/* ================================================================
   丝路长夜 · STORY SPINE
   主线叙事脊柱 · Narrative Backbone System

   一部游戏，一条脊柱，三十颗星辰连成史诗。
   This module transforms thirty scattered stories into a single
   cinematic journey — the spine of all things.

   Design Philosophy:
   · Cinema Noir meets Tang Dynasty scroll aesthetics
   · Every pixel breathes — nothing is static
   · The user is a traveler, not a reader
   · Darkness is sacred; light is earned
   ================================================================ */

/* ----------------------------------------------------------------
   SPINE ENTRY BUTTON — 浮于地球之上的主线入口
   ---------------------------------------------------------------- */
.spine-entry {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: 15;
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.8s var(--ease-out);
}
.spine-entry.visible {
  opacity: 1;
  pointer-events: auto;
}

/* ----------------------------------------------------------------
   SPINE TRIGGER — 左下角固定触发器
   The threshold between wandering and journeying
   ---------------------------------------------------------------- */
.spine-trigger {
  position: fixed;
  left: 36px;
  bottom: 40px;
  z-index: 15;
  display: flex;
  align-items: center;
  gap: 12px;
  cursor: pointer;
  border: none;
  background: none;
  padding: 0;
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 0.9s var(--ease-out), transform 0.9s var(--ease-out);
}
.spine-trigger.visible {
  opacity: 1;
  transform: translateY(0);
}
.spine-trigger__icon {
  width: 42px;
  height: 42px;
  border: 1px solid var(--amber);
  border-radius: 50%;
  display: grid;
  place-items: center;
  position: relative;
  transition: all 0.4s var(--ease-out);
  flex-shrink: 0;
}
.spine-trigger__icon::before {
  content: "";
  position: absolute;
  inset: 6px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(232,201,122,0.3), transparent 70%);
}
.spine-trigger__icon::after {
  content: "";
  position: absolute;
  inset: -6px;
  border: 1px solid var(--amber);
  border-radius: 50%;
  opacity: 0;
  animation: spine-pulse 3s ease-in-out infinite;
}
@keyframes spine-pulse {
  0%, 100% { transform: scale(0.8); opacity: 0; }
  50%       { transform: scale(1.2); opacity: 0.4; }
}
/* Inner camel-route SVG icon */
.spine-trigger__icon svg {
  width: 18px;
  height: 18px;
  fill: none;
  stroke: var(--amber);
  stroke-width: 1.2;
  stroke-linecap: round;
}
.spine-trigger__label {
  display: flex;
  flex-direction: column;
  gap: 2px;
  text-align: left;
}
.spine-trigger__cn {
  font-family: var(--serif);
  font-size: 14px;
  letter-spacing: 0.1em;
  color: var(--ivory);
  line-height: 1;
}
.spine-trigger__en {
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.4em;
  text-transform: uppercase;
  color: var(--muted);
}
.spine-trigger:hover .spine-trigger__icon {
  background: rgba(232,201,122,0.08);
  box-shadow: 0 0 32px rgba(232,201,122,0.25);
}
.spine-trigger:hover .spine-trigger__cn {
  color: var(--amber);
}

/* ----------------------------------------------------------------
   SPINE OVERLAY — 全屏叙事层
   The universe unfolds
   ---------------------------------------------------------------- */
.spine-overlay {
  position: fixed;
  inset: 0;
  z-index: 500;
  background: #050608;
  opacity: 0;
  pointer-events: none;
  transition: opacity 1.2s var(--ease-out);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}
.spine-overlay.open {
  opacity: 1;
  pointer-events: auto;
}

/* Background canvas for particles */
.spine-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}

/* Ambient top gradient — ember horizon */
.spine-overlay::before {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 40%;
  background: linear-gradient(180deg,
    rgba(196,122,58,0.04) 0%,
    transparent 100%
  );
  pointer-events: none;
  z-index: 1;
}
/* Ambient bottom gradient */
.spine-overlay::after {
  content: "";
  position: absolute;
  bottom: 0; left: 0; right: 0;
  height: 30%;
  background: linear-gradient(0deg,
    rgba(10,13,24,0.9) 0%,
    transparent 100%
  );
  pointer-events: none;
  z-index: 1;
}

