:root {
  --bg-wallpaper: #ede3d3;
  --bg-layer: #e6dac8;
  --gray-1: #f2f2f2;
  --gray-2: #d9d9d9;
  --gray-3: #bfbfbf;
  --gray-4: #8c8c8c;
  --gray-5: #595959;
  --text-primary: #404040;
  --shadow-soft: rgba(64, 64, 64, 0.16);
  --shadow-strong: rgba(56, 56, 56, 0.22);
  --glass-bg: rgba(255, 255, 255, 0.26);
  --glass-border: rgba(120, 120, 120, 0.28);
  --motion-fast: 220ms;
  --motion-mid: 420ms;
  --motion-slow: 800ms;
  --easing-main: cubic-bezier(0.22, 0.61, 0.36, 1);
}

* {
  box-sizing: border-box;
}

html,
body {
  width: 100%;
  height: 100%;
  margin: 0;
  font-family: "PingFang SC", "Microsoft YaHei", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--text-primary);
  overflow: hidden;
  overscroll-behavior: none;
  -ms-overflow-style: none;
  scrollbar-width: none;
}

html::-webkit-scrollbar,
body::-webkit-scrollbar {
  width: 0;
  height: 0;
}

body {
  background: var(--bg-wallpaper);
  padding-left: env(safe-area-inset-left);
  padding-right: env(safe-area-inset-right);
}

.app-shell {
  position: relative;
  min-height: 100%;
  overflow: hidden;
  display: grid;
  grid-template-rows: auto 1fr auto;
}

.wallpaper {
  position: absolute;
  inset: 0;
  z-index: 0;
  background:
    radial-gradient(130% 100% at 20% 10%, rgba(255, 255, 255, 0.22), transparent 70%),
    radial-gradient(120% 100% at 80% 90%, rgba(191, 191, 191, 0.1), transparent 65%),
    repeating-linear-gradient(
      -7deg,
      var(--bg-wallpaper) 0px,
      var(--bg-wallpaper) 11px,
      var(--bg-layer) 12px,
      var(--bg-layer) 13px
    );
  filter: saturate(0.95);
  animation: wallpaperShift 16s ease-in-out infinite alternate;
}

.top-bar,
.control-bar,
.stage {
  position: relative;
  z-index: 1;
}

.top-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 24px 28px 12px;
  width: min(1220px, 96vw);
  margin: 0 auto;
}

.top-right {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand {
  letter-spacing: 0.1em;
  font-size: 14px;
  font-weight: 600;
  color: var(--gray-5);
  padding: 7px 12px;
  border: 1px solid var(--glass-border);
  border-radius: 999px;
  background: var(--glass-bg);
  backdrop-filter: blur(3px);
}

.progress-text {
  font-size: 12px;
  color: #5f5f5f;
  letter-spacing: 0.08em;
  padding: 7px 12px;
  border: 1px solid var(--glass-border);
  border-radius: 999px;
  background: var(--glass-bg);
  backdrop-filter: blur(3px);
}

.mode-btn {
  border: 1px solid var(--gray-3);
  background: rgba(255, 255, 255, 0.35);
  color: var(--gray-5);
  height: 32px;
  border-radius: 999px;
  padding: 0 14px;
  font-size: 12px;
  cursor: pointer;
  transition: all var(--motion-fast) var(--easing-main);
}

.mode-btn:hover {
  border-color: var(--gray-4);
}

.stage {
  width: min(1120px, 96vw);
  margin: 0 auto;
  display: grid;
  grid-template-rows: minmax(0, 1fr) auto;
  gap: clamp(14px, 2vh, 24px);
  align-items: stretch;
}

.scene-canvas-wrap {
  position: relative;
  display: grid;
  place-items: center;
  height: clamp(360px, 60vh, 620px);
  min-height: 0;
  overflow: hidden;
}

.ambient-layer {
  position: absolute;
  inset: 8% 12%;
  pointer-events: none;
}

.ambient {
  position: absolute;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(217, 217, 217, 0.55) 0%, rgba(217, 217, 217, 0) 70%);
  filter: blur(6px);
  animation: floatSlow 9s ease-in-out infinite alternate;
}

.ambient.a1 {
  width: 220px;
  height: 220px;
  left: 8%;
  top: 12%;
}

.ambient.a2 {
  width: 180px;
  height: 180px;
  right: 12%;
  top: 18%;
  animation-delay: 1.2s;
}

.ambient.a3 {
  width: 240px;
  height: 240px;
  left: 36%;
  bottom: 6%;
  animation-delay: 2.2s;
}

.scene-canvas {
  width: min(980px, 94vw);
  height: min(580px, 64vh);
  transition: transform 320ms var(--easing-main), opacity 320ms var(--easing-main);
  will-change: transform;
  filter: drop-shadow(0 18px 24px var(--shadow-soft));
}

