CSS
/* ==========================================
   ベース設定
   ========================================== */
html {
    scroll-behavior: smooth;
}
body {
    margin: 0;
    padding: 0;
    font-family: 'Helvetica Neue', Arial, 'Hiragino Kaku Gothic ProN', sans-serif;
    color: #333333;
    background-color: #ffffff;
    line-height: 1.8;
}

/* 💡 ロゴを押した時にヘッダーに隠れず、画面の「本当の一番上」にピタッと戻るための設定 */
#top {
    display: block;
    height: 0;
    margin-top: -100px; /* ヘッダーの高さ分をマイナスして吸収します */
    padding-top: 100px;
    visibility: hidden;
}

/* ヘッダー */
header {
    background-color: rgba(255, 255, 255, 0.95);
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    position: fixed;
    width: 100%;
    top: 0;
    left: 0;
    z-index: 1000;
}
.header-inner {
    max-width: 1140px;
    margin: 0 auto;
    padding: 10px 20px; 
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-sizing: border-box;
}

/* 画像ロゴ用のリンク・表示設定 */
.logo-link {
    text-decoration: none;
    display: flex;
    align-items: center;
}
.logo {
    display: flex;
    align-items: center;
    height: 54px; 
}
.logo img {
    height: 50px;       
    width: auto;        
    display: block;
    object-fit: contain;
}

nav {
    display: flex;
    align-items: center;
}
nav a {
    color: #555555;
    text-decoration: none;
    margin-left: 25px;
    font-size: 15px;
    font-weight: 500;
    transition: color 0.3s, background-color 0.3s;
    white-space: nowrap; /* テキストの意図しない改行を防止 */
}
nav a:hover {
    color: #005caf;
}

/* お問い合わせボタンのアクセント装飾（PC用） */
nav a[href*="contact.html"] {
    background-color: #00b9a2;
    color: #ffffff;
    padding: 6px 16px;
    border-radius: 20px;
    margin-left: 20px;
}
nav a[href*="contact.html"]:hover {
    background-color: #009683;
    color: #ffffff;
}

/* ==========================================
   メインビジュアル (Heroセクション)
   ========================================== */
.hero {
    min-height: 90vh;
    background-image: url('img/main-visual.jpg');
    background-size: cover;
    background-position: center;
    margin-top: 74px; /* 💡 ヘッダーの太さに合わせて調整 */
    position: relative;
    display: flex;
    align-items: center;
    overflow: hidden;
}
.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(255, 255, 255, 0.6);
    z-index: 1;
}
.hero-inner {
    width: 100%;
    max-width: 1140px;
    margin: 0 auto;
    padding: 80px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 50px;
    position: relative;
    z-index: 2;
    box-sizing: border-box;
    flex-wrap: wrap;
}
.hero-content {
    flex: 1.2;
    min-width: 320px;
}
.hero h1 {
    font-size: 3.6rem;
    color: #002b5b;
    line-height: 1.3;
    margin-top: 0;
    margin-bottom: 25px;
    font-weight: 700;
    letter-spacing: -0.5px;
    text-shadow: 0 0 15px rgba(255,255,255,0.8);
}
.hero h1 span {
    color: #00b9a2;
}
.hero p {
    font-size: 1.15rem;
    color: #222222;
    margin-bottom: 35px;
    font-weight: 700;
    text-shadow: 0 0 10px rgba(255,255,255,0.9);
}

/* 右側の3枚斜め重なり画像エリア */
.hero-images-stack {
    flex: 0.8;
    min-width: 420px;
    height: 500px;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
}
.hero-stack-card {
    position: absolute;
    width: 380px;
    height: 285px;
    border-radius: 14px;
    overflow: hidden;
    box-shadow: 0 12px 35px rgba(0,0,0,0.15);
    background-color: #cbd5e1;
    border: 4px solid #ffffff;
    transition: transform 0.4s ease, z-index 0.4s, box-shadow 0.4s;
}
.hero-stack-card img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

/* 【通常静止時】の重なりと傾き */
.card-first {
    z-index: 3;
    transform: translate(0, 0) rotate(-4deg);
}
.card-second {
    z-index: 2;
    transform: translate(35px, -35px) rotate(6deg);
}
.card-third {
    z-index: 1;
    transform: translate(-40px, 40px) rotate(-12deg);
}

/* マウスホバー時の自動ローテーションアニメーション */
.hero-images-stack:hover .card-first {
    animation: rotateCard1 6s infinite ease-in-out;
}
.hero-images-stack:hover .card-second {
    animation: rotateCard2 6s infinite ease-in-out;
}
.hero-images-stack:hover .card-third {
    animation: rotateCard3 6s infinite ease-in-out;
}