/* ----------------------------------------------------------------
   SPINE HEADER — 顶部导航栏
   ---------------------------------------------------------------- */
.spine-header {
  position: relative;
  z-index: 10;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 28px 40px;
  border-bottom: 1px solid rgba(232,201,122,0.08);
  flex-shrink: 0;
}
.spine-header__brand {
  display: flex;
  align-items: center;
  gap: 14px;
}
.spine-header__logo {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--amber);
  box-shadow: 0 0 12px rgba(232,201,122,0.6);
}
.spine-header__title {
  font-family: var(--serif);
  font-size: 16px;
  letter-spacing: 0.16em;
  color: var(--ivory);
}
.spine-header__sub {
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.4em;
  text-transform: uppercase;
  color: var(--muted);
  margin-top: 2px;
}
.spine-header__nav {
  display: flex;
  align-items: center;
  gap: 24px;
}
.spine-header__progress {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.22em;
  color: var(--muted);
}
.spine-header__progress em {
  color: var(--amber);
  font-style: normal;
}
.spine-close {
  width: 36px;
  height: 36px;
  border: 1px solid var(--line);
  background: none;
  color: var(--ivory-dim);
  cursor: pointer;
  display: grid;
  place-items: center;
  transition: all 0.3s var(--ease);
  border-radius: 50%;
  flex-shrink: 0;
}
.spine-close:hover {
  border-color: var(--amber);
  color: var(--amber);
  transform: rotate(90deg);
}
.spine-close svg {
  width: 14px;
  height: 14px;
  stroke: currentColor;
  stroke-width: 1.5;
  fill: none;
}

/* ----------------------------------------------------------------
   SPINE LAYOUT — 双栏结构: 时间轴 + 章节内容
   ---------------------------------------------------------------- */
.spine-body {
  position: relative;
  z-index: 5;
  flex: 1;
  display: grid;
  grid-template-columns: 280px 1fr;
  min-height: 0;
}

/* ----------------------------------------------------------------
   TIMELINE RAIL — 左侧时间轴
   The silk road as a vertical river of time
   ---------------------------------------------------------------- */
.spine-timeline {
  border-right: 1px solid rgba(232,201,122,0.08);
  display: flex;
  flex-direction: column;
  overflow-y: auto;
  scrollbar-width: thin;
  scrollbar-color: rgba(232,201,122,0.2) transparent;
  padding: 32px 0;
  position: relative;
}
.spine-timeline::-webkit-scrollbar { width: 2px; }
.spine-timeline::-webkit-scrollbar-thumb { background: rgba(232,201,122,0.25); }

/* Vertical amber thread running through timeline */
.spine-timeline::before {
  content: "";
  position: absolute;
  left: 40px;
  top: 48px;
  bottom: 48px;
  width: 1px;
  background: linear-gradient(180deg,
    transparent 0%,
    rgba(232,201,122,0.3) 8%,
    rgba(232,201,122,0.3) 92%,
    transparent 100%
  );
  pointer-events: none;
}

.spine-segment {
  padding: 0 28px 0 0;
  margin-bottom: 8px;
}
.spine-segment__label {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 8px 12px 8px 56px;
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.4em;
  text-transform: uppercase;
  color: var(--muted);
  position: relative;
}
.spine-segment__label::before {
  content: "";
  position: absolute;
  left: 36px;
  width: 9px;
  height: 1px;
  background: var(--amber);
  opacity: 0.4;
}

/* Individual chapter node */
.spine-node {
  position: relative;
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 10px 12px 10px 54px;
  cursor: pointer;
  transition: background 0.3s var(--ease);
  border-radius: 0;
}
.spine-node:hover {
  background: rgba(232,201,122,0.04);
}
.spine-node.active {
  background: rgba(232,201,122,0.06);
}
.spine-node.active .spine-node__dot {
  background: var(--amber);
  box-shadow: 0 0 8px rgba(232,201,122,0.5);
}

/* The amber dot on the timeline */
.spine-node__dot {
  position: absolute;
  left: 37px;
  top: 16px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  border: 1px solid var(--amber);
  background: transparent;
  flex-shrink: 0;
  transition: all 0.3s var(--ease);
}
.spine-node.read .spine-node__dot {
  background: var(--amber);
  opacity: 0.6;
}

.spine-node__content {
  flex: 1;
  min-width: 0;
}
.spine-node__num {
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.3em;
  color: var(--muted);
  margin-bottom: 3px;
}
.spine-node__cn {
  font-family: var(--serif);
  font-size: 15px;
  letter-spacing: 0.04em;
  color: var(--ivory-dim);
  line-height: 1.3;
  transition: color 0.3s var(--ease);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.spine-node:hover .spine-node__cn,
.spine-node.active .spine-node__cn {
  color: var(--ivory);
}
.spine-node__meta {
  font-family: var(--mono);
  font-size: 8.5px;
  letter-spacing: 0.18em;
  color: var(--muted);
  margin-top: 3px;
  opacity: 0.7;
}

