/* ========================================
   基本設定
   ======================================== */
:root {
    /* カラーパレット */
    --color-navy: #1a2332;
    --color-navy-light: #2d3e50;
    --color-dark-gray: #3a4048;
    --color-gray: #6b7280;
    --color-light-gray: #e5e7eb;
    --color-white: #ffffff;
    --color-accent: #4a7c9e;
    
    /* フォント */
    --font-sans: 'Noto Sans JP', sans-serif;
    --font-serif: 'Noto Serif JP', serif;
    
    /* スペーシング */
    --section-padding: 120px;
    --section-padding-mobile: 80px;
    --container-max-width: 1200px;
    
    /* トランジション */
    --transition: all 0.3s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

body {
    font-family: var(--font-sans);
    color: var(--color-dark-gray);
    line-height: 1.8;
    background-color: var(--color-white);
    overflow-x: hidden;
}

.container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 40px;
}

/* ========================================
   ヘッダー
   ======================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: rgba(26, 35, 50, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    transition: var(--transition);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 0;
}

.logo h1 {
    font-family: var(--font-serif);
    font-size: 28px;
    font-weight: 600;
    color: var(--color-white);
    letter-spacing: 0.1em;
}

.nav-list {
    display: flex;
    list-style: none;
    gap: 40px;
}

.nav-link {
    color: var(--color-white);
    text-decoration: none;
    font-size: 14px;
    font-weight: 400;
    letter-spacing: 0.05em;
    transition: var(--transition);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 1px;
    background-color: var(--color-accent);
    transition: width 0.3s ease;
}

.nav-link:hover {
    color: var(--color-accent);
}

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

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 10px;
}

.nav-toggle span {
    width: 25px;
    height: 2px;
    background-color: var(--color-white);
    transition: var(--transition);
}

/* ========================================
   ヒーローセクション
   ======================================== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding-top: 80px;
    overflow: hidden;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, var(--color-navy) 0%, var(--color-navy-light) 50%, var(--color-dark-gray) 100%);
    z-index: -1;
}

.hero-background::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        linear-gradient(30deg, transparent 40%, rgba(74, 124, 158, 0.1) 40%, rgba(74, 124, 158, 0.1) 60%, transparent 60%),
        linear-gradient(150deg, transparent 40%, rgba(74, 124, 158, 0.05) 40%, rgba(74, 124, 158, 0.05) 60%, transparent 60%);
    background-size: 100px 100px;
}

.hero-content {
    text-align: center;
    color: var(--color-white);
    max-width: 900px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
}

.hero-title {
    font-family: var(--font-serif);
    font-size: 42px;
    font-weight: 600;
    line-height: 1.6;
    margin-bottom: 40px;
    letter-spacing: 0.05em;
}

.hero-lead {
    font-size: 18px;
    font-weight: 300;
    line-height: 2;
    margin-bottom: 50px;
    color: rgba(255, 255, 255, 0.9);
}

.hero-cta {
    display: inline-block;
    padding: 16px 50px;
    background-color: transparent;
    color: var(--color-white);
    text-decoration: none;
    font-size: 15px;
    font-weight: 500;
    letter-spacing: 0.1em;
    border: 1px solid var(--color-white);
    transition: var(--transition);
}

.hero-cta:hover {
    background-color: var(--color-white);
    color: var(--color-navy);
}

/* ========================================
   セクション共通
   ======================================== */
section {
    padding: var(--section-padding) 0;
}

.section-header {
    text-align: center;
    margin-bottom: 80px;
}

.section-title {
    font-family: var(--font-serif);
    font-size: 36px;
    font-weight: 600;
    color: var(--color-navy);
    margin-bottom: 10px;
    letter-spacing: 0.05em;
}

.section-subtitle {
    font-size: 13px;
    font-weight: 300;
    color: var(--color-gray);
    letter-spacing: 0.2em;
    text-transform: uppercase;
}

/* ========================================
   事業概要セクション
   ======================================== */
.services {
    background-color: #fafbfc;
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 50px;
}

.service-item {
    background-color: var(--color-white);
    padding: 50px 40px;
    border-top: 3px solid var(--color-navy);
    transition: var(--transition);
}

.service-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
}

.service-number {
    font-family: var(--font-serif);
    font-size: 16px;
    font-weight: 600;
    color: var(--color-accent);
    margin-bottom: 25px;
    letter-spacing: 0.1em;
}

.service-title {
    font-size: 20px;
    font-weight: 600;
    color: var(--color-navy);
    margin-bottom: 20px;
    letter-spacing: 0.02em;
}

.service-description {
    font-size: 15px;
    line-height: 1.9;
    color: var(--color-dark-gray);
}

/* ========================================
   私たちの視点セクション
   ======================================== */
.perspective {
    background-color: var(--color-navy);
    color: var(--color-white);
}

