/* ============================================================
   岳麓书院 · 3D  /  style.css
   Ink-and-paper interface for an explorable architectural model.
   ============================================================ */

:root {
  --ink: #1e1c17;
  --ink-soft: #4d483d;
  --muted: #7d7565;
  --paper: #f5f0e4;
  --paper-2: #ebe3d1;
  --glass: rgba(247, 243, 233, 0.84);
  --glass-strong: rgba(250, 247, 239, 0.94);
  --line: rgba(54, 46, 34, 0.18);
  --line-soft: rgba(54, 46, 34, 0.1);
  --cinnabar: #a43b2b;
  --cinnabar-deep: #7f2b20;
  --gold: #ad8a4b;
  --shadow: 0 24px 70px rgba(31, 25, 16, 0.2);
  --serif: "Songti SC", "STSong", "STZhongsong", "SimSun", "Noto Serif SC", serif;
  --kai: "STKaiti", "KaiTi", "Kaiti SC", "FangSong", serif;
  --sans: "Microsoft YaHei", "PingFang SC", "Hiragino Sans GB", "Segoe UI", sans-serif;
}

body.night {
  --ink: #e9e2d3;
  --ink-soft: #c8c1b2;
  --muted: #999184;
  --paper: #111922;
  --paper-2: #182330;
  --glass: rgba(15, 22, 30, 0.82);
  --glass-strong: rgba(17, 25, 34, 0.94);
  --line: rgba(221, 205, 174, 0.2);
  --line-soft: rgba(221, 205, 174, 0.1);
  --cinnabar: #c4684e;
  --cinnabar-deep: #a44d36;
  --gold: #c5a25c;
  --shadow: 0 24px 80px rgba(0, 0, 0, 0.5);
}

* { box-sizing: border-box; }

html, body {
  height: 100%;
  margin: 0;
  overflow: hidden;
  background: #101210;
}

body {
  font-family: var(--sans);
  color: var(--ink);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  user-select: none;
}

button {
  font: inherit;
  color: inherit;
  border: 0;
  background: none;
  cursor: pointer;
}

button:focus-visible,
[role="button"]:focus-visible {
  outline: 2px solid var(--cinnabar);
  outline-offset: 3px;
}

#app { position: fixed; inset: 0; }

#scene {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
  touch-action: none;
  cursor: grab;
  outline: none;
}

#scene:active { cursor: grabbing; }

#grade {
  position: fixed;
  inset: 0;
  z-index: 3;
  pointer-events: none;
  background:
    linear-gradient(180deg, rgba(27, 43, 53, 0.26), transparent 32%, transparent 68%, rgba(74, 44, 22, 0.2)),
    radial-gradient(ellipse at 52% 42%, rgba(255, 231, 190, 0.09), transparent 58%);
  mix-blend-mode: soft-light;
}

body.night #grade {
  background:
    linear-gradient(180deg, rgba(10, 22, 40, 0.32), transparent 38%, transparent 68%, rgba(5, 9, 14, 0.3)),
    radial-gradient(ellipse at 52% 45%, rgba(255, 184, 104, 0.06), transparent 55%);
}

#grain {
  position: fixed;
  inset: -6%;
  z-index: 3;
  pointer-events: none;
  opacity: 0.045;
  mix-blend-mode: overlay;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='180' height='180'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.82' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='180' height='180' filter='url(%23n)' opacity='0.6'/%3E%3C/svg%3E");
  background-size: 180px 180px;
  animation: grainShift 1.1s steps(5) infinite;
}

body.night #grain { opacity: 0.055; }

@keyframes grainShift {
  0% { transform: translate3d(0, 0, 0); }
  20% { transform: translate3d(-1.5%, 1%, 0); }
  40% { transform: translate3d(1%, -1.5%, 0); }
  60% { transform: translate3d(-1%, -1%, 0); }
  80% { transform: translate3d(1.5%, 1.5%, 0); }
  100% { transform: translate3d(0, 0, 0); }
}

