.article-container {
    display: grid;
    gap: 25px;
    /* デスクトップ: 2列 */
    grid-template-columns: repeat(2, 1fr);
}

/* 超大画面: 3列 */
@media (min-width: 1400px) {
    .article-container {
        grid-template-columns: repeat(3, 1fr);
    }
}

/* タブレット: 2列維持 */
@media (max-width: 1024px) {
    .article-container {
        grid-template-columns: repeat(2, 1fr);
        gap: 20px;
    }
}

/* スマホ: 1列 */
@media (max-width: 768px) {
    .article-container {
        grid-template-columns: 1fr;
        gap: 20px;
    }
}

.article-card {
    display: flex;
    flex-direction: column;
    background: linear-gradient(145deg, #1E293B, #334155);
    border: 1px solid rgba(16, 185, 129, 0.2);
    border-radius: 12px;
    overflow: hidden;
    text-decoration: none;
    color: inherit;
    transition: all 0.3s ease;
    opacity: 0;
    transform: translateY(30px);
    animation: slideInUp 0.6s ease-out forwards;
    position: relative;
    height: 100%;
    min-height: 400px;
}

.article-card:nth-child(1) { animation-delay: 0.1s; }
.article-card:nth-child(2) { animation-delay: 0.2s; }
.article-card:nth-child(3) { animation-delay: 0.3s; }
.article-card:nth-child(4) { animation-delay: 0.4s; }
.article-card:nth-child(5) { animation-delay: 0.5s; }
.article-card:nth-child(6) { animation-delay: 0.6s; }
.article-card:nth-child(n+7) { animation-delay: 0.7s; }

@keyframes slideInUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.article-card:hover {
    transform: translateY(-10px) scale(1.02);
    box-shadow: 0 20px 50px rgba(16, 185, 129, 0.25);
    border-color: rgba(16, 185, 129, 0.6);
}

.article-card:hover::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(circle at center, rgba(16, 185, 129, 0.1) 0%, transparent 70%);
    pointer-events: none;
    z-index: 1;
}

.card-thumbnail {
    width: 100%;
    height: 200px;
    object-fit: cover;
    background: linear-gradient(45deg, #374151, #4B5563);
    border-bottom: 2px solid rgba(16, 185, 129, 0.3);
}

.default-card-thumbnail {
    width: 100%;
    height: 200px;
    background: linear-gradient(45deg, #374151, #4B5563);
    border-bottom: 2px solid rgba(16, 185, 129, 0.3);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #6B7280;
    font-size: 1em;
    font-weight: 500;
}

.card-content {
    padding: 20px;
    display: flex;
    flex-direction: column;
    flex-grow: 1;
    position: relative;
    z-index: 2;
}

.card-header {
    margin-bottom: 12px;
}

.card-title {
    font-size: 1.25em;
    color: #A7F3D0;
    margin: 0 0 8px 0;
    text-shadow: 0 0 5px rgba(16, 185, 129, 0.4);
    font-weight: 600;
    line-height: 1.3;
}

.card-date {
    color: #94A3B8;
    font-size: 0.85em;
    margin: 0 0 8px 0;
    font-weight: 500;
}

.card-category {
    display: inline-block;
    padding: 4px 8px;
    border-radius: 4px;
    font-size: 0.75em;
    font-weight: 500;
    margin-bottom: 12px;
}

.card-category.tech {
    background: rgba(94, 170, 168, 0.2);
    color: #10B981;
    border: 1px solid rgba(16, 185, 129, 0.3);
}
.card-category.design {
    background: rgba(147, 51, 234, 0.2);
    color: #A78BFA;
    border: 1px solid rgba(147, 51, 234, 0.3);
}
.card-category.diy{
    background: rgba(234, 179, 8, 0.2);
    color: #F59E0B;
    border: 1px solid rgba(234, 179, 8, 0.3);
}
.card-category.hobby{
    background: rgba(244, 114, 182, 0.2);
    color: #EC4899;
    border: 1px solid rgba(244, 114, 182, 0.3);
}
.card-category.travel{
    background: rgba(59, 130, 246, 0.2);
    color: #3B82F6;
    border: 1px solid rgba(59, 130, 246, 0.3);
}
.card-category.other{
    background: rgba(156, 163, 175, 0.2);
    color: #9CA3AF;
    border: 1px solid rgba(156, 163, 175, 0.3);
}

.card-summary {
    color: #CBD5E1;
    line-height: 1.6;
    margin: 0 0 15px 0;
    display: -webkit-box;
    line-clamp: 3;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
    flex-grow: 1;
    font-size: 0.95em;
}

.card-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-bottom: 15px;
}

.tag {
    background: rgba(100, 116, 139, 0.3);
    color: #CBD5E1;
    padding: 2px 6px;
    border-radius: 3px;
    font-size: 0.7em;
    border: 1px solid rgba(100, 116, 139, 0.5);
}

.card-footer {
    margin-top: auto;
    padding-top: 15px;
    border-top: 1px solid rgba(16, 185, 129, 0.2);
    display: flex;
    justify-content: flex-end;
}

.read-more {
    color: #10B981;
    font-size: 0.9em;
    font-weight: 500;
    text-shadow: 0 0 3px rgba(16, 185, 129, 0.5);
}

.loading {
    text-align: center;
    color: #94A3B8;
    padding: 40px;
    font-size: 1.1em;
}

.error {
    text-align: center;
    color: #EF4444;
    padding: 40px;
    font-size: 1.1em;
    background: rgba(239, 68, 68, 0.1);
    border: 1px solid rgba(239, 68, 68, 0.3);
    border-radius: 8px;
}

/* スマホでのカード調整 */
@media (max-width: 768px) {
    .card-content {
        padding: 16px;
    }
    
    .card-title {
        font-size: 1.2em;
    }

    .card-thumbnail,
    .default-card-thumbnail {
        height: 180px;
    }

    .article-card {
        min-height: 350px;
    }
}

@media (max-width: 480px) {
    .article-container {
        gap: 15px;
    }
    
    .card-thumbnail,
    .default-card-thumbnail {
        height: 160px;
    }

    .article-card {
        min-height: 320px;
    }
}