/* CSS Variables */
:root {
    --bg-primary: #1a1a1a;
    --bg-secondary: #2a2a2a;
    --bg-tertiary: #333333;
    --text-primary: #ffffff;
    --text-secondary: #b0b0b0;
    --text-muted: #888888;
    --accent-pink: #ff6b9d;
    --accent-purple: #c44cff;
    --accent-gradient: linear-gradient(135deg, var(--accent-pink), var(--accent-purple));
    --border-color: #404040;
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.4);
    --shadow-hover: 0 8px 30px rgba(0, 0, 0, 0.6);
    --transition: all 0.3s ease;
    --header-height: 70px;
    --font-family: 'Poppins', sans-serif;
}

/* Reset */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

a {
    text-decoration: none;
    color: inherit;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
}

.header-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 20px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.5rem;
    font-weight: 700;
}

.logo-icon {
    font-size: 1.8rem;
}

.logo-text {
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav {
    display: flex;
    gap: 5px;
}

.nav-link {
    padding: 10px 20px;
    border-radius: 25px;
    font-weight: 500;
    color: var(--text-secondary);
    transition: var(--transition);
}

.nav-link:hover {
    color: var(--text-primary);
    background: var(--bg-tertiary);
}

.nav-link.active {
    background: var(--accent-gradient);
    color: var(--text-primary);
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 15px;
}

.lang-toggle {
    padding: 8px 16px;
    border-radius: 20px;
    background: var(--bg-tertiary);
    color: var(--text-primary);
    font-weight: 600;
    transition: var(--transition);
}

.lang-toggle:hover {
    background: var(--accent-gradient);
}

/* Ad Containers */
.ad-container {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 90px;
}

.ad-container.ad-header {
    max-width: 728px;
    margin: calc(var(--header-height) + 20px) auto 0;
    padding: 10px;
}

.ad-container.ad-mid {
    max-width: 728px;
    margin: 40px auto;
    padding: 10px;
}

.ad-container.ad-footer {
    max-width: 728px;
    margin: 0 auto 30px;
    padding: 10px;
}

/* 広告コードが入ったらプレースホルダーを非表示 */
.ad-container:has(iframe) .ad-placeholder,
.ad-container:has(ins) .ad-placeholder,
.ad-container:has(script + *) .ad-placeholder {
    display: none;
}

/* Ad Placeholder (広告未設定時) */
.ad-placeholder {
    background: var(--bg-secondary);
    border: 2px dashed var(--border-color);
    border-radius: 8px;
    padding: 20px 40px;
    text-align: center;
    color: var(--text-muted);
    font-size: 0.9rem;
    width: 100%;
    max-width: 728px;
    height: 90px;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Main Content */
.main {
    padding-top: 20px;
    min-height: calc(100vh - var(--header-height));
}

/* Hero Section */
.hero {
    text-align: center;
    padding: 40px 20px;
    max-width: 800px;
    margin: 0 auto;
}

.hero h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 15px;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero p {
    font-size: 1.1rem;
    color: var(--text-secondary);
}

/* Category Cards */
.categories {
    padding: 20px;
    max-width: 1200px;
    margin: 0 auto;
}

.category-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
}

.category-card {
    background: var(--bg-secondary);
    border-radius: 16px;
    padding: 30px 20px;
    text-align: center;
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.category-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
    border-color: var(--accent-pink);
}

.category-icon {
    font-size: 3rem;
    margin-bottom: 15px;
}

.category-card h3 {
    font-size: 1.2rem;
    margin-bottom: 8px;
}

.category-count {
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* Gallery Section */
.gallery-section {
    padding: 40px 20px;
    max-width: 1400px;
    margin: 0 auto;
}

.gallery-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    flex-wrap: wrap;
    gap: 15px;
}

.gallery-header h2 {
    font-size: 1.8rem;
}

.sort-select {
    padding: 10px 20px;
    border-radius: 25px;
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    font-family: inherit;
    font-size: 0.9rem;
    cursor: pointer;
}

.sort-select:focus {
    outline: none;
    border-color: var(--accent-pink);
}

/* Masonry-style Gallery Grid */
.gallery {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 20px;
}

.gallery-item {
    position: relative;
    border-radius: 12px;
    overflow: hidden;
    background: var(--bg-secondary);
    cursor: pointer;
    transition: var(--transition);
}

