/* ============================================================
   NEBULA ARCHIVE · shelf.css
   首页：100vh 沉浸画布区 / HUD / 2D 回退网格 / 加载层 / tooltip
   ============================================================ */

/* ---------- hero 沉浸区 ---------- */
.hero {
  position: relative;
  height: 100vh;
  height: 100svh;
  min-height: 560px;
  overflow: hidden;
  isolation: isolate;
}

/* 3D 画布挂载点（DOM 契约：A 的 renderer canvas 铺满此处） */
#scene-container {
  position: absolute;
  inset: 0;
  z-index: 1;
}
#scene-container canvas {
  width: 100% !important;
  height: 100% !important;
  display: block;
  touch-action: none;
}

/* hero 文案：左上氛围层（书架是视觉主角，文案退居左侧窄栏），不拦截指针 */
.hero-copy {
  position: absolute;
  inset: 0;
  z-index: 3;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  justify-content: flex-start;
  padding: calc(var(--nav-h) + 6vh) 0 0 clamp(20px, 4.5vw, 64px);
  text-align: left;
  pointer-events: none;
  max-width: min(26vw, 360px);
}
.hero-copy .kicker {
  opacity: 0;
  animation: rise-in 0.9s var(--ease) 0.25s forwards;
}
.hero-title {
  margin-top: 0.6rem;
  font-size: clamp(2rem, 4.2vw, 3.4rem);
  font-weight: 900;
  letter-spacing: 0.12em;
  background: linear-gradient(100deg, var(--star) 20%, var(--cyan) 48%, var(--magenta) 76%, var(--amber) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  filter: drop-shadow(0 0 26px rgba(79, 216, 255, 0.25));
  opacity: 0;
  animation: rise-in 1s var(--ease) 0.45s forwards;
}
.hero-title-en {
  margin-top: 0.35rem;
  font-family: var(--font-mono);
  font-size: clamp(0.62rem, 1.1vw, 0.78rem);
  letter-spacing: 0.5em;
  color: var(--text-dim);
  opacity: 0;
  animation: rise-in 1s var(--ease) 0.65s forwards;
}
.hero-sub {
  margin-top: 1.1rem;
  max-width: 22em;
  color: var(--text-dim);
  font-size: clamp(0.8rem, 1.2vw, 0.92rem);
  opacity: 0;
  animation: rise-in 1s var(--ease) 0.85s forwards;
}
.hero-meta {
  margin-top: 1.4rem;
  padding-top: 0.9rem;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 0.66rem;
  letter-spacing: 0.28em;
  color: var(--text-faint);
  opacity: 0;
  animation: rise-in 1s var(--ease) 1.05s forwards;
}
@keyframes rise-in {
  from { opacity: 0; transform: translateY(18px); }
  to { opacity: 1; transform: translateY(0); }
}

/* 底部渐隐：轻收边，让画布融入页面但不吞掉底层书 */
.hero::after {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  height: 10vh;
  z-index: 2;
  pointer-events: none;
  background: linear-gradient(180deg, transparent, rgba(5, 7, 15, 0.42));
}

/* 下滑提示 */
.scroll-cue {
  position: absolute;
  left: 50%;
  bottom: 18px;
  z-index: 4;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  color: var(--text-faint);
  font-family: var(--font-mono);
  font-size: 0.62rem;
  letter-spacing: 0.4em;
  pointer-events: none;
  animation: cue-bob 2.6s ease-in-out infinite;
}
.scroll-cue::after {
  content: "";
  width: 1px;
  height: 26px;
  background: linear-gradient(180deg, var(--cyan), transparent);
}
@keyframes cue-bob {
  0%, 100% { transform: translate(-50%, 0); opacity: 0.85; }
  50% { transform: translate(-50%, 7px); opacity: 0.45; }
}

/* ---------- HUD（左下：藏書计数 + 操作提示） ---------- */
#hud {
  position: absolute;
  left: 18px;
  bottom: 18px;
  z-index: 5;
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 12px 16px;
  border: 1px solid var(--line);
  border-left: 2px solid var(--cyan);
  border-radius: var(--radius-sm);
  background: rgba(5, 7, 15, 0.62);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  color: var(--text-dim);
  pointer-events: none;
}
#hud .hud-count { color: var(--star); font-size: 0.82rem; }
#hud .hud-count b { color: var(--amber); font-weight: 400; font-size: 1.05rem; }
#hud .hud-hint { display: flex; flex-wrap: wrap; gap: 4px 14px; }
#hud .hud-hint span::before { content: "▸ "; color: var(--cyan); }
body[data-view="2d"] #hud .hud-3d-only { display: none; }

