:root{
    --bg: #f7f7f7;         /* ページ全体の背景色 */
    --panel: #ffffff;      /* カードや面の背景色 */
    --accent: #111111;     /* 強調色（黒） */
    --muted: #888888;      /* 補助的なグレー */
    /* 面のサイズ（レスポンシブ）：最小140px、推奨28vw、最大280px */
    --cube-size: clamp(140px, 28vw, 280px);
}

html {
    overflow-x: hidden; /* 横スクロールを防止 */
}

/*-----------------------------------------------------------
    グローバルメニュー（上部右寄り）
-----------------------------------------------------------*/
global-nav {
    display: block;
    position: sticky;
    top: 0;
    z-index: 1000;
    background: var(--panel);
    border-bottom: 1px solid #e5e5e5;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.global-nav {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 40px;
    width: 90%;
}

.global-nav__list {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    justify-content: flex-end;
    align-items: center;
    gap: 2px;
    height: 60px;
}

.global-nav > li,
.global-nav__list > li {
    display: flex;
    align-items: center;
}

.global-nav > li > a,
.global-nav__list > li > a {
    display: flex;
    align-items: center;
    padding: 8px 18px;
    color: var(--accent);
    text-decoration: none;
    font-size: 0.95rem;
    font-weight: 500;
    letter-spacing: 0.02em;
    transition: all 200ms ease;
    border-radius: 4px;
}

.global-nav > li > a:hover,
.global-nav__list > li > a:hover {
    background: #f0f0f0;
    color: var(--accent);
}

.global-nav > li > a:active,
.global-nav__list > li > a:active {
    background: #e8e8e8;
}

/* モバイル対応（768px以下） */
@media (max-width: 768px) {
    .global-nav {
        padding: 0 24px;
        position: relative;
    }

    .global-nav__list {
        gap: 0;
        height: 50px;
        display: flex;
    }

    .global-nav > li > a,
    .global-nav__list > li > a {
        padding: 6px 12px;
        font-size: 0.9rem;
    }

    /* タブレット以上の場合はハンバーガーアイコンを非表示 */
    .global-nav__hamburger {
        display: none;
    }
}

/* モバイル対応（480px以下） */
@media (max-width: 480px) {
    global-nav {
        position: static;
    }

    .global-nav {
        padding: 0 16px;
        position: relative;
        display: flex;
        justify-content: space-between;
        align-items: center;
        height: 60px;
    }

    .global-nav__list {
        flex-wrap: wrap;
        gap: 0;
        height: auto;
        padding: 20px 0;
        justify-content: flex-start;
        /* ハンバーガーメニューの場合：デフォルトで右側に隠す */
        display: flex;
        flex-direction: column;
        position: absolute;
        top: 60px;
        right: 0;
        background: var(--panel);
        width: 80%;
        max-width: 300px;
        z-index: 999;
        border: 1px solid #e5e5e5;
        box-shadow: -2px 2px 10px rgba(0, 0, 0, 0.1);
        transform: translateX(100%);
        transition: transform 0.3s ease;
    }

    .global-nav__list.active {
        transform: translateX(0);
    }

    .global-nav > li,
    .global-nav__list > li {
        border-bottom: 1px solid #eee;
    }

    .global-nav > li:last-child,
    .global-nav__list > li:last-child {
        border-bottom: none;
    }

    .global-nav > li > a,
    .global-nav__list > li > a {
        padding: 15px 25px;
        font-size: 0.9rem;
        width: 100%;
        border-radius: 0;
    }

    /* ハンバーガーアイコン - 右に寄せる */
    .global-nav__hamburger {
        display: flex;
        flex-direction: column;
        gap: 6px;
        background: none;
        border: none;
        cursor: pointer;
        padding: 8px;
        z-index: 1001;
        margin-left: auto;
    }

    .global-nav__hamburger span {
        width: 24px;
        height: 2px;
        background: var(--accent);
        transition: all 250ms ease;
        display: block;
    }

    /* ハンバーガーアイコンのアニメーション */
    .global-nav__hamburger.active span:nth-child(1) {
        transform: rotate(45deg) translate(10px, 10px);
    }

