/* ═══════════════════ CSS Variables ═══════════════════ */
:root {
  --bg: #F5F0E8;
  --ink: #1a1a1a;
  --ink-mid: #4a4a4a;
  --ink-faint: #8a8a8a;
  --ink-ghost: rgba(26,26,26,0.07);
  --serif: 'Playfair Display', 'STFangsong', 'FangSong', Georgia, serif;
  --mono: 'Courier Prime', 'Courier New', 'STFangsong', monospace;
  --dur: 0.72s;
}

body.night {
  --bg: #0d0d0d;
  --ink: #c0c0b8;
  --ink-mid: #808078;
  --ink-faint: #484840;
  --ink-ghost: rgba(192,192,184,0.06);
}

/* ═══════════════════ Reset ═══════════════════ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html, body { width: 100%; height: 100%; overflow: hidden; }

body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--mono);
  transition: background var(--dur) ease, color var(--dur) ease;
}

button { cursor: pointer; font-family: inherit; background: none; border: none; }

/* ═══════════════════ Top Bar ═══════════════════ */
#top-bar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0.85rem 1.4rem;
  pointer-events: none;
}

#top-bar > * { pointer-events: auto; }

#toggle-btn {
  position: fixed;
  right: 1.4rem;
  top: 0.72rem;
  z-index: 110;
  border: 1px solid var(--ink-faint);
  border-radius: 14px;
  padding: 2px 10px;
  font-size: 0.98rem;
  color: var(--ink);
  line-height: 1.5;
  transition: border-color 0.25s, color 0.25s, background 0.25s;
}
#toggle-btn:hover { border-color: var(--ink); }

.night-icon { display: none; }
body.night .day-icon { display: none; }
body.night .night-icon { display: inline; }

#top-bar h1 {
  text-align: center;
  font-family: var(--serif);
  font-weight: 400;
  font-size: 1.02rem;
  letter-spacing: 0.14em;
  color: var(--ink-mid);
  transition: color var(--dur);
}

#hint {
  position: fixed;
  right: 1.4rem;
  top: 2.8rem;
  font-size: 0.62rem;
  color: var(--ink-faint);
  letter-spacing: 0.04em;
  white-space: nowrap;
  transition: color var(--dur);
  pointer-events: none;
  text-align: right;
  line-height: 1.6;
}

/* ═══════════════════ Main View ═══════════════════ */
#main-view {
  width: 100vw;
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
}

#tree-svg {
  width: min(90vw, 860px);
  height: min(94vh, 700px);
}

/* ═══════════════════ Tree Lines ═══════════════════ */
#tree-canvas {
  color: var(--ink);
  transition: color var(--dur) ease;
}
body.night #tree-canvas {
  color: #686860;
}

.tree-line {
  fill: none;
  stroke: currentColor;
  stroke-linecap: round;
  stroke-linejoin: round;
  transition: stroke-width 0.18s ease;
}

.root-line  { stroke-width: 1.8; }
.thin       { stroke-width: 1.1; }

.trunk-fill {
  fill: currentColor;
  stroke: none;
  transition: opacity 0.2s;
}

.trunk-texture {
  fill: none;
  stroke: var(--bg);
  stroke-width: 0.9;
  opacity: 0.28;
  stroke-linecap: round;
}

.trunk-shadow {
  fill: currentColor;
  stroke: none;
  opacity: 0.22;
}

#trunk.trunk-hi .trunk-fill  { opacity: 0.82; }
#roots.root-hi  .root-line   { stroke-width: 2.4; opacity: 0.95; }

#trunk-zone, #root-zone { cursor: pointer; }

/* ═══════════════════ Branch Labels ═══════════════════ */
.branch-label-group {
  cursor: pointer;
}

.branch-label-group:hover .branch-label-dot {
  opacity: 0.9;
}

.branch-label-group:hover .branch-label {
  fill: var(--ink);
  opacity: 1;
}

.branch-label-dot {
  fill: var(--ink-faint);
  opacity: 0.5;
  transition: opacity 0.2s;
}

.branch-label {
  font-size: 9px;
  fill: var(--ink-faint);
  font-family: var(--mono);
  letter-spacing: 0.08em;
  transition: fill 0.2s;
  pointer-events: none;
}

