/* =========================================
   CSS Variables (カラーパレットと定数)
   ========================================= */
:root {
    --primary-color: #2563eb;
    --primary-dark: #1e40af;
    --primary-light: #3b82f6;
    --secondary-color: #10b981;
    --accent-color: #f59e0b;
    --danger-color: #ef4444;
    
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --text-light: #9ca3af;
    
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-dark: #111827;
    
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    
    --border-radius: 8px;
    --transition: all 0.3s ease;
}

/* =========================================
   基本スタイル
   ========================================= */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Noto Sans JP', sans-serif;
    color: var(--text-primary);
    line-height: 1.6;
    background-color: var(--bg-primary);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* =========================================
   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, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary-color);
}

.logo i {
    font-size: 1.5rem;
}

.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--text-primary);
    cursor: pointer;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
    align-items: center;
}

.nav-menu a {
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 500;
    transition: var(--transition);
}

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

/* =========================================
   ボタンスタイル
   ========================================= */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--border-radius);
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    transition: var(--transition);
    font-size: 1rem;
}

.btn-large {
    padding: 1rem 2rem;
    font-size: 1.125rem;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 2px solid var(--border-color);
}

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

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

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

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

.btn-white:hover {
    background: var(--bg-secondary);
}

.btn-outline-white {
    background: transparent;
    color: white;
    border: 2px solid white;
}

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

/* =========================================
   ヒーローセクション
   ========================================= */
.hero {
    padding: 8rem 0 4rem;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    margin-top: 60px;
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.hero-title {
    font-size: 3rem;
    font-weight: 900;
    line-height: 1.2;
    margin-bottom: 1.5rem;
}

.highlight {
    color: #fbbf24;
}

.hero-description {
    font-size: 1.125rem;
    line-height: 1.8;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.hero-cta {
    display: flex;
    gap: 1rem;
    margin-bottom: 3rem;
}

.hero-stats {
    display: flex;
    gap: 3rem;
}

.stat {
    text-align: center;
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 900;
    color: #fbbf24;
}

.stat-label {
    font-size: 0.875rem;
    opacity: 0.8;
}

.mockup-container {
    position: relative;
}

.mockup-screen {
    background: white;
    border-radius: 12px;
    padding: 1rem;
    box-shadow: var(--shadow-xl);
    position: relative;
    z-index: 1;
}

.mockup-screen img {
    width: 100%;
    border-radius: 8px;
    display: block;
}

.mockup-placeholder {
    aspect-ratio: 4/3;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 8px;
    color: white;
}

.mockup-placeholder i {
    font-size: 4rem;
    margin-bottom: 1rem;
}

.mockup-glow {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 120%;
    height: 120%;
    background: radial-gradient(circle, rgba(251, 191, 36, 0.3) 0%, transparent 70%);
    z-index: 0;
}

/* =========================================
   セクション共通スタイル
   ========================================= */
section {
    padding: 5rem 0;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 900;
    text-align: center;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.section-subtitle {
    text-align: center;
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: 3rem;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

/* =========================================
   課題セクション
   ========================================= */
.problem-section {
    background: var(--bg-secondary);
}

.problem-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.problem-card {
    background: white;
    padding: 2rem;
    border-radius: var(--border-radius);
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.problem-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.problem-icon {
    width: 60px;
    height: 60px;
    margin: 0 auto 1rem;
    background: linear-gradient(135deg, #f59e0b, #ef4444);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.5rem;
}

.problem-card h3 {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

.problem-card p {
    color: var(--text-secondary);
    font-size: 0.9375rem;
}

/* =========================================
   機能セクション
   ========================================= */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.feature-card {
    background: white;
    padding: 2.5rem;
    border-radius: var(--border-radius);
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.feature-card:hover {
    border-color: var(--primary-color);
    box-shadow: var(--shadow-lg);
    transform: translateY(-5px);
}

.feature-icon {
    width: 70px;
    height: 70px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.75rem;
    margin-bottom: 1.5rem;
}

.feature-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.feature-card > p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    line-height: 1.7;
}

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

.feature-list li {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
    font-size: 0.9375rem;
}

.feature-list i {
    color: var(--secondary-color);
}

/* =========================================
   使い方セクション
   ========================================= */
.howto-section {
    background: var(--bg-secondary);
}

.steps-container {
    max-width: 700px;
    margin: 0 auto;
}

.step-card {
    background: white;
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
    display: flex;
    gap: 2rem;
    align-items: flex-start;
    transition: var(--transition);
}

.step-card:hover {
    box-shadow: var(--shadow-xl);
    transform: translateX(10px);
}

.step-number {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.75rem;
    font-weight: 900;
    flex-shrink: 0;
}

