/* 自建文章评论与留言板；内容作用域为 .zf，顶栏修复仅作用于 .guestbook-header。 */
/* 留言板顶部与其他页面保持一致，不显示导航底部阴影。 */
#page-header.guestbook-header:not(.nav-fixed) #nav {
  box-shadow: none;
}

/* 留言板没有大图横幅，但顶栏仍覆盖全页背景图片，使用白色文字保持可读。 */
#page-header.guestbook-header:not(.nav-fixed) #nav #site-name,
#page-header.guestbook-header:not(.nav-fixed) #nav #page-name,
#page-header.guestbook-header:not(.nav-fixed) #nav #nav-right a,
#page-header.guestbook-header:not(.nav-fixed) #nav #toggle-menu,
#page-header.guestbook-header:not(.nav-fixed) #nav #menus > .menus_items > .menus_item > .site-page {
  color: #fff;
  text-shadow: var(--menu-shadow, 0 0 1px var(--theme-color));
}
#page-header.guestbook-header:not(.nav-fixed) #nav #menus > .menus_items > .menus_item > .site-page .menu_word {
  text-shadow: var(--menu-shadow, 0 0 1px var(--theme-color)) !important;
}

.zf {
  --zf-ink: #263f49;
  --zf-muted: #72858d;
  --zf-line: rgba(40, 73, 86, .11);
  --zf-panel: rgba(255, 255, 255, .9);
  --zf-input: #f5f8f9;
  --zf-wash: #eef8f6;
  --zf-accent: var(--theme-color, #39c5bb);
  --zf-primary: #176961;
  --zf-primary: color-mix(in srgb, var(--zf-accent) 40%, #001218);
  --zf-shadow: 0 12px 32px -24px rgba(23, 62, 70, .25);
  color: var(--zf-ink);
  font-size: 14px;
  line-height: 1.7;
  text-align: left;
  isolation: isolate;
}
[data-theme="dark"] .zf {
  --zf-ink: #d9e8ec;
  --zf-muted: #9aafb6;
  --zf-line: rgba(206, 231, 239, .13);
  --zf-panel: rgba(23, 35, 42, .94);
  --zf-input: #1b2c34;
  --zf-wash: #203b3b;
  --zf-shadow: 0 12px 32px -24px rgba(0, 0, 0, .65);
}
.zf *, .zf *::before, .zf *::after { box-sizing: border-box; }
.zf [hidden] { display: none !important; }
.zf h1, .zf h2, .zf h3, .zf p { margin: 0; padding: 0; color: inherit; }
#post-comment.zf { margin-top: 36px; padding-top: 30px; border-top: 1px solid var(--zf-line); }
.zf-header { display: flex; align-items: center; justify-content: space-between; gap: 20px; margin-bottom: 24px; }
.zf-heading { min-width: 0; }
.zf-eyebrow { display: block; margin-bottom: 8px; color: var(--zf-muted); font-size: 11px; font-weight: 700; letter-spacing: .14em; }
.zf .zf-title { font-size: 27px; font-weight: 700; line-height: 1.35; letter-spacing: -.025em; }
.zf .zf-description { margin-top: 10px; color: var(--zf-muted); font-size: 14px; }
.zf-content { display: grid; gap: 24px; min-width: 0; }
.zf-panel { min-width: 0; border: 1px solid var(--zf-line); border-radius: 20px; background: var(--zf-panel); box-shadow: var(--zf-shadow); }
.zf-compose { padding: 24px; }
.zf-compose-heading { display: flex; align-items: center; gap: 10px; margin-bottom: 20px; }
.zf .zf-compose-heading h3, .zf .zf-list-heading h3 { font-size: 16px; font-weight: 700; }
.zf-compose-icon { display: grid; place-items: center; flex: 0 0 34px; width: 34px; height: 34px; border-radius: 10px; color: var(--zf-primary); background: var(--zf-wash); }
[data-theme="dark"] .zf-compose-icon { color: var(--zf-accent); }
.zf-fields { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; }
.zf-field { min-width: 0; }
.zf-field label { display: flex; align-items: center; gap: 8px; margin-bottom: 8px; font-size: 13px; font-weight: 600; }
.zf-field label small { color: var(--zf-muted); font-size: 11px; font-weight: 400; }
.zf-field input, .zf-field textarea {
  display: block; width: 100%; margin: 0; padding: 12px 14px;
  border: 1px solid transparent; border-radius: 11px; outline: none;
  background: var(--zf-input); color: var(--zf-ink); font: inherit; font-size: 15px;
  transition: border-color .18s ease, box-shadow .18s ease;
}
.zf-field input { height: 46px; }
.zf-field textarea { min-height: 150px; max-height: 440px; resize: vertical; line-height: 1.8; }
.zf-field input::placeholder, .zf-field textarea::placeholder { color: var(--zf-muted); opacity: .78; }
.zf-field input:focus, .zf-field textarea:focus { border-color: var(--zf-accent); box-shadow: 0 0 0 3px var(--zf-wash); }
.zf-field input:disabled, .zf-field textarea:disabled { opacity: .75; }
.zf .zf-field [aria-invalid="true"], .zf .zf-page-input[aria-invalid="true"] { border-color: #c46c50; box-shadow: 0 0 0 3px rgba(196, 108, 80, .12); }
.zf-field--content { margin-top: 18px; }