#vignette {
  position: fixed;
  inset: 0;
  z-index: 4;
  pointer-events: none;
  background:
    radial-gradient(ellipse at 50% 44%, rgba(0, 0, 0, 0) 43%, rgba(17, 16, 13, 0.18) 100%),
    linear-gradient(to bottom, rgba(24, 22, 18, 0.16), rgba(0, 0, 0, 0) 22%, rgba(0, 0, 0, 0) 76%, rgba(17, 16, 14, 0.2));
  transition: opacity 0.6s ease;
}

body.night #vignette {
  background:
    radial-gradient(ellipse at 50% 44%, rgba(0, 0, 0, 0) 38%, rgba(0, 0, 0, 0.48) 100%),
    linear-gradient(to bottom, rgba(0, 0, 0, 0.3), rgba(0, 0, 0, 0) 25%);
}

#veil {
  position: fixed;
  inset: 0;
  z-index: 90;
  pointer-events: none;
  opacity: 0;
  background: #090b0d;
}

#veil.flash { animation: veilFlash 0.58s ease; }

@keyframes veilFlash {
  0% { opacity: 0; }
  18% { opacity: 0.8; }
  100% { opacity: 0; }
}

/* ------------------------------ brand ------------------------------ */
#brand {
  position: fixed;
  top: 28px;
  left: 32px;
  z-index: 20;
  display: flex;
  align-items: center;
  gap: 13px;
  pointer-events: none;
  text-shadow: 0 1px 18px rgba(250, 246, 236, 0.45);
}

#brand::before {
  content: "";
  position: absolute;
  inset: -18px -54px -20px -20px;
  z-index: -1;
  background: radial-gradient(ellipse at 24% 48%, rgba(247, 242, 231, 0.62), rgba(247, 242, 231, 0.22) 46%, transparent 72%);
  pointer-events: none;
}

body.night #brand { text-shadow: 0 2px 20px rgba(0, 0, 0, 0.8); }
body.night #brand::before {
  background: radial-gradient(ellipse at 24% 48%, rgba(9, 13, 18, 0.72), rgba(9, 13, 18, 0.3) 48%, transparent 74%);
}

.seal {
  width: 46px;
  height: 46px;
  display: grid;
  place-items: center;
  background: var(--cinnabar);
  color: #f7efe0;
  font-family: var(--kai);
  font-size: 27px;
  line-height: 1;
  border: 1px solid rgba(255, 240, 215, 0.36);
  box-shadow: inset 0 0 0 3px rgba(255, 240, 215, 0.12), 0 8px 24px rgba(75, 25, 18, 0.28);
  transform: rotate(-1.5deg);
}

.brand-copy h1 {
  margin: 0;
  font-family: var(--serif);
  font-size: 27px;
  font-weight: 600;
  letter-spacing: 0.17em;
  line-height: 1.1;
}

.brand-copy .sub {
  margin: 5px 0 0;
  font-size: 8.5px;
  letter-spacing: 0.25em;
  color: var(--ink);
  opacity: 0.7;
  font-weight: 600;
}

.brand-copy .sub span { color: var(--cinnabar); }

/* ----------------------------- toolbar ----------------------------- */
#toolbar {
  position: fixed;
  top: 26px;
  right: 28px;
  z-index: 25;
  display: flex;
  gap: 7px;
}

#toolbar button {
  height: 38px;
  padding: 0 13px;
  display: inline-flex;
  align-items: center;
  gap: 7px;
  border: 1px solid var(--line);
  border-radius: 2px;
  background: var(--glass);
  backdrop-filter: blur(14px) saturate(1.05);
  -webkit-backdrop-filter: blur(14px) saturate(1.05);
  color: var(--ink);
  font-size: 11px;
  letter-spacing: 0.12em;
  box-shadow: 0 4px 18px rgba(24, 20, 14, 0.08);
  transition: background 0.2s ease, color 0.2s ease, transform 0.2s ease, border-color 0.2s ease;
}

#toolbar button:hover {
  transform: translateY(-1px);
  border-color: rgba(120, 92, 50, 0.4);
  background: var(--glass-strong);
}

#toolbar button.active {
  background: var(--cinnabar);
  border-color: var(--cinnabar);
  color: #f8f0df;
}

#toolbar button:disabled { opacity: 0.55; cursor: wait; transform: none; }

#toolbar svg {
  width: 15px;
  height: 15px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.5;
  stroke-linecap: round;
  stroke-linejoin: round;
}

