body {
    font-family: 'Helvetica Neue', 'Arial', sans-serif;
    line-height: 1.6;
    margin: 0;
    padding: 0;
    background-color: #fff;
    color: #333;
}

.jashugan-container {
    max-width: 1100px;
    margin: 2rem auto;
    padding: 0 20px;
}




/* ヘッダー */
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0; /* Removed horizontal padding */
    border-bottom: 1px solid #eee;
    background-color: #fff;
    border-radius: 8px; /* Added border-radius */
}

header h1 {
    font-size: 1.8rem;
    margin: 0;
}

header h1 a {
    text-decoration: none;
    color: #333;
}

/* ナビゲーション */
header nav ul { /* Changed selector from 'nav ul' to 'header nav ul' */
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
}

nav li {
    margin-left: 20px;
}

nav a {
    text-decoration: none;
    color: #555;
    font-weight: bold;
    padding: 5px 5px;
    border-radius: 5px;
    transition: background-color 0.3s;
}

nav a:hover {
    background-color: #f4f4f9;
    color: #333;
}

.article-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
    margin-top: 2rem;
}

.article-card {
    background-color: #fff;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    overflow: hidden;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.article-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
}

.card-content {
    padding: 20px;
}

.card-content h2 {
    font-size: 1.25rem;
    margin-top: 0;
    margin-bottom: 10px;
}

.card-content a {
    text-decoration: none;
    color: #2c3e50;
    transition: color 0.3s ease;
}

.card-content a:hover {
    color: #3498db;
}

.card-content p {
    margin: 0 0 10px;
    font-size: 0.9rem;
    color: #666;
}

.date {
    font-size: 0.8rem;
    color: #999;
}

/* Hamburger Menu */
.hamburger-button {
    display: none; /* Hidden by default on desktop */
    background: none;
    border: none;
    cursor: pointer;
    padding: 10px;
    z-index: 1000;
}

.hamburger-icon {
    display: block;
    width: 24px;
    height: 2px;
    background-color: #333;
    position: relative;
    transition: background-color 0.3s ease-in-out;
}

.hamburger-icon::before,
.hamburger-icon::after {
    content: '';
    display: block;
    width: 24px;
    height: 2px;
    background-color: #333;
    position: absolute;
    transition: transform 0.3s ease-in-out;
}

.hamburger-icon::before {
    top: -8px;
}

.hamburger-icon::after {
    bottom: -8px;
}

/* Active state for hamburger */
.hamburger-button.is-active .hamburger-icon {
    background-color: transparent;
}

.hamburger-button.is-active .hamburger-icon::before {
    transform: translateY(8px) rotate(45deg);
}

.hamburger-button.is-active .hamburger-icon::after {
    transform: translateY(-8px) rotate(-45deg);
}

/* --- Sidebar Layout Styles --- */

.main-content-area {
    display: flex;
    gap: 2rem;
}

.article-content {
    flex: 3;
    min-width: 0;
}

.sidebar {
    flex: 1;
    position: sticky;
    top: 2rem;
    align-self: flex-start;
}

.sidebar-widget {
    background-color: #ffffff;
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}

.sidebar-widget h3 {
    font-size: 1.2rem;
    font-weight: bold;
    margin-top: 0;
    border-bottom: 2px solid #eee;
    padding-bottom: 0.5rem;
    margin-bottom: 1rem;
}

.sidebar-widget ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.sidebar-widget ul li a {
    text-decoration: none;
    color: #333;
    display: block;
    padding: 0.75rem 1rem;
    border-bottom: 1px solid #eee;
    transition: background-color 0.2s ease-in-out;
}

.sidebar-widget ul li:last-child a {
    border-bottom: none;
}

.sidebar-widget ul li a:hover {
    background-color: #e9ecef;
}

/* --- Footer Styles --- */
.site-footer {
    background-color: #f8f9fa; /* Light Gray */
    color: #333; /* Dark text */
    padding: 2rem 0;
    margin-top: 3rem;
    border-top: 4px solid #dee2e6; /* Lighter border */
}

.footer-content {
    display: flex;
    justify-content: space-around;
    flex-wrap: wrap;
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section {
    flex: 1;
    min-width: 200px;
}

.footer-section h4 {
    font-size: 1.2rem;
    font-weight: bold;
    margin-top: 0;
    margin-bottom: 1rem;
    color: #333; /* Dark text */
    border-bottom: 2px solid #dee2e6; /* Lighter border */
    padding-bottom: 0.5rem;
    display: inline-block;
}

.footer-section ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.footer-section ul li a {
    color: #555; /* Dark gray text */
    text-decoration: none;
    display: block;
    padding: 0.3rem 0;
    transition: color 0.2s ease-in-out;
}

.footer-section ul li a:hover {
    color: #007bff; /* Standard blue for links */
}

.footer-bottom {
    text-align: center;
    padding-top: 1rem;
    border-top: 1px solid #dee2e6; /* Lighter border */
    font-size: 0.9rem;
}


/* --- Mobile & Responsive Styles --- */
@media (max-width: 768px) {
    /* Sidebar */
    .main-content-area {
        flex-direction: column;
    }
    .sidebar {
        display: none;
    }

    /* Hamburger Menu & Mobile Nav */
    .hamburger-button {
        display: block;
    }
    header nav {
        display: none;
        position: absolute;
        top: 70px;
        left: 0;
        width: 100%;
        background-color: #fff;
        box-shadow: 0 4px 12px rgba(0,0,0,0.1);
        z-index: 100;
    }
    header nav.is-active {
        display: block;
    }
    header nav ul {
        flex-direction: column;
        align-items: center;
        padding: 20px 0;
    }
    header nav li {
        margin: 10px 0;
        margin-left: 0;
    }
}