body {
    font-family: "Helvetica Neue", Arial, sans-serif;
    background: linear-gradient(180deg, #f5f9ff 0%, #edf3fb 100%);
    margin: 0;
    padding: 0;
    color: #1f2937;
}

/* ヘッダー */
.hero {
    background: linear-gradient(135deg, #1d4ed8, #2563eb, #60a5fa);
    color: white;
    padding: 70px 20px;
    text-align: center;
    box-shadow: 0 4px 20px rgba(37, 99, 235, 0.25);
}

.small-hero {
    padding: 50px 20px;
}

.hero-content h1 {
    margin: 0;
    font-size: 3rem;
    font-weight: 700;
}

.hero-content p {
    margin-top: 12px;
    font-size: 1.1rem;
    opacity: 0.95;
}

/* 共通コンテンツ */
.container {
    max-width: 960px;
    margin: 40px auto;
    padding: 24px;
}

.section-title {
    font-size: 1.6rem;
    margin-bottom: 24px;
    color: #1e3a8a;
}

/* 一覧 */
.news-list {
    display: grid;
    gap: 20px;
}

.news-card {
    display: flex;
    align-items: flex-start;
    gap: 18px;
    background: #ffffff;
    border-radius: 20px;
    padding: 24px;
    box-shadow: 0 10px 28px rgba(0, 0, 0, 0.08);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.news-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 14px 32px rgba(0, 0, 0, 0.12);
}

.card-icon {
    font-size: 2rem;
    line-height: 1;
    background: #eff6ff;
    color: #2563eb;
    width: 56px;
    height: 56px;
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.card-content {
    flex: 1;
}

.news-date {
    display: inline-block;
    margin-bottom: 10px;
    font-size: 0.9rem;
    color: #4b5563;
    background: #eff6ff;
    padding: 6px 12px;
    border-radius: 999px;
}

.news-card a {
    text-decoration: none;
    color: #1d4ed8;
    font-weight: bold;
    font-size: 1.25rem;
}

.news-card a:hover {
    text-decoration: underline;
}

/* 詳細 */
.detail-card {
    display: block;
    padding: 32px;
}

.back-link {
    margin-top: 32px;
}

.back-link a {
    color: #1d4ed8;
    text-decoration: none;
    font-weight: bold;
}

.back-link a:hover {
    text-decoration: underline;
}

/* Markdown本文 */
.markdown-body {
    line-height: 1.8;
    font-size: 1rem;
    color: #374151;
}

.markdown-body h1,
.markdown-body h2,
.markdown-body h3 {
    color: #1e3a8a;
    margin-top: 1.5em;
    margin-bottom: 0.6em;
}

.markdown-body p {
    margin-bottom: 1em;
}

.markdown-body ul,
.markdown-body ol {
    padding-left: 1.5em;
    margin-bottom: 1em;
}

.markdown-body li {
    margin-bottom: 0.5em;
}

.markdown-body code {
    background: #eef2ff;
    padding: 2px 6px;
    border-radius: 6px;
    font-family: Consolas, monospace;
    font-size: 0.95em;
}

.markdown-body pre {
    background: #0f172a;
    color: #f8fafc;
    padding: 16px;
    border-radius: 12px;
    overflow-x: auto;
    margin-bottom: 1.2em;
}

.markdown-body pre code {
    background: transparent;
    padding: 0;
    color: inherit;
}

.markdown-body blockquote {
    border-left: 4px solid #60a5fa;
    margin: 1em 0;
    padding: 0.8em 1em;
    background: #f0f7ff;
    color: #334155;
    border-radius: 8px;
}

.markdown-body a {
    color: #2563eb;
}

.markdown-body hr {
    border: none;
    border-top: 1px solid #dbeafe;
    margin: 2em 0;
}