/* ========================================
   AI Merchant ZEK - Main Stylesheet
   エレガントなビジネスデザイン
======================================== */

/* ========================================
   1. リセット & 基本設定
======================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* カラー定義 - エレガントなビジネスカラー */
    --primary-color: #1a365d;        /* ディープネイビー */
    --secondary-color: #2c5282;      /* ミッドナイトブルー */
    --accent-color: #d4af37;         /* ゴールド */
    --accent-light: #f0e6c8;         /* ライトゴールド */
    --text-dark: #1a202c;            /* ダークグレー */
    --text-medium: #4a5568;          /* ミディアムグレー */
    --text-light: #718096;           /* ライトグレー */
    --bg-light: #f7fafc;             /* ライト背景 */
    --bg-white: #ffffff;
    --border-color: #e2e8f0;
    --success-color: #48bb78;
    --warning-color: #ed8936;
    --error-color: #f56565;
    --info-color: #4299e1;
    
    /* フォント */
    --font-ja: 'Noto Sans JP', sans-serif;
    --font-heading: 'Playfair Display', serif;
    
    /* スペーシング */
    --section-padding: 100px 0;
    --container-max-width: 1200px;
    
    /* トランジション */
    --transition: all 0.3s ease;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-ja);
    font-size: 16px;
    line-height: 1.8;
    color: var(--text-dark);
    background-color: var(--bg-white);
    overflow-x: hidden;
}

.container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 20px;
}

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

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

ul {
    list-style: none;
}

/* ========================================
   2. ヘッダー & ナビゲーション
======================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.05);
    z-index: 1000;
    transition: var(--transition);
}

.nav-container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 80px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    font-size: 1.3rem;
    color: var(--primary-color);
}

.logo-icon {
    font-size: 1.8rem;
}

.nav-menu {
    display: flex;
    gap: 40px;
    align-items: center;
}

.nav-menu a {
    font-weight: 500;
    color: var(--text-dark);
    position: relative;
    padding: 5px 0;
}

.nav-menu a:hover,
.nav-menu a.active {
    color: var(--primary-color);
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-color);
    transition: width 0.3s ease;
}

.nav-menu a:hover::after,
.nav-menu a.active::after {
    width: 100%;
}

.nav-cta {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white !important;
    padding: 10px 25px;
    border-radius: 25px;
}

.nav-cta::after {
    display: none;
}

.nav-cta:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(26, 54, 93, 0.3);
}

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

.mobile-menu-toggle span {
    width: 25px;
    height: 3px;
    background: var(--primary-color);
    transition: var(--transition);
}

/* ========================================
   3. ヒーローセクション
======================================== */
.hero {
    padding: 160px 0 100px;
    background: linear-gradient(135deg, #f7fafc 0%, #edf2f7 100%);
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
    min-height: 90vh;
}

.hero-content {
    padding: 0 40px 0 80px;
}

.hero-badge {
    display: inline-block;
    background: linear-gradient(135deg, var(--accent-color), #e6c04d);
    color: white;
    padding: 8px 20px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 20px;
    letter-spacing: 1px;
}

.hero-title {
    font-family: var(--font-heading);
    font-size: 3.5rem;
    font-weight: 700;
    line-height: 1.2;
    color: var(--primary-color);
    margin-bottom: 25px;
}

.hero-title .highlight {
    background: linear-gradient(135deg, var(--accent-color), #e6c04d);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.2rem;
    color: var(--text-medium);
    margin-bottom: 40px;
    line-height: 1.8;
}

.hero-cta {
    display: flex;
    gap: 20px;
    margin-bottom: 50px;
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    padding-top: 30px;
    border-top: 2px solid var(--border-color);
}

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

.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--accent-color);
    font-family: var(--font-heading);
}

.stat-label {
    font-size: 0.9rem;
    color: var(--text-medium);
    margin-top: 5px;
}

.hero-image {
    position: relative;
}

.hero-image img {
    border-radius: 20px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.1);
    width: 100%;
    height: auto;
    object-fit: cover;
}