.gallery-item:hover {
    transform: scale(1.02);
    box-shadow: var(--shadow-hover);
}

.gallery-item img {
    width: 100%;
    height: auto;
    display: block;
    transition: var(--transition);
}

.gallery-item:hover img {
    transform: scale(1.05);
}

.gallery-item-overlay {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    padding: 15px;
    background: linear-gradient(transparent, rgba(0, 0, 0, 0.8));
    opacity: 0;
    transition: var(--transition);
}

.gallery-item:hover .gallery-item-overlay {
    opacity: 1;
}

.gallery-item-category {
    display: inline-block;
    padding: 4px 12px;
    border-radius: 15px;
    background: var(--accent-gradient);
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: capitalize;
}

/* Gallery Empty State */
.gallery-empty {
    text-align: center;
    padding: 80px 20px;
    color: var(--text-muted);
}

.empty-icon {
    font-size: 4rem;
    margin-bottom: 20px;
}

.gallery-empty p {
    font-size: 1.1rem;
}

/* Lightbox */
.lightbox {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.95);
    display: none;
    justify-content: center;
    align-items: center;
    z-index: 2000;
}

.lightbox.active {
    display: flex;
}

.lightbox-close {
    position: absolute;
    top: 20px;
    right: 30px;
    font-size: 40px;
    color: var(--text-primary);
    transition: var(--transition);
}

.lightbox-close:hover {
    color: var(--accent-pink);
    transform: scale(1.1);
}

.lightbox-nav {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    font-size: 30px;
    color: var(--text-primary);
    padding: 20px;
    transition: var(--transition);
}

.lightbox-nav:hover {
    color: var(--accent-pink);
}

.lightbox-prev {
    left: 20px;
}

.lightbox-next {
    right: 20px;
}

.lightbox-content {
    max-width: 90vw;
    max-height: 90vh;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.lightbox-content img {
    max-width: 100%;
    max-height: 80vh;
    object-fit: contain;
    border-radius: 8px;
}

.lightbox-info {
    margin-top: 20px;
    display: flex;
    gap: 20px;
    align-items: center;
}

.lightbox-category {
    padding: 6px 16px;
    border-radius: 20px;
    background: var(--accent-gradient);
    font-size: 0.85rem;
    font-weight: 600;
    text-transform: capitalize;
}

.lightbox-counter {
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* Footer */
.footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: 40px 20px;
    margin-top: 60px;
}

.footer-container {
    max-width: 1200px;
    margin: 0 auto;
    text-align: center;
}

.footer p {
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-top: 10px;
}

/* Loading Spinner */
.loading {
    display: flex;
    justify-content: center;
    padding: 40px;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 4px solid var(--bg-tertiary);
    border-top-color: var(--accent-pink);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

/* Responsive Design - Tablet */
@media (max-width: 768px) {
    :root {
        --header-height: auto;
    }

    .header {
        position: sticky;
        height: auto;
    }

    .header-container {
        flex-wrap: wrap;
        padding: 10px 15px;
        height: auto;
        gap: 10px;
    }

    .logo {
        flex: 1;
    }

    .nav {
        order: 3;
        width: 100%;
        justify-content: center;
        margin-top: 5px;
        flex-wrap: wrap;
        gap: 5px;
    }

    .nav-link {
        padding: 8px 12px;
        font-size: 0.85rem;
        /* タッチ用に最小サイズ確保 */
        min-height: 44px;
        display: flex;
        align-items: center;
    }

    .ad-header {
        margin-top: 15px;
        height: 60px;
        margin-left: 10px;
        margin-right: 10px;
    }

    .ad-mid, .ad-footer {
        height: 60px;
        margin-left: 10px;
        margin-right: 10px;
    }

    .hero {
        padding: 30px 15px;
    }

    .hero h1 {
        font-size: 1.6rem;
        line-height: 1.3;
    }

    .hero p {
        font-size: 0.95rem;
    }

    .categories {
        padding: 15px;
    }

    .category-cards {
        gap: 12px;
    }

    .category-card {
        padding: 20px 15px;
    }

    .category-icon {
        font-size: 2.5rem;
    }

    .gallery-section {
        padding: 20px 10px;
    }

    .gallery {
        grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
        gap: 8px;
    }

    .gallery-item {
        border-radius: 8px;
    }

    /* モバイルではオーバーレイを常に表示 */
    .gallery-item-overlay {
        opacity: 1;
        background: linear-gradient(transparent 50%, rgba(0, 0, 0, 0.7));
        padding: 10px;
    }

