:root {
    --primary-color: #1a252f;      /* より濃くコントラストの高いネイビーブラック */
    --secondary-color: #2c3e50;    /* 落ち着いたダークブルー */
    --background-color: #f1f5f9;   /* 背景色を少し暗めにしてカード（白）の輪郭をはっきりさせる */
    --card-background: #ffffff;
    --text-color: #0f172a;         /* 本文用の色を限りなく黒に近いダークグレーに */
    --text-muted: #475569;         /* 補足文や日付の色を濃くして可読性をアップ */
    --border-color: #cbd5e1;       /* 境界線を少し濃くして要素の境目を明確に */
    --accent-color: #6d28d9;       /* アクセントカラーをより濃いパープルに */
    --max-width: 800px;
    --font-family: 'Outfit', 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    background-color: var(--background-color);
    color: var(--text-color);
    font-family: var(--font-family);
    line-height: 1.8;
    padding-bottom: 4rem;
}

header {
    background-color: var(--card-background);
    border-bottom: 1px solid var(--border-color);
    padding: 1.5rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 4px rgba(0,0,0,0.02);
}

.header-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.site-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
    letter-spacing: -0.5px;
    transition: color 0.2s ease;
}

.site-title:hover {
    color: var(--accent-color);
}

.admin-link {
    font-size: 0.875rem;
    color: var(--text-muted);
    text-decoration: none;
    border: 1px solid var(--border-color);
    padding: 0.35rem 0.75rem;
    border-radius: 6px;
    transition: all 0.2s ease;
}

.admin-link:hover {
    background-color: var(--primary-color);
    color: #fff;
    border-color: var(--primary-color);
}

main {
    max-width: var(--max-width);
    margin: 2rem auto 0 auto;
    padding: 0 1.5rem;
}

/* Profile Card */
.profile-card {
    background-color: var(--card-background);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.5rem;
    margin-bottom: 2rem;
    display: flex;
    gap: 1.25rem;
    align-items: center;
    box-shadow: 0 4px 6px rgba(0,0,0,0.01);
}

.profile-avatar {
    width: 64px;
    height: 64px;
    border-radius: 50%;
    background-color: var(--primary-color);
    color: #fff;
    font-size: 1.75rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    box-shadow: 0 4px 8px rgba(44, 62, 80, 0.15);
}

.profile-info {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.profile-name {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--primary-color);
}

.profile-description {
    font-size: 0.925rem;
    color: var(--text-muted);
    line-height: 1.6;
}

@media (max-width: 576px) {
    .profile-card {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }
}

/* Filter controls */
.filter-card {
    background-color: var(--card-background);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.25rem;
    margin-bottom: 2rem;
    box-shadow: 0 4px 6px rgba(0,0,0,0.01);
}

.filter-form {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    align-items: center;
}

.filter-group {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.filter-group label {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.filter-select {
    padding: 0.5rem 2rem 0.5rem 0.75rem;
    font-size: 0.9rem;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    background-color: #fff;
    color: var(--text-color);
    cursor: pointer;
    outline: none;
    transition: border-color 0.2s ease;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 24 24' stroke='%237f8c8d'%3E%3Cpath stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M19 9l-7 7-7-7'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 0.75rem center;
    background-size: 1rem;
}

.filter-select:focus {
    border-color: var(--primary-color);
}

.filter-btn {
    padding: 0.5rem 1rem;
    font-size: 0.9rem;
    font-weight: 600;
    background-color: var(--primary-color);
    color: #fff;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    transition: background-color 0.2s ease;
    align-self: flex-end;
}

.filter-btn:hover {
    background-color: var(--secondary-color);
}

.filter-clear {
    padding: 0.5rem 1rem;
    font-size: 0.9rem;
    color: var(--text-muted);
    text-decoration: none;
    border: 1px solid transparent;
    border-radius: 6px;
    align-self: flex-end;
    transition: all 0.2s ease;
}

.filter-clear:hover {
    border-color: var(--border-color);
    background-color: #fff;
}

/* Article List */
.article-list {
    display: flex;
    flex-direction: column;
    gap: 0.75rem; /* 間隔を1.5remから0.75remへ狭く */
}

.article-card {
    background-color: var(--card-background);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 0.5rem 1rem; /* パディングをさらに狭く */
    transition: transform 0.15s ease, box-shadow 0.15s ease;
    display: block;
    text-decoration: none;
    color: inherit;
    box-shadow: 0 2px 4px rgba(0,0,0,0.01);
}

.article-card:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.02);
    border-color: #cbd5e1;
}

.article-card-content {
    display: flex;
    gap: 1rem;
    align-items: center;
    flex-wrap: wrap; /* モバイル画面で収まらない場合は折り返す */
}

.article-date {
    font-size: 0.85rem;
    color: var(--text-muted);
    font-weight: 500;
    flex-shrink: 0;
}

