body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 20px;
    background-color: #f0f0f0;
}
.header {
    background-color: #333;
    padding: 10px 0;
    margin-bottom: 20px;
}
.header ul {
    list-style-type: none;
    padding: 0;
    margin: 0;
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
}
.header li {
    margin: 5px 10px;
}
.header a {
    color: white;
    text-decoration: none;
    padding: 5px 10px;
    border-radius: 5px;
    transition: background-color 0.3s;
}
.header a:hover, .header a.active {
    background-color: #555;
}
.gallery {
    margin: 0 auto;
}
.gallery-sizer, .gallery-item {
    width: calc(25% - 20px);
}
.gallery-item {
    margin-bottom: 20px;
    background: white;
    border-radius: 5px;
    overflow: hidden;
    box-shadow: 0 2px 10px rgba(0,0,0,0.15);
}
@media (max-width: 1200px) {
    .gallery-sizer, .gallery-item { width: calc(33.333% - 20px); }
}
@media (max-width: 900px) {
    .gallery-sizer, .gallery-item { width: calc(50% - 20px); }
}
@media (max-width: 600px) {
    .gallery-sizer, .gallery-item { width: calc(100% - 20px); }
}
.gallery-item img {
    width: 100%;
    height: auto;
    display: block;
}



/*** いいね機能で追加 ***/
.image-container {
    position: relative;
}

.like-button {
    position: absolute;
    bottom: 10px;
    right: 10px;
    background: rgba(255, 255, 255, 0.7);
    border: none;
    border-radius: 50%;
    padding: 5px 10px;
    cursor: pointer;
    transition: background 0.3s, transform 0.1s;
}

.like-button:hover {
    background: rgba(255, 255, 255, 0.9);
    transform: scale(1.1);
}

.like-button .heart-icon {
    color: #ff4136;
    font-style: normal;
}

.like-button .like-count {
    margin-left: 5px;
    font-size: 14px;
}

.like-button.liked .heart-icon {
    animation: heart-beat 0.3s;
}

@keyframes heart-beat {
    0% { transform: scale(1); }
    50% { transform: scale(1.3); }
    100% { transform: scale(1); }
}