/* 子页（关于/联系/版权）通用样式 —— 极简深色阅读页
   —— 颜色全部接入 styles.css :root 主变量系统，子页可在此处覆盖语义层 */

body.sub-page {
    /* 子页语义色（如需微调子页观感，改这一处即可） */
    --sub-bg: var(--c-bg-near-black);
    --sub-text: color-mix(in srgb, var(--c-white) 85%, transparent);
    --sub-text-muted: color-mix(in srgb, var(--c-white) 78%, transparent);
    --sub-text-faint: color-mix(in srgb, var(--c-white) 40%, transparent);
    --sub-text-link: color-mix(in srgb, var(--c-white) 70%, transparent);
    --sub-border: color-mix(in srgb, var(--c-white) 6%, transparent);
    --sub-header-bg: color-mix(in srgb, var(--c-black) 40%, transparent);

    margin: 0;
    background: var(--sub-bg);
    color: var(--sub-text);
    font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.sub-header {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 18px 40px;
    border-bottom: 1px solid var(--sub-border);
    background: var(--sub-header-bg);
}

.sub-header-back {
    color: var(--sub-text-link);
    text-decoration: none;
    font-size: 14px;
    transition: color var(--duration-normal) ease;
}

.sub-header-back:hover {
    color: var(--c-white);
}

.sub-header-brand {
    font-size: 18px;
    font-weight: 700;
    letter-spacing: 2px;
    color: var(--c-white);
}

.sub-main {
    flex: 1;
    display: flex;
    justify-content: center;
    padding: 60px 24px;
}

.sub-article {
    max-width: 720px;
    width: 100%;
}

.sub-title {
    font-size: 32px;
    font-weight: 700;
    color: var(--c-white);
    margin: 0 0 32px;
    letter-spacing: 1px;
}

.sub-body {
    font-size: 16px;
    line-height: 1.9;
    color: var(--sub-text-muted);
}

.sub-body p {
    margin: 0 0 16px;
}

.sub-footer {
    text-align: center;
    padding: 18px 24px 24px;
    font-size: 12px;
    color: var(--sub-text-faint);
    border-top: 1px solid var(--sub-border);
}

.sub-footer-sep {
    margin: 0 8px;
    opacity: 0.4;
}

/* ============ 简化版顶部导航（子页面专用） ============ */
/* 导航绝对居中：不受 logo 宽度影响，始终在 header 视觉正中 */
.sub-header-nav {
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    display: flex;
    align-items: center;
    gap: 32px;
}

.sub-header-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    color: var(--c-white);
    font-size: 18px;
    font-weight: 700;
    letter-spacing: 2px;
    transition: opacity var(--duration-normal) ease;
}

.sub-header-logo:hover {
    opacity: 0.85;
}

.sub-header-logo-img {
    width: 32px;
    height: 32px;
    border-radius: var(--radius-sm);
}

.sub-header-nav-list {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    gap: 28px;
}

.sub-header-nav-link {
    color: var(--sub-text-link);
    text-decoration: none;
    font-size: 15px;
    transition: color var(--duration-normal) ease;
    padding: 4px 2px;
    border-bottom: 2px solid transparent;
}

.sub-header-nav-link:hover {
    color: var(--c-white);
}

/* 当前页高亮：金色文字 + 金色下划线 */
.sub-header-nav-link.is-current {
    color: var(--c-gold);
    border-bottom-color: var(--c-gold);
}

.sub-header-nav-link.is-current:hover {
    color: var(--c-gold-light);
}