/* ========================================
   4. ボタンスタイル
======================================== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 15px 35px;
    border-radius: 30px;
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition);
    border: 2px solid transparent;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(26, 54, 93, 0.3);
}

.btn-outline {
    background: transparent;
    border: 2px solid var(--primary-color);
    color: var(--primary-color);
}

.btn-outline:hover {
    background: var(--primary-color);
    color: white;
}

.btn-large {
    padding: 18px 40px;
    font-size: 1.1rem;
}

.btn-block {
    width: 100%;
    justify-content: center;
}

/* ========================================
   5. セクション共通スタイル
======================================== */
section {
    padding: var(--section-padding);
}

.section-header {
    text-align: center;
    max-width: 800px;
    margin: 0 auto 60px;
}

.section-badge {
    display: inline-block;
    background: var(--accent-light);
    color: var(--accent-color);
    padding: 6px 18px;
    border-radius: 15px;
    font-size: 0.85rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    margin-bottom: 15px;
}

.section-title {
    font-family: var(--font-heading);
    font-size: 2.8rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 20px;
    line-height: 1.3;
}

.section-subtitle {
    font-size: 1.1rem;
    color: var(--text-medium);
    line-height: 1.8;
}

/* ========================================
   6. 課題セクション
======================================== */
.problems {
    background: var(--bg-light);
}

.problems-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
    margin-top: 50px;
}

.problem-card {
    background: white;
    padding: 40px 30px;
    border-radius: 15px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.05);
    transition: var(--transition);
    text-align: center;
}

.problem-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.1);
}

.problem-icon {
    font-size: 3rem;
    margin-bottom: 20px;
}

.problem-card h3 {
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 15px;
}

.problem-card p {
    color: var(--text-medium);
    line-height: 1.7;
}

/* ========================================
   7. 特徴セクション
======================================== */
.features {
    background: white;
}

.features-content {
    margin-top: 60px;
}

.feature-large {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
    margin-bottom: 80px;
}

.feature-large-image img {
    border-radius: 15px;
    box-shadow: 0 15px 50px rgba(0, 0, 0, 0.1);
}

.feature-large-text h3 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 20px;
}

.feature-description {
    font-size: 1.1rem;
    color: var(--text-medium);
    line-height: 1.8;
    margin-bottom: 30px;
}

.feature-list {
    list-style: none;
}

.feature-list li {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 0;
    color: var(--text-dark);
    font-weight: 500;
}

.feature-list i {
    color: var(--success-color);
    font-size: 1.2rem;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

.feature-card {
    background: white;
    padding: 35px;
    border-radius: 15px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.05);
    transition: var(--transition);
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.1);
}

.feature-icon {
    width: 70px;
    height: 70px;
    border-radius: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
    font-size: 1.8rem;
    color: white;
}

.feature-card h3 {
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 15px;
}

.feature-card p {
    color: var(--text-medium);
    line-height: 1.7;
}

/* ========================================
   8. システム機能セクション
======================================== */
.system-features {
    background: var(--bg-light);
}

.system-image {
    margin: 50px 0 60px;
}

.system-image img {
    border-radius: 15px;
    box-shadow: 0 15px 50px rgba(0, 0, 0, 0.1);
}

.system-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 40px;
}

.system-card {
    background: white;
    padding: 40px;
    border-radius: 15px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.05);
    position: relative;
    transition: var(--transition);
}

.system-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.1);
}

.system-number {
    position: absolute;
    top: -15px;
    left: 30px;
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--accent-color), #e6c04d);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    color: white;
    font-size: 1.2rem;
}

.system-card h3 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin: 25px 0 15px;
}

.system-card p {
    color: var(--text-medium);
    line-height: 1.7;
}

/* ========================================
   9. プランセクション
======================================== */
.plans {
    background: white;
}

.plans-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
    margin-top: 60px;
}

.plan-card {
    background: white;
    border: 2px solid var(--border-color);
    border-radius: 20px;
    padding: 40px 35px;
    position: relative;
    transition: var(--transition);
}