.category-tag {
    background-color: #f1f5f9;
    color: var(--secondary-color);
    padding: 0.1rem 0.4rem;
    border-radius: 4px;
    font-size: 0.725rem;
    font-weight: 600;
    flex-shrink: 0;
}

.article-card-title {
    font-size: 1rem; /* 1行に収まりやすいようサイズダウン */
    font-weight: 600;
    color: var(--primary-color);
    line-height: 1.4;
    transition: color 0.15s ease;
}

.article-card:hover .article-card-title {
    color: var(--accent-color);
}

/* Article Detail */
.article-detail-header {
    margin-bottom: 2rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 1.5rem;
}

.article-detail-meta {
    display: flex;
    gap: 1rem;
    align-items: center;
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-bottom: 0.75rem;
}

.article-detail-title {
    font-size: 2rem;
    font-weight: 800;
    color: var(--primary-color);
    line-height: 1.3;
}

.paragraph-section {
    margin-bottom: 2.5rem;
}

.paragraph-subtitle {
    font-size: 1.35rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 1rem;
    border-left: 4px solid var(--primary-color);
    padding-left: 0.75rem;
}

.paragraph-text {
    font-size: 1.05rem;
    color: var(--text-color);
    margin-bottom: 1.5rem;
    white-space: pre-wrap;
    text-align: justify;
}

.photo-gallery {
    display: grid;
    gap: 1rem;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    margin-top: 1rem;
}

.photo-item {
    border-radius: 8px;
    overflow: hidden;
    border: 1px solid var(--border-color);
    background-color: #f8fafc;
}

.photo-item img {
    width: 100%;
    height: auto;
    display: block;
    transition: transform 0.3s ease;
}

.photo-item img:hover {
    transform: scale(1.03);
}

.back-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    margin-top: 2rem;
    transition: color 0.2s ease;
}

.back-link:hover {
    color: var(--accent-color);
}

/* Mobile & PC Layout adjustments for images */
@media (min-width: 768px) {
    /* PC: Horizontal arrangement is default via grid template-columns */
}

@media (max-width: 767px) {
    /* Mobile: Vertical arrangement */
    .photo-gallery {
        grid-template-columns: 1fr;
    }
}

/* Pagination */
.pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 0.5rem;
    margin-top: 3rem;
}

.pagination-link, .pagination-current {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 2.25rem;
    height: 2.25rem;
    padding: 0 0.75rem;
    font-size: 0.875rem;
    font-weight: 600;
    border-radius: 6px;
    text-decoration: none;
    transition: all 0.2s ease;
}

.pagination-link {
    background-color: var(--card-background);
    border: 1px solid var(--border-color);
    color: var(--text-color);
}

.pagination-link:hover {
    background-color: var(--primary-color);
    color: #fff;
    border-color: var(--primary-color);
    transform: translateY(-1px);
}

.pagination-current {
    background-color: var(--accent-color);
    color: #fff;
    border: 1px solid var(--accent-color);
}

/* Photo Zoom modal */
.photo-item img {
    cursor: pointer;
}

#photo-modal {
    border: none;
    background: transparent;
    padding: 0;
    max-width: 90vw;
    max-height: 90vh;
    overflow: visible;
    margin: auto;
    outline: none;
}

#photo-modal::backdrop {
    background-color: rgba(0, 0, 0, 0.85);
    backdrop-filter: blur(8px);
}

.modal-wrapper {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
}

#modal-image {
    max-width: 100%;
    max-height: 90vh;
    object-fit: contain;
    border-radius: 8px;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
}

.modal-close {
    position: absolute;
    top: -40px;
    right: 0;
    background: transparent;
    border: none;
    color: #fff;
    font-size: 2rem;
    cursor: pointer;
    line-height: 1;
    padding: 5px;
    transition: opacity 0.2s ease;
}

.modal-close:hover {
    opacity: 0.7;
}

@media (max-width: 767px) {
    .modal-close {
        top: 10px;
        right: 10px;
        background: rgba(0, 0, 0, 0.5);
        border-radius: 50%;
        width: 36px;
        height: 36px;
        display: flex;
        align-items: center;
        justify-content: center;
    }
}

.modal-nav {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background: rgba(0, 0, 0, 0.4);
    border: none;
    color: #fff;
    font-size: 1.5rem;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    display: none;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: background 0.2s ease, transform 0.2s ease;
    z-index: 10;
}

.modal-nav:hover {
    background: rgba(0, 0, 0, 0.7);
    transform: translateY(-50%) scale(1.05);
}

.prev-btn {
    left: -64px;
}

.next-btn {
    right: -64px;
}

@media (max-width: 767px) {
    .prev-btn {
        left: 10px;
    }
    .next-btn {
        right: 10px;
    }
    .modal-nav {
        width: 36px;
        height: 36px;
        font-size: 1.2rem;
    }
}