:root {
            --md-primary-color: #5D7C77;
            --md-surface-color: #FFFFFF;
            --md-background-color: #F8F7F4;
            --md-on-primary-color: #FFFFFF;
            --md-on-surface-color: #3C3C3C;
            --md-on-background-color: #3C3C3C;
            --md-accent-color: #D4C9B5;
            --md-header-color: #fefefe;
        }

        *,
        *::before,
        *::after {
            box-sizing: border-box;
        }

        body {
            font-family: 'Noto Sans JP', 'Roboto', sans-serif;
            margin: 0;
            background-color: var(--md-background-color);
            color: var(--md-on-background-color);
            font-size: 1.1rem;
            line-height: 1.9;
            font-weight: 400;
            overflow-x: hidden;
        }

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

        .container {
            max-width: 960px;
            margin: 0 auto;
            padding: 0 32px;
        }

        h1, h2, h3, h4 {
            font-family: 'Noto Serif JP', serif;
            font-weight: 400;
        }
        
        header {
            width: 100%;
            height: 100vh;
            background-color: var(--md-background-color);
            display: flex;
            justify-content: center;
            align-items: center;
            position: relative;
            overflow: hidden; 
        }
        
        header::before {
           display: none;
        }

        .header-logo {
            position: fixed;
            top: 20px;
            left: 20px;
            z-index: 1000;
            display: block;
            transition: opacity 0.3s ease, transform 0.3s ease;
        }

        .header-logo.is-scrolled {
            opacity: 0.7;
        }

        .header-logo:hover {
            opacity: 1 !important;
        }

        .header-logo img {
            height: 30px; /* PCサイズ */
            width: auto;
            display: block;
        }

        @media (max-width: 767px) {
            .header-logo img {
                height: 25px; /* スマホサイズ */
            }
        }

        /* ハンバーガーメニュー */
        .menu-trigger {
            position: fixed;
            top: 20px;
            right: 20px;
            width: 44px;
            height: 44px;
            background: none;
            border: none;
            cursor: pointer;
            z-index: 2000;
            padding: 0;
        }

        .menu-trigger span {
            display: block;
            position: absolute;
            left: 7px;
            width: 30px;
            height: 2px;
            background-color: var(--md-on-surface-color);
            transition: all 0.4s;
            border-radius: 4px;
        }

        .menu-trigger span:nth-of-type(1) { top: 12px; }
        .menu-trigger span:nth-of-type(2) { top: 21px; }
        .menu-trigger span:nth-of-type(3) { top: 30px; }

        /* メニューオープン時の三本線アニメーション */
        .menu-trigger.is-active span:nth-of-type(1) {
            transform: translateY(9px) rotate(-45deg);
        }
        .menu-trigger.is-active span:nth-of-type(2) {
            opacity: 0;
        }
        .menu-trigger.is-active span:nth-of-type(3) {
            transform: translateY(-9px) rotate(45deg);
        }

        .full-menu {
            position: fixed;
            top: 0;
            right: -100%;
            width: 100%;
            height: 100vh;
            background-color: rgba(255, 255, 255, 0.98);
            z-index: 1500;
            display: flex;
            justify-content: center;
            align-items: center;
            transition: right 0.6s cubic-bezier(0.19, 1, 0.22, 1);
        }

        .full-menu.is-active {
            right: 0;
        }

        .full-menu ul {
            list-style: none;
            padding: 0;
            margin: 0;
            text-align: center;
        }

        .full-menu ul li {
            margin: 2rem 0;
            opacity: 0;
            transform: translateY(20px);
            transition: all 0.4s ease;
        }

        .full-menu.is-active ul li {
            opacity: 1;
            transform: translateY(0);
        }

        .full-menu.is-active ul li:nth-child(1) { transition-delay: 0.2s; }
        .full-menu.is-active ul li:nth-child(2) { transition-delay: 0.3s; }
        .full-menu.is-active ul li:nth-child(3) { transition-delay: 0.4s; }

        .full-menu ul li a {
            font-family: 'Noto Serif JP', serif;
            font-size: 1.8rem;
            color: var(--md-primary-color);
            text-decoration: none;
            font-weight: 700;
            transition: color 0.3s;
        }