.zf-input-footer { display: flex; justify-content: space-between; gap: 12px; margin-top: 9px; color: var(--zf-muted); font-size: 11px; }
.zf-counter { flex-shrink: 0; font-variant-numeric: tabular-nums; }
.zf-counter.is-over-limit { color: #a34343; }
[data-theme="dark"] .zf-counter.is-over-limit { color: #f1aba8; }
.zf-form-footer { display: flex; align-items: center; justify-content: space-between; gap: 14px; margin-top: 20px; }
.zf-form-note { color: var(--zf-muted); font-size: 12px; }
.zf button { font-family: inherit; cursor: pointer; -webkit-tap-highlight-color: transparent; }
.zf .zf-button {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  min-height: 40px; padding: 10px 18px; border: 1px solid transparent; border-radius: 10px;
  font-size: 13px; font-weight: 600; line-height: 1.4; white-space: nowrap;
  transition: background .18s ease, border-color .18s ease, opacity .18s ease;
}
.zf .zf-button--primary { min-width: 112px; background: var(--zf-primary); color: #fff; }
.zf .zf-button--primary:not(:disabled):hover { filter: brightness(1.12); }
.zf .zf-button--soft { border-color: var(--zf-line); background: var(--zf-wash); color: var(--zf-ink); }
.zf .zf-button--soft:not(:disabled):hover { border-color: var(--zf-accent); }
.zf .zf-text-button { padding: 5px 0; border: 0; background: transparent; color: var(--zf-muted); font-size: 12px; line-height: 1.6; }
.zf .zf-text-button:not(:disabled):hover { color: var(--zf-primary); }
[data-theme="dark"] .zf .zf-text-button:not(:disabled):hover { color: var(--zf-accent); }
.zf button:focus-visible { outline: 2px solid var(--zf-accent); outline-offset: 3px; }
.zf button:disabled { cursor: default; opacity: .5; }
.zf .zf-form-status { margin-top: 14px; padding: 11px 13px; border-radius: 10px; background: var(--zf-wash); color: var(--zf-ink); font-size: 12px; overflow-wrap: anywhere; }
.zf .zf-own-preview { max-height: 140px; margin-top: 8px; overflow: auto; white-space: pre-wrap; }
.zf .zf-form-status[data-tone="error"] { color: #a34343; background: #fff1ef; }
[data-theme="dark"] .zf .zf-form-status[data-tone="error"] { color: #f1aba8; background: #3c2729; }
.zf-reply-context { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 18px; padding: 10px 12px; border-left: 3px solid var(--zf-accent); border-radius: 4px 10px 10px 4px; background: var(--zf-wash); font-size: 12px; }
.zf-reply-context > span { min-width: 0; overflow-wrap: anywhere; }
.zf-reply-context button { flex-shrink: 0; }
.zf-discussion { padding: 24px; scroll-margin-top: 88px; }
.zf-list-toolbar { display: flex; align-items: center; justify-content: space-between; gap: 16px; padding-bottom: 18px; border-bottom: 1px solid var(--zf-line); }
.zf-list-heading { display: flex; align-items: center; gap: 10px; min-width: 0; }
.zf-count { padding: 2px 8px; border-radius: 6px; background: var(--zf-input); color: var(--zf-muted); font-size: 11px; font-variant-numeric: tabular-nums; }
.zf-thread, .zf-message { padding: 22px 0; border-bottom: 1px solid var(--zf-line); }
.zf-thread:last-child, .zf-message:last-child { border-bottom: 0; }
.zf-item { display: grid; grid-template-columns: minmax(0, 1fr); gap: 0; min-width: 0; }
.zf-item-body { min-width: 0; }
.zf-meta { display: flex; align-items: baseline; flex-wrap: wrap; gap: 5px 10px; min-width: 0; line-height: 1.5; }
.zf-nickname { max-width: 100%; font-size: 14px; font-weight: 650; overflow-wrap: anywhere; }
.zf-time { color: var(--zf-muted); font-size: 11px; font-variant-numeric: tabular-nums; }
.zf-own { padding: 1px 6px; border-radius: 5px; background: var(--zf-wash); color: var(--zf-primary); font-size: 10px; }
[data-theme="dark"] .zf-own { color: var(--zf-accent); }
.zf .zf-item-content { margin-top: 8px; font-size: 14px; line-height: 1.85; white-space: pre-wrap; overflow-wrap: anywhere; }
.zf-item-footer { display: flex; justify-content: flex-end; margin-top: 7px; }
.zf-replies { margin: 15px 0 0 16px; padding: 4px 14px 0; border-left: 2px solid var(--zf-line); border-radius: 0 12px 12px 0; background: var(--zf-input); }
.zf-replies .zf-item { padding: 13px 0; border-bottom: 1px solid var(--zf-line); }
.zf-replies .zf-item:last-of-type { border-bottom: 0; }
