/* ============================
   Simple Structure Section
   「シンプルな構成。だから、すぐ使える。」
   白背景版（旧デザイン）
   ============================ */

.section-simple-structure {
    background: #ffffff;
    padding: 100px 0;
}

/* セクション見出し */
.simple-structure-headline {
    font-size: 2.5rem;
    font-weight: 700;
    color: #1a1a1a;
    text-align: center;
    margin-bottom: 60px;
    letter-spacing: 0.02em;
}

/* カード4点（2列×2行） */
.structure-cards-all {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 32px;
    max-width: 900px;
    margin: 0 auto;
}

.structure-card {
    background: #ffffff;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    border: 1px solid rgba(31, 79, 216, 0.08);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    opacity: 0;
    transform: translateY(30px);
}

.structure-card.visible {
    opacity: 1;
    transform: translateY(0);
}

.structure-card:nth-child(1) { transition-delay: 0ms; }
.structure-card:nth-child(2) { transition-delay: 100ms; }
.structure-card:nth-child(3) { transition-delay: 200ms; }
.structure-card:nth-child(4) { transition-delay: 300ms; }
.structure-card:nth-child(5) { transition-delay: 400ms; }
.structure-card:nth-child(6) { transition-delay: 500ms; }

.structure-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 40px rgba(31, 79, 216, 0.15);
    border-color: rgba(31, 79, 216, 0.2);
}

.structure-card-image {
    width: 100%;
    height: 220px;
    overflow: hidden;
    background: #f5f8fc;
    display: block;
}

.structure-card-image {
    transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    object-fit: cover;
}

.structure-card:hover .structure-card-image {
    transform: scale(1.05);
}

.structure-card-content {
    padding: 28px 24px;
    text-align: center;
}

.structure-card-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: #1B2430;
    margin-bottom: 8px;
    letter-spacing: 0.02em;
}

.structure-card-subtitle {
    font-size: 0.875rem;
    font-weight: 600;
    color: #1F4FD8;
    margin-bottom: 12px;
    letter-spacing: 0.05em;
}

.structure-card-description {
    font-size: 0.9375rem;
    color: #5B6B82;
    line-height: 1.6;
    letter-spacing: 0.02em;
    margin: 0;
}

/* レスポンシブ対応 */
@media (max-width: 900px) {
    .structure-cards-all {
        grid-template-columns: repeat(2, 1fr);
        gap: 28px;
        max-width: 100%;
        padding: 0 20px;
    }
}

@media (max-width: 768px) {
    .section-simple-structure {
        padding: 60px 0;
    }
    
    .simple-structure-headline {
        font-size: 1.75rem;
        margin-bottom: 48px;
    }
    
    .structure-cards-all {
        grid-template-columns: 1fr;
        gap: 24px;
    }
    
    .structure-card-image {
        height: 200px;
    }
    
    .structure-card-content {
        padding: 24px 20px;
    }
    
    .structure-card-title {
        font-size: 1.125rem;
    }
}

@media (max-width: 480px) {
    .simple-structure-headline {
        font-size: 1.5rem;
    }
    
    .structure-card-image {
        height: 180px;
    }
    
    .structure-card-content {
        padding: 20px 16px;
    }
}