/* ==========================================================================
   loading.css — Loading screen animations: SVG world map + flight path
   加载屏幕动画：SVG 世界地图 + 信件飞行路径
   ========================================================================== */

/* --- Loading screen container / 加载屏幕容器 --- */
#loading-screen {
  background: linear-gradient(135deg, var(--bg-black) 0%, var(--bg-dark-rose) 40%, var(--bg-deep-magenta) 100%);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

/* --- Map container / 地图容器 --- */
.loading-map-container {
  position: relative;
  width: 90vw;
  max-width: 800px;
  opacity: 0;
  -webkit-transform: translateZ(0);
  transform: translateZ(0);
}

.loading-map-container.visible {
  -webkit-animation: fadeInMap 1s ease forwards;
  animation: fadeInMap 1s ease forwards;
}

@-webkit-keyframes fadeInMap {
  from { opacity: 0; -webkit-transform: scale(0.95) translateZ(0); }
  to   { opacity: 1; -webkit-transform: scale(1) translateZ(0); }
}
@keyframes fadeInMap {
  from { opacity: 0; transform: scale(0.95) translateZ(0); }
  to   { opacity: 1; transform: scale(1) translateZ(0); }
}

/* --- SVG map styling / SVG 地图样式 --- */
.loading-map-svg {
  width: 100%;
  height: auto;
  display: block;
}

.loading-map-svg .continent {
  fill: rgba(255, 255, 255, 0.06);
  stroke: rgba(255, 255, 255, 0.12);
  stroke-width: 0.5;
}

.loading-map-svg .flight-arc {
  fill: none;
  stroke: var(--pink-primary);
  stroke-width: 2;
  stroke-linecap: round;
  stroke-dasharray: 8 4;
  opacity: 0;
}

.loading-map-svg .flight-arc.animating {
  opacity: 0.8;
  -webkit-animation: drawArc 4s linear forwards;
  animation: drawArc 4s linear forwards;
}

@-webkit-keyframes drawArc {
  from { stroke-dashoffset: 600; }
  to   { stroke-dashoffset: 0; }
}
@keyframes drawArc {
  from { stroke-dashoffset: 600; }
  to   { stroke-dashoffset: 0; }
}

/* --- City dots (pulsing) / 城市圆点（脉冲） --- */
.city-dot {
  position: absolute;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--pink-primary);
  opacity: 0;
  -webkit-transform: translate(-50%, -50%) translateZ(0);
  transform: translate(-50%, -50%) translateZ(0);
  pointer-events: none;
}

.city-dot.active {
  opacity: 1;
  -webkit-animation: pulseDot 1.5s ease-in-out infinite;
  animation: pulseDot 1.5s ease-in-out infinite;
}

@-webkit-keyframes pulseDot {
  0%, 100% {
    -webkit-transform: translate(-50%, -50%) scale(1) translateZ(0);
    box-shadow: 0 0 6px var(--pink-glow), 0 0 16px var(--pink-glow);
  }
  50% {
    -webkit-transform: translate(-50%, -50%) scale(1.6) translateZ(0);
    box-shadow: 0 0 12px var(--pink-primary), 0 0 30px var(--pink-glow);
  }
}
@keyframes pulseDot {
  0%, 100% {
    transform: translate(-50%, -50%) scale(1) translateZ(0);
    box-shadow: 0 0 6px var(--pink-glow), 0 0 16px var(--pink-glow);
  }
  50% {
    transform: translate(-50%, -50%) scale(1.6) translateZ(0);
    box-shadow: 0 0 12px var(--pink-primary), 0 0 30px var(--pink-glow);
  }
}

/* --- City labels / 城市标签 --- */
.city-label {
  position: absolute;
  font-size: 11px;
  color: var(--text-secondary);
  white-space: nowrap;
  opacity: 0;
  -webkit-transform: translateZ(0);
  transform: translateZ(0);
  pointer-events: none;
}

.city-label.visible {
  -webkit-animation: fadeInLabel 0.6s ease forwards;
  animation: fadeInLabel 0.6s ease forwards;
}

@-webkit-keyframes fadeInLabel {
  from { opacity: 0; -webkit-transform: translateY(4px) translateZ(0); }
  to   { opacity: 1; -webkit-transform: translateY(0) translateZ(0); }
}
@keyframes fadeInLabel {
  from { opacity: 0; transform: translateY(4px) translateZ(0); }
  to   { opacity: 1; transform: translateY(0) translateZ(0); }
}

/* --- Flying sprite (balloon + envelope) / 飞行精灵（气球+信封） --- */
.flight-sprite {
  position: absolute;
  width: 40px;
  height: 70px;
  opacity: 0;
  -webkit-transform: translateZ(0);
  transform: translateZ(0);
  pointer-events: none;
  /* offset-path set by JS */
}

/* When using CSS offset-path / 使用 CSS offset-path 时 */
.flight-sprite.offset-path-mode {
  offset-rotate: 0deg;
  -webkit-animation: flyAlongPath 4s linear forwards, spriteAppear 0.3s ease forwards;
  animation: flyAlongPath 4s linear forwards, spriteAppear 0.3s ease forwards;
}

@-webkit-keyframes flyAlongPath {
  from { offset-distance: 0%; }
  to   { offset-distance: 100%; }
}
@keyframes flyAlongPath {
  from { offset-distance: 0%; }
  to   { offset-distance: 100%; }
}

