/* ==========================================================================
   CSS Variables & Theme
   ========================================================================== */
:root {
    /* Colors - Deep Navy & Royal Gold Theme */
    --color-bg-base: #060913;
    /* Deep Navy/Black */
    --color-bg-alt: #101524;
    /* Lighter Navy */
    --color-text-main: #E5EAF5;
    /* Off-white for readability */
    --color-text-muted: #A3AAB8;
    /* Muted text */

    --color-gold-base: #D4AF37;
    /* Metallic Gold */
    --color-gold-light: #F3E5AB;
    /* Light Gold / Shine */
    --color-gold-dark: #A67C00;
    /* Dark Gold / Shadow */

    /* Gemstone Accents (use sparingly) */
    --color-ruby: #9B111E;
    --color-sapphire: #0F52BA;
    --color-emerald: #50C878;

    /* Typography */
    --font-heading: 'Cinzel', serif;
    /* Classical English */
    --font-body: 'Noto Sans JP', sans-serif;
    --font-serif-jp: 'Noto Serif JP', serif;

    /* Spacing & Layout */
    --section-padding: 80px;
    --section-padding-mobile: 40px;
    --container-width: 1200px;

    /* Utilities */
    --transition-slow: 0.5s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    --transition-fast: 0.3s ease;

    /* UI Overlays */
    --gold-gradient: linear-gradient(135deg, var(--color-gold-light) 0%, var(--color-gold-base) 50%, var(--color-gold-dark) 100%);
    --bg-gradient: radial-gradient(circle at center, var(--color-bg-alt) 0%, var(--color-bg-base) 100%);
}

/* ==========================================================================
   Reset & Base Styles
   ========================================================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
    overflow-x: hidden;
}

body {
    font-family: var(--font-body);
    background-color: var(--color-bg-base);
    background-image: var(--bg-gradient);
    color: var(--color-text-main);
    line-height: 1.6;
    overflow-x: hidden;
    width: 100%;
    position: relative;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Basic Typography */
h1,
h2,
h3,
h4,
.en {
    font-family: var(--font-heading);
    font-weight: 600;
}

h1,
h2,
h3 {
    margin-bottom: 1rem;
    line-height: 1.3;
}

p {
    margin-bottom: 1.5rem;
}

a {
    color: var(--color-gold-base);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--color-gold-light);
}

ul {
    list-style: none;
}

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

/* ==========================================================================
   Layout & Utilities
   ========================================================================== */
.container {
    width: 100%;
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 20px;
}

.section-padding {
    padding: var(--section-padding) 0;
}

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

.mt-4 {
    margin-top: 2rem;
}

/* Section Headers */
.section-title {
    /* iPhone等の細い画面(320px等)で折り返さないよう最小サイズを1.5remまで下げる */
    font-size: clamp(1.5rem, 5vw, 3rem);
    color: var(--color-gold-base);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    position: relative;
    display: inline-block;
    padding-bottom: 0px;
    /* 余白を削る */
    margin-bottom: 0.5rem;
    /* タイトルのすぐ下に装飾が来るように縮小 */
    line-height: 1.2;
}

/* .section-title::after (元の短い線) を削除 */

/* ==========================================================================
   Section Ornaments
   ========================================================================== */
/* ==========================================================================
   Section Dividers
   ========================================================================== */
.section-divider {
    width: 100%;
    padding: 3rem 0;
    /* セクションとセクションの間隔を十分にとる */
    display: flex;
    justify-content: center;
    position: relative;
    z-index: 10;
}

.section-ornament-bottom {
    margin: 0 auto;
    width: 100%;
    max-width: 800px;
    /* 800pxの長さに広げる */
    height: 3px;
    background: var(--gold-gradient);
    /* 左右の意匠を40pxずつ外側にずらすため、それに合わせて線の幅も広げるように調整 */
    background-size: calc(100% + 0px) 100%;
    background-position: center;
    background-repeat: no-repeat;
    position: relative;
    opacity: 1.0;
}

