/* ==========================================================================
   opening.css — Opening animation styles for 3 variants:
   skyline (dual city silhouette), particles (narrative), paperplane (journey)
   开场动画样式：三个变体 — 双城剪影、粒子叙事、纸飞机旅途
   ========================================================================== */

/* --- Shared: Opening screen container / 共享：开场屏幕容器 --- */
#opening-screen {
  background: radial-gradient(ellipse at 50% 40%, var(--bg-deep-magenta) 0%, var(--bg-dark-rose) 30%, var(--bg-black) 100%);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  position: relative;
}

/* --- Shared: Canvas layer for particle effects / 共享：粒子效果画布层 --- */
.opening-canvas {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 1;
}

/* --- Shared: SVG layer / 共享：SVG 层 --- */
.opening-svg-layer {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 2;
}

/* --- Shared: Text overlay layer / 共享：文字覆盖层 --- */
.opening-text-layer {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 3;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

/* --- Shared: Text styles / 共享：文字样式 --- */
.opening-text {
  position: absolute;
  color: var(--text-secondary);
  font-size: 14px;
  letter-spacing: 3px;
  opacity: 0;
  -webkit-transform: translateY(8px) translateZ(0);
  transform: translateY(8px) translateZ(0);
  -webkit-transition: opacity 0.8s ease, -webkit-transform 0.8s ease;
  transition: opacity 0.8s ease, transform 0.8s ease;
  text-align: center;
  white-space: nowrap;
  font-family: 'Georgia', 'PingFang SC', serif;
}

.opening-text.visible {
  opacity: 1;
  -webkit-transform: translateY(0) translateZ(0);
  transform: translateY(0) translateZ(0);
}

.opening-text.center {
  top: 50%;
  left: 50%;
  -webkit-transform: translate(-50%, -50%) translateZ(0);
  transform: translate(-50%, -50%) translateZ(0);
}

.opening-text.center.visible {
  -webkit-transform: translate(-50%, -50%) translateZ(0);
  transform: translate(-50%, -50%) translateZ(0);
}

/* --- Title text with golden shimmer / 标题文字金色微光 --- */
.opening-title {
  font-size: 20px;
  letter-spacing: 4px;
  color: var(--gold);
  text-shadow: 0 2px 12px rgba(0, 0, 0, 0.4);
  font-family: 'Georgia', 'PingFang SC', serif;
}

.opening-subtitle {
  font-size: 13px;
  color: var(--text-muted);
  letter-spacing: 2px;
  margin-top: 12px;
}

/* --- City label text / 城市标签文字 --- */
.opening-city-label {
  position: absolute;
  font-size: 12px;
  letter-spacing: 2px;
  color: rgba(255, 255, 255, 0.6);
  opacity: 0;
  -webkit-transition: opacity 0.8s ease;
  transition: opacity 0.8s ease;
  white-space: nowrap;
  font-family: 'Georgia', 'PingFang SC', serif;
}

.opening-city-label.visible {
  opacity: 1;
}

/* --- Distance text / 距离文字 --- */
.opening-distance {
  position: absolute;
  bottom: 38%;
  left: 50%;
  -webkit-transform: translate(-50%, -50%) translateZ(0);
  transform: translate(-50%, -50%) translateZ(0);
  font-size: 18px;
  letter-spacing: 6px;
  color: rgba(201, 169, 78, 0.7);
  opacity: 0;
  -webkit-transition: opacity 1s ease;
  transition: opacity 1s ease;
  font-family: 'Georgia', serif;
  font-weight: 300;
}

.opening-distance.visible {
  opacity: 1;
}

/* --- Progress bar / 进度条 --- */
.opening-progress-bar {
  position: absolute;
  bottom: 80px;
  left: 50%;
  -webkit-transform: translateX(-50%) translateZ(0);
  transform: translateX(-50%) translateZ(0);
  width: 60vw;
  max-width: 400px;
  height: 2px;
  background: rgba(255, 255, 255, 0.08);
  border-radius: 1px;
  overflow: hidden;
  opacity: 0;
  z-index: 5;
  -webkit-transition: opacity 0.4s ease;
  transition: opacity 0.4s ease;
}

.opening-progress-bar.visible {
  opacity: 1;
}

.opening-progress-fill {
  width: 0%;
  height: 100%;
  background: linear-gradient(90deg, var(--pink-primary), var(--gold-soft));
  border-radius: 1px;
  -webkit-transition: width 0.1s linear;
  transition: width 0.1s linear;
}