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

/* JS fallback mode — JS sets left/top directly */
.flight-sprite.js-path-mode {
  opacity: 1;
  -webkit-transition: none;
  transition: none;
}

/* --- Heart balloons / 心形气球 --- */
.balloon-group {
  position: absolute;
  top: 0;
  left: 50%;
  -webkit-transform: translateX(-50%) translateZ(0);
  transform: translateX(-50%) translateZ(0);
  display: flex;
  gap: 2px;
  -webkit-animation: balloonSway 2s ease-in-out infinite;
  animation: balloonSway 2s ease-in-out infinite;
}

@-webkit-keyframes balloonSway {
  0%, 100% { -webkit-transform: translateX(-50%) rotate(-3deg) translateZ(0); }
  50%      { -webkit-transform: translateX(-50%) rotate(3deg) translateZ(0); }
}
@keyframes balloonSway {
  0%, 100% { transform: translateX(-50%) rotate(-3deg) translateZ(0); }
  50%      { transform: translateX(-50%) rotate(3deg) translateZ(0); }
}

/* Individual heart shape using CSS / 单个心形用 CSS 实现 */
.heart-balloon {
  position: relative;
  width: 14px;
  height: 13px;
}

.heart-balloon::before,
.heart-balloon::after {
  content: '';
  position: absolute;
  top: 0;
  width: 8px;
  height: 13px;
  border-radius: 8px 8px 0 0;
  background: linear-gradient(180deg, #ff6b9d 0%, #FF1493 50%, #c2185b 100%);
}

.heart-balloon::before {
  left: 0;
  -webkit-transform: rotate(-45deg);
  transform: rotate(-45deg);
  -webkit-transform-origin: 100% 100%;
  transform-origin: 100% 100%;
}

.heart-balloon::after {
  right: 0;
  -webkit-transform: rotate(45deg);
  transform: rotate(45deg);
  -webkit-transform-origin: 0% 100%;
  transform-origin: 0% 100%;
}

/* Metallic foil shimmer overlay / 金属箔微光 */
.heart-balloon .shimmer {
  position: absolute;
  top: 1px;
  left: 3px;
  width: 4px;
  height: 5px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.35);
  -webkit-filter: blur(1px);
  filter: blur(1px);
  pointer-events: none;
}

/* Balloon strings / 气球绳子 */
.balloon-strings {
  position: absolute;
  top: 13px;
  left: 50%;
  -webkit-transform: translateX(-50%);
  transform: translateX(-50%);
  width: 16px;
  height: 20px;
}

.balloon-strings .string {
  position: absolute;
  width: 1px;
  height: 20px;
  background: rgba(255, 255, 255, 0.3);
}

.balloon-strings .string:first-child {
  left: 3px;
  -webkit-transform: rotate(-5deg);
  transform: rotate(-5deg);
}

.balloon-strings .string:last-child {
  right: 3px;
  -webkit-transform: rotate(5deg);
  transform: rotate(5deg);
}

/* Envelope below strings / 绳子下方的信封 */
.sprite-envelope {
  position: absolute;
  bottom: 5px;
  left: 50%;
  -webkit-transform: translateX(-50%) translateZ(0);
  transform: translateX(-50%) translateZ(0);
  width: 18px;
  height: 12px;
  background: #f5e6d0;
  border-radius: 1px;
  border: 1px solid #d4c4a8;
  overflow: hidden;
}

/* Envelope flap / 信封盖 */
.sprite-envelope::before {
  content: '';
  position: absolute;
  top: -1px;
  left: -1px;
  right: -1px;
  height: 7px;
  background: #e8d5bc;
  -webkit-clip-path: polygon(0 0, 50% 70%, 100% 0);
  clip-path: polygon(0 0, 50% 70%, 100% 0);
}

/* Tiny heart on envelope / 信封上的小爱心 */
.sprite-envelope::after {
  content: '';
  position: absolute;
  bottom: 1px;
  left: 50%;
  -webkit-transform: translateX(-50%);
  transform: translateX(-50%);
  width: 4px;
  height: 4px;
  background: var(--pink-primary);
  border-radius: 50%;
}

/* --- Progress bar / 进度条 --- */
.loading-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;
}

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

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

/* --- Bottom text / 底部文字 --- */
.loading-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;
}

.loading-bottom-text.visible {
  -webkit-animation: fadeInText 0.8s ease forwards;
  animation: fadeInText 0.8s ease forwards;
}

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

.loading-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;
}

.loading-arrival-text.visible {
  -webkit-animation: fadeInText 0.6s ease forwards;
  animation: fadeInText 0.6s ease forwards;
}

/* --- Fade out entire loading screen / 整个加载屏幕淡出 --- */
#loading-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 adjustments / 响应式调整 --- */
@media (max-width: 480px) {
  .city-label {
    font-size: 9px;
  }
  .flight-sprite {
    width: 30px;
    height: 55px;
  }
  .heart-balloon {
    width: 11px;
    height: 10px;
  }
  .heart-balloon::before,
  .heart-balloon::after {
    width: 6px;
    height: 10px;
    border-radius: 6px 6px 0 0;
  }
  .balloon-strings {
    top: 10px;
    height: 16px;
  }
  .balloon-strings .string {
    height: 16px;
  }
  .sprite-envelope {
    width: 14px;
    height: 10px;
  }
  .loading-bottom-text {
    font-size: 12px;
    bottom: 40px;
  }
  .loading-arrival-text {
    font-size: 14px;
    bottom: 18px;
  }
  .loading-progress-bar {
    bottom: 70px;
  }
}