:root {
            /* --- デザイン設定 --- */
            --deep-sea: #00121a;
            --mid-sea: #002b3d;
            --shallow-sea: #004d66;
            --aqua-accent: #00bcd4;
            --text-main: #e0f7fa;
            --text-sub: #b2ebf2;
            --glass-bg: rgba(255, 255, 255, 0.05);
            --glass-border: rgba(255, 255, 255, 0.1);

            /* --- メンテナンス用サイズ設定 --- */
            --profile-width-pc: 180px;  /* PC版の画像幅 */
            --profile-width-sp: 140px;  /* スマホ版の画像幅 */
            --container-width: 1100px;
        }

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

        html {
            scroll-behavior: smooth;
        }

        body {
            background-color: var(--deep-sea);
            background: linear-gradient(180deg, var(--mid-sea) 0%, var(--deep-sea) 100%);
            color: var(--text-main);
            font-family: 'Noto Sans JP', sans-serif;
            line-height: 1.8;
            overflow-x: hidden;
        }

        header {
            height: clamp(200px, 25vh, 400px);
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            text-align: center;
            position: relative;
            background: radial-gradient(circle at center, var(--shallow-sea) 0%, transparent 80%);
        }

        .hero-title {
            font-family: 'Shippori Mincho', serif;
            font-size: clamp(2.2rem, 8vw, 4.5rem);
            letter-spacing: 0.25em;
            margin-bottom: 0.5rem;
            text-shadow: 0 0 25px rgba(0, 188, 212, 0.6);
        }

        .hero-subtitle {
            font-size: clamp(0.8rem, 2vw, 1rem);
            letter-spacing: 0.4em;
            color: var(--aqua-accent);
            text-transform: uppercase;
            opacity: 0.9;
        }

        nav {
            position: sticky;
            top: 0;
            background: rgba(0, 18, 26, 0.85);
            backdrop-filter: blur(12px);
            padding: 1rem;
            z-index: 100;
            display: flex;
            justify-content: center;
            flex-wrap: wrap;
            border-bottom: 1px solid rgba(0, 188, 212, 0.2);
        }

        nav a {
            color: var(--text-main);
            text-decoration: none;
            margin: 5px 15px;
            font-size: 0.85rem;
            transition: 0.3s;
            padding: 5px 0;
            letter-spacing: 0.1em;
        }

        nav a:hover {
            color: var(--aqua-accent);
            text-shadow: 0 0 10px var(--aqua-accent);
        }

        .container {
            max-width: var(--container-width);
            margin: 0 auto;
            padding: clamp(2rem, 5vw, 2rem) 1.5rem;
        }

        section {
            margin-bottom: clamp(3rem, 10vw, 8rem);
        }

        h2 {
            font-family: 'Shippori Mincho', serif;
            font-size: 1.8rem;
            margin-bottom: 2rem;
            text-align: center;
            display: flex;
            align-items: center;
            justify-content: center;
        }

        h2::before, h2::after {
            content: "";
            width: 40px;
            height: 1px;
            background: var(--aqua-accent);
            margin: 0 15px;
        }

        h3 {
            color: var(--aqua-accent);
            margin-bottom: 1.5rem;
            font-size: 1.2rem;
            border-left: 3px solid var(--aqua-accent);
            padding-left: 15px;
        }

        .glass-panel {
            background: var(--glass-bg);
            border: 1px solid var(--glass-border);
            border-radius: 15px;
            padding: clamp(1.5rem, 5vw, 2.5rem);
            backdrop-filter: blur(8px);
        }

        /* --- Profile --- */
        .profile-flex {
            display: flex;
            gap: 2.5rem;
            align-items: center;
            flex-wrap: wrap;
        }

        .profile-img-wrap {
            width: var(--profile-width-pc);
            flex-shrink: 0;
            display: flex;
            align-items: center;
            justify-content: center;
        }

        .profile-img-wrap img {
            width: 100%;
            height: auto;
            display: block;
        }

        .profile-text {
            flex: 1;
            min-width: 280px;
        }

        .sns-links {
            display: flex;
            gap: 15px;
            margin-top: 1.5rem;
            flex-wrap: wrap;
        }

        .sns-icon {
            color: var(--text-main);
            text-decoration: none;
            transition: 0.3s ease;
            display: flex;
            align-items: center;
            justify-content: center;
            width: 40px;
            height: 40px;
            background: rgba(255, 255, 255, 0.05);
            border-radius: 50%;
            border: 1px solid var(--glass-border);
        }