.zf-replies .zf-nickname { font-size: 12px; }
.zf-replies .zf-item-content { font-size: 13px; }
.zf-reply-to { color: var(--zf-muted); font-size: 11px; overflow-wrap: anywhere; }
.zf-reply-more { padding: 6px 0 13px; }
.zf-inline-error { padding: 6px 0 12px; color: var(--zf-muted); font-size: 12px; }
.zf-list-status { padding: 30px 10px; text-align: center; }
.zf .zf-state-title { font-size: 15px; font-weight: 600; }
.zf .zf-state-description { max-width: 360px; margin: 8px auto 18px; color: var(--zf-muted); font-size: 12px; overflow-wrap: anywhere; }
.zf-empty-mark { display: grid; place-items: center; width: 52px; height: 52px; margin: 0 auto 14px; border: 1px dashed var(--zf-line); border-radius: 16px; background: var(--zf-input); color: var(--zf-muted); font-size: 24px; }
.zf-skeleton { display: grid; gap: 9px; max-width: 220px; margin: 0 auto 20px; }
.zf-skeleton span { height: 8px; border-radius: 8px; background: var(--zf-line); animation: zf-pulse 1.4s ease-in-out infinite; }
.zf-skeleton span:nth-child(2) { width: 75%; animation-delay: .15s; }
.zf-skeleton span:nth-child(3) { width: 45%; animation-delay: .3s; }
.zf-pagination { display: flex; align-items: center; justify-content: center; flex-wrap: wrap; gap: 6px; padding-top: 22px; border-top: 1px solid var(--zf-line); }
.zf-pagination .zf-button { min-width: 34px; min-height: 34px; padding: 7px 10px; font-size: 12px; background: var(--zf-input); color: var(--zf-ink); }
.zf-pagination .zf-button[aria-current="page"] { background: var(--zf-primary); color: #fff; opacity: 1; }
.zf-page-gap { padding: 0 5px; color: var(--zf-muted); }
.zf-page-jump, .zf-page-jump-label { display: inline-flex; align-items: center; gap: 6px; }
.zf-page-jump { margin: 0 0 0 8px; color: var(--zf-muted); font-size: 12px; }
.zf-page-input { width: 76px; min-width: 0; height: 34px; margin: 0; padding: 4px 6px; border: 1px solid var(--zf-line); border-radius: 8px; background: var(--zf-input); color: var(--zf-ink); font: inherit; font-variant-numeric: tabular-nums; text-align: center; }
.zf-page-input:focus { outline: 2px solid var(--zf-accent); outline-offset: 2px; }
.zf-page-input:disabled { opacity: .5; }
.zf-page-summary { flex-basis: 100%; margin-top: 5px; color: var(--zf-muted); text-align: center; font-size: 11px; }
.zf .zf-noscript { margin-top: 20px; color: var(--zf-muted); }
.zf-sr-only { position: absolute; width: 1px; height: 1px; padding: 0; overflow: hidden; clip-path: inset(50%); white-space: nowrap; }
.zf--messages .zf-content { grid-template-columns: minmax(0, 1fr); align-items: start; }
.zf--messages .zf-compose { position: static; }
.zf--messages .zf-fields { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.zf--messages .zf-form-footer { align-items: center; flex-direction: row; }
.zf--messages .zf-button--primary { width: auto; }
.zf--messages .zf-field textarea { min-height: 180px; }
@keyframes zf-pulse { 0%, 100% { opacity: .4; } 50% { opacity: 1; } }
@media (max-width: 600px) {
  #post-comment.zf { margin-top: 26px; padding-top: 24px; }
  .zf-header { align-items: flex-start; gap: 12px; }
  .zf .zf-title { font-size: 24px; }
  .zf .zf-description { font-size: 13px; }
  .zf-header > .zf-button { padding: 8px 12px; min-height: 36px; }
  .zf-compose, .zf-discussion { padding: 18px 15px; border-radius: 16px; }
  .zf-content { gap: 18px; }
  .zf-fields, .zf--messages .zf-fields { grid-template-columns: minmax(0, 1fr); gap: 14px; }
  .zf-field input, .zf-field textarea { font-size: 16px; }
  .zf-page-jump { flex-basis: 100%; justify-content: center; margin: 8px 0 0; }
  .zf-page-input { font-size: 16px; }
  .zf-form-footer, .zf--messages .zf-form-footer { flex-direction: column; align-items: stretch; gap: 12px; }
  .zf .zf-button--primary, .zf--messages .zf-button--primary { width: 100%; min-height: 44px; }
  .zf-form-note { font-size: 11px; }
  .zf-replies { margin-left: 14px; padding-right: 10px; padding-left: 10px; }
  .zf-meta { gap: 4px 8px; }
  .zf-nickname { font-size: 13px; }
  .zf .zf-item-content { font-size: 13px; }
}
@media (prefers-reduced-motion: reduce) {
  .zf *, .zf *::before, .zf *::after { animation: none !important; transition: none !important; }
}