#toolbar .ico {
  width: 15px;
  text-align: center;
  font-size: 15px;
  line-height: 1;
}

/* --------------------------- route panel --------------------------- */
#route-panel {
  position: fixed;
  top: 116px;
  left: 32px;
  z-index: 24;
  width: 258px;
  padding: 21px 19px 16px;
  background: var(--glass);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
  backdrop-filter: blur(20px) saturate(1.05);
  -webkit-backdrop-filter: blur(20px) saturate(1.05);
  opacity: 0;
  transform: translateX(-12px);
  pointer-events: none;
  transition: opacity 0.35s ease, transform 0.35s ease;
}

#route-panel.open {
  opacity: 1;
  transform: none;
  pointer-events: auto;
}

#route-panel::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(to right, var(--cinnabar), rgba(164, 59, 43, 0));
}

.panel-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
}

.eyebrow {
  font-size: 7.5px;
  letter-spacing: 0.27em;
  color: var(--muted);
  font-weight: 600;
}

.panel-head h2 {
  margin: 7px 0 0;
  font-family: var(--serif);
  font-size: 20px;
  font-weight: 600;
  letter-spacing: 0.08em;
}

.icon-btn {
  flex: none;
  width: 28px;
  height: 28px;
  display: grid;
  place-items: center;
  font-size: 21px;
  font-weight: 300;
  line-height: 1;
  color: var(--muted);
  border-radius: 50%;
  transition: background 0.2s, color 0.2s;
}

.icon-btn:hover { background: rgba(120, 90, 50, 0.1); color: var(--ink); }

#route-list {
  list-style: none;
  margin: 15px -7px 0;
  padding: 0;
  max-height: calc(100vh - 370px);
  overflow: auto;
  scrollbar-width: thin;
  scrollbar-color: rgba(130, 105, 65, 0.35) transparent;
}

#route-list::-webkit-scrollbar { width: 4px; }
#route-list::-webkit-scrollbar-thumb { background: rgba(130, 105, 65, 0.35); }

#route-list li {
  display: grid;
  grid-template-columns: 29px 1fr auto;
  align-items: center;
  gap: 7px;
  padding: 9px 7px;
  border-bottom: 1px dashed var(--line-soft);
  cursor: pointer;
  transition: background 0.2s, color 0.2s;
}

#route-list li:hover { background: rgba(255, 252, 243, 0.5); }
body.night #route-list li:hover { background: rgba(255, 245, 220, 0.06); }

#route-list .num {
  font-size: 8.5px;
  letter-spacing: 0.12em;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}

#route-list .rname {
  font-family: var(--serif);
  font-size: 13.5px;
  letter-spacing: 0.08em;
}

#route-list .rgroup {
  font-size: 8px;
  letter-spacing: 0.08em;
  color: var(--muted);
}

#route-list li.active {
  background: rgba(164, 59, 43, 0.09);
}

#route-list li.active .num,
#route-list li.active .rname { color: var(--cinnabar); }
#route-list li.active .rname { font-weight: 600; }

.route-note {
  margin: 13px 0 0;
  font-size: 9px;
  line-height: 1.7;
  color: var(--muted);
  letter-spacing: 0.05em;
}

/* ----------------------------- info ----------------------------- */
#info {
  position: fixed;
  top: 102px;
  right: 28px;
  z-index: 30;
  width: 356px;
  padding: 27px 27px 23px;
  background:
    linear-gradient(155deg, rgba(252, 249, 241, 0.96), rgba(239, 231, 214, 0.92));
  border: 1px solid rgba(89, 69, 38, 0.22);
  box-shadow: var(--shadow);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  opacity: 0;
  transform: translateX(18px);
  pointer-events: none;
  transition: opacity 0.4s ease, transform 0.4s cubic-bezier(0.22, 0.8, 0.3, 1);
}

body.night #info {
  background: linear-gradient(155deg, rgba(20, 29, 39, 0.97), rgba(14, 21, 30, 0.94));
  border-color: rgba(212, 190, 150, 0.22);
}

#info.open {
  opacity: 1;
  transform: none;
  pointer-events: auto;
}

#info::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(to right, var(--cinnabar), var(--gold) 48%, rgba(173, 138, 75, 0));
}