        .sns-icon:hover {
            color: var(--aqua-accent);
            border-color: var(--aqua-accent);
            background: rgba(0, 188, 212, 0.1);
            transform: translateY(-3px);
        }

        .sns-icon svg {
            width: 20px;
            height: 20px;
            fill: currentColor;
        }

        /* Music Video Grid */
        .mv-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
            gap: 2rem;
        }

        .mv-card {
            background: rgba(255,255,255,0.03);
            border: 1px solid var(--glass-border);
            border-radius: 12px;
            overflow: hidden;
            transition: 0.3s ease;
            display: flex;
            flex-direction: column;
        }

        .mv-card:hover {
            transform: translateY(-5px);
            border-color: var(--aqua-accent);
            background: rgba(255,255,255,0.06);
        }

        .video-container {
            position: relative;
            width: 100%;
            padding-top: 56.25%;
            background: #000;
        }

        .video-container iframe {
            position: absolute;
            top: 0; left: 0; width: 100%; height: 100%;
            border: 0;
        }

        .mv-info {
            padding: 1.2rem;
            text-align: center;
            flex-grow: 1;
        }

        .mv-title {
            font-size: 1rem;
            font-weight: bold;
            color: var(--text-main);
        }

        .video-actions {
            display: flex;
            flex-direction: column;
            gap: 0.6rem;
            padding: 0 1.2rem 1.5rem;
        }

        .video-btn {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: 8px;
            padding: 10px;
            border-radius: 30px;
            font-size: 0.75rem;
            text-decoration: none;
            transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
            border: 1px solid var(--glass-border);
            font-weight: bold;
            position: relative;
            overflow: hidden;
        }

        .btn-youtube {
            background: rgba(255, 255, 255, 0.05);
            color: var(--text-main);
        }

        .btn-youtube:hover {
            background: #ff0000;
            color: white;
            border-color: #ff0000;
            transform: translateY(-3px);
            box-shadow: 0 5px 15px rgba(255, 0, 0, 0.4);
        }

        .btn-youtube:active {
            transform: translateY(-1px);
        }

        .btn-showmore {
            background: rgba(0, 188, 212, 0.1);
            color: var(--aqua-accent);
            border-color: rgba(0, 188, 212, 0.3);
        }

        .btn-showmore:hover {
            background: var(--aqua-accent);
            color: var(--deep-sea);
            transform: translateY(-3px);
            box-shadow: 0 5px 15px rgba(0, 188, 212, 0.4);
        }

        .btn-showmore:active {
            transform: translateY(-1px);
        }

        /* Discography Layout Styles */
        .disco-content {
            display: flex;
            flex-direction: column;
            gap: 3rem;
        }

        .album-info-top {
            text-align: center;
            margin-bottom: 1rem;
        }

        .album-year {
            color: var(--aqua-accent);
            font-size: 1rem;
            letter-spacing: 0.3em;
            margin-bottom: 0.5rem;
        }

        .album-name {
            font-family: 'Shippori Mincho', serif;
            font-size: clamp(1.8rem, 4vw, 2.4rem);
        }

        /* 2-Column Flexbox for PC */
        .album-main-flex {
            display: flex;
            align-items: flex-start;
            justify-content: center;
            gap: 3rem;
            flex-wrap: wrap;
        }

        .album-jacket-area {
            flex: 1;
            min-width: 300px;
            max-width: 400px;
            text-align: center;
        }

        .album-embed-area {
            flex: 1.5;
            min-width: 300px;
            width: 100%;
        }

        .jacket-link {
            display: block;
            transition: 0.4s cubic-bezier(0.22, 1, 0.36, 1);
            text-decoration: none;
        }

        .jacket-link:hover {
            transform: scale(1.03);
            filter: brightness(1.1);
        }

        .jacket-img {
            width: 100%;
            aspect-ratio: 1/1;
            object-fit: cover;
            border-radius: 8px;
            box-shadow: 0 15px 40px rgba(0,0,0,0.5);
            border: 1px solid rgba(255,255,255,0.1);
        }

        .jacket-caption {
            margin-top: 1.2rem;
            font-size: 0.85rem;
            color: var(--text-sub);
            letter-spacing: 0.1em;
            line-height: 1.5;
        }

        .apple-embed-container {
            width: 100%;
            border-radius: 10px;
            overflow: hidden;
            box-shadow: 0 10px 30px rgba(0,0,0,0.3);
            background: #000;
        }