.section-ornament-bottom::before,
.section-ornament-bottom::after {
    content: '';
    width: 50px;
    height: 50px;
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    /* マスク機能を使ってシルエットを切り抜き、金色のグラデーションで塗りつぶす */
    background: var(--gold-gradient);
    -webkit-mask-image: url("./assets/fleur-de-lis.png");
    mask-image: url("./assets/fleur-de-lis.png");
    -webkit-mask-size: contain;
    mask-size: contain;
    -webkit-mask-position: center;
    mask-position: center;
    -webkit-mask-repeat: no-repeat;
    mask-repeat: no-repeat;
    z-index: 2;
    /* 線の前に表示させて完全に隠す */
}

.section-ornament-bottom::before {
    left: -10px;
    /* 40px外側へ */
    /* 左側の意匠を外側（左）に向かせるため反転させる */
    transform: translateY(-50%) rotate(-90deg);
}

.section-ornament-bottom::after {
    right: -10px;
    /* 40px外側へ */
    /* 右側の意匠を外側（右）に向かせるため回転させる */
    transform: translateY(-50%) rotate(90deg);
}

.glow-text {
    text-shadow: 0 0 10px rgba(212, 175, 55, 0.5), 0 0 20px rgba(212, 175, 55, 0.3);
}

/* ==========================================================================
   Buttons
   ========================================================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 24px;
    font-family: var(--font-heading);
    font-size: 1rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    cursor: pointer;
    position: relative;
    overflow: hidden;
    border: 1px solid transparent;
    transition: all var(--transition-fast);
}

.btn-primary {
    background-color: var(--color-bg-base);
    color: var(--color-gold-base);
    border-color: var(--color-gold-base);
    box-shadow: inset 0 0 0 1px var(--color-gold-dark), 0 4px 15px rgba(0, 0, 0, 0.5);
    z-index: 1;
}

.btn-primary:hover {
    color: var(--color-bg-base);
    background-color: var(--color-gold-base);
    box-shadow: 0 0 20px rgba(212, 175, 55, 0.4);
}

.btn-primary .btn-shine {
    position: absolute;
    top: 0;
    left: -100%;
    width: 50%;
    height: 100%;
    background: linear-gradient(to right, rgba(255, 255, 255, 0) 0%, rgba(255, 255, 255, 0.3) 50%, rgba(255, 255, 255, 0) 100%);
    transform: skewX(-25deg);
    z-index: -1;
    transition: left 0.7s ease;
}

.btn-primary:hover .btn-shine {
    left: 200%;
}

.btn-secondary {
    background: transparent;
    color: var(--color-text-main);
    border-bottom: 1px solid var(--color-gold-base);
    padding: 8px 0;
}

.btn-secondary:hover {
    color: var(--color-gold-light);
    border-color: var(--color-gold-light);
}

.btn-large {
    padding: 16px 32px;
    font-size: 1.1rem;
}

.btn-huge {
    padding: 20px 40px;
    font-size: 1.3rem;
    letter-spacing: 0.1em;
}

.btn-header {
    padding: 8px 16px;
    font-size: 0.9rem;
    flex-shrink: 0;
    white-space: nowrap;
}

/* ==========================================================================
   A. Header
   ========================================================================== */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 100;
    transition: background-color var(--transition-fast), padding var(--transition-fast);
    padding: 20px 0;
    background: linear-gradient(to bottom, rgba(6, 9, 19, 0.9) 0%, rgba(6, 9, 19, 0) 100%);
}

.site-header.scrolled {
    background-color: rgba(6, 9, 19, 0.95);
    padding: 10px 0;
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(212, 175, 55, 0.2);
}

.header-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.header-logo {
    font-family: var(--font-heading);
    font-size: clamp(0.9rem, 4.5vw, 1.5rem);
    color: var(--color-gold-light);
    font-weight: 700;
    letter-spacing: 0.05em;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.5);
    white-space: nowrap;
}

.lang-selector-wrapper {
    position: relative;
    margin-right: auto;
    margin-left: 2rem;
}

.lang-selector-wrapper::after {
    content: '▼';
    font-size: 0.6rem;
    color: var(--color-gold-base);
    position: absolute;
    right: 8px;
    top: 50%;
    transform: translateY(-50%);
    pointer-events: none;
}

.lang-selector {
    appearance: none;
    -webkit-appearance: none;
    background: transparent;
    border: 1px solid rgba(212, 175, 55, 0.4);
    color: var(--color-gold-light);
    font-family: var(--font-heading);
    font-size: 0.85rem;
    padding: 4px 24px 4px 10px;
    border-radius: 4px;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.lang-selector:hover,
.lang-selector:focus {
    border-color: var(--color-gold-base);
    outline: none;
    box-shadow: 0 0 10px rgba(212, 175, 55, 0.2);
}