@keyframes rotateCard1 {
    0%, 100% {
        z-index: 3;
        transform: translate(0, 0) rotate(-4deg) scale(1.02);
        box-shadow: 0 15px 40px rgba(0,0,0,0.22);
    }
    33.33% {
        z-index: 2;
        transform: translate(90px, -75px) rotate(10deg);
        box-shadow: 0 12px 30px rgba(0,0,0,0.15);
    }
    66.66% {
        z-index: 1;
        transform: translate(-95px, 75px) rotate(-8deg);
        box-shadow: 0 8px 20px rgba(0,0,0,0.12);
    }
}
@keyframes rotateCard2 {
    0%, 100% {
        z-index: 2;
        transform: translate(90px, -75px) rotate(10deg);
        box-shadow: 0 12px 30px rgba(0,0,0,0.15);
    }
    33.33% {
        z-index: 1;
        transform: translate(-95px, 75px) rotate(-8deg);
        box-shadow: 0 8px 20px rgba(0,0,0,0.12);
    }
    66.66% {
        z-index: 3;
        transform: translate(0, 0) rotate(-4deg) scale(1.02);
        box-shadow: 0 15px 40px rgba(0,0,0,0.22);
    }
}
@keyframes rotateCard3 {
    0%, 100% {
        z-index: 1;
        transform: translate(-95px, 75px) rotate(-8deg);
        box-shadow: 0 8px 20px rgba(0,0,0,0.12);
    }
    33.33% {
        z-index: 3;
        transform: translate(0, 0) rotate(-4deg) scale(1.02);
        box-shadow: 0 15px 40px rgba(0,0,0,0.22);
    }
    66.66% {
        z-index: 2;
        transform: translate(90px, -75px) rotate(10deg);
        box-shadow: 0 12px 30px rgba(0,0,0,0.15);
    }
}

/* ==========================================
   共通セクション & 各パーツ
   ========================================== */
.section {
    padding: 90px 0;
}
.bg-gray {
    background-color: #f8fafc;
}
.section-inner {
    max-width: 1140px;
    margin: 0 auto;
    padding: 0 20px;
    box-sizing: border-box;
    text-align: center;
}
.section-title {
    font-size: 2.2rem;
    color: #002b5b;
    margin-bottom: 5px;
    position: relative;
    display: inline-block;
    font-weight: 700;
}
.section-title::after {
    content: '';
    display: block;
    width: 100%;
    height: 3px;
    background-color: #00b9a2;
    margin: 12px auto 0;
}
.section-sub {
    color: #aaa;
    font-size: 13px;
    margin-bottom: 60px;
    text-transform: uppercase;
    letter-spacing: 3px;
}

/* サービスカード */
.card-container {
    display: flex;
    justify-content: space-between;
    gap: 25px;
    flex-wrap: wrap;
}
.card {
    flex: 1;
    min-width: 280px;
    background: #ffffff;
    padding: 40px 30px;
    border-radius: 8px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.04);
    border-top: 4px solid #005caf;
    transition: all 0.3s ease;
    text-align: left;
}
.card:hover {
    transform: translateY(-8px);
    box-shadow: 0 15px 40px rgba(0,0,0,0.08);
}
.card h3 {
    color: #002b5b;
    font-size: 1.4rem;
    margin-top: 0;
    margin-bottom: 15px;
}

/* 私たちの強みセクション */
.strength-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 50px;
    margin-bottom: 60px;
    text-align: left;
    flex-wrap: wrap;
}
.strength-row:nth-child(even) {
    flex-direction: row-reverse;
}
.strength-text {
    flex: 1.2;
    min-width: 300px;
}
.strength-text h3 {
    color: #002b5b;
    font-size: 1.6rem;
    margin-top: 0;
    margin-bottom: 15px;
    display: flex;
    align-items: center;
}
.strength-text h3::before {
    content: '✓';
    color: #00b9a2;
    font-weight: bold;
    margin-right: 10px;
    font-size: 1.8rem;
}
.strength-text p {
    color: #555555;
    font-size: 1rem;
}

/* 強みエリアの写真ボックス */
.strength-img-box {
    flex: 0.8;
    min-width: 300px;
    height: 240px;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 5px 20px rgba(0,0,0,0.07);
    background-color: #cbd5e1;
    position: relative; 
    transition: box-shadow 0.4s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}
.strength-img-box img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
    position: absolute;
    top: 0;
    left: 0;
    z-index: 1;
    transition: transform 0.4s ease;
}
.strength-label-overlay {
    position: absolute;
    top: 16px;
    left: 16px;
    z-index: 3;
    color: #ffffff; 
    font-size: 13px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 2px;
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    pointer-events: none;
    white-space: nowrap; 
    transition: top 0.4s ease, left 0.4s ease, transform 0.4s ease, font-size 0.4s ease, color 0.4s ease;
}
.strength-img-box::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 2;
    background: linear-gradient(135deg, rgba(0,0,0,0.6) 0%, rgba(0,0,0,0) 60%);
    transition: background 0.4s ease;
}
.strength-img-box:hover {
    box-shadow: 0 12px 28px rgba(0,0,0,0.15);
}
.strength-img-box:hover img {
    transform: scale(1.08);
}
.strength-img-box:hover::before {
    background: rgba(0,0,0,0.5); 
}
.strength-img-box:hover .strength-label-overlay {
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%); 
    font-size: 18px; 
    color: #ffffff; 
    text-shadow: 0 2px 10px rgba(0,0,0,0.3); 
}