.scene-canvas-wrap.art-swapping .scene-canvas {
  animation: artSwapIn 260ms var(--easing-main);
}

.scene-meta {
  text-align: center;
  padding-bottom: 16px;
  max-width: 920px;
  margin: 0 auto;
  width: 100%;
  min-height: clamp(110px, 17vh, 210px);
  display: grid;
  align-content: start;
  justify-items: center;
  padding-top: 6px;
}

.slide-content .scene-meta {
  display: grid;
  place-items: center;
}

.scene-title {
  margin: 0;
  font-size: clamp(24px, 4vw, 40px);
  font-weight: 500;
  color: var(--gray-5);
}

.scene-subtitle {
  margin: 10px 0 0;
  font-size: clamp(13px, 2vw, 16px);
  color: var(--gray-4);
  letter-spacing: 0.06em;
}

.slide-text {
  margin: 0;
  width: min(900px, 88vw);
  font-size: clamp(24px, 4.2vw, 48px);
  line-height: 1.45;
  font-weight: 500;
  color: #4a4a4a;
  letter-spacing: 0.01em;
  text-wrap: pretty;
  white-space: normal;
  overflow-wrap: break-word;
  word-break: normal;
  text-shadow: 0 2px 18px rgba(237, 227, 211, 0.75);
  min-height: 2.9em;
  padding: 16px 20px;
  border-radius: 18px;
  border: 1px solid var(--glass-border);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.34), rgba(255, 255, 255, 0.18));
  backdrop-filter: blur(4px);
  box-shadow: 0 12px 28px rgba(90, 90, 90, 0.1);
}

.slide-line {
  display: block;
  white-space: normal;
  max-width: 100%;
}

.slide-line + .slide-line {
  margin-top: 0.18em;
}

.restart-btn {
  margin-top: 18px;
  height: 42px;
  padding: 0 22px;
  border-radius: 999px;
  border: 1px solid #676767;
  background: rgba(255, 255, 255, 0.7);
  color: #4d4d4d;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.04em;
  cursor: pointer;
  transition: all var(--motion-fast) var(--easing-main);
  box-shadow: 0 8px 18px rgba(80, 80, 80, 0.12);
}

.restart-btn:hover {
  background: rgba(255, 255, 255, 0.9);
  border-color: #5d5d5d;
  transform: translateY(-1px);
}

.slide-kicker {
  margin: 0 0 12px;
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: #6c6c6c;
  border: 1px solid rgba(108, 108, 108, 0.4);
  padding: 5px 10px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.35);
  box-shadow: 0 4px 12px rgba(80, 80, 80, 0.08);
}

.phrase {
  display: inline;
  opacity: 0;
  transform: translateY(10px);
  animation: phraseIn 460ms var(--easing-main) forwards;
  animation-delay: var(--phrase-delay, 0ms);
  white-space: normal;
  max-width: 100%;
}

.control-bar {
  display: flex;
  justify-content: center;
  gap: 12px;
  padding: 0 16px 30px;
}

.control-btn {
  border: 1px solid transparent;
  min-width: 112px;
  height: 40px;
  border-radius: 999px;
  font-size: 14px;
  cursor: pointer;
  transition: all var(--motion-fast) var(--easing-main);
}

.control-btn.primary {
  background: var(--gray-5);
  color: var(--gray-1);
}

.control-btn.primary:hover {
  background: #505050;
}

.control-btn.secondary {
  border-color: var(--gray-3);
  background: rgba(255, 255, 255, 0.35);
  color: var(--gray-5);
}

.control-btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.scene-content {
  opacity: 1;
  transform: translateY(0);
  transition:
    opacity var(--motion-mid) var(--easing-main),
    transform var(--motion-mid) var(--easing-main);
}

.scene-content.is-entering {
  opacity: 0;
  transform: translateY(16px);
}

.scene-content.is-exiting {
  opacity: 0;
  transform: translateY(-16px);
}

.dot {
  transform-origin: center;
  animation: pulse 2.2s infinite ease-in-out;
}

.line {
  stroke-linecap: round;
}

.line.soft {
  opacity: 0.68;
}

.plane {
  transform-origin: center;
  animation: fadeIn var(--motion-slow) var(--easing-main) both;
}

.solid {
  filter: drop-shadow(0 12px 18px var(--shadow-strong));
}

.dot.ghost {
  opacity: 0.7;
  animation-duration: 2.8s;
}

.hint {
  font-size: 12px;
  color: var(--gray-4);
  margin-top: 12px;
}

.load-error {
  margin: 18vh auto 0;
  width: min(760px, 88vw);
  text-align: center;
  color: #5a5a5a;
  font-size: 16px;
}

.control-bar,
.hint {
  opacity: 0;
  pointer-events: none;
}

.theme-problem .slide-text {
  color: #474747;
}

.theme-chapter .slide-kicker,
.theme-finale .slide-kicker {
  border-color: rgba(89, 89, 89, 0.48);
  color: #575757;
}

