:root {
    --bg: #ffffff;
    --text: #1f2328;
    --muted: #6b7280;
    --accent: #e30425;
    --border: #e5e7eb;
}
@media (prefers-color-scheme: dark) {
    :root {
        --bg: #16181d;
        --text: #e6e7ea;
        --muted: #9aa1ab;
        --accent: #ff6b81;
        --border: #2c313a;
    }
}
* { box-sizing: border-box; }
body {
    margin: 0;
    padding: 48px 20px 80px;
    font-family: "Noto Sans JP", -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Sans", "Yu Gothic", sans-serif;
    line-height: 1.7;
    color: var(--text);
    background: var(--bg);
    -webkit-font-smoothing: antialiased;
}
h1, h2, .version, ul {
    max-width: 720px;
    margin-left: auto;
    margin-right: auto;
}
h1 {
    margin-top: 0;
    font-size: 1.6rem;
    font-weight: 700;
    line-height: 1.4;
    text-align: center;
}
h1::after {
    content: "";
    display: block;
    width: 48px;
    height: 3px;
    margin: 16px auto 0;
    border-radius: 2px;
    background: var(--accent);
}
h2 {
    margin-top: 12px;
    font-size: 0.8rem;
    font-weight: 500;
    text-align: center;
    color: var(--muted);
}
.version {
    margin-top: 2.5rem;
    margin-bottom: 0;
    padding-bottom: 0.5rem;
    font-size: 1.05rem;
    font-weight: 600;
    color: var(--text);
    border-bottom: 1px solid var(--border);
}
ul {
    margin-top: 0.7rem;
    margin-bottom: 0;
    padding: 0;
    list-style: none;
}
li {
    position: relative;
    padding-left: 1.3rem;
    color: var(--text);
}
li::before {
    content: "";
    position: absolute;
    left: 0.3rem;
    top: 0.75em;
    width: 5px;
    height: 5px;
    border-radius: 50%;
    background: var(--accent);
}
.date-format-note {
    max-width: 720px;
    margin: 4px auto 0;
    font-size: 0.8rem;
    text-align: center;
    color: var(--muted);
}