        .full-menu ul li a:hover {
            color: var(--md-accent-color);
        }

        .header-background-image {
            position: absolute;
            top: 5%;
            left: 5%;
            width: 90%;
            height: 90%;
            background-image: url('../images/header1.png');
            background-size: cover;
            background-position: center;
            border-radius: 59% 37% 61% 35% / 40% 51% 42% 50%;
        }

        .header-title {
            writing-mode: vertical-rl;
            text-orientation: mixed;
            color: var(--md-header-color);
            font-size: 3.4rem;
            letter-spacing: .3em;
            text-shadow: none;
            position: relative;
            padding: 2.0rem 1.8rem;
            opacity: 0; 
            animation: fadeInTitle 1.5s ease-out 0.5s forwards;
            z-index: 1; 
        }
        
        .section {
            padding: 120px 0;
            text-align: center;
        }

        .section-title {
            font-size: 3.2rem;
            margin-bottom: 2rem; 
        }
        
        .section-description {
            font-size: 1.2rem;
            max-width: 600px;
            margin: 0 auto 80px auto;
        }

        .fade-in {
            opacity: 0;
            transform: translateY(30px);
            transition: opacity 0.8s ease-out, transform 0.8s ease-out;
            transition-delay: var(--delay, 0s);
        }

        .fade-in.visible {
            opacity: 1;
            transform: translateY(0);
        }
        
        #features .feature-grid {
            display: grid;
            grid-template-columns: 1fr;
            gap: 32px;
            text-align: left;
        }

        .feature-item {
            background-color: var(--md-surface-color);
            border-radius: 12px;
            overflow: hidden;
            box-shadow: 0 1px 3px rgba(0,0,0,0.12), 0 1px 2px rgba(0,0,0,0.24);
            transition: box-shadow 0.3s cubic-bezier(.25,.8,.25,1), transform 0.3s ease;
        }
        
        .feature-item:hover {
            box-shadow: 0 10px 20px rgba(0,0,0,0.19), 0 6px 6px rgba(0,0,0,0.23);
            transform: translateY(-4px);
        }

        .feature-item .card-content {
            padding: 32px;
        }

        .feature-item h3 {
            font-size: 1.8rem;
            color: var(--md-primary-color);
            margin-top: 0;
            margin-bottom: 1rem;
        }
        
        .feature-item > img {
            width: 100%;
            height: 250px;
            object-fit: cover;
        }

        #features-2 .feature-grid-detailed {
            display: grid;
            grid-template-columns: 1fr;
            gap: 64px;
        }
        .feature-item-detailed {
            display: flex;
            align-items: center;
            gap: 48px;
            transition: transform 0.3s ease;
        }
        .feature-item-detailed:hover {
            transform: translateY(-4px);
        }
        .feature-item-detailed .image-wrapper {
            flex: 0 0 40%;
            max-width: 40%;
        }
        .feature-item-detailed .image-wrapper img {
            width: 100%;
            height: 300px;
            display: block;
            object-fit: cover;
            border-radius: 35% 65% 60% 40% / 55% 40% 60% 45%;
            transition: border-radius 0.4s ease-in-out;
        }
        .feature-item-detailed:hover .image-wrapper img {
             border-radius: 65% 35% 40% 60% / 45% 60% 40% 55%;
        }
        .feature-item-detailed .content-wrapper {
            flex: 1;
            text-align: left;
        }
        .feature-item-detailed h3 {
            font-size: 1.8rem;
            color: var(--md-primary-color);
            margin-top: 0;
            margin-bottom: 1rem;
        }

        .mineral-graph {
            margin-top: 2rem;
            font-size: 1rem;
        }
        .graph-item {
            display: flex;
            align-items: center;
            margin-bottom: 1.2rem;
        }
        .graph-item .label {
            width: 150px;
            flex-shrink: 0;
            font-weight: 500;
        }
        .bar-wrapper {
            flex-grow: 1;
            background-color: #ECECEC;
            border-radius: 4px;
            height: 28px;
        }
        .bar {
            height: 100%;
            background-color: var(--md-accent-color);
            border-radius: 4px;
            display: flex;
            align-items: center;
            justify-content: flex-end;
            color: var(--md-on-background-color);
            padding-right: 12px;
            font-weight: bold;
            font-size: 0.9rem;
            min-width: 40px;
        }
        .comparison-text {
            text-align: right;
            font-size: 1.5rem;
            font-weight: bold;
            color: var(--md-primary-color);
            margin-top: 1.5rem;
        }
        .comparison-text strong {
            font-size: 2.5rem;
        }

