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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans JP", "Hiragino Kaku Gothic ProN", "Hiragino Sans", Meiryo, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #fff;
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
}

header {
    position: sticky;
    top: 0;
    background-color: #fff;
    z-index: 100;
    margin-bottom: 40px;
    padding: 20px 0;
    border-bottom: 1px solid #e0e0e0;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

header h1 {
    font-size: 24px;
    font-weight: normal;
    margin: 0;
    letter-spacing: 0.05em;
}

nav {
    display: flex;
    gap: 20px;
}

nav a {
    color: #666;
    text-decoration: none;
    font-size: 14px;
    transition: color 0.2s;
}

nav a:hover {
    color: #000;
}

main {
    min-height: 60vh;
}

.content-section {
    animation: fadeIn 0.3s ease-in;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

h2 {
    font-size: 18px;
    font-weight: normal;
    margin-bottom: 30px;
    color: #666;
}

.post-list {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.post-item {
    padding: 15px 0;
    border-bottom: 1px solid #f0f0f0;
}

.post-item:last-child {
    border-bottom: none;
}

.post-date {
    font-size: 12px;
    color: #999;
    margin-bottom: 5px;
}

.post-title {
    font-size: 14px;
    color: #333;
    text-decoration: none;
    display: inline-block;
    transition: color 0.2s;
}

.post-title:hover {
    color: #000;
}

.post-category {
    font-size: 11px;
    color: #999;
    margin-left: 10px;
}

.about-content {
    line-height: 1.8;
}

.about-content p {
    margin-bottom: 15px;
    font-size: 14px;
    color: #666;
}

footer {
    margin-top: 60px;
    padding-top: 20px;
    border-top: 1px solid #e0e0e0;
    text-align: center;
    font-size: 12px;
    color: #999;
}

/* モーダルスタイル */
.modal {
    display: block;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgba(0, 0, 0, 0.4);
    animation: fadeIn 0.3s ease-in;
}

.modal-content {
    background-color: #fff;
    margin: 5% auto;
    padding: 30px;
    border: 1px solid #e0e0e0;
    width: 90%;
    max-width: 700px;
    max-height: 80vh;
    overflow-y: auto;
    position: relative;
    animation: slideDown 0.3s ease-out;
}

@keyframes slideDown {
    from {
        transform: translateY(-50px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.modal-close {
    color: #999;
    float: right;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
    line-height: 1;
    transition: color 0.2s;
}

.modal-close:hover {
    color: #000;
}

.modal-content h2 {
    margin-top: 0;
    margin-bottom: 10px;
    font-size: 20px;
    color: #333;
}

.modal-content .post-date {
    margin-bottom: 15px;
}

.modal-content .post-category {
    display: inline-block;
    margin-bottom: 20px;
    margin-left: 0;
}

.post-content {
    line-height: 1.8;
    font-size: 14px;
    color: #333;
}

.post-content p {
    margin-bottom: 15px;
}

.post-content h1,
.post-content h2,
.post-content h3 {
    margin-top: 20px;
    margin-bottom: 10px;
    color: #333;
}

.post-content h1 {
    font-size: 24px;
}

.post-content h2 {
    font-size: 20px;
}

.post-content h3 {
    font-size: 18px;
}

.post-content a {
    color: #666;
    text-decoration: underline;
}

.post-content a:hover {
    color: #000;
}

.post-content strong {
    font-weight: bold;
}

.post-content em {
    font-style: italic;
}

.post-content img {
    max-width: 100%;
    max-height: 600px;
    width: auto;
    height: auto;
    display: block;
    margin: 20px auto;
    border-radius: 4px;
    object-fit: contain;
}

/* レスポンシブ対応 */
@media (max-width: 600px) {
    body {
        padding: 15px;
    }

    header h1 {
        font-size: 20px;
    }

    nav {
        flex-wrap: nowrap;
        gap: 20px;
    }

    .post-item {
        padding: 12px 0;
    }

    .modal-content {
        margin: 10% auto;
        padding: 20px;
        width: 95%;
    }
}