/* === 內容容器置中 === */
.game-container {
  text-align: center;
  position: absolute;
  top: 18%;
  left: 50%;
  transform: translateX(-50%);
}

/* === 主標題 === */
.game-title {
  margin-top: -2%;
  font-size: 4rem;
  background: linear-gradient(90deg, #00ccff, #00ffee, #00ccff);
  background-clip: text;
  -webkit-background-clip: text;
  color: transparent;
  text-transform: uppercase;
  letter-spacing: 5px;
  opacity: 0;
  margin-bottom: 1.5rem;

  animation:
    cyberFlashIn 1.5s ease-out forwards,
    glowLoop 3s infinite ease-in-out;
}

/* === 副標題 === */
.game-subtitle {
  font-size: 1.2rem;
  color: rgba(0, 255, 255, 0.75);
  text-shadow: 0 0 5px rgba(0, 255, 255, 0.5);
  letter-spacing: 1px;
  opacity: 0;
  margin-bottom: 2.5rem;

  animation:
    subtitleFadeIn 2.2s ease-out forwards;
  animation-delay: 1.2s;
}

/* === 沙漏動畫 === */
.sandglass-container {
  margin: 30px auto;
  animation: flicker 2s infinite;
}

/* === 沙漏 === */
.sandglass {
  width: 200px;
  height: auto;
  filter: drop-shadow(0 0 6px #ffa500);
  animation: rotatePingPong 6s ease-in-out infinite;
  transform-origin: center;
  transition: filter 0.2s ease, transform 0.2s ease;
}

/* === 藝術就是爆炸 === */
#explosion-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  pointer-events: none; /* 不擋點擊 */
  z-index: 5000;
}


/* === 按鈕 === */
.button-group .btn {
  background: transparent;
  border: 2px solid #00ccff;
  color: #ffffff;
  padding: 15px 30px;
  font-size: 1rem;
  margin: 0 10px;
  cursor: pointer;
  border-radius: 4px;
  position: relative;
  overflow: hidden;
  z-index: 1;

  opacity: 0;
  transform: translateY(40px) scale(0.95);
  animation: btnEnter 1s ease-out forwards;
}

.btn {
  position: relative;
  overflow: hidden;
  z-index: 1;
}

.btn::after {
  content: "";
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(120deg, transparent, rgba(0, 255, 255, 0.4), transparent);
  transform: skewX(-20deg);
  transition: left 0.6s ease;
  z-index: 0;
}

.btn:hover::after {
  left: 100%;
}

/* 各按鈕延遲出現 */
.button-group .btn:nth-child(1) {
  animation-delay: 2.8s;
}
.button-group .btn:nth-child(2) {
  animation-delay: 3s;
}

/* === 按鈕流光效果 === */
.button-group .btn::before {
  content: "";
  position: absolute;
  top: 50%;
  left: -75%;
  width: 150%;
  height: 300%;
  background: linear-gradient(120deg, transparent, rgba(0, 255, 255, 0.4), transparent);
  transform: translateY(-50%) rotate(25deg);
  transition: all 0.5s ease;
  z-index: 0;
}

.button-group .btn:hover::before {
  left: 100%;
}

.button-group .btn:hover {
  box-shadow: 0 0 15px #00ccff, 0 0 30px #00ccff;
}

/* === 動畫定義區 === */

/* 主標題閃現進場 */
@keyframes cyberFlashIn {
  0% {
    transform: translateY(-60px) scale(0.9);
    opacity: 0;
    filter: blur(6px);
    letter-spacing: 1em;
  }
  40% {
    opacity: 1;
    filter: blur(1px);
    transform: translateY(10px) scale(1.1);
  }
  100% {
    transform: translateY(0) scale(1);
    letter-spacing: 4px;
    filter: blur(0);
  }
}

/* 主標題閃爍循環 */
@keyframes glowLoop {
  0%, 100% {
    text-shadow: 0 0 10px #00ccff, 0 0 20px #00ffee, 0 0 30px #00ccff;
  }
  50% {
    text-shadow: 0 0 20px #00ffee, 0 0 40px #00ccff, 0 0 60px #00ffee;
  }
}

/* 副標題漸顯閃光 */
@keyframes subtitleFadeIn {
  0% {
    opacity: 0;
    transform: translateY(20px);
    filter: brightness(0.2) blur(4px);
  }
  50% {
    opacity: 0.6;
    transform: translateY(10px);
    filter: brightness(1.4) blur(1px);
  }
  100% {
    opacity: 1;
    transform: translateY(0);
    filter: brightness(1) blur(0);
  }
}

/* 沙漏旋轉 */
@keyframes rotatePingPong {
  0% {
    transform: rotate(0deg);
    filter: brightness(1);
  }
  30% {
    transform: rotate(180deg);
    filter: brightness(1.5) drop-shadow(0 0 8px #a066ff);
  }
  35% {
    transform: rotate(180deg) scale(1.02) skewX(1deg); /* 卡頓點1 */
  }
  40% {
    transform: rotate(180deg) scale(1) skewX(0deg);
  }
  60% {
    transform: rotate(360deg);
    filter: brightness(1.8) drop-shadow(0 0 12px #ffcc00);
  }
  65% {
    transform: rotate(360deg) scale(1.02) skewY(-1deg); /* 卡頓點2 */
  }
  70% {
    transform: rotate(360deg);
  }
  85% {
    transform: rotate(180deg);
    filter: brightness(1.5) drop-shadow(0 0 8px #66aaff);
  }
  90% {
    transform: rotate(180deg) scale(1.02) skewX(-1deg); /* 卡頓點3 */
  }
  95% {
    transform: rotate(180deg) scale(1) skewX(0deg);
  }
  100% {
    transform: rotate(0deg);
    filter: brightness(1);
  }
}



/* 按鈕進場 */
@keyframes btnEnter {
  0% {
    opacity: 0;
    transform: translateY(30px) scale(0.9);
    filter: brightness(0.5) blur(2px);
  }
  50% {
    opacity: 0.7;
    transform: translateY(10px) scale(1.05);
    filter: brightness(1.5) blur(0.5px);
  }
  100% {
    opacity: 1;
    transform: translateY(0) scale(1);
    filter: brightness(1) blur(0);
  }
}

/* 沙漏閃爍 */
@keyframes flicker {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.6; }
}