.lang-selector option {
    background-color: var(--color-bg-base);
    color: var(--color-text-main);
}

.header-nav {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.header-nav ul {
    display: flex;
    gap: 1.5rem;
}

.header-nav a {
    color: var(--color-text-main);
    font-family: var(--font-heading);
    font-size: 0.9rem;
    position: relative;
    padding-bottom: 4px;
    white-space: nowrap;
}

.header-nav ul a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 1px;
    background-color: var(--color-gold-base);
    transition: width var(--transition-fast);
}

.header-nav ul a:hover::after {
    width: 100%;
}

.menu-toggle {
    display: none;
    background: transparent;
    border: none;
    cursor: pointer;
    flex-direction: column;
    gap: 6px;
    z-index: 101;
}

.menu-toggle span {
    display: block;
    width: 30px;
    height: 2px;
    background-color: var(--color-gold-base);
    transition: all var(--transition-fast);
}

/* ==========================================================================
   B. HERO
   ========================================================================== */
.hero-section {
    position: relative;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding-top: 100px;
    padding-bottom: 80px;
}

.hero-media-wrapper {
    position: relative;
    max-width: 920px;
    margin: 0 auto 3rem;
    padding: 10px;
    /* Space for the golden frame */
    border: 2px solid var(--color-gold-dark);
    box-shadow: 0 0 30px rgba(0, 0, 0, 0.8), inset 0 0 15px rgba(212, 175, 55, 0.2);
    background-color: var(--color-bg-base);
}

/* Corner Ornaments for the Hero Frame */
.ornament {
    position: absolute;
    width: 30px;
    height: 30px;
    border: 2px solid var(--color-gold-base);
    z-index: 2;
}

.ornament-tl {
    top: -5px;
    left: -5px;
    border-right: none;
    border-bottom: none;
}

.ornament-tr {
    top: -5px;
    right: -5px;
    border-left: none;
    border-bottom: none;
}

.ornament-bl {
    bottom: -5px;
    left: -5px;
    border-right: none;
    border-top: none;
}

.ornament-br {
    bottom: -5px;
    right: -5px;
    border-left: none;
    border-top: none;
}

.video-container {
    position: relative;
    width: 100%;
    padding-bottom: 56.25%;
    /* 16:9 Aspect Ratio */
    overflow: hidden;
    background: #000;
}

.hero-video {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    opacity: 1.0;
}

.hero-content {
    text-align: center;
    position: relative;
    z-index: 10;
}

.hero-title {
    /* 画面幅920px時におよそ4remになるように比率を調整: 64px / 920px ≈ 6.95vw 
       iPhone等でのはみ出しを防ぐため最小値を1.5remに下げ、必要なら折り返すようにする */
    font-size: clamp(1.5rem, 6.95vw, 4rem);
    color: var(--color-gold-light);
    margin-bottom: 0.5rem;
    text-shadow: 0 4px 10px rgba(0, 0, 0, 0.8);
    background: var(--gold-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    line-height: 1.2;
}

.hero-subtitle {
    font-family: var(--font-serif-jp);
    /* 画面幅920px時におよそ1.5rem(24px)になるように比率を調整: 24px / 920px ≈ 2.6vw */
    font-size: clamp(1rem, 2.6vw, 1.5rem);
    color: var(--color-text-main);
    margin-bottom: 1rem;
    font-weight: 600;
    line-height: 1.4;
}

.hero-desc {
    font-size: min(1.1rem, 2.5vw);
    color: var(--color-text-muted);
    margin-bottom: 2.5rem;
    line-height: 1.8;
    white-space: nowrap;
}

.hero-actions {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 2rem;
    flex-wrap: wrap;
}

.badge-coop {
    position: absolute;
    right: 5%;
    bottom: 0;
    width: 120px;
    height: 120px;
    border-radius: 50%;
    border: 1px solid var(--color-gold-dark);
    background: rgba(6, 9, 19, 0.8);
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--color-gold-light);
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    transform: rotate(5deg);
    animation: floatBadge 6s ease-in-out infinite;
}

