/* §7.4：直接展示用户提供的透明印章，以 SVG 视窗收拢外围留白，原图不重绘。 */
.author-signature {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex: 0 0 44px;
  width: 44px;
  height: 44px;
  margin-left: 12px;
  padding: 0;
  background: transparent;
}

.author-signature svg {
  display: block;
  width: 100%;
  height: 100%;
}

:root[data-theme="dark"] .signature-image { filter: brightness(1.35); }

.signature-trigger { border: 0; cursor: pointer; }
.signature-trigger:focus-visible::before {
  position: absolute;
  inset: 3px;
  content: "";
  border: 2px solid currentColor;
  pointer-events: none;
}

/* §2.1、§3.6：参照框架页的 440px 名片、56px 印章、40px 内边距与背景竖排寄语。
   姓名和联系方式为主，寄语与“匠”水印为次；保留原生 dialog 的键盘与焦点行为。
   参考的中文网络字体采用本机楷体/宋体回退，保持本地 HTML 离线可用。 */
.signature-preview {
  --card-ink: #8b4513;
  --card-seal: #b91c1c;
  --card-paper: #fdfcf8;
  --card-text: #27272a;
  --card-muted: #71717a;
  --card-line: rgba(139, 69, 19, 0.15);
  --card-dot: #e5e5e5;
  --card-icon-bg: rgba(139, 69, 19, 0.05);
  --card-serif: "ZCOOL XiaoWei", "Songti SC", "SimSun", serif;
  --card-brush: "Ma Shan Zheng", "KaiTi", "STKaiti", cursive;
  width: 440px;
  max-width: calc(100vw - 32px);
  max-height: calc(100dvh - 32px);
  padding: 0;
  overflow: auto;
  color: var(--card-text);
  background-color: var(--card-paper);
  background-image: radial-gradient(var(--card-dot) 0.8px, transparent 0.8px);
  background-size: 20px 20px;
  border: 1px solid var(--card-line);
  border-radius: 12px;
  box-shadow: 0 30px 60px rgba(0, 0, 0, 0.12), 0 8px 24px rgba(139, 69, 19, 0.08);
}
:root[data-theme="dark"] .signature-preview {
  --card-ink: #f17945;
  --card-seal: #f17945;
  --card-paper: var(--surface);
  --card-text: var(--text);
  --card-muted: var(--muted);
  --card-line: var(--line);
  --card-dot: var(--line);
  --card-icon-bg: var(--surface-raised);
}
.signature-preview::backdrop {
  background: rgba(0, 0, 0, 0.18);
  backdrop-filter: blur(2px);
}
:root[data-theme="dark"] .signature-preview::backdrop { background: rgba(0, 0, 0, 0.48); }
.signature-preview-close {
  position: absolute;
  z-index: 3;
  top: 0;
  right: 0;
  width: 44px;
  height: 44px;
  padding: 0;
  display: grid;
  place-items: center;
  color: var(--card-muted);
  background: transparent;
  border: 0;
  border-radius: 6px;
  cursor: pointer;
}
.signature-preview-close:hover { color: var(--card-ink); }
.signature-preview-close:focus-visible,
.signature-contact .signature-copy:focus-visible {
  outline: 2px solid var(--card-ink);
  outline-offset: -2px;
}
.signature-card-layout { position: relative; isolation: isolate; overflow: hidden; }
.signature-card-layout::before {
  position: absolute;
  right: -20px;
  bottom: -30px;
  z-index: -1;
  content: "匠";
  color: var(--card-seal);
  opacity: 0.03;
  font-family: var(--card-brush);
  font-size: 160px;
  line-height: 1;
  pointer-events: none;
}
.signature-card-main { position: relative; z-index: 1; min-width: 0; }
.signature-identity {
  position: relative;
  display: flex;
  align-items: center;
  gap: 20px;
  padding: 40px 40px 24px;
}
.signature-identity::after {
  position: absolute;
  right: 40px;
  bottom: 0;
  left: 40px;
  height: 1px;
  content: "";
  background: linear-gradient(90deg, transparent, var(--card-line), transparent);
}
.signature-preview-art.author-signature {