        /* Single Section Styles - 余白を大幅に詰めました */
        .single-section-title {
            text-align: center;
            font-family: 'Shippori Mincho', serif;
            font-size: 1.5rem;
            margin-top: 0.1rem; /* さらに縮小 */
            margin-bottom:  0.1rem;
            letter-spacing: 0.3em;
            color: var(--text-main);
        }

        .single-description {
            text-align: center;
            font-size: 0.75rem;
            color: var(--text-sub);
            margin-top: 0.1rem; /* さらに縮小 */
            margin-bottom: 0.1rem; /* さらに縮小 */
            letter-spacing: 0.05em;
            line-height: 1.4;
            opacity: 0.8;
        }

        .single-grid {
            display: grid;
            grid-template-columns: repeat(5, 1fr);
            gap: 1.5rem;
            border-top: 1px solid var(--glass-border);
            padding-top: 1.5rem; /* 上の線との間隔をさらに縮小 */
            margin-top: 0;
        }

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

        .single-jacket-link {
            display: block;
            margin-bottom: 0.8rem;
            transition: 0.4s cubic-bezier(0.22, 1, 0.36, 1);
            text-decoration: none;
        }

        .single-jacket-link:hover {
            transform: scale(1.05);
            filter: brightness(1.2);
        }

        .single-jacket-img {
            width: 100%;
            aspect-ratio: 1/1;
            object-fit: cover;
            border-radius: 4px;
            box-shadow: 0 5px 15px rgba(0,0,0,0.4);
            border: 1px solid rgba(255,255,255,0.05);
        }

        .single-title {
            font-size: 0.8rem;
            font-weight: 500;
            margin-bottom: 0.8rem;
            color: var(--text-main);
            min-height: 2.4em;
            display: flex;
            align-items: center;
            justify-content: center;
        }

        .btn-showmore {
            display: inline-block;
            padding: 4px 12px;
            font-size: 0.7rem;
            color: var(--aqua-accent);
            text-decoration: none;
            border: 1px solid var(--aqua-accent);
            border-radius: 4px;
            transition: 0.3s;
            letter-spacing: 0.05em;
        }

        .btn-showmore:hover {
            background: var(--aqua-accent);
            color: var(--deep-sea);
        }

        .jacket-link {
            display: block;
            transition: 0.4s cubic-bezier(0.22, 1, 0.36, 1);
            text-decoration: none;
        }

        .jacket-link:hover {
            transform: scale(1.03);
            filter: brightness(1.1);
        }

        .jacket-img {
            width: 100%;
            aspect-ratio: 1/1;
            object-fit: cover;
            border-radius: 8px;
            box-shadow: 0 15px 40px rgba(0,0,0,0.5);
            border: 1px solid rgba(255,255,255,0.1);
        }

        .jacket-caption {
            margin-top: 1.2rem;
            font-size: 0.85rem;
            color: var(--text-sub);
            letter-spacing: 0.1em;
            line-height: 1.5;
        }

        .apple-embed-container {
            width: 100%;
            border-radius: 10px;
            overflow: hidden;
            box-shadow: 0 10px 30px rgba(0,0,0,0.3);
            background: #000;
        }

        /* --- Footer Button Configuration --- */
        .disco-footer {
            display: flex;
            justify-content: flex-end; /* PCでは右寄せ */
            margin-top: 1rem;
        }

        /* Equipment */
        .equipment-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: 1.5rem;
        }

        .eq-item {
            margin-bottom: 1rem;
            padding-bottom: 0.8rem;
            border-bottom: 1px solid rgba(255,255,255,0.05);
        }

        .eq-item b {
            display: block;
            color: var(--aqua-accent);
            font-size: 0.75rem;
            text-transform: uppercase;
            letter-spacing: 0.15em;
        }

        /* --- Contact Form (Ajax) --- */
        #contact {
            max-width: 700px;
            margin-left: auto;
            margin-right: auto;
        }

        .form-container {
            position: relative;
            min-height: 400px;
            display: flex;
            flex-direction: column;
        }

        .contact-form {
            transition: opacity 0.5s ease, transform 0.5s ease;
        }

        .contact-form.hidden {
            opacity: 0;
            transform: translateY(-20px);
            pointer-events: none;
            position: absolute;
            width: 100%;
        }

        .form-group {
            margin-bottom: 1.2rem;
        }

        .form-group label {
            display: block;
            font-size: 0.75rem;
            margin-bottom: 0.5rem;
            color: var(--text-sub);
            letter-spacing: 0.1em;
        }