@keyframes floatBadge {

    0%,
    100% {
        transform: translateY(0) rotate(5deg);
    }

    50% {
        transform: translateY(-10px) rotate(8deg);
    }
}

.badge-inner {
    padding: 15px;
    border: 1px dashed var(--color-gold-base);
    border-radius: 50%;
    width: 90%;
    height: 90%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.scroll-indicator {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 10;
}

.scroll-indicator .arrow {
    width: 20px;
    height: 20px;
    border-right: 2px solid var(--color-gold-base);
    border-bottom: 2px solid var(--color-gold-base);
    transform: rotate(45deg);
    animation: bounce 2s infinite;
}

@keyframes bounce {

    0%,
    20%,
    50%,
    80%,
    100% {
        transform: translateY(0) rotate(45deg);
    }

    40% {
        transform: translateY(-10px) rotate(45deg);
    }

    60% {
        transform: translateY(-5px) rotate(45deg);
    }
}

/* Background Particles Effect (simulated with CSS) */
.bg-particles {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 0;
    background-image: radial-gradient(circle at 20% 30%, rgba(212, 175, 55, 0.05) 0%, transparent 50%),
        radial-gradient(circle at 80% 70%, rgba(155, 17, 30, 0.05) 0%, transparent 50%),
        radial-gradient(circle at 50% 90%, rgba(15, 82, 186, 0.05) 0%, transparent 50%);
}

/* ==========================================================================
   C. Concept
   ========================================================================== */
.concept-section {
    position: relative;
    background-color: var(--color-bg-alt);
    border-top: 1px solid rgba(212, 175, 55, 0.1);
    border-bottom: 1px solid rgba(212, 175, 55, 0.1);
}

.concept-content p {
    font-family: var(--font-serif-jp);
    /* iPhone等の細い画面で折り返さないよう最小サイズを0.85remまで下げる */
    font-size: clamp(0.85rem, 2.6vw, 1.5rem);
    line-height: 1.8;
    color: var(--color-text-main);
    margin-bottom: 1rem;
}

/* Pattern Overlay */
.pattern-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0.03;
    pointer-events: none;
    background-image: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M54.627 0l.83.83-1.66 1.66-.83-.83-.83.83-1.66-1.66.83-.83-.83-.83 1.66-1.66.83.83.83-.83 1.66 1.66-.83.83.83.83-1.66 1.66zm-51.254 0L4.2 1.66l-1.66 1.66-.83-.83-.83.83-1.66-1.66.83-.83-.83-.83 1.66-1.66.83.83.83-.83 1.66 1.66-.83.83.83.83-1.66 1.66z' fill='%23D4AF37' fill-opacity='1' fill-rule='evenodd'/%3E%3C/svg%3E");
}

/* ==========================================================================
   D. How to Play
   ========================================================================== */
.howto-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: clamp(10px, 2vw, 30px);
    margin-top: 3rem;
    width: 100%;
}

.howto-card {
    background: rgba(16, 21, 36, 0.6);
    border: 1px solid rgba(212, 175, 55, 0.3);
    padding: clamp(15px, 3vw, 40px) clamp(10px, 2vw, 20px);
    text-align: center;
    position: relative;
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
    aspect-ratio: 1 / 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    min-width: 0;
}

.howto-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.5), 0 0 15px rgba(212, 175, 55, 0.2);
    border-color: var(--color-gold-base);
}

.card-frame {
    position: absolute;
    top: 10px;
    left: 10px;
    right: 10px;
    bottom: 10px;
    border: 1px dashed rgba(212, 175, 55, 0.2);
    pointer-events: none;
}

.card-image {
    width: 100%;
    height: auto;
    aspect-ratio: 16 / 9;
    object-fit: cover;
    border-radius: 8px;
    margin-bottom: 1.5rem;
    border: 1px solid var(--color-gold-dark);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.5);
}

.card-icon {
    width: 60px;
    height: 60px;
    margin: 0 auto 1.5rem;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--color-gold-dark) 0%, var(--color-bg-base) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
}

.card-icon::after {
    content: '';
    position: absolute;
    width: 30px;
    height: 30px;
    background-color: var(--color-gold-light);
    mask-size: contain;
    mask-repeat: no-repeat;
    mask-position: center;
    -webkit-mask-size: contain;
    -webkit-mask-repeat: no-repeat;
    -webkit-mask-position: center;
}

