:root {
    --primary-color: #1877f2;
    --secondary-color: #6a1b9a;
    --bg-color: #f8f9fa;
    --card-bg: #ffffff;
    --text-main: #333333;
    --text-muted: #666666;
    --border-color: #e0e0e0;
    --accent-color: #e7f3ff;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Helvetica Neue", Arial, "Hiragino Kaku Gothic ProN", "Hiragino Sans", Meiryo, sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.6;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
.header {
    background-color: var(--primary-color);
    color: white;
    padding: 40px 0;
    text-align: center;
    margin-bottom: 30px;
}

.header h1 {
    font-size: 2rem;
    margin-bottom: 10px;
}

.subtitle {
    opacity: 0.9;
    font-size: 1rem;
}

/* Search Section */
.search-section {
    background-color: var(--card-bg);
    padding: 20px;
    border-radius: 12px;
    box-shadow: var(--shadow);
    margin-bottom: 30px;
}

.search-box {
    position: relative;
    margin-bottom: 20px;
}

.search-box i {
    position: absolute;
    left: 15px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
}

.search-box input {
    width: 100%;
    padding: 15px 15px 15px 45px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.2s;
}

.search-box input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.category-filters {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.filter-btn {
    padding: 8px 16px;
    border: 1px solid var(--border-color);
    background-color: var(--card-bg);
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.2s;
}

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

.filter-btn.active {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

/* Info Section */
.archive-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding: 0 5px;
}

#resultCount {
    font-size: 0.9rem;
    color: var(--text-muted);
}

.sort-box select {
    padding: 5px 10px;
    border-radius: 4px;
    border: 1px solid var(--border-color);
    background-color: white;
}

/* Archive List */
.post-archive {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.archive-entry {
    background-color: var(--card-bg);
    border-radius: 8px;
    padding: 20px;
    border-left: 5px solid var(--primary-color);
    box-shadow: var(--shadow);
    transition: transform 0.2s;
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.archive-entry:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.entry-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: 10px;
    font-size: 0.85rem;
}

.entry-date {
    color: var(--text-muted);
}

.entry-category {
    background-color: var(--accent-color);
    color: var(--primary-color);
    padding: 2px 8px;
    border-radius: 4px;
    font-weight: bold;
}

.entry-title {
    font-size: 1.25rem;
    margin-bottom: 10px;
    color: var(--text-main);
}

.entry-content {
    font-size: 0.95rem;
    color: var(--text-muted);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    text-overflow: ellipsis;
}

.entry-footer {
    margin-top: 15px;
    text-align: right;
}

.view-link {
    color: var(--primary-color);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: bold;
}

.view-link:hover {
    text-decoration: underline;
}

/* Footer */
.footer {
    margin-top: 50px;
    padding: 30px 0;
    text-align: center;
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* Responsive */
.load-more-btn {
    display: block;
    margin: 40px auto;
    padding: 12px 40px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border: none;
    border-radius: 25px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    box-shadow: 0 4px 15px rgba(24, 119, 242, 0.3);
}

.load-more-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(106, 27, 154, 0.4);
}

.load-more-btn:active {
    transform: translateY(0);
}

@media (max-width: 600px) {
    .header {
        padding: 30px 0;
    }

    .header h1 {
        font-size: 1.5rem;
    }

    .search-section {
        padding: 15px;
    }
}