#info-close { position: absolute; top: 11px; right: 12px; }

.info-kicker {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 8.5px;
  letter-spacing: 0.22em;
  color: var(--muted);
  font-weight: 600;
}

.info-kicker i {
  width: 20px;
  height: 1px;
  background: var(--line);
}

#info-name {
  margin: 12px 0 3px;
  font-family: var(--serif);
  font-size: 32px;
  font-weight: 600;
  letter-spacing: 0.12em;
  line-height: 1.15;
}

.info-en {
  margin: 0;
  font-size: 8.5px;
  letter-spacing: 0.27em;
  color: var(--muted);
}

.info-rule {
  margin: 17px 0 15px;
  height: 1px;
  background: var(--line-soft);
  position: relative;
}

.info-rule span {
  position: absolute;
  left: 0;
  top: -1px;
  width: 46px;
  height: 2px;
  background: var(--cinnabar);
}

.info-text {
  margin: 0;
  font-family: var(--serif);
  font-size: 14px;
  line-height: 1.98;
  letter-spacing: 0.035em;
  color: var(--ink-soft);
  text-align: justify;
}

.text-link {
  margin-top: 19px;
  padding: 0 0 4px;
  border-bottom: 1px solid var(--line);
  font-size: 10.5px;
  letter-spacing: 0.14em;
  color: var(--ink);
  transition: color 0.2s, border-color 0.2s;
}

.text-link span { margin-left: 5px; color: var(--cinnabar); }
.text-link:hover { color: var(--cinnabar); border-color: var(--cinnabar); }

/* --------------------------- hotspots --------------------------- */
#labels {
  position: fixed;
  inset: 0;
  z-index: 15;
  pointer-events: none;
  transition: opacity 0.35s ease;
}

#labels.off { opacity: 0; }

.hotspot {
  position: absolute;
  top: 0;
  left: 0;
  display: inline-flex;
  align-items: center;
  gap: 0;
  padding: 9px;
  border: 0;
  border-radius: 2px;
  background: transparent;
  color: var(--ink);
  font-size: 10px;
  letter-spacing: 0.1em;
  line-height: 1;
  white-space: nowrap;
  box-shadow: none;
  pointer-events: auto;
  transition: opacity 0.25s ease;
  will-change: transform;
}

.hs-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--cinnabar);
  box-shadow:
    0 0 0 3px rgba(164, 59, 43, 0.14),
    0 0 12px rgba(164, 59, 43, 0.5);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.hs-name {
  margin-left: 8px;
  padding: 5px 8px;
  border: 1px solid var(--line);
  border-radius: 2px;
  background: var(--glass);
  box-shadow: 0 3px 12px rgba(26, 20, 12, 0.12);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  opacity: 0;
  transform: translateX(-5px);
  pointer-events: none;
  transition: opacity 0.22s ease, transform 0.22s ease;
}

.hotspot:hover .hs-dot,
body.labels-full .hs-dot {
  transform: scale(1.25);
}

.hotspot:hover .hs-name,
.hotspot.active .hs-name,
body.labels-full .hs-name {
  opacity: 1;
  transform: none;
}

.hotspot.active .hs-dot {
  background: #f8f0df;
  box-shadow:
    0 0 0 3px rgba(164, 59, 43, 0.5),
    0 0 16px rgba(255, 229, 190, 0.55);
}

.hotspot.active .hs-name {
  background: var(--cinnabar);
  border-color: var(--cinnabar);
  color: #f8f0df;
}

.hotspot.hidden {
  opacity: 0 !important;
  pointer-events: none;
}

body.walking #labels { opacity: 0; pointer-events: none; }

/* ----------------------------- hint ----------------------------- */
#hint {
  position: fixed;
  left: 50%;
  bottom: 25px;
  z-index: 18;
  transform: translateX(-50%);
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 8px 14px;
  border: 1px solid var(--line);
  border-radius: 2px;
  background: var(--glass);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  color: var(--ink-soft);
  font-size: 9.5px;
  letter-spacing: 0.09em;
  white-space: nowrap;
  box-shadow: 0 4px 18px rgba(20, 16, 10, 0.08);
  pointer-events: none;
}

.hint-dot {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--cinnabar);
  box-shadow: 0 0 0 3px rgba(164, 59, 43, 0.1);
}

