/* --- リセット & 基本設定 --- */
        :root {
            --color-navy: #001f3f;
            --color-navy-rgb: 0, 31, 63;
            --color-slate: #0f172a;
            --color-slate-rgb: 15, 23, 42;
            --color-footer: #005C95; /* フッター色変更 */
            --color-white: #ffffff;
            --font-jp: 'Zen Kaku Gothic New', sans-serif;
            --font-en: 'Marcellus', serif;
            --container-width: 1200px;
        }

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

        html {
            scroll-behavior: smooth;
        }

        body {
            font-family: var(--font-jp);
            color: var(--color-white);
            line-height: 1.8;
            background-color: var(--color-navy);
            overflow-x: hidden; /* 横スクロール防止 */
        }

        a {
            text-decoration: none;
            color: inherit;
            transition: opacity 0.3s;
        }

        ul {
            list-style: none;
        }

        img {
            max-width: 100%;
            height: auto;
            display: block;
        }

        /* --- ユーティリティ --- */
        .container {
            width: 100%;
            max-width: var(--container-width);
            margin: 0 auto;
            padding: 0 24px;
        }

        .font-eng {
            font-family: var(--font-en);
        }

        .text-center { text-align: center; }
        .text-justify { text-align: justify; }
        .uppercase { text-transform: uppercase; }
        .tracking-wide { letter-spacing: 0.2em; }
        .tracking-widest { letter-spacing: 0.3em; }
        .drop-shadow { filter: drop-shadow(0 4px 6px rgba(0,0,0,0.3)); }

        .hidden-md { display: none; } /* モバイルのみ表示 */

        @media (min-width: 768px) {
            .hidden-md { display: block; }
            .block-md { display: none; } /* デスクトップのみ表示 */
            .text-center-md { text-align: center; }
            .br-hidden-md { display: none; }
        }

        /* --- 背景固定 --- */
        .fixed-bg {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100dvh;
            z-index: -2;
            background-image: url('/assets/img/bg.jpg');
            background-size: cover;
            background-position: center;
            background-repeat: no-repeat;
            background-color: var(--color-navy);
        }

        .fixed-overlay {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            z-index: -1;
            background-color: rgba(var(--color-navy-rgb), 0.5);
        }

        /* --- ヒーローセクション --- */
        .hero {
            position: relative;
            height: 100vh;
            display: flex;
            align-items: center;
            justify-content: center;
            overflow: hidden;
        }

        .hero-content {
            text-align: center;
            display: flex;
            flex-direction: column;
            align-items: center;
            position: relative;
            z-index: 10;
            /* 常に天地中央に配置するためパディングなし */
            padding-bottom: 0;
        }

        .hero-logo {
            width: 250px;
            margin-bottom: 32px;
            filter: drop-shadow(0 10px 20px rgba(0,0,0,0.3));
        }
        @media (min-width: 768px) {
            .hero-logo { width: 480px; }
        }

        .hero-subtitle {
            font-family: var(--font-en);
            font-size: 14px;
            letter-spacing: 0.3em;
            text-transform: uppercase;
            opacity: 0.9;
            text-shadow: 0 2px 4px rgba(0,0,0,0.3);
        }
        @media (min-width: 768px) {
            .hero-subtitle { font-size: 16px; }
        }

        /* --- Scroll Indicator (Line Animation) --- */
        .scroll-indicator {
            position: absolute;
            bottom: 0; /* 画面最下部に配置 */
            left: 50%;
            transform: translateX(-50%);
            display: flex;
            flex-direction: column;
            align-items: center;
            gap: 16px;
            cursor: pointer;
            opacity: 0.8;
            transition: opacity 0.3s;
            z-index: 20;
        }
        .scroll-indicator:hover {
            opacity: 1;
        }

        .scroll-text {
            font-family: var(--font-en);
            font-size: 12px;
            letter-spacing: 0.3em;
            opacity: 0.8;
            margin-bottom: 8px;
        }

        .scroll-line {
            width: 1px;
            height: 80px; /* 線の長さ */
            background-color: rgba(255, 255, 255, 0.2);
            position: relative;
            overflow: hidden;
            /* 画面外にはみ出させる */
            margin-bottom: -40px;
        }

        .scroll-line::after {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background-color: #fff;
            animation: scroll-line-anim 1.5s cubic-bezier(0.77, 0, 0.175, 1) infinite;
        }