/* Fallback simple CSS icons for placeholders */
.icon-set::after {
    background-color: var(--color-emerald);
    clip-path: polygon(50% 0%, 100% 25%, 100% 75%, 50% 100%, 0% 75%, 0% 25%);
}

.icon-secure::after {
    background-color: var(--color-ruby);
    clip-path: polygon(20% 0%, 80% 0%, 100% 100%, 0% 100%);
}

.icon-shine::after {
    background-color: var(--color-sapphire);
    clip-path: polygon(50% 0%, 90% 20%, 100% 60%, 75% 100%, 25% 100%, 0% 60%, 10% 20%);
}

.card-title {
    font-size: clamp(0.9rem, 2.5vw, 1.25rem);
    /* 極少画面ではみ出ないように縮小可能に */
    color: var(--color-gold-light);
    margin-bottom: 1rem;
    white-space: normal;
    word-break: keep-all;
    overflow-wrap: break-word;
    line-height: 1.3;
}

.card-desc {
    color: var(--color-text-main);
    font-size: clamp(0.75rem, 2vw, 0.95rem);
    /* 極少画面ではみ出ないように縮小可能に */
    white-space: normal;
    word-break: keep-all;
    overflow-wrap: break-word;
    line-height: 1.5;
}

.howto-note {
    color: var(--color-text-muted);
}

/* ==========================================================================
   E. Multiplayer
   ========================================================================== */
.multi-section {
    background-image: linear-gradient(rgba(6, 9, 19, 0.9), rgba(6, 9, 19, 0.9)), url('./assets/hero-fallback.jpg');
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
    position: relative;
}

.multi-box {
    background: rgba(6, 9, 19, 0.85);
    border: 2px solid var(--color-gold-dark);
    padding: 60px 40px;
    max-width: 800px;
    margin: 0 auto;
    position: relative;
    backdrop-filter: blur(5px);
}

.box-frame {
    position: absolute;
    top: 5px;
    left: 5px;
    right: 5px;
    bottom: 5px;
    border: 1px solid rgba(212, 175, 55, 0.4);
}

.multi-desc {
    /* iPhone等の細い画面で折り返さないよう最小サイズを0.85remまで下げる */
    font-size: clamp(0.85rem, 2.6vw, 1.5rem);
    margin-bottom: 2rem;
    line-height: 1.6;
}

.multi-image {
    width: 100%;
    height: auto;
    border-radius: 8px;
    border: 1px solid var(--color-gold-dark);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.5);
    aspect-ratio: 16 / 9;
    object-fit: cover;
}

/* ==========================================================================
   F. Gallery
   ========================================================================== */
.gallery-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.gallery-item {
    position: relative;
    overflow: hidden;
    margin: 0;
}

.item-frame {
    border: 3px solid #222;
    padding: 5px;
    background: var(--color-gold-dark);
    position: relative;
    transition: transform var(--transition-fast);
}

.gallery-img {
    width: 100%;
    aspect-ratio: 1 / 1;
    object-fit: cover;
    display: block;
    transition: transform 0.8s ease;
}

.gallery-img.placeholder {
    background: linear-gradient(45deg, var(--color-bg-base), var(--color-bg-alt));
}

.gallery-item:hover .item-frame {
    border-color: var(--color-gold-base);
}

.gallery-item:hover .gallery-img {
    transform: scale(1.05);
}

.gallery-item figcaption {
    text-align: center;
    padding: 10px 0;
    font-family: var(--font-heading);
    color: var(--color-text-muted);
    font-size: 0.9rem;
    letter-spacing: 0.05em;
    text-transform: uppercase;
}

/* ==========================================================================
   G. Specs
   ========================================================================== */
.specs-table-wrapper {
    max-width: 800px;
    margin: 0 auto;
    border: 1px solid rgba(212, 175, 55, 0.3);
    background: rgba(16, 21, 36, 0.5);
}

.specs-table {
    width: 100%;
    border-collapse: collapse;
}

.specs-table th,
.specs-table td {
    padding: 20px;
    border-bottom: 1px solid rgba(212, 175, 55, 0.1);
}

.specs-table tr:last-child th,
.specs-table tr:last-child td {
    border-bottom: none;
}