.plan-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.1);
    border-color: var(--primary-color);
}

.plan-featured {
    border-color: var(--accent-color);
    box-shadow: 0 10px 40px rgba(212, 175, 55, 0.2);
    transform: scale(1.05);
}

.plan-badge-top {
    position: absolute;
    top: -15px;
    left: 50%;
    transform: translateX(-50%);
    background: linear-gradient(135deg, var(--accent-color), #e6c04d);
    color: white;
    padding: 8px 25px;
    border-radius: 20px;
    font-weight: 700;
    font-size: 0.85rem;
    letter-spacing: 1px;
}

.plan-header {
    text-align: center;
    margin-bottom: 25px;
}

.plan-name {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 10px;
}

.plan-badge {
    display: inline-block;
    background: var(--accent-light);
    color: var(--accent-color);
    padding: 5px 15px;
    border-radius: 12px;
    font-size: 0.85rem;
    font-weight: 600;
}

.plan-price {
    text-align: center;
    margin-bottom: 15px;
}

.price-amount {
    font-size: 3rem;
    font-weight: 700;
    color: var(--primary-color);
    font-family: var(--font-heading);
}

.price-tax {
    font-size: 0.9rem;
    color: var(--text-medium);
}

.plan-period {
    text-align: center;
    color: var(--text-medium);
    font-size: 0.95rem;
    margin-bottom: 20px;
    padding-bottom: 20px;
    border-bottom: 2px solid var(--border-color);
}

.plan-description {
    margin-bottom: 25px;
}

.plan-description p {
    color: var(--text-medium);
    line-height: 1.7;
}

.plan-features {
    list-style: none;
    margin-bottom: 30px;
}

.plan-features li {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 10px 0;
    color: var(--text-dark);
}

.plan-features i {
    color: var(--success-color);
    font-size: 1.1rem;
    margin-top: 4px;
}

/* ========================================
   10. FAQセクション
======================================== */
.faq {
    background: var(--bg-light);
}

.faq-list {
    max-width: 900px;
    margin: 50px auto 0;
}

.faq-item {
    background: white;
    border-radius: 12px;
    margin-bottom: 15px;
    overflow: hidden;
    box-shadow: 0 3px 15px rgba(0, 0, 0, 0.05);
}

.faq-question {
    width: 100%;
    padding: 25px 30px;
    background: none;
    border: none;
    text-align: left;
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--primary-color);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: var(--transition);
}

.faq-question:hover {
    background: var(--bg-light);
}

.faq-question i {
    transition: transform 0.3s ease;
}

.faq-item.active .faq-question i {
    transform: rotate(180deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
}

.faq-item.active .faq-answer {
    max-height: 500px;
}

.faq-answer p {
    padding: 0 30px 25px;
    color: var(--text-medium);
    line-height: 1.8;
}

.faq-answer a {
    color: var(--primary-color);
    text-decoration: underline;
}

/* ========================================
   11. お問い合わせセクション
======================================== */
.contact {
    background: white;
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 60px;
    margin-top: 60px;
}

.contact-info h3 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 30px;
}

.info-item {
    display: flex;
    gap: 20px;
    margin-bottom: 25px;
    padding: 20px;
    background: var(--bg-light);
    border-radius: 12px;
}

.info-item i {
    font-size: 1.5rem;
    color: var(--accent-color);
    margin-top: 5px;
}

.info-item strong {
    display: block;
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 5px;
}

.info-item p {
    color: var(--text-medium);
    line-height: 1.6;
}

/* フォームスタイル */
.contact-form {
    background: var(--bg-light);
    padding: 40px;
    border-radius: 15px;
}

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

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.form-group label {
    display: block;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 8px;
}

.required {
    color: var(--error-color);
    font-size: 0.85rem;
    margin-left: 5px;
}

.optional {
    color: var(--text-light);
    font-size: 0.85rem;
    margin-left: 5px;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 15px;
    border: 2px solid var(--border-color);
    border-radius: 10px;
    font-size: 1rem;
    font-family: var(--font-ja);
    transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(26, 54, 93, 0.1);
}