        #usage-examples .usage-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 32px;
            margin-top: 80px;
        }
        #usage-examples .usage-item {
            text-align: center;
        }
        #usage-examples .usage-item img {
            width: 100%;
            aspect-ratio: 1 / 1;
            object-fit: cover;
            border-radius: 12px;
            margin-bottom: 1.5rem;
            box-shadow: 0 4px 15px rgba(0,0,0,0.1);
        }
        #usage-examples .usage-item h4 {
            font-size: 1.5rem;
            color: var(--md-primary-color);
        }

        .parallax-bg {
            padding: 120px 0;
            background-size: cover;
            background-position: center;
            background-attachment: fixed;
            color: var(--md-on-primary-color);
        }
        
        #process-bg {
            background-image: url('../images/img05.png');
        }

        .parallax-content-box {
            background-color: rgba(0,0,0,0.55);
            padding: 48px;
            border-radius: 12px;
            text-align: center;
        }
        .parallax-content-box .section-title {
            color: var(--md-on-primary-color);
            border-bottom: 2px solid var(--md-on-primary-color);
            padding-bottom: 10px;
        }

        .product-content {
            display: flex;
            align-items: center;
            gap: 64px;
            text-align: left;
        }
        .product-image {
            flex: 1;
        }
        .product-image img {
            max-width: 100%;
            border-radius: 65% 35% 55% 45% / 60% 50% 50% 40%;
            box-shadow: 0 10px 25px rgba(0,0,0,0.1);
            transition: border-radius 0.5s ease-in-out;
        }
        .product-image img:hover {
            border-radius: 30% 70% 70% 30% / 30% 30% 70% 70%;
        }

        .product-description {
            flex: 1.2;
        }
        .product-description .section-title {
            text-align: left;
        }

        #testimonials, #faq {
            background-color: #F0EEE9;
        }
        
        .testimonial-item {
            background-color: var(--md-surface-color);
            padding: 32px;
            margin-bottom: 24px;
            border-radius: 12px;
            box-shadow: 0 4px 15px rgba(0,0,0,0.08);
            display: flex;
            align-items: flex-start;
            gap: 24px;
            text-align: left;
        }
        .testimonial-item .testimonial-icon {
            width: 64px;
            height: 64px;
            border-radius: 50%;
            object-fit: cover;
            flex-shrink: 0;
        }
        .testimonial-item .testimonial-content {
            flex-grow: 1;
        }
        .testimonial-item blockquote {
            font-size: 1.1em;
            margin: 0 0 1rem 0;
            padding: 0;
            position: relative;
        }
        .testimonial-item blockquote::before {
            content: '“';
            font-family: 'Noto Serif JP', serif;
            position: absolute;
            left: -1.2rem;
            top: -1rem;
            font-size: 3rem;
            color: var(--md-accent-color);
            opacity: 0.8;
        }
        .testimonial-item span {
            display: block;
            text-align: right;
            font-size: 1rem;
            color: #777;
            margin-top: 1rem;
        }

        #faq .card-list-item {
            padding: 0;
            background-color: transparent;
            box-shadow: none;
            border-left: none;
            border-bottom: 1px solid #ddd;
        }
        #faq .card-list-item:first-of-type {
            border-top: 1px solid #ddd;
        }
        .faq-item summary {
            display: flex;
            justify-content: space-between;
            align-items: center;
            font-weight: 500;
            cursor: pointer;
            color: var(--md-on-surface-color);
            font-size: 1.2rem;
            padding: 24px 0;
            list-style: none;
        }
        .faq-item summary::-webkit-details-marker {
            display: none;
        }
        .faq-item summary::after {
            content: '+';
            font-size: 2rem;
            font-weight: 300;
            color: var(--md-primary-color);
            transition: transform 0.3s ease;
        }
        .faq-item[open] > summary::after {
            content: '−';
        }
        .faq-item .faq-answer {
            padding: 0 0 24px 0;
            text-align: left;
        }
        .faq-item .faq-answer p {
            margin: 0;
        }
        
