/* --- 基本設定 --- */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

/* ★追加: remの基準となるフォントサイズを設定 */
html {
    font-size: 100%; /* 16pxを基準にする */
}

body {
    font-family: 'Rajdhani', 'Noto Sans JP', sans-serif;
    background-color: #0a0a14;
    color: #f0f0f0;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    font-size: 1rem; /* ★変更: 16pxに設定 */
    line-height: 1.7; /* ★追加: 本文の行間を読みやすく設定 */
}

/* メニュー展開時の背景スクロール禁止 */
body.no-scroll {
    overflow: hidden;
}

main {
    flex: 1;
}

/* --- ヘッダー全体 --- */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    transition: background-color 0.3s ease;
}

.site-header.scrolled {
    background-color: rgba(10, 10, 20, 0.8);
    backdrop-filter: blur(10px);
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1400px;
    margin: 0 auto;
    padding: 20px 40px;
    position: relative;
    z-index: 2;
}

#particle-canvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
}

/* --- ロゴ --- */
.logo {
    cursor: pointer;
    z-index: 1100; /* メニューより手前に */
}

.logo img {
    height: 50px;
    width: auto;
    display: block;
    transition: opacity 0.3s ease;
}

/* --- ナビゲーション --- */
.nav-area {
    display: flex;
    align-items: center;
}
.main-nav ul {
    list-style: none;
    display: flex;
    gap: 40px;
}
.main-nav a {
    text-decoration: none;
    color: #e0e0e0;
    font-size: 18px;
    font-weight: 400;
    letter-spacing: 1.5px;
    padding: 8px 0;
    position: relative;
    transition: color 0.3s ease;
}
.main-nav a:hover { color: #ffffff; }
.main-nav a::after {
    content: ''; position: absolute; bottom: 0; left: 0;
    width: 100%; height: 2px;
    background: linear-gradient(90deg, #00f2ff, #ff00c8, #00f2ff);
    background-size: 200% 100%; transform: scaleX(0);
    transform-origin: center;
    transition: transform 0.4s cubic-bezier(0.19, 1, 0.22, 1);
    animation: wave-flow 2s linear infinite; opacity: 0;
}
.main-nav a:hover::after { transform: scaleX(1); opacity: 1; }
@keyframes wave-flow {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}

/* --- ハンバーガーメニューボタン --- */
.hamburger {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 10px;
    z-index: 1100;
}
.hamburger-icon {
    display: block; position: relative;
    width: 30px; height: 2px;
    background-color: #e0e0e0;
    transition: background-color 0.3s ease;
}
.hamburger-icon::before,
.hamburger-icon::after {
    content: ''; position: absolute;
    width: 100%; height: 2px;
    background-color: #e0e0e0;
    transition: all 0.3s ease;
}
.hamburger-icon::before { top: -10px; }
.hamburger-icon::after { top: 10px; }

/* Active State Animation */
.hamburger.is-active .hamburger-icon { background-color: transparent; }
.hamburger.is-active .hamburger-icon::before { top: 0; transform: rotate(45deg); }
.hamburger.is-active .hamburger-icon::after { top: 0; transform: rotate(-45deg); }


/* --- ヒーローセクション --- */
.hero-section {
    position: relative; height: 100vh;
    display: flex; align-items: center; justify-content: center;
    overflow: hidden;
}
.hero-image-container {
    position: absolute; top: 0; left: 0;
    width: 100%; height: 100%;
    background-image: url('../images/main_visual.png');
    background-size: cover; background-position: center 30%;
    filter: brightness(0.8); z-index: -1;
}
.hero-tagline {
    text-align: center; color: white;
    text-shadow: 0px 2px 10px rgba(0, 0, 0, 0.7);
    padding: 0 20px;
}
.hero-tagline h1 {
    font-family: 'Noto Sans JP', sans-serif;
    font-size: 3.5rem; font-weight: 600;
    letter-spacing: 4px;
    line-height: 1.3; /* ★追加: 見出しの行間を調整 */
}
.hero-tagline p {
    font-size: 1.2rem; margin-top: 10px;
    letter-spacing: 1px;
}

/* --- 言語切り替え --- */
.lang-switcher {
    margin-left: 30px; /* SNSリンクとの間隔 */
    font-family: 'Rajdhani', sans-serif;
    font-size: 16px;
    font-weight: 600;
    letter-spacing: 1px;
}
.lang-switcher a {
    text-decoration: none;
    color: #a0a0b0;
    transition: color 0.3s ease;
    padding: 0 4px;
}
.lang-switcher a:hover {
    color: #ffffff;
}
.lang-switcher .lang-active {
    color: #00f2ff;
    cursor: default;
}

/* --- SNSリンク --- */
.social-links {
    display: flex;
    align-items: center;
    gap: 25px;
    margin-left: 30px;
}
.social-links a {
    color: #e0e0e0; text-decoration: none; font-size: 1.1rem;
    transition: color 0.3s ease, transform 0.3s ease;
}
.social-links a:hover {
    color: #00f2ff;
    transform: translateY(-2px);
}


/* --- レスポンシブ対応 --- */
@media (max-width: 900px) {
    .header-container { padding: 15px 20px; }

    .hamburger { display: block; }

    /* nav-area をメニューパネルとして画面外に配置 */
    .nav-area {
        position: fixed;
        top: 0; left: -100%;
        width: 80%; max-width: 300px;
        height: 100vh;
        background-color: rgba(10, 10, 20, 0.95);
        backdrop-filter: blur(10px);
        flex-direction: column;
        justify-content: center;
        align-items: center;
        transition: left 0.4s ease-in-out;
        z-index: 1050;
        padding: 40px;
    }
    .nav-area.is-active { left: 0; }

    .main-nav ul {
        flex-direction: column;
        text-align: center;
        gap: 30px;
        margin-bottom: 40px; /* 下の要素との間隔 */
    }
    .main-nav a { font-size: 22px; }

    .lang-switcher {
        margin-left: 0;
        margin-bottom: 40px; /* SNSリンクとの間隔 */
        font-size: 20px;
    }

    .social-links {
        margin-left: 0;
        gap: 30px;
    }
    .social-links a { font-size: 1.3rem; }
}

@media (max-width: 768px) {
    .hero-tagline h1 { font-size: 2.5rem; letter-spacing: 2px; }
    .hero-tagline p { font-size: 1rem; }
}

/* --- フッター --- */
.site-footer-main {
    background-color: #05050a;
    padding: 40px 0;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}
.footer-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 40px;
    text-align: center;
}
.footer-links { margin-bottom: 25px; }
.footer-links a {
    color: #a0a0b0; text-decoration: none; margin: 0 15px;
    transition: color 0.3s ease;
}
.footer-links a:hover { color: #ffffff; }
.footer-social { margin-bottom: 25px; }
.footer-social a {
    color: #a0a0b0; font-size: 1.3rem; margin: 0 15px;
    transition: color 0.3s ease, transform 0.3s ease;
    display: inline-block;
}
.footer-social a:hover {
    color: #00f2ff;
    transform: translateY(-3px);
}
.copyright {
    color: #848493; /* ★変更: コントラスト比を改善 */
    font-size: 0.9rem;
    letter-spacing: 1px;
}