/* ----------------------------------------------------------------
   CHAPTER STAGE — 右侧章节主舞台
   Where stories become cinema
   ---------------------------------------------------------------- */
.spine-stage {
  display: flex;
  flex-direction: column;
  overflow: hidden;
  position: relative;
}

/* Chapter hero — full bleed visual zone */
.spine-hero {
  position: relative;
  height: 45vh;
  min-height: 280px;
  flex-shrink: 0;
  overflow: hidden;
  background: #0a0d18;
}

/* Hero background layer — animated gradient / media placeholder */
.spine-hero__bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse at 30% 60%, rgba(196,122,58,0.12) 0%, transparent 55%),
    radial-gradient(ellipse at 70% 30%, rgba(232,201,122,0.06) 0%, transparent 45%),
    linear-gradient(180deg, #0e1322 0%, #07090f 100%);
  transition: opacity 0.8s var(--ease-out);
}
/* Hero media (image / video) overlay */
.spine-hero__media {
  position: absolute;
  inset: 0;
  object-fit: cover;
  opacity: 0;
  transition: opacity 1.4s var(--ease-out);
}
.spine-hero__media.loaded {
  opacity: 0.38;
}

/* Cinematic noise grain texture */
.spine-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.75' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.04'/%3E%3C/svg%3E");
  background-size: 200px 200px;
  pointer-events: none;
  opacity: 0.6;
  mix-blend-mode: overlay;
}

/* Hero content overlay */
.spine-hero__overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg,
    transparent 0%,
    transparent 40%,
    rgba(5,6,8,0.6) 75%,
    rgba(5,6,8,0.9) 100%
  );
}

/* Hero text — anchored to bottom */
.spine-hero__text {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  padding: 0 48px 40px;
}

/* Chapter number & region badge */
.spine-hero__badge {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 16px;
}
.spine-hero__num {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.4em;
  color: var(--amber);
  text-transform: uppercase;
}
.spine-hero__region {
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: var(--muted);
  border: 1px solid rgba(232,201,122,0.2);
  padding: 3px 10px;
}
.spine-hero__rarity {
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.3em;
  color: var(--amber);
  border: 1px solid var(--amber);
  padding: 3px 8px;
}

/* Main chapter title */
.spine-hero__cn {
  font-family: var(--serif);
  font-size: clamp(36px, 4vw, 60px);
  font-weight: 500;
  letter-spacing: 0.06em;
  line-height: 1.1;
  color: var(--ivory);
  text-shadow: 0 4px 40px rgba(0,0,0,0.7), 0 0 80px rgba(232,201,122,0.08);
  margin-bottom: 8px;
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 0.8s var(--ease-out), transform 0.8s var(--ease-out);
}
.spine-hero__en {
  font-family: var(--serif);
  font-size: clamp(14px, 1.4vw, 18px);
  font-style: italic;
  letter-spacing: 0.08em;
  color: var(--ivory-dim);
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 0.8s var(--ease-out) 0.1s, transform 0.8s var(--ease-out) 0.1s;
}
.spine-stage.loaded .spine-hero__cn,
.spine-stage.loaded .spine-hero__en {
  opacity: 1;
  transform: none;
}

/* Hero decorative element — glowing horizontal line */
.spine-hero__rule {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg,
    transparent 0%,
    rgba(232,201,122,0.25) 30%,
    rgba(232,201,122,0.5) 50%,
    rgba(232,201,122,0.25) 70%,
    transparent 100%
  );
}

/* ----------------------------------------------------------------
   CHAPTER CONTENT — 章节内容区域
   ---------------------------------------------------------------- */
.spine-content {
  flex: 1;
  overflow-y: auto;
  scrollbar-width: thin;
  scrollbar-color: rgba(232,201,122,0.15) transparent;
  padding: 48px;
}
.spine-content::-webkit-scrollbar { width: 3px; }
.spine-content::-webkit-scrollbar-thumb { background: rgba(232,201,122,0.2); }