        @keyframes scroll-line-anim {
            0% { transform: translateY(-100%); }
            100% { transform: translateY(100%); }
        }

        /* --- セクション共通 --- */
        .section {
            padding: 96px 0;
            position: relative;
            z-index: 10;
        }
        @media (min-width: 768px) {
            .section { padding: 128px 0; }
        }

        /* セクション背景（擬似要素で実装してマスクを可能にする） */
        #contact::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background-color: rgba(var(--color-slate-rgb), 0.6);
            backdrop-filter: blur(2px);
            z-index: -1;
        }

        /* コンセプトセクション：上部から徐々に背景を表示 */
        /* #concept::before {
            -webkit-mask-image: linear-gradient(to bottom, transparent 0%, black 400px);
            mask-image: linear-gradient(to bottom, transparent 0%, black 400px);
        } */

        .section-header {
            text-align: center;
            margin-bottom: 64px;
        }

        .section-title {
            font-size: 24px;
            font-weight: 500;
            letter-spacing: 0.2em;
            text-shadow: 0 2px 4px rgba(0,0,0,0.3);
        }
        @media (min-width: 768px) {
            .section-title { font-size: 30px; }
        }

        /* --- Concept Section --- */
        .concept-title {
            font-size: 24px;
            font-weight: 500;
            letter-spacing: 0.2em;
            line-height: 1.8;
            margin-bottom: 32px;
            text-shadow: 0 2px 4px rgba(0,0,0,0.3);
        }
        @media (min-width: 768px) {
            .concept-title { font-size: 30px; }
        }

        .concept-divider {
            width: 48px;
            height: 1px;
            background-color: rgba(255,255,255,0.3);
            margin: 32px auto;
        }

        .concept-text {
            max-width: 672px;
            margin: 0 auto;
            text-align: justify;
            font-weight: 300;
            opacity: 0.95;
            /* コンセプト文を大きく、行間を広く */
            font-size: 18px;
            line-height: 2.4;
        }
        @media (min-width: 768px) {
            .concept-text { text-align: center; }
        }
        .concept-text p {
            margin-bottom: 0;
        }
        .spacer { height: 16px; }

        /* --- Contact Section --- */
        .contact-box {
            /* 枠線を左右140pxずつ（計280px）拡大 */
            max-width: 952px;
            margin: 0 auto;
            padding: 40px;
            border: 1px solid rgba(255, 255, 255, 0.3);
            text-align: center;
        }
        @media (min-width: 768px) {
            .contact-box { padding: 64px; }
        }

        .contact-text {
            margin-bottom: 40px;
            opacity: 0.9;
            font-weight: 300;
        }

        .contact-btn {
            display: inline-flex;
            align-items: center;
            gap: 12px;
            background-color: white;
            color: var(--color-navy);
            padding: 16px 32px;
            border-radius: 2px;
            font-family: var(--font-en);
            font-weight: 500;
            letter-spacing: 0.15em;
            transition: background-color 0.3s;
        }
        .contact-btn:hover {
            background-color: #e6e6e6;
        }
        .contact-btn svg {
            transition: transform 0.3s;
        }
        .contact-btn:hover svg.arrow {
            transform: translateX(4px);
        }

        /* --- Footer --- */
        footer {
            background-color: var(--color-footer);
            color: rgba(255, 255, 255, 0.6);
            /* 天地幅拡大 */
            padding: 140px 0;
            font-size: 14px;
            font-weight: 300;
            position: relative;
            z-index: 20;
        }

        .footer-content {
            display: flex;
            flex-direction: column;
            align-items: center;
            gap: 24px;
        }

        .footer-logo img {
            /* ロゴを2倍に拡大 */
            height: 96px;
            opacity: 0.8;
            transition: opacity 0.3s;
        }
        .footer-logo img:hover {
            opacity: 1;
        }

        .copyright {
            position: absolute;
            bottom: 10px;
            left: 0;
            width: 100%;
            text-align: center;
            font-family: var(--font-jp);
            font-size: 12px;
            opacity: 0.6;
        }

        /* --- Animations --- */
        .fade-up {
            opacity: 0;
            transform: translateY(30px);
            transition: opacity 0.8s ease-out, transform 0.8s ease-out;
        }
        .fade-up.is-visible {
            opacity: 1;
            transform: translateY(0);
        }

        .delay-100 { transition-delay: 100ms; }
        .delay-200 { transition-delay: 200ms; }
        .delay-300 { transition-delay: 300ms; }