        .form-group input, 
        .form-group textarea {
            width: 100%;
            padding: 0.9rem;
            background: rgba(0, 0, 0, 0.3);
            border: 1px solid var(--glass-border);
            border-radius: 8px;
            color: var(--text-main);
            font-family: inherit;
            outline: none;
            transition: 0.3s;
        }

        .form-group textarea {
            min-height: 150px;
            resize: vertical;
        }

        .form-group input:focus, 
        .form-group textarea:focus {
            border-color: var(--aqua-accent);
            background: rgba(255, 255, 255, 0.08);
        }

        .submit-btn {
            width: 100%;
            padding: 1rem;
            background: transparent;
            border: 1px solid var(--aqua-accent);
            border-radius: 30px;
            color: var(--aqua-accent);
            font-weight: bold;
            letter-spacing: 0.2em;
            cursor: pointer;
            transition: 0.3s;
        }

        .submit-btn:hover:not(:disabled) {
            background: var(--aqua-accent);
            color: var(--deep-sea);
            box-shadow: 0 0 15px var(--aqua-accent);
        }

        .submit-btn:disabled {
            opacity: 0.5;
            cursor: not-allowed;
        }

        /* Success Message Overlay */
        #success-message {
            display: none;
            text-align: center;
            margin: auto;
            animation: fadeInUp 0.8s ease forwards;
        }

        .success-icon { font-size: 2.5rem; color: var(--aqua-accent); display: block; margin-bottom: 1rem; }
        .success-text { font-family: 'Shippori Mincho', serif; font-size: 1.4rem; margin-bottom: 0.5rem; }
        .success-subtext { font-size: 0.85rem; color: var(--text-sub); }

        @keyframes fadeInUp {
            from { opacity: 0; transform: translateY(20px); }
            to { opacity: 1; transform: translateY(0); }
        }


        footer { text-align: center; padding: 4rem 1rem; color: var(--text-sub); font-size: 0.8rem; border-top: 1px solid var(--glass-border); }

        @media (max-width: 900px) {
            .single-grid { grid-template-columns: repeat(3, 1fr); }
        }

        @media (max-width: 600px) {
            .profile-flex { flex-direction: column; text-align: center; }
            section { margin-bottom: 8rem; }
            .album-main-flex { gap: 2rem; }
            .album-jacket-area { max-width: 100%; }
            .single-grid { grid-template-columns: repeat(2, 1fr); gap: 1rem; }
        }    


    /* 5枚目以降（動的に追加されるクラス）の初期スタイル */
    .mv-grid .mv-card.auto-hidden-mv {
        display: none;
        opacity: 0;
        transition: opacity 0.4s ease-in-out;
    }

    /* JavaScriptで表示させる際のアクティブ用 */
    .mv-grid .mv-card.show-mv {
        display: block !important;
        opacity: 1;
    }

    /* 「もっと見る」ボタンエリアの装飾 */
    .mv-more-btn-area {
        text-align: center;
        margin-top: 2rem;
        margin-bottom: 2rem;
    }

    .toggle-btn {
        background: rgba(255, 255, 255, 0.15);
        color: #ffffff;
        border: 1px solid rgba(255, 255, 255, 0.3);
        padding: 0.8rem 2.5rem;
        font-size: 1rem;
        border-radius: 30px;
        cursor: pointer;
        backdrop-filter: blur(8px);
        -webkit-backdrop-filter: blur(8px);
        transition: all 0.3s ease;
        box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    }

    .toggle-btn:hover {
        background: rgba(255, 255, 255, 0.3);
        transform: translateY(-2px);
        box-shadow: 0 6px 20px rgba(255, 255, 255, 0.15);
    }

    .toggle-btn:active {
        transform: translateY(0);
    }

/* Equipmentセクション内のテキストリンク（記事への導線）のみ指定 */
.eq-item a {
    color: #e0f7fa; /* 通常時はテキストと同じ白 */
    text-decoration: underline; /* リンクとわかるように下線を表示 */
    text-decoration-color: rgba(255, 255, 255, 0.4); /* 下線をほんのり馴染ませる */
    transition: color 0.2s ease, text-decoration-color 0.2s ease;
    display: inline-block; /* 改行や余白の崩れを防止 */
    margin-bottom: 0.25rem;
}

/* マウスを乗せた時（ホバー時）の演出 */
.eq-item a:hover {
    color: #79a3b1; /* サブアクセントカラー（青緑系）に変化させて「押せる感」を演出 */
    text-decoration-color: #79a3b1;
}