    .global-nav__hamburger.active span:nth-child(2) {
        opacity: 0;
    }

    .global-nav__hamburger.active span:nth-child(3) {
        transform: rotate(-45deg) translate(8px, -8px);
    }
}

body{
    margin: 0 auto;
    width: 90%;
    overflow-x: hidden; /* 横スクロールを防止 */
}

/*-----------------------------------------------------------
    トップページ
-----------------------------------------------------------*/
.wrap{
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-self: center;
    gap: 48px;
    padding: 40px;
}

/*-----------------------------------------------------------
    左サイド（メニュー）
-----------------------------------------------------------*/
.stage{
    width: 60%;
    display: flex;
    align-items: center;
    justify-content: center;
}
.cube-wrap{
    width: var(--cube-size);
    height: var(--cube-size);
    perspective: 1200px;
}
.cube{
    width: 100%;
    height: 100%;
    position: relative;
    transform-style: preserve-3d;
    transform: rotateX(-20deg) rotateY(20deg);
    transition: transform 700ms cubic-bezier(.2,.9,.2,1);
    touch-action: none;
}

/* キューブの各面 */
.face{
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    backface-visibility: hidden;
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.06);
    box-shadow: 0 6px 18px rgba(2, 6, 23, 0.6), inset 0 1px 0 rgba(255, 255, 255, 0.02);
    font-weight: 600;
    font-size: 18px;
    letter-spacing: 0.6px;
    background: linear-gradient(180deg, rgba(255,255,255,0.03), rgba(255,255,255,0.01));
}

/* 各面の配置 */
.face.front  { transform: translateZ(calc(var(--cube-size) / 2)); }
.face.back   { transform: rotateY(180deg) translateZ(calc(var(--cube-size) / 2)); }
.face.right  { transform: rotateY(90deg)  translateZ(calc(var(--cube-size) / 2)); }
.face.left   { transform: rotateY(-90deg) translateZ(calc(var(--cube-size) / 2)); }
.face.top    { transform: rotateX(90deg)  translateZ(calc(var(--cube-size) / 2)); }
.face.bottom { transform: rotateX(-90deg) translateZ(calc(var(--cube-size) / 2)); }

/* 小さい画面では遠近感を調整して自然に見えるようにする */
@media (max-width: 900px) {
    .cube-wrap { perspective: 900px; }
}
@media (max-width: 480px) {
    .cube-wrap { perspective: 700px; }
}

/*-----------------------------------------------------------
    右サイドメニュー
-----------------------------------------------------------*/
.side{
    width: 300px;
    display: flex;
    align-items: center;
    justify-content: center;
}
.menu{
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: 18px;
}
.menu li{
    padding: 12px 18px;
    border-radius: 8px;
    background: transparent;
    color: var(--muted);
    cursor: pointer;
    transition: all 250ms ease;
    user-select: none;
}
.menu li:hover{
    color: #fff;
    transform: translateX(-8px);
    background: linear-gradient(90deg, rgba(255,255,255,0.02), rgba(255,255,255,0.01));
}
@media (max-width:480px){
    .side{ width: 100%; }
    
}
/*-----------------------------------------------------------
    About セクション
-----------------------------------------------------------*/
.content-section.about{
    background: #fafafa;
    padding: 80px 40px;
    margin: 0 -40px;
}

.about__container{
    max-width: 900px;
    margin: 0 auto;
}

.about__intro{
    margin-bottom: 64px;
    border-bottom: 2px solid #e5e5e5;
    padding-bottom: 32px;
}

.about__title{
    font-size: 2.5rem;
    font-weight: 300;
    letter-spacing: -0.02em;
    margin: 0 0 8px 0;
    color: var(--accent);
}

.about__tagline{
    font-size: 0.95rem;
    color: #999;
    font-weight: 400;
    margin: 0;
    letter-spacing: 0.05em;
}

.about__content{
    display: grid;
    gap: 48px;
}

.about__bio,
.about__focus,
.about__philosophy,
.about__expertise{
    line-height: 1.8;
}

.about__bio h3,
.about__focus h3,
.about__philosophy h3,
.about__expertise h3{
    font-size: 1.3rem;
    font-weight: 600;
    margin: 0 0 16px 0;
    color: var(--accent);
    letter-spacing: -0.01em;
}

