:root {
    /* カラーパレット (和モダン) */
    --color-bg: #FCFAF2; /* 鳥の子色 (温かみのある白) */
    --color-bg-alt: #F2EFE8; /* 薄いグレーベースの白 */
    --color-text: #2B2B2B; /* 墨色 */
    --color-text-light: #595959;
    --color-primary: #1D3A5A; /* 藍色 (誠実、伝統) */
    --color-accent: #D24040; /* 朱色 (研ぎ陣の既存アクセント) */
    --color-border: #E0DCD1;
    --color-white: #FFFFFF;
    
    /* 余白 */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 6rem;
    
    /* タイポグラフィ */
    --font-heading: 'Noto Serif JP', serif;
    --font-body: 'Noto Sans JP', sans-serif;
    
    /* 角丸 */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 16px;
    
    /* トランジション */
    --transition-fast: 0.2s ease-in-out;
    --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* リセット */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

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

body {
    font-family: var(--font-body);
    color: var(--color-text);
    background-color: var(--color-bg);
    line-height: 1.6;
    letter-spacing: 0.05em;
    overflow-x: hidden;
}

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

ul, ol {
    list-style: none;
}

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

/* タイポグラフィ */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: 500;
    line-height: 1.4;
    color: var(--color-primary);
    letter-spacing: 0.1em;
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: var(--spacing-lg);
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 40px;
    height: 2px;
    background-color: var(--color-accent);
    margin: var(--spacing-sm) auto 0;
}

.section-subtitle {
    display: block;
    font-family: var(--font-body);
    font-size: 0.875rem;
    color: var(--color-accent);
    margin-bottom: var(--spacing-xs);
    font-weight: 700;
    letter-spacing: 0.15em;
}

/* 共通コンテナ */
.container {
    width: 100%;
    max-width: 1080px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

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

.section-alt {
    background-color: var(--color-bg-alt);
}

/* ヘッダー */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: rgba(252, 250, 242, 0.95);
    backdrop-filter: blur(8px);
    z-index: 1000;
    border-bottom: 1px solid var(--color-border);
    transition: var(--transition-normal);
}

.header-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 80px;
}

.logo a {
    display: block;
}

.logo img {
    height: 44px;
    width: auto;
    object-fit: contain;
}

.nav-list {
    display: flex;
    gap: var(--spacing-md);
}

.nav-link {
    font-family: var(--font-heading);
    font-weight: 500;
    font-size: 0.95rem;
    padding: 8px 0;
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--color-accent);
    transition: var(--transition-fast);
}

.nav-link:hover::after {
    width: 100%;
}

.header-contact {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.btn-tel {
    display: flex;
    align-items: center;
    gap: 8px;
    background-color: var(--color-primary);
    color: var(--color-white);
    padding: 10px 20px;
    border-radius: var(--radius-sm);
    font-weight: 700;
    font-size: 0.9rem;
    transition: var(--transition-normal);
}

.btn-tel:hover {
    background-color: #12253B;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(29, 58, 90, 0.2);
}

/* ハンバーガーメニュー (スマホ用) */
.menu-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 10px;
}

.menu-icon, .menu-icon::before, .menu-icon::after {
    display: block;
    width: 24px;
    height: 2px;
    background-color: var(--color-primary);
    transition: var(--transition-fast);
}

.menu-icon {
    position: relative;
}

.menu-icon::before {
    content: '';
    position: absolute;
    top: -8px;
    left: 0;
}

.menu-icon::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 0;
}

/* フッター */
.footer {
    background-color: var(--color-primary);
    color: var(--color-white);
    padding: var(--spacing-lg) 0 var(--spacing-md);
}

.footer-inner {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.footer-logo {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
}

.footer-desc {
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.8);
}

.footer-nav ul {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-sm);
}

.footer-nav a {
    color: rgba(255, 255, 255, 0.8);
    font-size: 0.9rem;
}

.footer-nav a:hover {
    color: var(--color-white);
}

.footer-contact h4 {
    color: var(--color-white);
    margin-bottom: var(--spacing-sm);
    font-size: 1.1rem;
}

.footer-tel {
    font-size: 1.5rem;
    font-weight: 700;
    display: block;
    margin-bottom: var(--spacing-xs);
    color: var(--color-white);
}

.footer-address {
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.8);
}

.copy {
    text-align: center;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: var(--spacing-md);
    font-size: 0.8rem;
    color: rgba(255, 255, 255, 0.6);
}

/* ユーティリティ */
.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.text-center { text-align: center; }

/* アニメーション用クラス */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}
.fade-in.is-visible {
    opacity: 1;
    transform: translateY(0);
}

/* レスポンシブ */
@media screen and (max-width: 900px) {
    .header-inner {
        height: 60px;
    }
    
    .menu-toggle {
        display: block;
        z-index: 1001;
    }

    /* .nav acts as overlay container */
    .nav {
        position: fixed;
        top: 60px;
        left: 0;
        width: 100%;
        height: calc(100vh - 60px);
        background-color: var(--color-bg-alt);
        flex-direction: column;
        justify-content: flex-start;
        align-items: center;
        padding-top: var(--spacing-xl);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all var(--transition-normal);
        display: flex;
    }

    .header.is-open .nav {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .nav-list {
        display: flex;
        flex-direction: column;
        gap: var(--spacing-md);
        text-align: center;
    }

    .nav-link {
        font-size: 1.25rem;
        display: inline-block;
        padding: 10px;
    }

    .header-contact {
        position: fixed;
        bottom: 50px;
        left: 50%;
        transform: translateX(-50%) translateY(50px);
        opacity: 0;
        visibility: hidden;
        transition: all var(--transition-normal);
        transition-delay: 0.1s;
        z-index: 1000;
    }

    .header.is-open .header-contact {
        transform: translateX(-50%) translateY(0);
        opacity: 1;
        visibility: visible;
    }

    /* ハンバーガーアイコンのアニメーション */
    .header.is-open .menu-icon {
        background-color: transparent;
    }
    
    .header.is-open .menu-icon::before {
        transform: translateY(8px) rotate(45deg);
    }
    
    .header.is-open .menu-icon::after {
        transform: translateY(-8px) rotate(-45deg);
    }
    
    .footer-inner {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }
    
    .section {
        padding: var(--spacing-lg) 0;
    }
    
    .section-title {
        font-size: 2rem;
    }
}