/* 会社概要テーブル */
.company-table {
    width: 100%;
    max-width: 800px;
    margin: 0 auto;
    border-collapse: collapse;
    text-align: left;
}
.company-table th, .company-table td {
    padding: 20px;
    border-bottom: 1px solid #e2e8f0;
}
.company-table th {
    width: 25%;
    color: #002b5b;
    font-weight: bold;
    vertical-align: top;
}
.address-text {
    color: #333333;
    display: inline-block;
    margin-bottom: 15px;
}

/* Googleマップ */
.map-container {
    width: 100%;
    max-width: 600px;
    height: 250px;
    border-radius: 6px;
    overflow: hidden;
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
}
.map-container iframe {
    width: 100%;
    height: 100%;
    border: 0;
}

/* ボタン */
.btn {
    display: inline-block;
    padding: 14px 40px;
    background-color: #005caf;
    color: #ffffff;
    text-decoration: none;
    border-radius: 50px;
    font-weight: bold;
    box-shadow: 0 5px 20px rgba(0,92,175,0.25);
    transition: all 0.3s;
    border: none;
    cursor: pointer;
    font-size: 16px;
}
.btn:hover {
    background-color: #004481;
    transform: translateY(-2px);
}

/* ==========================================
   💻 レスポンシブ調整（スマホ・タブレット対応）
   ========================================== */
@media (max-width: 768px) {
    /* 1. ヘッダーをスマホ用に整理 */
    .header-inner {
        flex-direction: column;
        gap: 10px;
        padding: 10px 15px;
    }
    
    .logo img {
        height: 36px; 
    }

    nav {
        width: 100%;
        justify-content: center;
        flex-wrap: wrap;
        gap: 8px 12px;
    }

    nav a {
        margin-left: 0;
        font-size: 13px;
    }

    nav a[href*="contact.html"] {
        margin-left: 0;
        padding: 4px 12px;
        font-size: 12px;
    }

    /* 2. ヒーローセクションのレスポンシブ最適化 */
    .hero {
        margin-top: 100px; /* 上下に広がったヘッダー分調整 */
        min-height: auto;
    }

    .hero-inner {
        flex-direction: column;
        text-align: center;
        gap: 30px;
        padding: 40px 15px;
    }

    .hero-content {
        min-width: 100%;
    }

    .hero h1 {
        font-size: 2.2rem;
        margin-bottom: 15px;
    }

    .hero p {
        font-size: 1rem;
        margin-bottom: 25px;
    }

    /* 重なり画像エリアをスマホ画面幅に収まるようスケールダウン */
    .hero-images-stack {
        min-width: unset;
        width: 100%;
        max-width: 320px;
        height: 260px;
        margin: 0 auto;
    }

    .hero-stack-card {
        width: 220px;
        height: 155px;
    }

    /* スマホ用の傾き・配置調整 */
    .card-first {
        transform: translate(0, 0) rotate(-4deg);
    }
    .card-second {
        transform: translate(20px, -20px) rotate(6deg);
    }
    .card-third {
        transform: translate(-20px, 20px) rotate(-10deg);
    }

    /* 3. 各セクション余白・要素の縦並び化 */
    .section {
        padding: 50px 0;
    }

    .strength-row, 
    .strength-row:nth-child(even) {
        flex-direction: column;
        gap: 20px;
    }

    .strength-text, 
    .strength-img-box {
        min-width: 100%;
    }

    .strength-img-box {
        height: 200px;
    }

    .strength-text h3 {
        font-size: 1.3rem;
    }

    /* 4. 会社概要テーブルの崩れ防止（縦型レイアウト化） */
    .company-table, 
    .company-table tbody, 
    .company-table tr, 
    .company-table th, 
    .company-table td {
        display: block;
        width: 100%;
        box-sizing: border-box;
    }

    .company-table tr {
        border-bottom: 1px solid #e2e8f0;
    }

    .company-table th {
        width: 100%;
        padding: 12px 0 4px 0;
        border-bottom: none;
        color: #00b9a2;
    }

    .company-table td {
        padding: 0 0 12px 0;
        border-bottom: none;
    }
}

@media (max-width: 480px) {
    .hero h1 {
        font-size: 1.8rem;
    }
    
    nav a {
        font-size: 12px;
    }
}