.branch-label-line {
  stroke: var(--ink-faint);
  stroke-width: 0.6;
  opacity: 0.35;
}

/* ═══════════════════ Layer Panel ═══════════════════ */
#layer-panel {
  position: fixed;
  top: 0;
  bottom: 0;
  width: min(42vw, 420px);
  background: var(--bg);
  z-index: 200;
  padding: 3.2rem 1.6rem 2rem;
  overflow-y: auto;
  transition: transform 0.42s cubic-bezier(0.4,0,0.2,1), background var(--dur);
  /* 默认从左侧滑出 */
  left: 0;
  border-right: 1px solid var(--ink-ghost);
  transform: translateX(-102%);
}

#layer-panel.from-right {
  left: auto;
  right: 0;
  border-right: none;
  border-left: 1px solid var(--ink-ghost);
  transform: translateX(102%);
}

#layer-panel.open {
  transform: translateX(0);
}

.layer-panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.8rem;
  padding-bottom: 0.8rem;
  border-bottom: 1px solid var(--ink-ghost);
}

.layer-panel-title {
  font-family: var(--serif);
  font-size: 1.05rem;
  font-weight: 400;
  letter-spacing: 0.16em;
  color: var(--ink);
  text-transform: uppercase;
}

#layer-panel-close {
  font-size: 1.05rem;
  color: var(--ink-faint);
  transition: color 0.2s;
  line-height: 1;
}
#layer-panel-close:hover { color: var(--ink); }

.layer-item {
  padding: 1rem 0;
  border-bottom: 1px solid var(--ink-ghost);
  cursor: pointer;
  transition: opacity 0.18s;
}
.layer-item:last-child { border-bottom: none; }
.layer-item:hover { opacity: 0.72; }

.layer-item-title {
  font-family: var(--serif);
  font-size: 0.94rem;
  color: var(--ink);
  margin-bottom: 0.28rem;
  font-style: italic;
  line-height: 1.4;
}

.layer-item-date {
  font-size: 0.66rem;
  letter-spacing: 0.12em;
  color: var(--ink-faint);
  margin-bottom: 0.5rem;
}

.layer-item-body {
  font-size: 0.8rem;
  line-height: 1.75;
  color: var(--ink-mid);
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.loading-text {
  text-align: center;
  padding: 2.5rem 0;
  font-size: 0.8rem;
  color: var(--ink-faint);
  letter-spacing: 0.08em;
  opacity: 0.55;
}

/* ═══════════════════ Item Popup ═══════════════════ */
#item-popup {
  position: fixed;
  inset: 0;
  background: rgba(13,13,13,0.72);
  z-index: 350;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 2rem;
  backdrop-filter: blur(2px);
}
#item-popup.hidden { display: none; }

#item-card {
  position: relative;
  background: var(--bg);
  border: 1px solid var(--ink-ghost);
  padding: 2.4rem;
  max-width: 520px;
  width: 100%;
  max-height: 78vh;
  overflow-y: auto;
  box-shadow: 0 8px 40px rgba(0,0,0,0.18);
}

body.night #item-card {
  background: #111110;
  border-color: rgba(192,192,184,0.1);
}

#item-popup-close {
  position: absolute;
  top: 0.85rem;
  right: 0.85rem;
  font-size: 1.05rem;
  color: var(--ink-faint);
  transition: color 0.2s;
}
#item-popup-close:hover { color: var(--ink); }

.item-popup-layer {
  font-size: 0.62rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin-bottom: 0.5rem;
}

.item-popup-date {
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  color: var(--ink-faint);
  margin-bottom: 1rem;
}

.item-popup-title {
  font-family: var(--serif);
  font-size: 1.18rem;
  font-weight: 400;
  font-style: italic;
  line-height: 1.45;
  color: var(--ink);
  margin-bottom: 1.2rem;
  padding-bottom: 0.9rem;
  border-bottom: 1px solid var(--ink-ghost);
}

.item-popup-body {
  font-size: 0.88rem;
  line-height: 1.92;
  color: var(--ink-mid);
  white-space: pre-wrap;
  word-break: break-word;
}