/* --- Bottom text area / 底部文字区域 --- */
.opening-bottom-text {
  position: absolute;
  bottom: 44px;
  left: 0;
  right: 0;
  text-align: center;
  font-size: 14px;
  letter-spacing: 2px;
  color: var(--text-secondary);
  opacity: 0;
  -webkit-transform: translateY(8px) translateZ(0);
  transform: translateY(8px) translateZ(0);
  pointer-events: none;
  z-index: 5;
  font-family: 'Georgia', 'PingFang SC', serif;
}

.opening-bottom-text.visible {
  -webkit-animation: openingFadeInUp 0.8s ease forwards;
  animation: openingFadeInUp 0.8s ease forwards;
}

.opening-arrival-text {
  position: absolute;
  bottom: 20px;
  left: 0;
  right: 0;
  text-align: center;
  font-size: 16px;
  color: var(--pink-soft);
  opacity: 0;
  -webkit-transform: translateZ(0);
  transform: translateZ(0);
  pointer-events: none;
  z-index: 5;
}

.opening-arrival-text.visible {
  -webkit-animation: openingFadeInUp 0.6s ease forwards;
  animation: openingFadeInUp 0.6s ease forwards;
}

/* ==========================================================================
   Variant A: "skyline" — Dual City Skyline
   变体A：双城剪影
   ========================================================================== */

/* Skyline SVG container / 天际线 SVG 容器 */
.skyline-scene {
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 2;
  overflow: hidden;
}

/* Sydney skyline group / 悉尼天际线组 */
.skyline-sydney {
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 40%;
  -webkit-transform: translateY(100%) translateZ(0);
  transform: translateY(100%) translateZ(0);
  -webkit-transition: -webkit-transform 1.2s cubic-bezier(0.25, 0.46, 0.45, 0.94), opacity 1.2s ease;
  transition: transform 1.2s cubic-bezier(0.25, 0.46, 0.45, 0.94), opacity 1.2s ease;
  opacity: 0;
}

.skyline-sydney.visible {
  -webkit-transform: translateY(0) translateZ(0);
  transform: translateY(0) translateZ(0);
  opacity: 1;
}

.skyline-sydney.exit {
  -webkit-transform: translateX(-100%) translateZ(0);
  transform: translateX(-100%) translateZ(0);
  opacity: 0;
  -webkit-transition: -webkit-transform 1.5s ease-in, opacity 1.5s ease-in;
  transition: transform 1.5s ease-in, opacity 1.5s ease-in;
}

/* Sanhe skyline group / 三合镇天际线组 */
.skyline-sanhe {
  position: absolute;
  bottom: 0;
  right: 0;
  width: 100%;
  height: 40%;
  -webkit-transform: translateX(100%) translateZ(0);
  transform: translateX(100%) translateZ(0);
  -webkit-transition: -webkit-transform 1.5s cubic-bezier(0.25, 0.46, 0.45, 0.94), opacity 1.5s ease;
  transition: transform 1.5s cubic-bezier(0.25, 0.46, 0.45, 0.94), opacity 1.5s ease;
  opacity: 0;
}

.skyline-sanhe.visible {
  -webkit-transform: translateX(0) translateZ(0);
  transform: translateX(0) translateZ(0);
  opacity: 1;
}

/* Skyline SVG fill gradient / 天际线 SVG 渐变填充 */
.skyline-fill {
  fill: url(#skylineGradient);
}

.skyline-fill-sanhe {
  fill: url(#skylineGradientSanhe);
}

/* Envelope SVG for skyline variant / 天际线变体信封 SVG */
.skyline-envelope {
  position: absolute;
  z-index: 3;
  opacity: 0;
  -webkit-transition: opacity 0.6s ease;
  transition: opacity 0.6s ease;
  pointer-events: none;
}

.skyline-envelope.visible {
  opacity: 1;
}

/* ==========================================================================
   Variant B: "particles" — Particle Narrative
   变体B：粒子叙事
   ========================================================================== */

/* Central light point / 中心光点 */
.particles-light {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--gold);
  -webkit-transform: translate(-50%, -50%) translateZ(0);
  transform: translate(-50%, -50%) translateZ(0);
  box-shadow: 0 0 20px var(--gold), 0 0 40px rgba(255, 215, 0, 0.3);
  opacity: 0;
  z-index: 2;
  -webkit-transition: opacity 0.5s ease;
  transition: opacity 0.5s ease;
}