/* ---------- hover 书名浮层 ----------
   A 的 interaction.js 以 cursor+offset 定位 left/top（光标右下），
   因此这里不做 translate 偏移，仅负责视觉样式。 */
#book-tooltip {
  position: fixed;
  z-index: 90;
  max-width: 260px;
  padding: 8px 14px;
  border: 1px solid rgba(79, 216, 255, 0.5);
  border-radius: var(--radius-sm);
  background: rgba(8, 12, 26, 0.92);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.55), 0 0 18px rgba(79, 216, 255, 0.18);
  pointer-events: none;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--star);
}

/* ---------- 加载层（星空动画） ---------- */
#loading {
  position: absolute;
  inset: 0;
  z-index: 20;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1.4rem;
  background:
    radial-gradient(900px 500px at 50% 30%, rgba(79, 216, 255, 0.07), transparent 65%),
    var(--bg);
  transition: opacity 0.6s var(--ease);
}
#loading.is-done { opacity: 0; pointer-events: none; }

.loading-orbit {
  position: relative;
  width: 120px;
  height: 120px;
}
.loading-orbit .ring {
  position: absolute;
  inset: 0;
  border-radius: 50%;
  border: 1px solid transparent;
}
.loading-orbit .ring:nth-child(1) {
  border-top-color: var(--cyan);
  border-right-color: rgba(79, 216, 255, 0.25);
  animation: orbit-spin 1.6s linear infinite;
}
.loading-orbit .ring:nth-child(2) {
  inset: 16px;
  border-top-color: var(--magenta);
  border-left-color: rgba(255, 79, 154, 0.25);
  animation: orbit-spin 2.4s linear infinite reverse;
}
.loading-orbit .ring:nth-child(3) {
  inset: 34px;
  border-top-color: var(--amber);
  animation: orbit-spin 3.4s linear infinite;
}
.loading-orbit .core {
  position: absolute;
  inset: 48px;
  border-radius: 50%;
  background: radial-gradient(circle at 35% 35%, var(--star), var(--cyan) 60%, transparent 75%);
  box-shadow: 0 0 24px rgba(79, 216, 255, 0.8);
  animation: core-pulse 2s ease-in-out infinite;
}
/* 加载层内的小星野 */
.loading-stars {
  position: absolute;
  inset: 0;
  overflow: hidden;
  pointer-events: none;
}
.loading-stars i {
  position: absolute;
  width: 2px; height: 2px;
  border-radius: 50%;
  background: var(--star);
  opacity: 0;
  animation: twinkle 2.8s ease-in-out infinite;
}
.loading-stars i:nth-child(1) { left: 14%; top: 22%; animation-delay: 0s; }
.loading-stars i:nth-child(2) { left: 28%; top: 68%; animation-delay: 0.5s; background: var(--cyan); }
.loading-stars i:nth-child(3) { left: 44%; top: 14%; animation-delay: 1.1s; }
.loading-stars i:nth-child(4) { left: 63%; top: 76%; animation-delay: 0.3s; background: var(--amber); }
.loading-stars i:nth-child(5) { left: 78%; top: 28%; animation-delay: 1.6s; }
.loading-stars i:nth-child(6) { left: 88%; top: 60%; animation-delay: 0.9s; background: var(--magenta); }
.loading-stars i:nth-child(7) { left: 8%; top: 82%; animation-delay: 2s; }
.loading-stars i:nth-child(8) { left: 55%; top: 45%; animation-delay: 1.4s; }
@keyframes orbit-spin { to { transform: rotate(360deg); } }
@keyframes core-pulse {
  0%, 100% { transform: scale(1); opacity: 1; }
  50% { transform: scale(0.82); opacity: 0.7; }
}
@keyframes twinkle {
  0%, 100% { opacity: 0; transform: scale(0.6); }
  50% { opacity: 0.95; transform: scale(1.25); }
}
.loading-text {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.4em;
  text-indent: 0.4em;
  color: var(--text-dim);
}
.loading-text::after {
  content: "…";
  animation: dots 1.4s steps(4) infinite;
}
@keyframes dots { 0% { content: ""; } 25% { content: "."; } 50% { content: ".."; } 75% { content: "..."; } }
#loading .loading-error {
  max-width: 30em;
  padding: 0 1.4rem;
  text-align: center;
  color: var(--danger);
  font-size: 0.9rem;
}