.specs-table th {
    text-align: left;
    color: var(--color-gold-base);
    font-family: var(--font-heading);
    width: 30%;
    font-weight: 600;
    background: rgba(212, 175, 55, 0.05);
}

.specs-table td {
    font-family: var(--font-body);
}

/* ==========================================================================
   Bottom CTA & Footer
   ========================================================================== */
.bottom-cta-section {
    padding: 100px 0;
    background: radial-gradient(circle at center, rgba(212, 175, 55, 0.1) 0%, transparent 60%);
}

.cta-heading {
    font-family: var(--font-serif-jp);
    /* HEROタイトルより少し控えめだが十分に大きく表示: Heroサブタイトルよりは少し大きい 2rem(32px) に調整 */
    /* iPhone等の細い枠でも折り返さないよう最小は1.1remに */
    font-size: clamp(1.1rem, 3.8vw, 2rem);
    margin-bottom: 2rem;
    line-height: 1.4;
}

.site-footer {
    padding: 30px 0;
    background-color: #000;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.copyright {
    color: var(--color-text-muted);
    font-size: 0.9rem;
    margin: 0;
    font-family: var(--font-heading);
}

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

.fade-in-visible {
    opacity: 1;
    transform: translateY(0);
}

/* ==========================================================================
   Responsive
   ========================================================================== */
@media screen and (max-width: 1024px) {
    .howto-card {
        padding: clamp(10px, 2vw, 20px) 10px;
    }

    .card-image {
        margin-bottom: 0.75rem;
    }

    .card-title {
        margin-bottom: 0.5rem;
    }

    .gallery-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .badge-coop {
        width: 100px;
        height: 100px;
        font-size: 0.75rem;
        right: 0;
    }
}

@media screen and (max-width: 800px) {
    .howto-grid {
        grid-template-columns: 1fr;
        justify-items: center;
    }

    .howto-card {
        width: 100%;
        max-width: 800px;
        aspect-ratio: auto;
        padding: 30px 20px;
    }
}

@media screen and (max-width: 860px) {

    /* Menu Toggle */
    .menu-toggle {
        display: flex;
    }

    .lang-selector-wrapper {
        margin-left: auto;
        margin-right: 1.5rem;
    }

    .header-nav {
        position: fixed;
        top: 60px;
        left: 0;
        width: 100%;
        background-color: var(--color-bg-base);
        flex-direction: column;
        padding: 2rem;
        transform: translateY(-150%);
        visibility: hidden;
        border-bottom: 1px solid var(--color-gold-dark);
        z-index: 99;
    }

    .header-nav.active {
        transform: translateY(0);
        visibility: visible;
        transition: transform var(--transition-slow), visibility 0s 0s;
    }

    .header-nav ul {
        flex-direction: column;
        align-items: center;
        gap: 2rem;
    }

    .menu-toggle.active span:nth-child(1) {
        transform: translateY(8px) rotate(45deg);
    }

    .menu-toggle.active span:nth-child(2) {
        opacity: 0;
    }

    .menu-toggle.active span:nth-child(3) {
        transform: translateY(-8px) rotate(-45deg);
    }

    /* Layout Adjustments */
    .hero-section {
        padding-top: 80px;
    }

    .hero-actions {
        flex-direction: column;
        gap: 1rem;
    }

    .btn-large {
        width: 100%;
        max-width: 300px;
    }

    .badge-coop {
        display: none;
        /* Hide on mobile to save space */
    }

    .specs-table th,
    .specs-table td {
        display: block;
        width: 100%;
        text-align: center;
    }

    .specs-table th {
        border-bottom: none;
        padding-bottom: 5px;
    }

    .specs-table td {
        padding-top: 5px;
    }

    .section-padding {
        padding: var(--section-padding-mobile) 0;
    }
}

@media screen and (max-width: 480px) {
    .gallery-grid {
        grid-template-columns: 1fr;
    }

    .hero-media-wrapper {
        padding: 5px;
    }

    .multi-box {
        padding: 30px 20px;
    }

    .specs-table th,
    .specs-table td {
        /* iPhone等で要素の幅を最大化して折り返しを防ぐため左右の余白を削る */
        padding-left: 2px;
        padding-right: 2px;
        font-size: 1rem;
        /* 余裕を持たせるため文字サイズも少しだけ小さくする */
    }
}