.perspective .section-title {
    color: var(--color-white);
}

.perspective .section-subtitle {
    color: rgba(255, 255, 255, 0.6);
}

.perspective-content {
    max-width: 800px;
    margin: 0 auto;
}

.perspective-text {
    font-size: 18px;
    line-height: 2.2;
    text-align: center;
    font-weight: 400;
    letter-spacing: 0.05em;
}

/* ========================================
   会社概要セクション
   ======================================== */
.company {
    background-color: var(--color-white);
}

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

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

.company-table tr {
    border-bottom: 1px solid var(--color-light-gray);
}

.company-table th,
.company-table td {
    padding: 30px 20px;
    text-align: left;
    vertical-align: top;
}

.company-table th {
    width: 180px;
    font-size: 15px;
    font-weight: 600;
    color: var(--color-navy);
    letter-spacing: 0.05em;
}

.company-table td {
    font-size: 15px;
    line-height: 1.9;
    color: var(--color-dark-gray);
}

.company-table td ol {
    margin-left: 20px;
}

.company-table td ol li {
    margin-bottom: 8px;
}

/* ========================================
   お問い合わせセクション
   ======================================== */
.contact {
    background-color: #fafbfc;
}

.contact-content {
    max-width: 700px;
    margin: 0 auto;
    text-align: center;
}

.contact-text {
    font-size: 16px;
    line-height: 2;
    color: var(--color-dark-gray);
    margin-bottom: 40px;
}

.contact-email {
    margin-top: 50px;
}

.email-link {
    display: inline-block;
    font-size: 24px;
    font-weight: 500;
    color: var(--color-navy);
    text-decoration: none;
    padding: 20px 40px;
    border: 2px solid var(--color-navy);
    transition: var(--transition);
    letter-spacing: 0.05em;
}

.email-link:hover {
    background-color: var(--color-navy);
    color: var(--color-white);
}

/* ========================================
   フッター
   ======================================== */
.footer {
    background-color: var(--color-navy);
    color: var(--color-white);
    padding: 60px 0;
}

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

.footer-logo {
    font-family: var(--font-serif);
    font-size: 24px;
    font-weight: 600;
    letter-spacing: 0.1em;
    margin-bottom: 20px;
}

.footer-copyright {
    font-size: 12px;
    font-weight: 300;
    color: rgba(255, 255, 255, 0.7);
    letter-spacing: 0.05em;
}

/* ========================================
   レスポンシブデザイン
   ======================================== */

/* タブレット */
@media (max-width: 1024px) {
    .container {
        padding: 0 30px;
    }
    
    .services-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .hero-title {
        font-size: 36px;
    }
    
    .section-title {
        font-size: 32px;
    }
}

/* スマートフォン */
@media (max-width: 768px) {
    :root {
        --section-padding: 80px;
    }
    
    .container {
        padding: 0 20px;
    }
    
    /* ナビゲーション */
    .nav-list {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        flex-direction: column;
        background-color: var(--color-navy);
        padding: 30px 20px;
        gap: 0;
        transform: translateX(100%);
        transition: transform 0.3s ease;
    }
    
    .nav-list.active {
        transform: translateX(0);
    }
    
    .nav-list li {
        border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    }
    
    .nav-link {
        display: block;
        padding: 15px 0;
    }
    
    .nav-toggle {
        display: flex;
    }
    
    .nav-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(7px, 7px);
    }
    
    .nav-toggle.active span:nth-child(2) {
        opacity: 0;
    }
    
    .nav-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -7px);
    }
    
    /* ヒーローセクション */
    .hero {
        min-height: 100svh;
        padding: 100px 0 60px;
    }
    
    .hero-title {
        font-size: 26px;
        line-height: 1.7;
        margin-bottom: 30px;
    }
    
    .hero-lead {
        font-size: 15px;
        margin-bottom: 40px;
    }
    
    .hero-cta {
        padding: 14px 40px;
        font-size: 14px;
    }
    
    /* セクション */
    .section-header {
        margin-bottom: 60px;
    }
    
    .section-title {
        font-size: 28px;
    }
    
    .section-subtitle {
        font-size: 12px;
    }
    
    /* サービス */
    .service-item {
        padding: 40px 30px;
    }
    
    .service-title {
        font-size: 18px;
    }
    
    .service-description {
        font-size: 14px;
    }
    
    /* 視点セクション */
    .perspective-text {
        font-size: 16px;
        line-height: 2;
    }
    
    /* 会社概要 */
    .company-table th,
    .company-table td {
        display: block;
        width: 100%;
        padding: 15px 0;
    }
    
    .company-table th {
        font-weight: 700;
        padding-bottom: 10px;
    }
    
    .company-table td {
        padding-bottom: 25px;
    }
    
    /* お問い合わせ */
    .email-link {
        font-size: 18px;
        padding: 16px 30px;
    }
    
    /* ユーティリティ */
    .pc-only {
        display: none;
    }
}

/* 大画面 */
@media (min-width: 1441px) {
    :root {
        --container-max-width: 1400px;
    }
}

/* ユーティリティクラス */
.pc-only {
    display: inline;
}

@media (max-width: 768px) {
    .pc-only {
        display: none;
    }
}