/* Chapter intro text */
.spine-excerpt {
  font-family: var(--serif);
  font-size: clamp(18px, 1.6vw, 22px);
  line-height: 1.85;
  color: var(--ivory);
  font-style: italic;
  letter-spacing: 0.02em;
  margin-bottom: 40px;
  border-left: 2px solid var(--amber);
  padding-left: 24px;
  opacity: 0;
  transform: translateX(-8px);
  transition: opacity 0.9s var(--ease-out) 0.15s, transform 0.9s var(--ease-out) 0.15s;
}
.spine-stage.loaded .spine-excerpt {
  opacity: 1;
  transform: none;
}

/* Full story body */
.spine-body-text {
  font-family: var(--serif);
  font-size: clamp(16px, 1.4vw, 19px);
  line-height: 1.9;
  color: var(--ivory-dim);
  letter-spacing: 0.02em;
  text-wrap: pretty;
  margin-bottom: 48px;
  opacity: 0;
  transition: opacity 0.9s var(--ease-out) 0.3s;
}
.spine-stage.loaded .spine-body-text {
  opacity: 1;
}
.spine-body-text p {
  margin-bottom: 20px;
}
.spine-body-text p:last-child {
  color: var(--amber);
  font-style: italic;
  border-top: 1px solid rgba(232,201,122,0.15);
  padding-top: 24px;
  margin-top: 32px;
}

/* ----------------------------------------------------------------
   MEDIA GALLERY — 图片/视频媒体墙
   Visual storytelling through curated imagery
   ---------------------------------------------------------------- */
.spine-media-section {
  margin-bottom: 48px;
  opacity: 0;
  transition: opacity 0.9s var(--ease-out) 0.45s;
}
.spine-stage.loaded .spine-media-section {
  opacity: 1;
}
.spine-media-label {
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.4em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  gap: 12px;
}
.spine-media-label::after {
  content: "";
  flex: 1;
  height: 1px;
  background: rgba(232,201,122,0.1);
}

/* Media grid — asymmetric cinematic layout */
.spine-media-grid {
  display: grid;
  grid-template-columns: 1.618fr 1fr;
  grid-template-rows: auto auto;
  gap: 4px;
}
.spine-media-item {
  position: relative;
  overflow: hidden;
  background: #0e1322;
  cursor: pointer;
}
.spine-media-item:first-child {
  grid-row: 1 / 3;
}
.spine-media-item img,
.spine-media-item video {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: transform 0.6s var(--ease-out), opacity 0.4s var(--ease);
  min-height: 140px;
}
.spine-media-item:hover img,
.spine-media-item:hover video {
  transform: scale(1.04);
}
.spine-media-item::after {
  content: "";
  position: absolute;
  inset: 0;
  background: rgba(5,6,8,0.2);
  transition: background 0.3s var(--ease);
  pointer-events: none;
}
.spine-media-item:hover::after {
  background: rgba(5,6,8,0.05);
}
/* Placeholder shimmer */
.spine-media-placeholder {
  width: 100%;
  min-height: 180px;
  background: linear-gradient(
    110deg,
    rgba(19,24,42,0.8) 8%,
    rgba(26,32,64,0.6) 18%,
    rgba(19,24,42,0.8) 33%
  );
  background-size: 200% 100%;
  animation: spine-shimmer 1.8s linear infinite;
  display: flex;
  align-items: center;
  justify-content: center;
}
@keyframes spine-shimmer {
  0%   { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}
.spine-media-placeholder__icon {
  width: 32px;
  height: 32px;
  border: 1px solid rgba(232,201,122,0.15);
  border-radius: 50%;
  display: grid;
  place-items: center;
}
.spine-media-placeholder__icon svg {
  width: 14px;
  height: 14px;
  stroke: rgba(232,201,122,0.3);
  fill: none;
  stroke-width: 1;
}

/* ----------------------------------------------------------------
   GEO COORDINATES — 地理坐标信息条
   ---------------------------------------------------------------- */
.spine-geo {
  display: flex;
  gap: 32px;
  flex-wrap: wrap;
  padding: 24px 0;
  border-top: 1px solid rgba(232,201,122,0.08);
  border-bottom: 1px solid rgba(232,201,122,0.08);
  margin-bottom: 40px;
  opacity: 0;
  transition: opacity 0.9s var(--ease-out) 0.5s;
}
.spine-stage.loaded .spine-geo {
  opacity: 1;
}
.spine-geo__field {
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.spine-geo__k {
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.35em;
  text-transform: uppercase;
  color: var(--muted);
}
.spine-geo__v {
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.12em;
  color: var(--ivory);
}