.about__bio p,
.about__focus p,
.about__philosophy p{
    margin: 0;
    color: #555;
    font-size: 1rem;
    line-height: 1.8;
}

.expertise__list{
    list-style: none;
    padding: 0;
    margin: 0;
    display: grid;
    gap: 12px;
}

.expertise__list li{
    padding: 12px 16px;
    background: white;
    border-left: 3px solid #ddd;
    color: #444;
    font-size: 0.95rem;
    transition: all 200ms ease;
}

.expertise__list li:hover{
    border-left-color: var(--accent);
    background: #f5f5f5;
}

.about__closing{
    margin: 32px 0 0 0;
    padding: 24px 16px;
    border-top: 2px solid #e5e5e5;
    color: #666;
    font-size: 0.95rem;
    line-height: 1.8;
}

/* レスポンシブ */
@media (max-width: 768px){
    /* #about / .content-section.about のレスポンシブ調整（タブレット） */
    .content-section.about,
    #about.content-section.about {
        padding: 60px 24px;
        margin: 0 -24px;
    }
    .about__title,
    #about .about__title {
        font-size: 2rem;
    }
    /* モバイル寄りの幅では1列レイアウトにしテキストの読みやすさを優先 */
    .about__content,
    #about .about__content {
        gap: 40px;
        grid-template-columns: 1fr;
    }
    .about__bio,
    #about .about__bio {
        font-size: 0.98rem;
    }
}

@media (max-width: 480px){
    /* #about / .content-section.about の更なる微調整（スマホ） */
    .content-section.about,
    #about.content-section.about {
        padding: 40px 16px;
        margin: 0 -16px;
    }
    .about__intro,
    #about .about__intro {
        margin-bottom: 40px;
        padding-bottom: 24px;
    }
    .about__title,
    #about .about__title {
        font-size: 1.5rem;
    }
    .about__content,
    #about .about__content {
        gap: 28px;
        grid-template-columns: 1fr;
    }
    /* ボディテキストをやや大きめにして可読性を確保 */
    .about__bio p,
    #about .about__bio p {
        font-size: 1rem;
    }
}

/*-----------------------------------------------------------
    Skills セクション
-----------------------------------------------------------*/
.content-section.skills {
    background: #fafafa;
    padding: 80px 40px;
    margin: 0 -40px;
}

.skills__container {
    max-width: 900px;
    margin: 0 auto;
}

.skills__header {
    margin-bottom: 64px;
    border-bottom: 2px solid #e5e5e5;
    padding-bottom: 32px;
}

.skills__title {
    font-size: 2.5rem;
    font-weight: 300;
    letter-spacing: -0.02em;
    margin: 0;
    color: var(--accent);
}

.skills__tagline{
    font-size: 0.95rem;
    color: #999;
    font-weight: 400;
    margin: 0;
    letter-spacing: 0.05em;
}

.skills__content {
    display: grid;
    gap: 48px;
}

.skill-category {
    line-height: 1.8;
}

.skill-category__title {
    font-size: 1.3rem;
    font-weight: 600;
    margin: 0 0 16px 0;
    color: var(--accent);
    letter-spacing: -0.01em;
}

.skill-category__box {
    background: white;
    padding: 24px;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(2, 6, 23, 0.04);
}

.skill-list {
    list-style: none;
    padding: 0;
    margin: 0 0 16px 0;
    display: grid;
    gap: 10px;
}

.skill-list li {
    padding: 8px 12px;
    border-left: 3px solid #ddd;
    color: #444;
    font-size: 0.95rem;
    transition: all 200ms ease;
}

.skill-list li:hover {
    border-left-color: var(--accent);
    background: #f5f5f5;
}

.skill-category__desc {
    margin: 0;
    color: #666;
    font-size: 0.95rem;
    line-height: 1.6;
}

/* レスポンシブ */
@media (max-width: 768px) {
    /* #skills / .content-section.skills のレスポンシブ調整（タブレット） */
    .content-section.skills,
    #skills.content-section.skills {
        padding: 60px 24px;
        margin: 0 -24px;
    }
    .skills__title,
    #skills .skills__title {
        font-size: 2rem;
    }
    /* スキルカテゴリを縦並びにしてボックス幅を広げる */
    .skills__content,
    #skills .skills__content {
        gap: 40px;
        grid-template-columns: 1fr;
    }
    .skill-category__box,
    #skills .skill-category__box {
        padding: 20px;
    }
}