/* ═══════════════════ Overlay Views ═══════════════════ */
.overlay-view {
  position: fixed;
  inset: 0;
  background: var(--bg);
  z-index: 50;
  padding: 5.2rem 1.6rem 2rem;
  opacity: 0;
  pointer-events: none;
  transform: translateY(18px);
  transition: opacity 0.38s ease, transform 0.38s ease, background var(--dur);
  overflow-y: auto;
}

.overlay-view.active {
  opacity: 1;
  pointer-events: all;
  transform: translateY(0);
}

.view-header {
  text-align: center;
  margin-bottom: 2.6rem;
}

.view-title {
  font-family: var(--serif);
  font-size: 2.1rem;
  font-weight: 400;
  letter-spacing: 0.26em;
  color: var(--ink);
}

.view-sub {
  margin-top: 0.5rem;
  font-size: 0.78rem;
  color: var(--ink-faint);
  letter-spacing: 0.08em;
}

.back-btn {
  position: fixed;
  top: 1rem;
  left: 1.3rem;
  font-size: 0.86rem;
  color: var(--ink-mid);
  letter-spacing: 0.05em;
  z-index: 60;
  transition: color 0.2s;
}
.back-btn:hover { color: var(--ink); }

.close-btn {
  font-size: 1.05rem;
  color: var(--ink-faint);
  transition: color 0.2s;
  line-height: 1;
}
.close-btn:hover { color: var(--ink); }

/* ═══════════════════ Rings View ═══════════════════ */
#rings-wrap {
  display: flex;
  justify-content: center;
}

#rings-svg {
  width: min(88vw, 480px);
  height: min(88vw, 480px);
  color: var(--ink);
  transition: color var(--dur);
}

body.night #rings-svg { color: #484840; }

.ring-arc {
  fill: none;
  stroke: currentColor;
  cursor: pointer;
  transition: opacity 0.2s, stroke-width 0.15s;
}
.ring-arc:hover { stroke-width: 3.2 !important; opacity: 1 !important; }

.ring-date-label {
  font-family: var(--serif);
  font-size: 8px;
  fill: currentColor;
  opacity: 0.5;
  pointer-events: none;
}

.ring-text {
  font-family: var(--mono);
  font-size: 9.5px;
  fill: currentColor;
  opacity: 0.85;
  pointer-events: auto;
  cursor: pointer;
  letter-spacing: 0.01em;
}
body.night .ring-text { opacity: 0.65; }
.ring-text:hover { opacity: 1 !important; }

@keyframes ring-uncoil {
  0%   { opacity: 0.72; transform: none; }
  20%  { transform: translateX(-12px) rotate(1deg); }
  50%  { opacity: 0.5; transform: translateX(8px) rotate(-0.5deg); }
  100% { opacity: 0; transform: translateX(-340px); filter: blur(0.5px); }
}
.ring-text.ring-exit {
  animation: ring-uncoil 0.52s cubic-bezier(0.4,0,1,0.8) forwards;
  pointer-events: none !important;
}

/* ═══════════════════ Diary Columns ═══════════════════ */
.diary-col {
  position: fixed;
  top: 4.5rem;
  bottom: 1.5rem;
  width: calc(50vw - 1rem);
  overflow-x: hidden;
  overflow-y: auto;
  opacity: 0;
  padding: 0 1.2rem;
  font-size: 0.73rem;
  line-height: 1.88;
  color: var(--ink-mid);
  font-family: var(--mono);
  letter-spacing: 0.015em;
  transition: opacity 0.5s ease;
  pointer-events: none;
  word-break: break-word;
  white-space: pre-wrap;
}
#col-left  { left: 0; }
#col-right { right: 0; }

/* 旧列隐藏 */
#rings-view.diary-mode .diary-col { display: none; }

/* 进入年轮界面就在右侧 */
#rings-view #rings-wrap {
  position: fixed;
  right: 5vw; top: 0; bottom: 0;
  width: min(50vw, 520px);
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg);
  z-index: 52;
  transition: background var(--dur);
}
#rings-view #rings-svg {
  width: min(47vw, 480px);
  height: min(47vw, 480px);
}