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

/* ========================================
   12. フッター
======================================== */
.footer {
    background: var(--primary-color);
    color: white;
    padding: 60px 0 20px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1.5fr;
    gap: 50px;
    margin-bottom: 40px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    font-size: 1.3rem;
    margin-bottom: 20px;
}

.footer-description {
    color: rgba(255, 255, 255, 0.8);
    line-height: 1.8;
}

.footer-section h4 {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 20px;
    color: var(--accent-color);
}

.footer-links li {
    margin-bottom: 12px;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.8);
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--accent-color);
    padding-left: 5px;
}

.footer-bottom {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.6);
}

/* ========================================
   13. 法的ページスタイル
======================================== */
.breadcrumb {
    background: var(--bg-light);
    padding: 20px 0;
    margin-top: 80px;
}

.breadcrumb .container {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 0.95rem;
    color: var(--text-medium);
}

.breadcrumb .separator {
    color: var(--text-light);
}

.legal-page {
    padding: 60px 0;
    background: white;
}

.page-header {
    text-align: center;
    max-width: 800px;
    margin: 0 auto 60px;
}

.page-header h1 {
    font-family: var(--font-heading);
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 20px;
}

.page-intro {
    font-size: 1.05rem;
    color: var(--text-medium);
    line-height: 1.8;
}

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

.legal-section {
    margin-bottom: 50px;
}

.legal-section h2 {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 25px;
    padding-bottom: 15px;
    border-bottom: 3px solid var(--accent-color);
    display: flex;
    align-items: center;
    gap: 15px;
}

.legal-section h2 i {
    color: var(--accent-color);
}

.legal-box {
    background: var(--bg-light);
    padding: 35px;
    border-radius: 12px;
    border-left: 4px solid var(--accent-color);
}

.legal-box h3 {
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--primary-color);
    margin: 30px 0 15px;
}

.legal-box h3:first-child {
    margin-top: 0;
}

.legal-box p {
    color: var(--text-medium);
    line-height: 1.8;
    margin-bottom: 15px;
}

.legal-box ol,
.legal-box ul {
    margin-left: 25px;
    margin-bottom: 20px;
}

.legal-box ol {
    list-style: decimal;
}

.legal-box ul {
    list-style: disc;
}

.legal-box li {
    color: var(--text-medium);
    line-height: 1.8;
    margin-bottom: 10px;
}

.legal-table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
}

.legal-table th,
.legal-table td {
    padding: 15px;
    border: 1px solid var(--border-color);
    text-align: left;
}

.legal-table th {
    background: var(--primary-color);
    color: white;
    font-weight: 600;
    width: 30%;
}

.legal-table td {
    background: white;
}

.plan-detail {
    display: block;
    font-size: 0.9rem;
    color: var(--text-light);
    margin-top: 5px;
}

.note {
    font-size: 0.9rem;
    color: var(--text-light);
    margin-top: 15px;
    font-style: italic;
}

.notice-box {
    padding: 20px;
    border-radius: 10px;
    margin: 20px 0;
    display: flex;
    gap: 15px;
    align-items: flex-start;
}

.notice-box i {
    font-size: 1.5rem;
    margin-top: 3px;
}

.notice-box.warning {
    background: #fff5f5;
    border: 2px solid var(--error-color);
}

.notice-box.warning i {
    color: var(--error-color);
}

.notice-box.info {
    background: #ebf8ff;
    border: 2px solid var(--info-color);
}

.notice-box.info i {
    color: var(--info-color);
}

.notice-box p {
    margin: 0;
    color: var(--text-dark);
}

.contact-box {
    background: var(--bg-light);
    padding: 35px;
    border-radius: 12px;
}

.company-info {
    margin: 30px 0;
}

.company-info h3 {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 25px;
}

.contact-item {
    display: flex;
    gap: 20px;
    margin-bottom: 20px;
    padding: 15px;
    background: white;
    border-radius: 8px;
}

.contact-item i {
    font-size: 1.3rem;
    color: var(--accent-color);
    margin-top: 3px;
}