.particles-light.visible {
  opacity: 1;
  -webkit-animation: particleBreathe 1.5s ease-in-out infinite;
  animation: particleBreathe 1.5s ease-in-out infinite;
}

@-webkit-keyframes particleBreathe {
  0%, 100% {
    -webkit-transform: translate(-50%, -50%) scale(1) translateZ(0);
    box-shadow: 0 0 20px var(--gold), 0 0 40px rgba(255, 215, 0, 0.3);
  }
  50% {
    -webkit-transform: translate(-50%, -50%) scale(1.8) translateZ(0);
    box-shadow: 0 0 40px var(--gold), 0 0 80px rgba(255, 215, 0, 0.4);
  }
}

@keyframes particleBreathe {
  0%, 100% {
    transform: translate(-50%, -50%) scale(1) translateZ(0);
    box-shadow: 0 0 20px var(--gold), 0 0 40px rgba(255, 215, 0, 0.3);
  }
  50% {
    transform: translate(-50%, -50%) scale(1.8) translateZ(0);
    box-shadow: 0 0 40px var(--gold), 0 0 80px rgba(255, 215, 0, 0.4);
  }
}

/* Pink halo around the light / 光点周围粉色光晕 */
.particles-halo {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 120px;
  height: 120px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(255, 20, 147, 0.2) 0%, transparent 70%);
  -webkit-transform: translate(-50%, -50%) scale(0) translateZ(0);
  transform: translate(-50%, -50%) scale(0) translateZ(0);
  z-index: 1;
  -webkit-transition: -webkit-transform 1s ease;
  transition: transform 1s ease;
}

.particles-halo.visible {
  -webkit-transform: translate(-50%, -50%) scale(1) translateZ(0);
  transform: translate(-50%, -50%) scale(1) translateZ(0);
}

/* Typewriter text / 打字机文字 */
.particles-typewriter {
  position: absolute;
  top: 42%;
  left: 50%;
  -webkit-transform: translate(-50%, -50%) translateZ(0);
  transform: translate(-50%, -50%) translateZ(0);
  font-size: 18px;
  letter-spacing: 3px;
  color: rgba(255, 255, 255, 0.85);
  font-family: 'Georgia', 'PingFang SC', 'STSong', serif;
  z-index: 4;
  white-space: nowrap;
  opacity: 0;
  -webkit-transition: opacity 0.3s ease;
  transition: opacity 0.3s ease;
}

.particles-typewriter.visible {
  opacity: 1;
}

/* Journey text snippets along the path / 旅途文字片段 */
.particles-journey-text {
  position: absolute;
  font-size: 14px;
  letter-spacing: 2px;
  color: rgba(255, 255, 255, 0.6);
  font-family: 'Georgia', 'PingFang SC', serif;
  z-index: 4;
  opacity: 0;
  -webkit-transition: opacity 0.8s ease;
  transition: opacity 0.8s ease;
  white-space: nowrap;
}

.particles-journey-text.visible {
  opacity: 1;
}

.particles-journey-text.fade-out {
  opacity: 0;
}

/* ==========================================================================
   Variant C: "paperplane" — Paper Plane Journey
   变体C：纸飞机旅途
   ========================================================================== */

/* Letter paper / 信纸 */
.paperplane-letter {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 200px;
  height: 260px;
  -webkit-transform: translate(-50%, 120%) translateZ(0);
  transform: translate(-50%, 120%) translateZ(0);
  background: linear-gradient(180deg, #FFF8F0 0%, #F5EDE0 100%);
  border: 2px solid var(--gold-soft);
  border-radius: 2px;
  z-index: 3;
  opacity: 0;
  -webkit-transition: opacity 0.6s ease, -webkit-transform 1s cubic-bezier(0.25, 0.46, 0.45, 0.94);
  transition: opacity 0.6s ease, transform 1s cubic-bezier(0.25, 0.46, 0.45, 0.94);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
  -webkit-perspective: 800px;
  perspective: 800px;
}

.paperplane-letter.visible {
  opacity: 1;
  -webkit-transform: translate(-50%, -50%) translateZ(0);
  transform: translate(-50%, -50%) translateZ(0);
}

/* Handwriting lines on the paper / 信纸上的手写线 */
.paperplane-letter::before {
  content: '';
  position: absolute;
  top: 30px;
  left: 20px;
  right: 20px;
  bottom: 30px;
  background: repeating-linear-gradient(
    180deg,
    transparent 0px,
    transparent 24px,
    rgba(200, 180, 160, 0.3) 24px,
    rgba(200, 180, 160, 0.3) 25px
  );
}

