.hero-venue {
    font-size: 1.4rem;
    font-weight: normal;
    color: var(--main-color);
    text-shadow: 0 2px 8px rgba(0,0,0,0.15);
}

/* --- 各セクション --- */
.about-flex, .miku-flex, .venue-flex {
    display: flex;
    align-items: center;
    gap: 3rem;
}
.miku-flex { flex-direction: row-reverse; } /* Swap image and text order */
.about-text, .miku-text, .venue-info { flex: 1; }
.about-logo, .miku-image, .venue-map { flex: 1; text-align: center; }

.gallery-slider {
    position: relative;
    width: 100%;
    max-width: 700px;
    margin: 0 auto;
    overflow: hidden;
    height: 400px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.slide {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    transition: opacity 0.5s;
    display: flex;
    align-items: center;
    justify-content: center;
}
.slide.active {
    opacity: 1;
    z-index: 2;
}

.slide img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 16px;
    box-shadow: 0 4px 24px 0 rgba(0,0,0,0.12);
}

.gallery-nav {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: 100%;
    display: flex;
    justify-content: space-between;
    z-index: 3;
    pointer-events: none;
}
.gallery-nav button {
    background: rgba(46,52,57,0.7);
    color: var(--main-color);
    border: none;
    font-size: 2rem;
    padding: 0.5rem 1rem;
    border-radius: 50%;
    cursor: pointer;
    pointer-events: auto;
    transition: background 0.2s;
}
.gallery-nav button:hover {
    background: var(--accent-color);
    color: var(--bg-color);
}
.team-content {
    text-align: center;
}
.team-content h3 {
    margin-top: 2rem;
    font-weight: normal;
    color: #aaa;
}
.team-content p {
    font-size: 1.5rem;
}
.team-content .init8-text {
    font-size: 1.5rem;
}

/* --- ページトップへ戻るボタン --- */
.back-to-top {
    position: fixed;
    right: 20px;
    bottom: 20px;
    writing-mode: vertical-rl;
    padding: 1rem 0.5rem;
    font-size: 0.8rem;
    transition: opacity 0.3s;
}
.back-to-top::before {
    content: "▲";
    display: block;
    margin-bottom: 0.5em;
}

/* --- セクション間の区切り線 --- */
.section-split {
    border: none;
    border-top: 2px solid var(--accent-color);
    margin: 60px auto;
    width: 60%;
    opacity: 0.3;
}

/* --- 免責事項・ライセンス情報セクション（統合） --- */
.disclaimer-license {
    background-color: rgba(255, 255, 255, 0.02);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding: 60px 5%;
    font-size: 0.85rem;
    line-height: 1.8;
    color: rgba(255, 255, 255, 0.7);
}
.disclaimer-license-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}
.disclaimer-license-content p {
    margin: 1em 0;
}
.disclaimer-license-content .disclaimer-text {
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: 2em;
}
.disclaimer-license-content a {
    color: var(--accent-color);
    text-decoration: underline;
}
.disclaimer-license-content a:hover {
    color: var(--main-color);
}
.disclaimer-license-content .copyright {
    margin-top: 1.5em;
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.6);
}
.info-separator {
    border: none;
    border-top: 1px solid rgba(255, 255, 255, 0.15);
    margin: 2em auto;
    width: 50%;
}

/* --- レスポンシブ対応 (スマホ) --- */
@media (max-width: 768px) {
    .nav {
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100vh;
        background-color: var(--bg-color);
        display: flex;
        justify-content: center;
        align-items: center;
        transform: translateX(100%);
        transition: transform 0.3s;
    }
    .nav.is-active {
        transform: translateX(0);
    }
    .nav-list {
        flex-direction: column;
        text-align: center;
        font-size: 1.5rem;
    }
    .header-sns {
        display: none;
    }
    .hamburger {
        display: block;
    }
    .hamburger.is-active span:nth-child(1) {
        transform: translateY(8px) rotate(45deg);
    }
    .hamburger.is-active span:nth-child(2) {
        opacity: 0;
    }
    .hamburger.is-active span:nth-child(3) {
        transform: translateY(-8px) rotate(-45deg);
    }

    .section-title { font-size: 2rem; }
    .section-title::before { font-size: 3.5rem; }

    /* ヒーローセクション調整 */
    .hero {
        padding-top: 60px; /* スマホ用に少し小さめの余白 */
    }
    .hero-logo {
        max-width: 300px;
        top: 15%;
    }
    .hero-subtitle, .hero-year {
        font-size: 1.2rem;
        padding: 0.5rem 1rem;
        width: 85vw;
    }
    .hero-event-info {
        padding: 1rem 1.5rem;
        margin-top: 1.5rem;
    }
    .hero-date {
        font-size: 1.6rem;
    }
    .hero-venue {
        font-size: 1.1rem;
    }

    .about-flex, .miku-flex, .venue-flex {
        flex-direction: column;
    }
}
.team-content img.kimitomiku-logo {
    max-width: 180px;
    height: auto;
    margin: 0.5em auto;
    display: block;
}
.team-content img.init8-logo {
    max-width: 32px;
    height: auto;
    vertical-align: middle;
    display: inline-block;
    margin-left: 0.5em;
}