/* ---------- 2D 回退网格（DOM 契约：默认 hidden，A 启用） ----------
   A 的 fallback.js 生成 .fb-grid / .fb-card / .fb-cover / .fb-meta /
   .fb-title / .fb-author / .fb-row / .fb-stars / .fb-status */
#fallback-grid {
  position: absolute;
  inset: 0;
  z-index: 2;
  overflow-y: auto;
  padding: calc(var(--nav-h) + 16vh) 1.4rem 90px;
  scrollbar-color: var(--wood-hi) transparent;
}
.fb-grid {
  width: min(1080px, 100%);
  margin-inline: auto;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 1.4rem;
}
.fb-card {
  position: relative;
  display: flex;
  flex-direction: column;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background: linear-gradient(165deg, var(--surface), var(--bg2));
  overflow: hidden;
  color: var(--text);
  transition: transform 0.25s var(--ease), border-color 0.25s var(--ease), box-shadow 0.25s var(--ease);
}
.fb-card:hover, .fb-card:focus-visible {
  transform: translateY(-6px);
  border-color: var(--cyan);
  box-shadow: 0 14px 34px rgba(0, 0, 0, 0.5), 0 0 22px rgba(79, 216, 255, 0.25);
}
.fb-cover {
  aspect-ratio: 2 / 3;
  width: 100%;
  height: auto;
  object-fit: cover;
  background: var(--surface-2);
}
.fb-meta { padding: 0.8rem 0.9rem 1rem; }
.fb-title {
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 1rem;
  color: var(--star);
}
.fb-author { margin-top: 2px; font-size: 0.78rem; color: var(--text-dim); }
.fb-row {
  margin-top: 0.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--text-faint);
}
.fb-stars { color: var(--amber); letter-spacing: 0.1em; }
.fb-status { color: var(--success); }

/* A 的数据错误面板（main.js showError） */
.scene-error {
  position: absolute;
  inset: 0;
  z-index: 6;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.8rem;
  padding: 2rem;
  text-align: center;
}
.scene-error p:first-child {
  font-family: var(--font-serif);
  font-size: 1.3rem;
  color: var(--danger);
}
.scene-error p { color: var(--text-dim); max-width: 34em; word-break: break-all; }
.scene-error button {
  margin-top: 0.6rem;
  padding: 0.6rem 1.6rem;
  border-radius: 999px;
  border: 1px solid var(--cyan);
  background: rgba(79, 216, 255, 0.12);
  color: var(--star);
  cursor: pointer;
  transition: background 0.2s var(--ease), box-shadow 0.2s var(--ease);
}
.scene-error button:hover { background: rgba(79, 216, 255, 0.24); box-shadow: 0 0 18px rgba(79, 216, 255, 0.3); }

/* ---------- 书架之下的「馆藏志」区 ---------- */
.archive-section { position: relative; padding: 4.5rem 0 1rem; }
.section-head { display: flex; align-items: baseline; gap: 1rem; flex-wrap: wrap; margin-bottom: 1.8rem; }
.section-head h2 { color: var(--star); }
.section-head .kicker { color: var(--amber); }
.archive-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.2rem;
}
.archive-cell {
  padding: 1.4rem 1.5rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(160deg, rgba(16, 26, 54, 0.6), rgba(10, 15, 30, 0.4));
}
.archive-cell h3 { color: var(--cyan); font-size: 1rem; margin-bottom: 0.5rem; }
.archive-cell:nth-child(2) h3 { color: var(--amber); }
.archive-cell:nth-child(3) h3 { color: var(--magenta); }
.archive-cell p { color: var(--text-dim); font-size: 0.9rem; }

/* ---------- 404 迷航页 ---------- */
.lost-actions {
  margin-top: 1.8rem;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.9rem;
  pointer-events: auto;
  opacity: 0;
  animation: rise-in 1s var(--ease) 1.05s forwards;
}
.hero .loading-stars { position: absolute; inset: 0; z-index: 1; }

/* ---------- 响应式 ---------- */
@media (max-width: 768px) {
  .hero-copy {
    max-width: 78vw;
    padding-top: calc(var(--nav-h) + 1.5vh);
  }
  .hero-title { font-size: 1.5rem; margin-top: 0.3rem; }
  .hero-title-en { display: none; }
  .hero-sub { display: none; }
  .hero-meta { display: none; }
  #hud { left: 12px; bottom: 12px; padding: 10px 12px; font-size: 0.66rem; }
  #hud .hud-hint { gap: 2px 10px; }
  .archive-grid { grid-template-columns: 1fr; }
  #fallback-grid { padding-top: calc(var(--nav-h) + 12vh); }
  .fb-grid { grid-template-columns: repeat(auto-fill, minmax(130px, 1fr)); gap: 1rem; }
}
@media (max-width: 390px) {
  .hero { min-height: 480px; }
  .hero-title { letter-spacing: 0.08em; }
  #hud .hud-hint span:nth-child(3) { display: none; }
  .fb-grid { grid-template-columns: repeat(2, 1fr); }
}