:root {
    --bg-color: #fdfbfb;
    --text-color: #4a4a4a;
    --accent-color: #6ed3ff;
    --accent-hover: #52c2f2;
    --tag-bg: #ffe4e1;
    --tag-text: #db7093;
    --card-bg: #ffffff;
    --box-shadow: 0 8px 24px rgba(0, 0, 0, 0.05);
    --border-radius-lg: 20px;
    --border-radius-md: 12px;
}

body {
    margin: 0;
    padding: 0;
    font-family: 'M PLUS Rounded 1c', 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
}

header {
    text-align: center;
    padding: 3rem 1rem 2rem;
}

header h1 {
    font-size: 2rem;
    margin-bottom: 0.5rem;
    color: #333;
}

header p {
    font-size: 1rem;
    color: #666;
    margin-bottom: 1.5rem;
}

.profile-btn {
    display: inline-block;
    padding: 0.8rem 1.5rem;
    background-color: var(--card-bg);
    color: var(--accent-color);
    text-decoration: none;
    border-radius: 50px;
    font-weight: bold;
    box-shadow: 0 4px 10px rgba(110, 211, 255, 0.2);
    transition: all 0.3s ease;
}

.profile-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 15px rgba(110, 211, 255, 0.3);
}

/* Filters Navigation */
.filters {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.8rem;
    padding: 1rem;
    margin-bottom: 2rem;
}

.filter-btn {
    padding: 0.6rem 1.2rem;
    border: 2px solid var(--accent-color);
    background: transparent;
    color: var(--accent-color);
    border-radius: 50px;
    font-size: 0.9rem;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.3s ease;
    outline: none;
}

.filter-btn:hover {
    background-color: rgba(110, 211, 255, 0.1);
}

.filter-btn.active {
    background-color: var(--accent-color);
    color: #fff;
}

/* Gallery Layout */
.gallery {
    display: grid;
    /* 画面幅に合わせてカードを280px以上で並べる */
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 2rem;
    padding: 0 2rem 4rem;
    max-width: 1400px;
    margin: 0 auto;
}

/* Card Design */
.card {
    background: var(--card-bg);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--box-shadow);
    overflow: hidden;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    display: flex;
    flex-direction: column;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 30px rgba(0, 0, 0, 0.08);
}

/* Image Wrapper for aspect ratio */
.card-img-wrap {
    width: 100%;
    position: relative;
    padding-top: 100%; /* 1:1 Aspect Ratio (Square) */
    overflow: hidden;
}

.card-img-wrap img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover; /* 画像をはみ出させずに中央で切り取る */
    transition: transform 0.5s ease;
}

.card:hover .card-img-wrap img {
    transform: scale(1.05); /* ホバー時に少しズーム */
}

/* Card Content Area */
.card-content {
    padding: 1.5rem;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
}

.card-category {
    display: inline-block;
    padding: 0.3rem 0.8rem;
    background-color: var(--tag-bg);
    color: var(--tag-text);
    border-radius: 50px;
    font-size: 0.75rem;
    font-weight: bold;
    margin-bottom: 0.8rem;
    align-self: flex-start;
}

.card-title {
    font-size: 1.1rem;
    font-weight: 700;
    margin: 0 0 1rem 0;
    color: #333;
}

/* Prompt Textbox */
.prompt-box {
    background-color: #f5f7fa;
    border-radius: var(--border-radius-md);
    padding: 1rem;
    height: 80px; /* 固定高でサイズを揃える */
    overflow-y: auto; /* 長い場合はスクロール */
    font-size: 0.85rem;
    line-height: 1.5;
    color: #555;
    margin-bottom: 1.5rem;
    border: 1px solid #e1e4e8;
}

/* Custom Scrollbar for Prompt Box */
.prompt-box::-webkit-scrollbar {
    width: 6px;
}
.prompt-box::-webkit-scrollbar-thumb {
    background: #ccc;
    border-radius: 10px;
}

/* Copy Button */
.copy-btn {
    width: 100%;
    padding: 0.8rem;
    background-color: var(--accent-color);
    color: #fff;
    border: none;
    border-radius: 50px;
    font-size: 1rem;
    font-weight: bold;
    cursor: pointer;
    transition: background-color 0.3s ease, transform 0.1s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    margin-top: auto; /* ボタンを常に下部に配置 */
}

.copy-btn:hover {
    background-color: var(--accent-hover);
}

.copy-btn:active {
    transform: scale(0.98);
}

/* Toast Message */
.toast {
    position: fixed;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    background: rgba(0,0,0,0.8);
    color: #fff;
    padding: 10px 20px;
    border-radius: 50px;
    font-size: 0.9rem;
    opacity: 1;
    transition: opacity 0.3s ease, bottom 0.3s ease;
    z-index: 1000;
}

.toast.hidden {
    opacity: 0;
    bottom: 10px;
    pointer-events: none;
}

/* Smartphone Responsive */
@media (max-width: 600px) {
    .gallery {
        grid-template-columns: repeat(auto-fill, minmax(140px, 1fr)); /* スマホでは2列程度に */
        gap: 1rem;
        padding: 0 1rem 3rem;
    }
    .card-content {
        padding: 1rem;
    }
    .card-title {
        font-size: 0.95rem;
    }
    .prompt-box {
        font-size: 0.75rem;
        height: 60px;
    }
    .copy-btn {
        font-size: 0.85rem;
        padding: 0.6rem;
    }
}