/* Gold decorative corner / 金色装饰角 */
.paperplane-letter::after {
  content: '';
  position: absolute;
  top: 8px;
  left: 8px;
  right: 8px;
  bottom: 8px;
  border: 1px solid rgba(240, 192, 64, 0.3);
  border-radius: 1px;
  pointer-events: none;
}

/* Paper plane 3D wrapper / 纸飞机 3D 包装 */
.paperplane-3d {
  position: absolute;
  top: 50%;
  left: 35%;
  z-index: 3;
  opacity: 0;
  -webkit-transform: translateZ(0);
  transform: translateZ(0);
  -webkit-transition: opacity 0.3s ease;
  transition: opacity 0.3s ease;
}

.paperplane-3d.visible {
  opacity: 1;
}

/* Paper plane SVG bob animation / 纸飞机上下浮动动画 */
.paperplane-bob {
  -webkit-animation: paperplaneBob 2s ease-in-out infinite;
  animation: paperplaneBob 2s ease-in-out infinite;
}

@-webkit-keyframes paperplaneBob {
  0%, 100% { -webkit-transform: translateY(0) rotate(-5deg) translateZ(0); }
  50% { -webkit-transform: translateY(-8px) rotate(0deg) translateZ(0); }
}

@keyframes paperplaneBob {
  0%, 100% { transform: translateY(0) rotate(-5deg) translateZ(0); }
  50% { transform: translateY(-8px) rotate(0deg) translateZ(0); }
}

/* Parallax landscape container / 视差景观容器 */
.paperplane-landscape {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
  z-index: 1;
}

/* Parallax layers / 视差层 */
.parallax-layer {
  position: absolute;
  top: 0;
  left: 0;
  height: 100%;
  -webkit-transform: translateZ(0);
  transform: translateZ(0);
  will-change: transform;
}

.parallax-layer.stars {
  width: 200%;
  z-index: 0;
}

.parallax-layer.clouds {
  width: 300%;
  z-index: 1;
}

.parallax-layer.landscape {
  width: 500%;
  z-index: 2;
}

/* ==========================================================================
   Shared Keyframe Animations
   共享关键帧动画
   ========================================================================== */

@-webkit-keyframes openingFadeInUp {
  from {
    opacity: 0;
    -webkit-transform: translateY(8px) translateZ(0);
  }
  to {
    opacity: 1;
    -webkit-transform: translateY(0) translateZ(0);
  }
}

@keyframes openingFadeInUp {
  from {
    opacity: 0;
    transform: translateY(8px) translateZ(0);
  }
  to {
    opacity: 1;
    transform: translateY(0) translateZ(0);
  }
}

@-webkit-keyframes openingFadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes openingFadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

/* Shooting star / 流星 */
@-webkit-keyframes shootingStar {
  0% {
    -webkit-transform: translateX(0) translateY(0) translateZ(0);
    opacity: 1;
  }
  100% {
    -webkit-transform: translateX(200px) translateY(100px) translateZ(0);
    opacity: 0;
  }
}

@keyframes shootingStar {
  0% {
    transform: translateX(0) translateY(0) translateZ(0);
    opacity: 1;
  }
  100% {
    transform: translateX(200px) translateY(100px) translateZ(0);
    opacity: 0;
  }
}

/* --- Fade out entire opening screen / 整个开场屏幕淡出 --- */
#opening-screen.fade-out {
  -webkit-animation: fadeOutScreen 0.6s ease forwards;
  animation: fadeOutScreen 0.6s ease forwards;
}

@-webkit-keyframes fadeOutScreen {
  from { opacity: 1; }
  to { opacity: 0; }
}

@keyframes fadeOutScreen {
  from { opacity: 1; }
  to { opacity: 0; }
}

/* ==========================================================================
   Responsive / 响应式
   ========================================================================== */

@media (max-width: 480px) {
  .opening-title {
    font-size: 16px;
    letter-spacing: 3px;
  }

  .opening-subtitle {
    font-size: 11px;
  }

  .opening-city-label {
    font-size: 10px;
  }

  .opening-distance {
    font-size: 14px;
    letter-spacing: 4px;
  }

  .opening-bottom-text {
    font-size: 12px;
    bottom: 40px;
  }

  .opening-arrival-text {
    font-size: 14px;
    bottom: 18px;
  }

  .opening-progress-bar {
    bottom: 70px;
  }

  .particles-typewriter {
    font-size: 15px;
  }

  .paperplane-letter {
    width: 160px;
    height: 210px;
  }
}