/* 日记文字面板（左侧） */
#diary-text-panel {
  position: fixed;
  top: 0; left: 5vw; bottom: 0;
  width: calc(91vw - min(50vw, 520px));
  opacity: 0;
  pointer-events: none;
  overflow-y: auto;
  padding: 5rem 2.5rem 2rem;
  font-size: 13px;
  line-height: 1.9;
  color: var(--ink-mid);
  font-family: var(--mono);
  letter-spacing: 0.015em;
  word-break: break-word;
  white-space: pre-wrap;
  transition: opacity 0.45s ease;
}
#rings-view.diary-mode #diary-text-panel {
  opacity: 1;
  pointer-events: auto;
}
#rings-view.diary-mode .view-header {
  visibility: hidden;
  pointer-events: none;
}

@keyframes excerpt-arrive {
  from { opacity: 0; transform: translateX(-18px); }
  to   { opacity: 1; transform: none; }
}
.ring-excerpt {
  display: inline;
  animation: excerpt-arrive 0.55s ease forwards;
  opacity: 0;
}

/* 蝴蝶字母动画 */
@keyframes butterfly-fly {
  0%   { transform: translate(var(--sx), var(--sy)) rotate(var(--sr)); opacity: 0; }
  12%  { transform: translate(var(--sx), var(--sy)) rotate(var(--sr)); opacity: 1; }
  44%  { transform: translate(var(--px), var(--py)) rotate(var(--mr)); opacity: 0.9; }
  100% { transform: translate(0px, 0px) rotate(0deg); opacity: 1; }
}
.butterfly-char {
  position: fixed;
  font-family: var(--mono);
  font-size: 13px;
  line-height: 1;
  color: var(--ink-mid);
  pointer-events: none;
  z-index: 1000;
  animation: butterfly-fly var(--dur, 1s) cubic-bezier(0.37, 0, 0.33, 1) var(--delay, 0ms) both;
}

.diary-mode-bar {
  position: fixed;
  top: 0.7rem;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  align-items: center;
  gap: 0.8rem;
  z-index: 300;
}
.dbar-date {
  font-size: 0.66rem;
  letter-spacing: 0.14em;
  color: var(--ink-faint);
}
.dbar-title {
  font-family: var(--serif);
  font-size: 0.82rem;
  font-style: italic;
  color: var(--ink-mid);
  max-width: 200px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.dbar-btn {
  font-size: 0.66rem;
  letter-spacing: 0.1em;
  color: var(--ink-faint);
  border: 1px solid var(--ink-faint);
  border-radius: 10px;
  padding: 1px 7px;
  cursor: pointer;
  font-family: var(--mono);
  background: none;
  transition: color 0.2s, border-color 0.2s;
}
.dbar-btn:hover { color: var(--ink); border-color: var(--ink); }

/* ═══════════════════ Diary Panel ═══════════════════ */
#diary-panel {
  position: fixed;
  right: 5vw; top: 0; bottom: 0;
  width: min(44vw, 500px);
  background: var(--bg);
  border-left: 1px solid var(--ink-ghost);
  padding: 3.2rem 1.8rem 2rem;
  transform: translateX(101%);
  transition: transform 0.42s cubic-bezier(0.4,0,0.2,1), background var(--dur);
  overflow-y: auto;
  z-index: 200;
}

#diary-panel.open { transform: translateX(0); }

#diary-close {
  position: absolute;
  top: 1rem;
  right: 1rem;
}

#lang-toggle {
  position: absolute;
  top: 1rem;
  right: 3rem;
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  color: var(--ink-faint);
  border: 1px solid var(--ink-faint);
  border-radius: 10px;
  padding: 1px 7px;
  transition: color 0.2s, border-color 0.2s;
}
#lang-toggle:hover { color: var(--ink); border-color: var(--ink); }

.diary-date {
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  color: var(--ink-faint);
  margin-bottom: 0.6rem;
}

.diary-title {
  font-family: var(--serif);
  font-size: 1.3rem;
  font-weight: 400;
  line-height: 1.45;
  margin-bottom: 1.4rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--ink-ghost);
}

.diary-body {
  font-size: 0.86rem;
  line-height: 1.92;
  color: var(--ink-mid);
  white-space: pre-wrap;
  word-break: break-word;
}