  flex: 0 0 56px;
  width: 56px;
  height: 56px;
  margin: 0;
  padding: 0;
  background: transparent;
}
.signature-identity h2 {
  margin: 0;
  font-family: var(--card-brush);
  font-size: 32px;
  font-weight: 400;
  letter-spacing: 2px;
  line-height: 1.1;
}
.signature-identity p {
  margin: 8px 0 0;
  color: var(--card-muted);
  font-family: var(--card-serif);
  font-size: 15px;
  letter-spacing: 0.15em;
  line-height: 1.6;
}
.signature-contacts {
  display: flex;
  flex-direction: column;
  gap: 24px;
  margin: 0;
  padding: 28px 40px;
  font-style: normal;
}
.signature-contact {
  display: flex;
  align-items: center;
  gap: 18px;
}
.signature-contact > div { min-width: 0; }
.signature-contact-icon {
  flex: 0 0 44px;
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
  color: var(--card-ink);
  background: var(--card-icon-bg);
  border: 1px solid var(--card-line);
  border-radius: 50%;
}
.signature-contact-label {
  display: block;
  margin-bottom: 4px;
  color: var(--card-muted);
  font-family: var(--card-serif);
  font-size: 13px;
  letter-spacing: 0.1em;
  line-height: 1.5;
}
.signature-contact .signature-copy {
  display: inline-block;
  padding: 0;
  background: transparent;
  border: 0;
  text-align: left;
  cursor: pointer;
  color: var(--card-text);
  font-family: var(--sans);
  font-size: 16px;
  font-weight: 500;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.05em;
  line-height: 1.5;
  text-decoration: none;
  text-underline-offset: 4px;
  overflow-wrap: anywhere;
  border-radius: 2px;
}
.signature-contact .signature-copy:hover { text-decoration: underline; }
.signature-motto {
  position: absolute;
  z-index: 0;
  top: 40px;
  right: 40px;
  display: flex;
  flex-direction: row-reverse;
  gap: 0;
  color: var(--card-muted);
  opacity: 0.4;
  font-family: var(--card-serif);
  font-size: 18px;
  line-height: 1.4;
  pointer-events: none;
}
.signature-motto p {
  margin: 0;
  writing-mode: vertical-rl;
  letter-spacing: 6px;
}
.signature-card-footer {
  position: relative;
  z-index: 1;
  padding: 16px 16px 24px;
  text-align: center;
  font-family: var(--card-serif);
}
.signature-card-footer p { margin: 0; }
.signature-card-quote {
  color: var(--card-ink);
  font-size: 14px;
  letter-spacing: 0.15em;
  line-height: 1.8;
  text-wrap: balance;
}
.signature-card-footer .signature-card-invite {
  margin-top: 6px;
  color: var(--card-muted);
  font-size: 12px;
  letter-spacing: 0.05em;
  line-height: 1.7;
}
.signature-motto-readable {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
}
@media (max-width: 480px) {
  .signature-identity { gap: 16px; padding: 40px 24px 24px; }
  .signature-identity::after { left: 24px; right: 24px; }
  .signature-identity p { font-size: 14px; letter-spacing: 0.05em; }
  .signature-contacts { padding: 28px 24px; }
  .signature-contact { gap: 16px; }
  .signature-contact .signature-copy { letter-spacing: 0; }
  .signature-motto { right: 16px; font-size: 14px; opacity: 0.12; }
  .signature-motto p { letter-spacing: 4px; }
  .signature-card-quote { letter-spacing: 0.05em; }
}
html.signature-preview-open { overflow: hidden; }

@media print {
  .signature-preview[open],
  .signature-preview::backdrop { display: none; }
  html.signature-preview-open { overflow: visible; }
}