/* ----------------------------------------------------------------
   CHAPTER ACTIONS — 章节底部操作区
   ---------------------------------------------------------------- */
.spine-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  padding-top: 8px;
  opacity: 0;
  transition: opacity 0.9s var(--ease-out) 0.6s;
}
.spine-stage.loaded .spine-actions {
  opacity: 1;
}
.spine-actions__left {
  display: flex;
  gap: 12px;
}
.spine-btn {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  padding: 12px 22px;
  cursor: pointer;
  border: 1px solid var(--line);
  background: none;
  color: var(--ivory-dim);
  transition: all 0.35s var(--ease);
  white-space: nowrap;
}
.spine-btn:hover {
  color: var(--amber);
  border-color: var(--amber);
  background: rgba(232,201,122,0.04);
}
.spine-btn--primary {
  background: var(--amber);
  color: var(--bg-0);
  border-color: var(--amber);
}
.spine-btn--primary:hover {
  background: var(--ivory);
  border-color: var(--ivory);
}
.spine-btn--primary.done {
  background: rgba(232,201,122,0.15);
  color: var(--amber);
  border-color: rgba(232,201,122,0.3);
}
.spine-btn--globe {
  display: flex;
  align-items: center;
  gap: 8px;
}
.spine-btn--globe svg {
  width: 12px;
  height: 12px;
  stroke: currentColor;
  fill: none;
  stroke-width: 1.5;
}

/* Prev / next chapter navigation */
.spine-nav {
  display: flex;
  gap: 8px;
}
.spine-nav-btn {
  width: 36px;
  height: 36px;
  border: 1px solid var(--line);
  background: none;
  color: var(--ivory-dim);
  cursor: pointer;
  display: grid;
  place-items: center;
  transition: all 0.3s var(--ease);
}
.spine-nav-btn:hover {
  border-color: var(--amber);
  color: var(--amber);
}
.spine-nav-btn:disabled {
  opacity: 0.2;
  cursor: not-allowed;
}
.spine-nav-btn svg {
  width: 14px;
  height: 14px;
  stroke: currentColor;
  fill: none;
  stroke-width: 1.5;
}

/* ----------------------------------------------------------------
   JOURNEY PROGRESS BAR — 旅程进度条
   At the very bottom, the road ahead
   ---------------------------------------------------------------- */
.spine-progress-bar {
  position: relative;
  z-index: 10;
  height: 3px;
  background: rgba(232,201,122,0.08);
  flex-shrink: 0;
}
.spine-progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--ember), var(--amber));
  transition: width 0.8s var(--ease-out);
  position: relative;
}
.spine-progress-fill::after {
  content: "";
  position: absolute;
  right: 0;
  top: 50%;
  width: 8px;
  height: 8px;
  background: var(--amber);
  border-radius: 50%;
  transform: translate(50%, -50%);
  box-shadow: 0 0 8px rgba(232,201,122,0.6);
}

/* ----------------------------------------------------------------
   CHAPTER TRANSITION — 章节切换动画
   ---------------------------------------------------------------- */
.spine-stage {
  transition: none;
}
.spine-stage.transitioning .spine-hero__cn,
.spine-stage.transitioning .spine-hero__en,
.spine-stage.transitioning .spine-excerpt,
.spine-stage.transitioning .spine-body-text,
.spine-stage.transitioning .spine-media-section,
.spine-stage.transitioning .spine-geo,
.spine-stage.transitioning .spine-actions {
  opacity: 0;
  transform: translateY(6px);
  transition: opacity 0.25s var(--ease), transform 0.25s var(--ease);
}

