/* R&D Page Styles */

.rd-hero {
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    padding: 150px 0 100px;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.rd-hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 20% 20%, rgba(0, 0, 0, 0.03) 1px, transparent 1px),
        radial-gradient(circle at 80% 80%, rgba(0, 0, 0, 0.03) 1px, transparent 1px);
    background-size: 50px 50px;
}

.rd-hero .hero-content {
    position: relative;
    z-index: 1;
}

.rd-hero h1 {
    font-size: 4rem;
    font-weight: 300;
    margin-bottom: 1rem;
    letter-spacing: 0.1em;
    color: #333;
}

.rd-hero p {
    font-size: 1.2rem;
    color: #666;
    max-width: 600px;
    margin: 0 auto;
}

.rd-main {
    padding: 80px 0;
    background: #fff;
}

.rd-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.rd-intro {
    text-align: center;
    margin-bottom: 80px;
}

.rd-intro h2 {
    font-size: 2.5rem;
    margin-bottom: 2rem;
    color: #333;
    font-weight: 300;
}

.rd-intro p {
    font-size: 1.1rem;
    line-height: 1.8;
    color: #666;
    max-width: 1000px;
    margin: 0 auto 1.5rem;
}

.rd-categories {
    margin-bottom: 80px;
}

.rd-categories h3 {
    font-size: 2rem;
    margin-bottom: 3rem;
    text-align: center;
    color: #333;
    font-weight: 300;
}

.category-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 2rem;
    margin-bottom: 2rem;
}

.category-item {
    background: #f8f9fa;
    padding: 2rem;
    border-radius: 12px;
    text-align: center;
    transition: all 0.3s ease;
    border: 1px solid #e9ecef;
}

.category-item:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
    background: #fff;
}

.category-item h4 {
    font-size: 1.3rem;
    margin-bottom: 1rem;
    color: #333;
    font-weight: 600;
}

.category-item p {
    font-size: 1rem;
    color: #666;
    line-height: 1.6;
}

.rd-articles h3 {
    font-size: 2rem;
    margin-bottom: 3rem;
    text-align: center;
    color: #333;
    font-weight: 300;
}

.article-list {
    display: grid;
    gap: 2rem;
    margin-bottom: 4rem;
}

.article-card {
    background: #fff;
    border: 1px solid #e9ecef;
    border-radius: 12px;
    padding: 2rem;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.article-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.08);
    border-color: #000;
}

.article-meta {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1rem;
}

.article-meta .category {
    background: #000;
    color: #fff;
    padding: 0.3rem 0.8rem;
    border-radius: 15px;
    font-size: 0.8rem;
    font-weight: 500;
}

.article-meta .date {
    color: #666;
    font-size: 0.9rem;
}

.article-card h4 {
    font-size: 1.4rem;
    margin-bottom: 1rem;
    color: #333;
    font-weight: 600;
    line-height: 1.4;
}

.article-card h4 a {
    color: #333;
    text-decoration: none;
    transition: color 0.3s ease;
}

.article-card h4 a:hover {
    color: #000;
}

.article-card p {
    font-size: 1rem;
    line-height: 1.7;
    color: #666;
    margin-bottom: 1.5rem;
}

.article-tags {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.tag {
    background: #f8f9fa;
    color: #666;
    padding: 0.2rem 0.6rem;
    border-radius: 12px;
    font-size: 0.8rem;
    border: 1px solid #e9ecef;
}

.coming-soon {
    text-align: center;
    padding: 3rem 2rem;
    background: #f8f9fa;
    border-radius: 12px;
    border: 2px dashed #dee2e6;
}

.coming-soon h4 {
    font-size: 1.3rem;
    margin-bottom: 1rem;
    color: #333;
    font-weight: 600;
}

.coming-soon p {
    color: #666;
    font-size: 1rem;
}

/* モバイル対応 */
@media screen and (max-width: 768px) {
    .rd-hero {
        padding: 120px 0 20px;
    }
    
    .rd-hero h1 {
        font-size: 2.5rem;
    }
    
    .rd-hero p {
        font-size: 1rem;
        padding: 0 1rem;
    }
    
    .rd-main {
        padding: 40px 0;
    }
    
    .rd-container {
        padding: 0 1rem;
    }
    
    .rd-intro {
        margin-bottom: 30px;
    }
    
    .rd-intro h2 {
        font-size: 2rem;
    }
    
    .rd-intro p {
        font-size: 1rem;
    }
    
    .rd-categories {
        margin-bottom: 60px;
    }
    
    .rd-categories h3,
    .rd-articles h3 {
        font-size: 1.5rem;
        margin-bottom: 2rem;
    }
    
    .category-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .category-item {
        padding: 1.5rem;
    }
    
    .article-card {
        padding: 1.5rem;
    }
    
    .article-card h4 {
        font-size: 1.2rem;
    }
    
    .coming-soon {
        padding: 2rem 1rem;
    }
}

@media screen and (max-width: 480px) {
    .rd-hero h1 {
        font-size: 2rem;
    }
    
    .category-item {
        padding: 1rem;
    }
    
    .article-card {
        padding: 1rem;
    }
    
    .article-meta {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }
}