#hint .sep { opacity: 0.4; margin: 0 1px; }

#hint kbd {
  font: inherit;
  font-size: 8.5px;
  color: var(--ink);
  border: 1px solid var(--line);
  border-radius: 2px;
  padding: 1px 4px;
  background: rgba(255, 255, 255, 0.25);
}

body.night #hint kbd { background: rgba(255, 255, 255, 0.06); }

/* ---------------------------- compass ---------------------------- */
#compass {
  position: fixed;
  right: 29px;
  bottom: 24px;
  z-index: 20;
  width: 82px;
  text-align: center;
  opacity: 0.92;
  cursor: pointer;
  transition: opacity 0.2s;
}

#compass:hover { opacity: 1; }

.compass-ring {
  position: relative;
  width: 62px;
  height: 62px;
  margin: 0 auto;
  border: 1px solid var(--line);
  border-radius: 50%;
  background: var(--glass);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 4px 18px rgba(20, 16, 10, 0.1), inset 0 0 0 4px rgba(255, 252, 244, 0.18);
}

body.night .compass-ring { box-shadow: 0 4px 22px rgba(0, 0, 0, 0.35), inset 0 0 0 4px rgba(255, 244, 220, 0.04); }

.compass-ring .c {
  position: absolute;
  font-family: var(--serif);
  font-size: 7.5px;
  line-height: 1;
  color: var(--muted);
  letter-spacing: 0;
}

.compass-ring .n { top: 5px; left: 50%; transform: translateX(-50%); color: var(--cinnabar); }
.compass-ring .e { right: 5px; top: 50%; transform: translateY(-50%); }
.compass-ring .s { bottom: 5px; left: 50%; transform: translateX(-50%); }
.compass-ring .w { left: 5px; top: 50%; transform: translateY(-50%); }

.needle {
  position: absolute;
  left: 50%;
  bottom: 50%;
  width: 1px;
  height: 21px;
  background: linear-gradient(to top, rgba(164, 59, 43, 0.1), var(--cinnabar));
  transform-origin: 50% 100%;
  transition: transform 0.12s linear;
  z-index: 2;
}

.needle::before {
  content: "";
  position: absolute;
  top: -3px;
  left: 50%;
  transform: translateX(-50%);
  border-left: 3px solid transparent;
  border-right: 3px solid transparent;
  border-bottom: 5px solid var(--cinnabar);
}

.compass-center {
  position: absolute;
  left: 50%;
  top: 50%;
  width: 4px;
  height: 4px;
  margin: -2px 0 0 -2px;
  border-radius: 50%;
  background: var(--ink);
  z-index: 3;
}

.compass-dir {
  margin-top: 6px;
  font-size: 7.5px;
  letter-spacing: 0.12em;
  color: var(--muted);
  white-space: nowrap;
}

/* ---------------------------- walkbar ---------------------------- */
#walkbar {
  position: fixed;
  top: 25px;
  left: 50%;
  z-index: 40;
  transform: translateX(-50%);
  display: none;
  align-items: center;
  gap: 13px;
  padding: 8px 9px 8px 14px;
  border: 1px solid var(--line);
  background: var(--glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  box-shadow: 0 8px 28px rgba(20, 16, 10, 0.16);
  font-size: 9.5px;
  letter-spacing: 0.08em;
  white-space: nowrap;
}

body.walking #walkbar { display: flex; }

.walk-mode {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--cinnabar);
  font-weight: 600;
}

.walk-mode::before {
  content: "";
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--cinnabar);
  animation: pulse 1.8s infinite;
}

@keyframes pulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(164, 59, 43, 0.35); }
  50% { box-shadow: 0 0 0 5px rgba(164, 59, 43, 0); }
}

.walk-tip { color: var(--ink-soft); }

#walk-exit {
  padding: 5px 10px;
  border: 1px solid var(--line);
  font-size: 9px;
  letter-spacing: 0.1em;
  color: var(--ink);
  background: rgba(255, 255, 255, 0.15);
  transition: background 0.2s, color 0.2s;
}

#walk-exit:hover { background: var(--cinnabar); color: #f8f0df; border-color: var(--cinnabar); }