@media (max-width: 480px) {
    /* #skills / .content-section.skills の更なる微調整（スマホ） */
    .content-section.skills,
    #skills.content-section.skills {
        padding: 40px 16px;
        margin: 0 -16px;
    }
    .skills__header,
    #skills .skills__header {
        margin-bottom: 40px;
        padding-bottom: 24px;
    }
    .skills__title,
    #skills .skills__title {
        font-size: 1.5rem;
    }
    .skill-category__title,
    #skills .skill-category__title {
        font-size: 1.05rem;
    }
    /* タッチでの誤操作を防ぐためボタン幅はフル幅に寄せる */
    .skill-category__box,
    #skills .skill-category__box {
        padding: 16px;
        width: 100%;
        box-sizing: border-box;
    }
    .skill-list li,
    #skills .skill-list li {
        font-size: 0.95rem;
        padding: 10px 12px;
    }
}

/* prefers-reduced-motion サポート */
@media (prefers-reduced-motion: reduce) {
    .skill-list li {
        transition: none;
    }
}

/*-----------------------------------------------------------
    Site-Works セクション（3D円形カルーセル）
-----------------------------------------------------------*/
.content-section.site-works {
    background: #fafafa;
    padding: 80px 40px;
    margin: 0 -40px;
}

.site-works__container {
    max-width: 1000px;
    margin: 0 auto;
}

.site-works__header {
    margin-bottom: 64px;
    border-bottom: 2px solid #e5e5e5;
    padding-bottom: 32px;
}

.site-works__title {
    font-size: 2.5rem;
    font-weight: 300;
    letter-spacing: -0.02em;
    margin: 0;
    color: var(--accent);
}

.site-works__desc {
    margin: 16px 0 0 0;
    color: #666;
    font-size: 0.95rem;
    line-height: 1.7;
}

/* 3Dカルーセルコンテナ */
.carousel-wrapper {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 32px;
}

.carousel-container {
    width: 100%;
    height: 400px;
    /* パースペクティブを大きくして、手前のサイズ拡大を目立たなくする */
    perspective: 10000px;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden; /* 横スクロールのはみ出しを防止 */
    box-sizing: border-box;
}

.carousel {
    position: relative;
    width: 100%;
    max-width: 450px; /* 最大幅を維持しつつ小さな画面では縮小 */
    height: 300px;
    transform-style: preserve-3d;
    /* JavaScriptで動的にrotateYが設定される */
}

.carousel__item {
    position: absolute;
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    backface-visibility: hidden;
    transform-origin: center center;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
    transition: opacity 600ms ease, transform 600ms ease;
}

.carousel__item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

/* インジケータ */
.carousel-indicators {
    display: flex;
    gap: 8px;
    justify-content: center;
}

.carousel-indicator {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    border: 2px solid var(--muted);
    background: transparent;
    cursor: pointer;
    transition: all 200ms ease;
}

.carousel-indicator.active {
    background: var(--accent);
    border-color: var(--accent);
    width: 12px;
    height: 12px;
}

/* レスポンシブ */
@media (max-width: 768px) {
    .content-section.site-works {
        padding: 60px 24px;
        margin: 0 -24px;
    }
    
    .site-works__title {
        font-size: 2rem;
    }
    
    .carousel-container {
        height: 350px;
    }
    
    .carousel {
        width: 250px;
        height: 250px;
    }
}

@media (max-width: 480px) {
    .content-section.site-works {
        padding: 40px 16px;
        margin: 0 -16px;
    }
    
    .site-works__header {
        margin-bottom: 40px;
        padding-bottom: 24px;
    }
    
    .site-works__title {
        font-size: 1.5rem;
    }
    
    .site-works__desc {
        font-size: 0.9rem;
    }
    
    .carousel-container {
        height: 300px;
    }
    
    .carousel {
        width: 200px;
        height: 200px;
    }
}

/*-----------------------------------------------------------
    system-works セクション
-----------------------------------------------------------*/
.system-works__container {
    max-width: 1000px;
    margin: 100px auto;
}