.contact-item strong {
    display: block;
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 5px;
}

.contact-item p {
    color: var(--text-medium);
    margin: 0;
}

.last-updated {
    text-align: center;
    padding-top: 40px;
    margin-top: 60px;
    border-top: 2px solid var(--border-color);
    color: var(--text-light);
    font-size: 0.9rem;
}

.page-navigation {
    display: flex;
    justify-content: space-between;
    gap: 20px;
    margin-top: 60px;
    max-width: 900px;
    margin-left: auto;
    margin-right: auto;
}

/* セキュリティページ特有のスタイル */
.security-principles {
    margin-top: 30px;
}

.principle-item {
    display: flex;
    gap: 20px;
    margin-bottom: 30px;
    padding: 25px;
    background: white;
    border-radius: 12px;
}

.principle-icon {
    width: 60px;
    height: 60px;
    border-radius: 12px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.8rem;
    flex-shrink: 0;
}

.principle-content h3 {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--primary-color);
    margin: 0 0 10px 0;
}

.principle-content p {
    margin: 0;
    color: var(--text-medium);
}

.classification-table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
}

.classification-table th,
.classification-table td {
    padding: 15px;
    border: 1px solid var(--border-color);
    text-align: left;
}

.classification-table thead {
    background: var(--primary-color);
    color: white;
}

.classification-table tbody tr:nth-child(even) {
    background: #f7fafc;
}

.label {
    display: inline-block;
    padding: 5px 12px;
    border-radius: 12px;
    font-size: 0.85rem;
    font-weight: 600;
}

.label-critical {
    background: #fed7d7;
    color: #c53030;
}

.label-high {
    background: #feebc8;
    color: #c05621;
}

.label-medium {
    background: #bee3f8;
    color: #2c5282;
}

.label-low {
    background: #c6f6d5;
    color: #276749;
}

.pdca-cycle {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 25px;
    margin: 30px 0;
}

.pdca-item {
    background: white;
    padding: 25px;
    border-radius: 12px;
    display: flex;
    gap: 20px;
    align-items: flex-start;
}

.pdca-icon {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 700;
    color: white;
    flex-shrink: 0;
}

.pdca-icon.plan {
    background: #48bb78;
}

.pdca-icon.do {
    background: #4299e1;
}

.pdca-icon.check {
    background: #ed8936;
}

.pdca-icon.act {
    background: #9f7aea;
}

.pdca-content h4 {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--primary-color);
    margin: 0 0 10px 0;
}

.pdca-content p {
    margin: 0;
    color: var(--text-medium);
    font-size: 0.95rem;
}

/* ========================================
   14. レスポンシブデザイン
======================================== */
@media (max-width: 1024px) {
    .hero {
        grid-template-columns: 1fr;
        padding: 140px 0 80px;
    }
    
    .hero-content {
        padding: 0 20px;
        text-align: center;
    }
    
    .hero-title {
        font-size: 3rem;
    }
    
    .hero-cta {
        justify-content: center;
    }
    
    .feature-large {
        grid-template-columns: 1fr;
    }
    
    .contact-content {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 80px;
        left: -100%;
        width: 100%;
        background: white;
        flex-direction: column;
        padding: 30px;
        box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
        transition: left 0.3s ease;
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .mobile-menu-toggle {
        display: flex;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-stats {
        grid-template-columns: 1fr;
    }
    
    .section-title {
        font-size: 2.2rem;
    }
    
    .plans-grid {
        grid-template-columns: 1fr;
    }
    
    .plan-featured {
        transform: scale(1);
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }
    
    .page-navigation {
        flex-direction: column;
    }
    
    .pdca-cycle {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .btn-large {
        padding: 15px 30px;
        font-size: 1rem;
    }
    
    .section-title {
        font-size: 1.8rem;
    }
    
    .price-amount {
        font-size: 2.5rem;
    }
}

/* ユーティリティクラス */
.mobile-only {
    display: none;
}

@media (max-width: 768px) {
    .mobile-only {
        display: inline;
    }
}