.page-main {
    max-width: 680px;
    width: 100%;
    padding: 120px 24px 200px;
}

.nav-back {
    position: fixed;
    top: 24px;
    left: 24px;
    text-decoration: none;
    color: var(--text-muted);
    font-size: 0.9rem;
    transition: color var(--transition-fast, 0.18s ease-out);
    z-index: 100;
    background: rgba(15, 23, 42, 0.8);
    padding: 8px 16px;
    border-radius: 999px;
    border: 1px solid var(--line-color, rgba(255, 255, 255, 0.1));
}

.nav-back:hover {
    color: #F8FAFC;
    border-color: var(--accent);
}

@media (max-width: 900px) {
    .nav-back {
        position: absolute;
    }
}

html,
body {
    margin: 0;
    padding: 0;
    background-color: var(--bg-base);
    color: var(--text-main);
    font-family: system-ui, -apple-system, sans-serif;
    line-height: 1.9;
    -webkit-font-smoothing: antialiased;
}

body {
    display: flex;
    justify-content: center;
}

h1,
h2,
h3 {
    font-family: "Hiragino Mincho ProN", "Yu Mincho", "游明朝", "MS Mincho", serif;
    font-weight: 600;
    color: #F8FAFC;
    letter-spacing: 0.05em;
}

h1 {
    font-size: 2.0rem;
    margin: 0 0 40px;
    line-height: 1.4;
}

h2 {
    font-size: 1.5rem;
    margin: 60px 0 24px;
    padding-bottom: 12px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

p {
    margin-bottom: 2em;
    text-align: justify;
}

ul {
    list-style: none;
    padding: 0;
    margin: 32px 0;
}

ul li {
    position: relative;
    padding-left: 1.5em;
    margin-bottom: 1em;
    color: #E2E8F0;
}

ul li::before {
    content: "—";
    position: absolute;
    left: 0;
    color: var(--text-muted);
}

p a,
li a {
    color: var(--accent);
    text-decoration: underline;
    text-underline-offset: 4px;
    transition: color var(--transition-fast, 0.18s ease-out);
}

p a:hover,
li a:hover {
    color: #C7D2FE;
}

blockquote {
    margin: 48px 0;
    padding: 0;
    text-align: center;
    font-size: 1.15rem;
    font-weight: 600;
    line-height: 1.6;
    color: #F3F4F6;
}

hr {
    border: none;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    margin: 60px 0;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin: 40px 0;
    font-size: 0.95rem;
}

th,
td {
    padding: 12px 16px;
    text-align: left;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

th {
    font-weight: 600;
    color: var(--text-muted);
    border-bottom: 1px solid rgba(255, 255, 255, 0.2);
}

td {
    vertical-align: top;
}

footer {
    margin-top: 120px;
    text-align: center;
    font-size: 0.85rem;
    color: var(--text-muted);
    opacity: 0.6;
}

@media (max-width: 600px) {
    h1 {
        font-size: 1.6rem;
    }
}