.system-works__header {
    margin-bottom: 64px;
    border-bottom: 2px solid #e5e5e5;
    padding-bottom: 32px;
}

.system-works__title {
    font-size: 1.5rem;
    font-weight: 300;
    letter-spacing: -0.02em;
    margin: 0;
    color: var(--accent);
}

.system-works__desc {
    margin: 16px 0 0 0;
    color: #666;
    font-size: 0.95rem;
    line-height: 1.7;
}

/*-----------------------------------------------------------
    sample-site セクション
-----------------------------------------------------------*/
.sample-site {
    margin: 60px 0;
}

.sample-site__container {
    background: var(--bg);
    border-radius: 8px;
    padding: 32px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

/* ギャラリーレイアウト（左メイン画像 + 右サムネイル） */
.sample-site__gallery {
    display: flex;
    gap: 24px;
    margin-bottom: 32px;
}

.sample-site__main-image {
    flex: 0 0 65%;
    overflow: hidden;
    border-radius: 6px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.sample-site__main-img {
    width: 100%;
    height: auto;
    display: block;
    transition: transform 0.3s ease;
}

.sample-site__main-img:hover {
    transform: scale(1.02);
}

/* サムネイル一覧（右側） */
.sample-site__thumbnails {
    flex: 0 0 20%;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.sample-site__thumbnail {
    width: 100%;
    height: auto;
    aspect-ratio: 16/9;
    object-fit: cover;
    cursor: pointer;
    border: 3px solid;
    border-radius: 4px;
    opacity: 0.6;
    transition: all 0.3s ease;
}

.sample-site__thumbnail:hover {
    opacity: 0.9;
    border-color: var(--muted);
}

.sample-site__thumbnail.active {
    opacity: 1;
    border-color: var(--accent);
}

/* コンテンツセクション */
.sample-site__content {
    margin-top: 32px;
}

.sample-site__title {
    margin: 0 0 24px 0;
    font-size: 1.6rem;
    color: var(--accent);
}

/* フレックスレイアウト（スキル + テキスト横並び） */
.sample-site__flex-row {
    display: flex;
    gap: 32px;
}

.sample-site_skills {
    flex: 0 0 35%;
}

.sample-site_skills h3 {
    margin: 0 0 12px 0;
    font-size: 1rem;
    color: var(--accent);
}

.sample-site_skills ul {
    margin: 0;
    padding-left: 20px;
    list-style: disc;
    color: #666;
    font-size: 0.95rem;
    line-height: 1.8;
}

.sample-site_skills li {
    margin-bottom: 8px;
}

.sample-site_text {
    flex: 1;
}

.sample-site__desc {
    margin: 0 0 16px 0;
    color: #666;
    font-size: 0.95rem;
    line-height: 1.8;
}

.sample-site__desc:last-child {
    margin-bottom: 0;
}

/* タブレット対応（768px以下） */
@media (max-width: 768px) {
    .sample-site__container {
        padding: 24px;
    }

    .sample-site__gallery {
        flex-direction: column;
        gap: 16px;
    }

    .sample-site__main-image {
        flex: none;
        width: 100%;
    }

    .sample-site__thumbnails {
        flex: none;
        width: 100%;
        flex-direction: column;
        gap: 12px;
    }

    .sample-site__flex-row {
        flex-direction: column;
        gap: 24px;
    }

    .sample-site_skills {
        flex: none;
        width: 100%;
    }

    .sample-site_text {
        flex: none;
        width: 100%;
    }

    .sample-site__title {
        font-size: 1.4rem;
    }
}

/* モバイル対応（480px以下） */
@media (max-width: 480px) {
    .sample-site__container {
        padding: 16px;
        margin: 40px 0;
    }

    .sample-site__gallery {
        gap: 12px;
    }

    .sample-site__thumbnails {
        flex-direction: row;
        gap: 8px;
        overflow-x: auto;
    }

    .sample-site__thumbnail {
        flex: 0 0 calc(20% - 6px);
        min-width: 60px;
    }

    .sample-site_skills h3 {
        font-size: 0.9rem;
    }

    .sample-site_skills ul {
        font-size: 0.85rem;
        line-height: 1.6;
    }