#joystick {
  position: fixed;
  left: 28px;
  bottom: 30px;
  z-index: 45;
  width: 116px;
  height: 116px;
  border-radius: 50%;
  border: 1px solid rgba(247, 240, 226, 0.36);
  background: radial-gradient(circle, rgba(20, 26, 24, 0.24), rgba(20, 26, 24, 0.5));
  backdrop-filter: blur(8px);
  display: none;
  touch-action: none;
  user-select: none;
}
body.walking.touchwalk #joystick { display: block; }

#joystick-knob {
  position: absolute;
  left: 50%;
  top: 50%;
  width: 46px;
  height: 46px;
  margin: -23px 0 0 -23px;
  border-radius: 50%;
  background: rgba(247, 240, 226, 0.72);
  border: 1px solid rgba(255, 252, 242, 0.8);
  box-shadow: 0 3px 14px rgba(0, 0, 0, 0.25);
  will-change: transform;
}

#joystick span {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -18px;
  text-align: center;
  font-size: 8px;
  letter-spacing: 0.18em;
  color: rgba(247, 240, 226, 0.72);
}

body.walking #info,
body.walking #route-panel,
body.walking #hint { display: none; }

/* --------------------------- crosshair --------------------------- */
#crosshair {
  position: fixed;
  left: 50%;
  top: 50%;
  z-index: 35;
  width: 26px;
  height: 26px;
  margin: -13px 0 0 -13px;
  display: none;
  pointer-events: none;
}

body.walking #crosshair { display: block; }

#crosshair i {
  position: absolute;
  background: rgba(255, 250, 237, 0.78);
  box-shadow: 0 0 3px rgba(0, 0, 0, 0.5);
}

#crosshair i:nth-child(1) {
  left: 50%; top: 0;
  width: 1px; height: 6px;
}

#crosshair i:nth-child(2) {
  left: 50%; bottom: 0;
  width: 1px; height: 6px;
}

body.walking.locked #scene { cursor: none; }
body.walking:not(.locked) #scene { cursor: crosshair; }

/* ----------------------------- toast ----------------------------- */
#toast {
  position: fixed;
  left: 50%;
  bottom: 86px;
  z-index: 55;
  transform: translate(-50%, 8px);
  max-width: min(88vw, 560px);
  padding: 9px 15px;
  background: rgba(28, 24, 18, 0.9);
  color: #f2eadb;
  border: 1px solid rgba(219, 191, 142, 0.22);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.24);
  font-size: 10.5px;
  line-height: 1.6;
  letter-spacing: 0.07em;
  text-align: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease, transform 0.3s ease;
}

#toast.show { opacity: 1; transform: translate(-50%, 0); }

/* ---------------------------- loading ---------------------------- */
#loading {
  position: fixed;
  inset: 0;
  z-index: 200;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background:
    radial-gradient(ellipse at 50% 38%, #2f2a21 0%, #1b1813 42%, #0f0e0c 100%);
  color: #eee5d2;
  transition: opacity 0.85s ease, visibility 0.85s ease;
}

#loading::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    repeating-linear-gradient(0deg, rgba(255, 245, 220, 0.018) 0 1px, transparent 1px 4px),
    radial-gradient(circle at 50% 50%, rgba(178, 132, 67, 0.08), transparent 46%);
  pointer-events: none;
}

#loading.done { opacity: 0; visibility: hidden; }

.load-inner {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  z-index: 1;
}

.load-seal {
  width: 58px;
  height: 58px;
  display: grid;
  place-items: center;
  border: 1px solid rgba(224, 184, 118, 0.55);
  color: #d9ae6a;
  font-family: var(--kai);
  font-size: 34px;
  margin-bottom: 22px;
  box-shadow: inset 0 0 0 4px rgba(217, 174, 106, 0.08);
  transform: rotate(-2deg);
}

.load-title {
  font-family: var(--serif);
  font-size: 38px;
  letter-spacing: 0.3em;
  padding-left: 0.3em;
  color: #f1e7d4;
}

.load-sub {
  margin-top: 12px;
  font-size: 8px;
  letter-spacing: 0.36em;
  color: rgba(232, 219, 193, 0.52);
}