/* ----------------------------------------------------------------
   FULLSCREEN MEDIA LIGHTBOX — 全屏媒体灯箱
   ---------------------------------------------------------------- */
.spine-lightbox {
  position: fixed;
  inset: 0;
  z-index: 600;
  background: rgba(5,6,8,0.95);
  display: grid;
  place-items: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.5s var(--ease-out);
  cursor: zoom-out;
}
.spine-lightbox.open {
  opacity: 1;
  pointer-events: auto;
}
.spine-lightbox img,
.spine-lightbox video {
  max-width: 90vw;
  max-height: 88vh;
  object-fit: contain;
  border: 1px solid rgba(232,201,122,0.15);
}
.spine-lightbox__close {
  position: absolute;
  top: 28px;
  right: 32px;
  width: 40px;
  height: 40px;
  border: 1px solid rgba(232,201,122,0.2);
  background: none;
  color: var(--ivory-dim);
  cursor: pointer;
  display: grid;
  place-items: center;
  border-radius: 50%;
  transition: all 0.3s var(--ease);
}
.spine-lightbox__close:hover {
  border-color: var(--amber);
  color: var(--amber);
}
.spine-lightbox__close svg {
  width: 16px;
  height: 16px;
  stroke: currentColor;
  fill: none;
  stroke-width: 1.5;
}
.spine-lightbox__caption {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  font-family: var(--serif);
  font-style: italic;
  font-size: 15px;
  letter-spacing: 0.06em;
  color: var(--ivory-dim);
  text-align: center;
  white-space: nowrap;
}

/* ----------------------------------------------------------------
   ROUTE MAP MINI — 内嵌路线微型地图
   The journey so far, visualized
   ---------------------------------------------------------------- */
.spine-route-section {
  margin-bottom: 48px;
  opacity: 0;
  transition: opacity 0.9s var(--ease-out) 0.55s;
}
.spine-stage.loaded .spine-route-section {
  opacity: 1;
}
.spine-route-label {
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.4em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  gap: 12px;
}
.spine-route-label::after {
  content: "";
  flex: 1;
  height: 1px;
  background: rgba(232,201,122,0.1);
}
.spine-route-canvas {
  width: 100%;
  height: 120px;
  background: rgba(10,13,24,0.6);
  border: 1px solid rgba(232,201,122,0.08);
  display: block;
}

/* ----------------------------------------------------------------
   AMBIENT PARTICLE FIELD — 环境粒子场
   Sand grains in the desert wind
   ---------------------------------------------------------------- */
@keyframes spine-float {
  0%   { transform: translateY(0) translateX(0) scale(1); opacity: 0; }
  15%  { opacity: 1; }
  85%  { opacity: 0.6; }
  100% { transform: translateY(-120px) translateX(20px) scale(0.4); opacity: 0; }
}
.spine-particle {
  position: absolute;
  border-radius: 50%;
  background: var(--amber);
  pointer-events: none;
  animation: spine-float linear infinite;
  will-change: transform, opacity;
}

/* ----------------------------------------------------------------
   RESPONSIVE
   ---------------------------------------------------------------- */
@media (max-width: 900px) {
  .spine-body {
    grid-template-columns: 1fr;
    grid-template-rows: auto 1fr;
  }
  .spine-timeline {
    border-right: none;
    border-bottom: 1px solid rgba(232,201,122,0.08);
    flex-direction: row;
    overflow-x: auto;
    overflow-y: hidden;
    padding: 16px 20px;
    max-height: 100px;
  }
  .spine-timeline::before { display: none; }
  .spine-segment { display: contents; }
  .spine-segment__label { display: none; }
  .spine-node {
    flex-direction: column;
    align-items: center;
    padding: 8px 12px;
    gap: 4px;
    min-width: 70px;
    text-align: center;
  }
  .spine-node__dot {
    position: static;
    margin-bottom: 4px;
  }
  .spine-node__num { display: none; }
  .spine-node__cn { font-size: 11px; white-space: normal; }
  .spine-node__meta { display: none; }
  .spine-header { padding: 20px 24px; }
  .spine-content { padding: 28px 24px; }
  .spine-hero { height: 32vh; min-height: 200px; }
  .spine-hero__text { padding: 0 24px 28px; }
  .spine-media-grid {
    grid-template-columns: 1fr;
    grid-template-rows: auto;
  }
  .spine-media-item:first-child { grid-row: auto; }
}

@media (max-width: 600px) {
  .spine-trigger { left: 20px; bottom: 24px; }
  .spine-trigger__label { display: none; }
  .spine-actions { flex-direction: column; align-items: flex-start; }
  .spine-geo { gap: 20px; }
  .spine-header__sub { display: none; }
}

/* ----------------------------------------------------------------
   REDUCED MOTION
   ---------------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  .spine-hero__cn,
  .spine-hero__en,
  .spine-excerpt,
  .spine-body-text,
  .spine-media-section,
  .spine-geo,
  .spine-actions,
  .spine-route-section {
    transition-duration: 0.2s !important;
    transition-delay: 0s !important;
  }
  .spine-trigger__icon::after,
  .spine-particle,
  @keyframes spine-shimmer { animation: none !important; }
}