    .sample-site__desc {
        font-size: 0.85rem;
    }

    .sample-site__title {
        font-size: 1.2rem;
    }

    .sample-site__flex-row {
        gap: 16px;
    }
}

/*-----------------------------------------------------------
    Contact Page
-----------------------------------------------------------*/
.contact-main {
    min-height: calc(100vh - 140px);
    padding: 60px 20px;
}

.contact-container {
    max-width: 800px;
    margin: 0 auto;
}

.contact-header {
    text-align: center;
    margin-bottom: 50px;
}

.contact-title {
    font-size: 3rem;
    color: var(--accent);
    font-weight: 700;
    margin-bottom: 15px;
    letter-spacing: 0.02em;
}

.contact-description {
    font-size: 1.1rem;
    color: var(--muted);
}

.contact-content {
    display: grid;
    gap: 40px;
}

.contact-info {
    background: var(--panel);
    padding: 30px;
    border-radius: 8px;
    border: 1px solid #e5e5e5;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.contact-info h2 {
    font-size: 1.5rem;
    color: var(--accent);
    margin-bottom: 15px;
    font-weight: 600;
}

.contact-info p {
    color: var(--muted);
    line-height: 1.8;
    margin-bottom: 10px;
}

.contact-email {
    margin-top: 20px;
    padding: 15px;
    background: var(--bg);
    border-radius: 4px;
    font-size: 0.95rem;
}

.contact-email strong {
    color: var(--accent);
    display: inline-block;
    margin-right: 10px;
}

/* フォームスタイル */
.contact-form {
    background: var(--panel);
    padding: 40px;
    border-radius: 8px;
    border: 1px solid #e5e5e5;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.form-group {
    margin-bottom: 25px;
}

.form-label {
    display: block;
    font-size: 0.95rem;
    color: var(--accent);
    font-weight: 600;
    margin-bottom: 8px;
}

.required {
    color: #d32f2f;
    font-weight: 700;
}

.form-input,
.form-textarea {
    width: 85%;
    padding: 12px 16px;
    font-size: 1rem;
    border: 1px solid #d0d0d0;
    border-radius: 4px;
    background: var(--panel);
    color: var(--accent);
    font-family: inherit;
    transition: all 0.3s ease;
}

.form-input:focus,
.form-textarea:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(17, 17, 17, 0.1);
}

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

.form-submit {
    width: 100%;
    padding: 15px 30px;
    background: var(--accent);
    color: var(--panel);
    font-size: 1.1rem;
    font-weight: 600;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.form-submit:hover {
    background: #333;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.form-submit:active {
    transform: translateY(0);
}

/* 送信完了・エラーメッセージ */
.message-box {
    background: var(--panel);
    padding: 60px 40px;
    border-radius: 8px;
    border: 1px solid #e5e5e5;
    text-align: center;
    margin: 50px auto;
}

.message-box h1 {
    font-size: 2rem;
    color: var(--accent);
    margin-bottom: 20px;
}

.message-box p {
    color: var(--muted);
    line-height: 1.8;
    margin-bottom: 15px;
}

.message-box.success {
    border-left: 4px solid #4caf50;
}

.message-box.error {
    border-left: 4px solid #d32f2f;
}

.btn-back {
    display: inline-block;
    margin-top: 30px;
    padding: 12px 30px;
    background: var(--accent);
    color: var(--panel);
    text-decoration: none;
    border-radius: 4px;
    font-weight: 600;
    transition: all 0.3s ease;
}

.btn-back:hover {
    background: #333;
    transform: translateY(-2px);
}

/* フッター */
.contact-footer {
    background: var(--panel);
    border-top: 1px solid #e5e5e5;
    padding: 30px 20px;
    text-align: center;
    color: var(--muted);
    font-size: 0.9rem;
}

/* タブレット対応 */
@media (max-width: 768px) {
    .contact-title {
        font-size: 2.5rem;
    }

    .contact-form {
        padding: 30px;
    }
}

/* モバイル対応 */
@media (max-width: 480px) {
    .contact-main {
        padding: 30px 15px;
    }

    .contact-title {
        font-size: 2rem;
    }

    .contact-info,
    .contact-form {
        padding: 20px;
    }

    .message-box {
        padding: 40px 20px;
    }
}