.load-track {
  width: 210px;
  height: 1px;
  margin-top: 39px;
  background: rgba(235, 219, 188, 0.15);
  overflow: hidden;
}

.load-track i {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(to right, #9e3b2b, #d1a35e);
  transition: width 0.5s ease;
}

.load-status {
  margin-top: 13px;
  font-size: 9px;
  letter-spacing: 0.16em;
  color: rgba(232, 219, 193, 0.54);
}

.load-foot {
  position: absolute;
  bottom: 34px;
  left: 50%;
  transform: translateX(-50%);
  font-family: var(--kai);
  font-size: 14px;
  letter-spacing: 0.3em;
  padding-left: 0.3em;
  color: rgba(232, 219, 193, 0.3);
}

/* ---------------------------- no UI ---------------------------- */
body.no-ui #brand,
body.no-ui #toolbar,
body.no-ui #labels,
body.no-ui #route-panel,
body.no-ui #info,
body.no-ui #hint,
body.no-ui #compass,
body.no-ui #walkbar,
body.no-ui #toast,
body.no-ui #crosshair { display: none !important; }

body.no-ui #scene { cursor: default; }

/* ---------------------------- responsive ---------------------------- */
@media (max-width: 980px) {
  #info { width: 320px; padding: 23px 22px 20px; }
  #toolbar button { padding: 0 10px; }
  #route-panel { width: 238px; }
}

@media (max-width: 780px) {
  #brand { top: 17px; left: 16px; gap: 10px; }
  .seal { width: 38px; height: 38px; font-size: 22px; }
  .brand-copy h1 { font-size: 21px; }
  .brand-copy .sub { font-size: 7.5px; letter-spacing: 0.18em; }

  #toolbar { top: 15px; right: 12px; gap: 4px; }
  #toolbar button { height: 34px; padding: 0 9px; gap: 5px; font-size: 10px; }
  #toolbar button svg, #toolbar .ico { width: 13px; height: 13px; font-size: 13px; }

  #route-panel {
    top: 78px;
    left: 12px;
    right: 12px;
    width: auto;
    max-height: 58vh;
    overflow: auto;
  }

  #route-list { max-height: none; }

  #info {
    top: auto;
    left: 10px;
    right: 10px;
    bottom: 10px;
    width: auto;
    max-height: 52vh;
    overflow: auto;
    padding: 22px 21px 18px;
    transform: translateY(16px);
  }

  #info.open { transform: none; }
  #info-name { font-size: 27px; }
  .info-text { font-size: 13.5px; line-height: 1.9; }

  #hint { display: none; }
  #compass { right: 12px; bottom: 34px; transform: scale(0.82); transform-origin: 100% 100%; }
  #toast { bottom: 78px; font-size: 10px; }
  #grain { display: none; }
  .hotspot { padding: 12px; }
  .hs-dot { width: 8px; height: 8px; }
}

@media (max-width: 560px) {
  #toolbar .txt { display: none; }
  #toolbar button { width: 34px; padding: 0; justify-content: center; }
  .brand-copy .sub { display: none; }
  .brand-copy h1 { font-size: 19px; }
  #route-panel { top: 70px; }
  .load-title { font-size: 30px; }
  .loading .load-foot { font-size: 12px; }
  #walkbar { top: 64px; max-width: calc(100vw - 24px); overflow: auto; }
  #walkbar .walk-tip { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
}

/* return link injected for the portfolio embedding */
#yl-back {
  position: fixed;
  left: 24px;
  bottom: 28px;
  z-index: 50;
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 8px 14px;
  border: 1px solid rgba(120, 95, 55, 0.32);
  border-radius: 99px;
  background: rgba(248, 243, 232, 0.84);
  color: #3a342a;
  font-size: 11px;
  letter-spacing: 0.08em;
  text-decoration: none;
  box-shadow: 0 6px 20px rgba(24, 19, 12, 0.16);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: background 0.2s ease, transform 0.2s ease;
}

#yl-back:hover {
  background: rgba(255, 251, 242, 0.96);
  transform: translateY(-2px);
}

body.walking #yl-back,
body.no-ui #yl-back { display: none; }

@media (max-width: 780px) {
  #yl-back { left: 12px; bottom: 18px; padding: 7px 12px; font-size: 10px; }
}