        #cta-bg {
            background-image: url('../images/img09.png');
            text-align: center;
        }
        #cta-bg h2 {
            font-size: 2.8rem;
            text-shadow: 0 2px 4px rgba(0,0,0,0.7);
            margin-bottom: 48px;
        }
        .cta-button {
            display: inline-block;
            background-color: var(--md-primary-color);
            color: var(--md-on-primary-color);
            padding: 24px 80px;
            text-decoration: none;
            font-size: 1.8rem;
            font-weight: 500;
            text-transform: uppercase;
            letter-spacing: 1px;
            border-radius: 50px;
            border: none;
            cursor: pointer;
            box-shadow: 0 6px 12px rgba(0,0,0,0.20), 0 4px 6px rgba(0,0,0,0.23);
            transition: background-color 0.3s, box-shadow 0.3s, transform 0.2s;
        }
        .cta-button:hover {
            background-color: #4A6560;
            box-shadow: 0 10px 20px rgba(0,0,0,0.19), 0 6px 6px rgba(0,0,0,0.23);
            transform: translateY(-3px);
        }
        .cta-button:active {
            transform: translateY(1px);
        }

        #footer-parallax {
            min-height: 400px;
            background-image: url('../images/img11.png');
        }

        footer {
            background-color: #EAE8E1;
            text-align: center;
            padding: 32px;
            font-size: 1rem;
            color: #555;
        }
        
        .floating-shop-button {
            position: fixed;
            bottom: 32px;
            right: 32px;
            z-index: 1000;
            height: 128px;
            width: 128px;
            border-radius: 100px;
            display: flex;
            align-items: center;
            justify-content: center;
            background-color: var(--md-primary-color);
            box-shadow: 0 8px 24px rgba(0,0,0,0.25);
            text-decoration: none;
            overflow: hidden;
            transition: width 0.4s cubic-bezier(0.68, -0.55, 0.27, 1.55), 
                        transform 0.4s ease, 
                        box-shadow 0.3s ease,
                        opacity 0.4s ease;
        }
        
        .floating-shop-button.is-hidden {
            opacity: 0;
            transform: translateY(100%);
            pointer-events: none;
        }

        .floating-shop-button span {
            opacity: 0;
            width: 0;
            white-space: nowrap;
            color: var(--md-on-primary-color);
            font-weight: 500;
            font-size: 1.5rem;
            transition: opacity 0.3s ease-in-out, width 0.2s ease-in-out;
        }

        .floating-shop-button svg {
            flex-shrink: 0;
            width: 56px;
            height: 56px;
            fill: var(--md-on-primary-color);
            transition: margin 0.4s cubic-bezier(0.68, -0.55, 0.27, 1.55);
        }

        @media (hover: hover) {
            .floating-shop-button:hover {
                width: 360px;
                transform: translateY(-8px);
                box-shadow: 0 12px 28px rgba(0,0,0,0.3);
                justify-content: flex-start;
                padding: 0 36px;
            }
            .floating-shop-button:hover span {
                opacity: 1;
                width: auto;
                margin-left: 24px;
            }
        }

        @media (min-width: 768px) {
            header {
                justify-content: flex-start;
                padding-left: 14%;
            }
            #features .feature-grid {
                grid-template-columns: repeat(2, 1fr);
                gap: 40px;
            }
        }

        @media (max-width: 767px) {
            .container {
                padding: 0 24px;
            }
            .section, .parallax-bg {
                padding-top: 80px;
                padding-bottom: 80px;
            }
            .header-title {
                font-size: 2.5rem;
            }
            .section-title {
                font-size: 2rem;
            }
            .product-content,
            .feature-item-detailed,
            #usage-examples .usage-grid {
                flex-direction: column;
                grid-template-columns: 1fr;
            }
            .feature-item-detailed .image-wrapper {
                max-width: 100%;
            }
            .cta-button {
                padding: 14px 48px;
                font-size: 1rem;
            }
            .floating-shop-button {
                width: 72px;
                height: 72px;
                bottom: 16px;
                right: 16px;
                box-shadow: 0 4px 12px rgba(0,0,0,0.25);
            }
            .floating-shop-button svg {
                width: 32px;
                height: 32px;
            }
            .testimonial-item .testimonial-icon {
                width: 48px;
                height: 48px;
            }
            .testimonial-item {
                gap: 16px;
                padding: 24px;
            }
            .header-background-image {
                height: 70%;
            }
        }