.theme-bullet .slide-text {
  font-size: clamp(22px, 3.9vw, 40px);
}

@keyframes pulse {
  0%,
  100% {
    transform: scale(1);
    opacity: 0.78;
  }
  50% {
    transform: scale(1.1);
    opacity: 1;
  }
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes phraseIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes artSwapIn {
  from {
    opacity: 0.58;
    transform: translateY(6px) scale(0.992);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

@keyframes floatSlow {
  from {
    transform: translateY(0px) translateX(0px) scale(1);
    opacity: 0.5;
  }
  to {
    transform: translateY(-12px) translateX(8px) scale(1.05);
    opacity: 0.78;
  }
}

@keyframes wallpaperShift {
  from {
    transform: scale(1) translateY(0px);
    opacity: 1;
  }
  to {
    transform: scale(1.02) translateY(-6px);
    opacity: 0.97;
  }
}

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

@media (max-width: 1280px) {
  .top-bar {
    padding: 18px 20px 8px;
  }
  .scene-canvas {
    width: min(900px, 94vw);
    height: min(500px, 58vh);
  }
  .scene-canvas-wrap {
    height: clamp(320px, 54vh, 560px);
  }
  .slide-text {
    font-size: clamp(22px, 3.7vw, 40px);
  }
}

@media (max-width: 900px) {
  .top-bar {
    width: min(100%, 100vw);
    padding: max(10px, env(safe-area-inset-top)) 14px 8px;
  }
  .brand,
  .progress-text {
    font-size: 11px;
    padding: 6px 10px;
  }
  .stage {
    width: min(100%, 100vw);
    gap: 10px;
    padding: 0 10px;
  }
  .scene-canvas-wrap {
    height: clamp(240px, 42vh, 360px);
  }
  .scene-canvas {
    width: min(700px, 96vw);
    height: min(320px, 40vh);
  }
  .scene-meta {
    min-height: 120px;
    padding-bottom: 8px;
  }
  .slide-kicker {
    font-size: 10px;
    letter-spacing: 0.12em;
    margin-bottom: 8px;
  }
  .slide-text {
    width: min(96vw, 720px);
    font-size: clamp(20px, 5.2vw, 30px);
    line-height: 1.42;
    padding: 12px 14px;
    min-height: 2.6em;
    border-radius: 14px;
  }
  .restart-btn {
    margin-top: 12px;
    height: 40px;
    padding: 0 18px;
    font-size: 13px;
  }
}

@media (max-width: 640px) {
  .wallpaper {
    background:
      radial-gradient(140% 100% at 30% 10%, rgba(255, 255, 255, 0.18), transparent 72%),
      radial-gradient(130% 100% at 80% 90%, rgba(191, 191, 191, 0.12), transparent 64%),
      repeating-linear-gradient(
        -7deg,
        var(--bg-wallpaper) 0px,
        var(--bg-wallpaper) 9px,
        var(--bg-layer) 10px,
        var(--bg-layer) 11px
      );
  }
  .top-bar {
    padding: max(8px, env(safe-area-inset-top)) 10px 6px;
  }
  .scene-canvas-wrap {
    height: clamp(200px, 34vh, 290px);
  }
  .scene-canvas {
    width: min(560px, 96vw);
    height: min(250px, 30vh);
  }
  .slide-text {
    width: min(96vw, 560px);
    font-size: clamp(18px, 6vw, 24px);
    line-height: 1.38;
    padding: 10px 12px;
  }
}

@media (max-width: 640px) and (orientation: landscape) {
  .top-bar {
    padding: 8px 10px 4px;
  }
  .scene-canvas-wrap {
    height: clamp(170px, 48vh, 230px);
  }
  .scene-canvas {
    height: min(200px, 42vh);
  }
  .slide-text {
    font-size: clamp(16px, 3.3vw, 22px);
    min-height: 2.2em;
  }
}

@media (max-height: 820px) {
  .scene-canvas-wrap {
    height: clamp(300px, 50vh, 500px);
  }
  .scene-canvas {
    height: min(460px, 52vh);
  }
  .slide-text {
    line-height: 1.35;
  }
}

@media (max-aspect-ratio: 4/3) {
  .stage {
    width: min(980px, 95vw);
  }
  .scene-canvas {
    width: min(840px, 92vw);
    height: min(440px, 48vh);
  }
  .scene-canvas-wrap {
    height: clamp(280px, 46vh, 460px);
  }
  .slide-text {
    width: min(820px, 92vw);
    font-size: clamp(20px, 3.4vw, 34px);
  }
}

@media (min-aspect-ratio: 21/9) {
  .stage {
    width: min(1380px, 92vw);
  }
  .scene-canvas {
    width: min(1120px, 78vw);
    height: min(580px, 62vh);
  }
  .slide-text {
    width: min(1120px, 80vw);
    font-size: clamp(28px, 3vw, 52px);
  }
}