.step-content h3 {
    font-size: 1.375rem;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

.step-content h3 i {
    color: var(--primary-color);
    margin-right: 0.5rem;
}

.step-content p {
    color: var(--text-secondary);
    line-height: 1.7;
}

.step-arrow {
    text-align: center;
    color: var(--primary-color);
    font-size: 2rem;
    margin: 1rem 0;
}

.howto-cta {
    text-align: center;
    margin-top: 3rem;
}

/* =========================================
   デモセクション
   ========================================= */
.demo-container {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 3rem;
    align-items: center;
}

.demo-video {
    background: var(--bg-secondary);
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

.video-placeholder {
    aspect-ratio: 16/9;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.video-placeholder i {
    font-size: 4rem;
    margin-bottom: 1rem;
}

.video-placeholder p {
    font-size: 1.25rem;
    font-weight: 700;
}

.video-placeholder small {
    font-size: 0.875rem;
    opacity: 0.8;
}

.demo-screenshots h3 {
    text-align: center;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.screenshot-grid {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    align-items: center;
}

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

.screenshot-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.screenshot-box {
    width: 200px;
    height: 150px;
    background: var(--bg-secondary);
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
}

.screenshot-box i {
    font-size: 3rem;
    margin-bottom: 0.5rem;
}

.screenshot-arrow {
    font-size: 2rem;
    color: var(--primary-color);
    margin: 0.5rem 0;
}

/* =========================================
   メリットセクション
   ========================================= */
.benefits-section {
    background: var(--bg-secondary);
}

.benefits-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.benefit-card {
    background: white;
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.benefit-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-5px);
}

.benefit-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--secondary-color), #34d399);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
}

.benefit-card h3 {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

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

/* =========================================
   対象ユーザーセクション
   ========================================= */
.target-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.target-card {
    background: white;
    padding: 2rem;
    border-radius: var(--border-radius);
    border: 2px solid var(--border-color);
    text-align: center;
    transition: var(--transition);
}

.target-card:hover {
    border-color: var(--primary-color);
    box-shadow: var(--shadow-lg);
    transform: translateY(-5px);
}

.target-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 1.5rem;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 2rem;
}

.target-card h3 {
    font-size: 1.375rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

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

/* =========================================
   CTAセクション
   ========================================= */
.cta-section {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    color: white;
    text-align: center;
}

.cta-content h2 {
    font-size: 2.5rem;
    font-weight: 900;
    margin-bottom: 1rem;
}

.cta-content > p {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.cta-buttons {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 3rem;
}

.cta-info {
    display: flex;
    justify-content: center;
    gap: 2rem;
    flex-wrap: wrap;
}

.cta-info p {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9375rem;
}

.cta-info i {
    color: #fbbf24;
}

/* =========================================
   フッター
   ========================================= */
.footer {
    background: var(--bg-dark);
    color: #d1d5db;
    padding: 3rem 0 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer-section h4 {
    color: white;
    margin-bottom: 1rem;
    font-size: 1.125rem;
}

.footer-section h4 i {
    color: var(--primary-light);
    margin-right: 0.5rem;
}

.footer-section p {
    line-height: 1.7;
    margin-bottom: 1rem;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section a {
    color: #d1d5db;
    text-decoration: none;
    transition: var(--transition);
}

.footer-section a:hover {
    color: var(--primary-light);
}

.social-links {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
}

.social-links a {
    width: 40px;
    height: 40px;
    background: #374151;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    transition: var(--transition);
}

.social-links a:hover {
    background: var(--primary-color);
    transform: translateY(-3px);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid #374151;
    font-size: 0.875rem;
}

/* =========================================
   レスポンシブデザイン
   ========================================= */
@media (max-width: 1024px) {
    .hero-content {
        grid-template-columns: 1fr;
    }
    
    .hero-image {
        order: -1;
    }
    
    .demo-container {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .mobile-menu-toggle {
        display: block;
    }
    
    .nav-menu {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 1rem;
        box-shadow: var(--shadow-lg);
        display: none;
    }
    
    .nav-menu.active {
        display: flex;
    }
    
    .hero {
        padding: 6rem 0 3rem;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-cta {
        flex-direction: column;
    }
    
    .hero-stats {
        gap: 1.5rem;
    }
    
    .section-title {
        font-size: 1.875rem;
    }
    
    .cta-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .cta-info {
        flex-direction: column;
        gap: 0.5rem;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 1.75rem;
    }
    
    .stat-number {
        font-size: 2rem;
    }
    
    .problem-grid,
    .features-grid,
    .benefits-grid,
    .target-grid {
        grid-template-columns: 1fr;
    }
}