    .gallery-item-category {
        font-size: 0.7rem;
        padding: 3px 8px;
    }

    .gallery-header {
        flex-direction: column;
        align-items: stretch;
        gap: 10px;
    }

    .gallery-header h2 {
        font-size: 1.4rem;
    }

    .sort-select {
        width: 100%;
        padding: 12px 15px;
    }

    /* ライトボックス - モバイル最適化 */
    .lightbox-close {
        top: 10px;
        right: 15px;
        font-size: 35px;
        padding: 10px;
        /* タッチ用 */
        min-width: 44px;
        min-height: 44px;
    }

    .lightbox-nav {
        padding: 15px;
        font-size: 24px;
        /* タッチ用 */
        min-width: 44px;
        min-height: 44px;
        display: flex;
        align-items: center;
        justify-content: center;
        background: rgba(0, 0, 0, 0.3);
        border-radius: 50%;
    }

    .lightbox-prev {
        left: 10px;
    }

    .lightbox-next {
        right: 10px;
    }

    .lightbox-content {
        max-width: 95vw;
        max-height: 85vh;
        padding: 10px;
    }

    .lightbox-content img {
        max-height: 70vh;
        border-radius: 4px;
    }

    .lightbox-info {
        margin-top: 15px;
        gap: 10px;
        flex-wrap: wrap;
        justify-content: center;
    }

    .lightbox-category {
        font-size: 0.8rem;
        padding: 5px 12px;
    }

    .lightbox-counter {
        font-size: 0.85rem;
    }

    .footer {
        padding: 30px 15px;
        margin-top: 40px;
    }

    .footer p {
        font-size: 0.8rem;
    }
}

/* Responsive Design - Mobile Small */
@media (max-width: 480px) {
    .logo-icon {
        font-size: 1.5rem;
    }

    .logo-text {
        font-size: 1.1rem;
    }

    .lang-toggle {
        padding: 6px 12px;
        font-size: 0.85rem;
    }

    .nav-link {
        padding: 6px 10px;
        font-size: 0.8rem;
    }

    .hero h1 {
        font-size: 1.4rem;
    }

    .hero p {
        font-size: 0.9rem;
    }

    .category-cards {
        grid-template-columns: 1fr;
    }

    .category-card {
        padding: 15px;
        display: flex;
        align-items: center;
        gap: 15px;
        text-align: left;
    }

    .category-icon {
        font-size: 2rem;
        margin-bottom: 0;
    }

    .category-card h3 {
        margin-bottom: 2px;
    }

    .gallery {
        grid-template-columns: repeat(2, 1fr);
        gap: 6px;
    }

    .gallery-item {
        border-radius: 6px;
    }

    .gallery-item-overlay {
        padding: 8px;
    }

    .gallery-item-category {
        font-size: 0.65rem;
        padding: 2px 6px;
    }

    .gallery-header h2 {
        font-size: 1.2rem;
    }

    /* ライトボックスのナビを下部に配置 */
    .lightbox-nav {
        top: auto;
        bottom: 100px;
        transform: none;
    }

    .lightbox-content img {
        max-height: 60vh;
    }

    .lightbox-info {
        position: absolute;
        bottom: 40px;
        left: 0;
        right: 0;
        justify-content: center;
    }
}

/* iPhone X以降のノッチ対応 */
@supports (padding: max(0px)) {
    .header {
        padding-left: max(15px, env(safe-area-inset-left));
        padding-right: max(15px, env(safe-area-inset-right));
    }

    .lightbox {
        padding: env(safe-area-inset-top) env(safe-area-inset-right) env(safe-area-inset-bottom) env(safe-area-inset-left);
    }

    .footer {
        padding-bottom: max(40px, env(safe-area-inset-bottom));
    }
}

/* 横向きモバイル */
@media (max-width: 812px) and (orientation: landscape) {
    .lightbox-content img {
        max-height: 75vh;
    }

    .lightbox-nav {
        top: 50%;
        bottom: auto;
        transform: translateY(-50%);
    }

    .lightbox-info {
        position: static;
    }

    .hero {
        padding: 20px 15px;
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus states for keyboard navigation */
a:focus-visible,
button:focus-visible,
select:focus-visible {
    outline: 2px solid var(--accent-pink);
    outline-offset: 2px;
}