.type-cursor {
  display: inline-block;
  width: 1px;
  height: 0.88em;
  background: currentColor;
  opacity: 0.55;
  margin-left: 1px;
  vertical-align: text-bottom;
  animation: cursor-blink 0.75s step-end infinite;
}
@keyframes cursor-blink {
  0%, 100% { opacity: 0.55; }
  50%       { opacity: 0; }
}

/* ═══════════════════ Core View ═══════════════════ */
#core-content {
  max-width: 640px;
  margin: 0 auto;
}

.core-entry {
  padding: 1.3rem 0;
  border-bottom: 1px solid var(--ink-ghost);
}
.core-entry:last-child { border-bottom: none; }

.core-label {
  font-size: 0.66rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin-bottom: 0.5rem;
}

.core-text {
  font-family: var(--serif);
  font-size: 1.02rem;
  line-height: 1.75;
  font-style: italic;
  color: var(--ink);
  white-space: pre-wrap;
  word-break: break-word;
}

/* ═══════════════════ Soul Popup ═══════════════════ */
#soul-popup {
  position: fixed;
  inset: 0;
  background: rgba(13,13,13,0.84);
  z-index: 400;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 2rem;
}
#soul-popup.hidden { display: none; }

#soul-card {
  position: relative;
  background: #100f0e;
  border: 1px solid #2a2a26;
  padding: 2.2rem;
  max-width: 420px;
  width: 100%;
  max-height: 72vh;
  overflow-y: auto;
}

#soul-card .close-btn {
  position: absolute;
  top: 0.85rem;
  right: 0.85rem;
  color: #555;
}

.soul-tag {
  font-size: 0.66rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: #656560;
  margin-bottom: 1rem;
}

.soul-title {
  font-family: var(--serif);
  font-size: 1.08rem;
  color: #c0c0b8;
  margin-bottom: 0.8rem;
  font-style: italic;
  line-height: 1.4;
}

.soul-body {
  font-size: 0.86rem;
  line-height: 1.88;
  color: #808078;
  white-space: pre-wrap;
  word-break: break-word;
}

/* ═══════════════════ Fireflies ═══════════════════ */
.ff-glow { fill: #b4dc38; }
.ff-core { fill: #d4f050; }
.ff-container { cursor: pointer; }

/* ═══════════════════ Animations ═══════════════════ */
@keyframes breathe {
  0%, 100% { transform: scale(1);     }
  50%       { transform: scale(1.007); }
}
#tree-canvas {
  transform-origin: 400px 410px;
  animation: breathe 5.4s ease-in-out infinite;
}

@keyframes ff-pulse {
  from { opacity: 0.22; }
  to   { opacity: 1;    }
}

@keyframes ff-drift-a {
  0%,100% { transform: translate(0,0);       }
  30%     { transform: translate(10px,-14px); }
  65%     { transform: translate(-8px,-9px);  }
  80%     { transform: translate(6px,-18px);  }
}
@keyframes ff-drift-b {
  0%,100% { transform: translate(0,0);       }
  25%     { transform: translate(-12px,-10px);}
  55%     { transform: translate(9px,-16px);  }
  78%     { transform: translate(-5px,-7px);  }
}
@keyframes ff-drift-c {
  0%,100% { transform: translate(0,0);       }
  38%     { transform: translate(7px,-13px);  }
  62%     { transform: translate(-11px,-19px);}
  85%     { transform: translate(4px,-8px);   }
}

/* ═══════════════════ Mobile ═══════════════════ */
@media (max-width: 680px) {
  #diary-panel {
    width: 100%;
    top: auto;
    height: 58vh;
    border-left: none;
    border-top: 1px solid var(--ink-ghost);
    transform: translateY(101%);
  }
  #diary-panel.open { transform: translateY(0); }

  #layer-panel {
    width: 100%;
    top: auto;
    bottom: 0;
    height: 62vh;
    border-right: none;
    border-top: 1px solid var(--ink-ghost);
    transform: translateY(102%) !important;
  }
  #layer-panel.open { transform: translateY(0) !important; }

  #hint { display: none; }
  .view-title { font-size: 1.55rem; }
  .overlay-view { padding-top: 4.5rem; }
}