#heartbeat {
  font-weight: bold;
  cursor: pointer;
  display: inline-block;

  /* 默认白天红色渐变 */
  background: linear-gradient(90deg, #ff0000, #ff5555);
  background-size: 200% 200%;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;

  animation: 
    heartbeat 1s infinite,
    heartbeat-sway 1s infinite,
    heartbeat-gradient 1s infinite,
    heartbeat-bright 1s infinite,
    heartbeat-rotate 1s infinite;
}

/* -------------------------------
   缩放心跳
   ------------------------------- */
@keyframes heartbeat {
  0%, 50%, 100% { transform: scale(1); opacity: 0.8; }
  25%, 75% { transform: scale(1.2); opacity: 1; }
}

/* -------------------------------
   左右轻微摆动
   ------------------------------- */
@keyframes heartbeat-sway {
  0%, 100% { transform: rotate(0deg); }
  25% { transform: rotate(-5deg); }
  50% { transform: rotate(5deg); }
  75% { transform: rotate(-3deg); }
}

/* -------------------------------
   渐变轻微晃动
   ------------------------------- */
@keyframes heartbeat-gradient {
  0% { background-position: 0% 50%; }
  50% { background-position: 10% 50%; }
  100% { background-position: 0% 50%; }
}

/* -------------------------------
   渐变亮度闪烁
   ------------------------------- */
@keyframes heartbeat-bright {
  0%, 100% { filter: brightness(1); }
  25% { filter: brightness(1.3); }
  50% { filter: brightness(0.9); }
  75% { filter: brightness(1.2); }
}

/* -------------------------------
   渐变方向微旋转
   ------------------------------- */
@keyframes heartbeat-rotate {
  0%, 100% { transform: rotate(0deg); }
  25% { transform: rotate(2deg); }
  50% { transform: rotate(-2deg); }
  75% { transform: rotate(1deg); }
}

/* ===========================================
   夜间模式：高饱和鲜粉→紫色渐变
   =========================================== */
[data-theme="dark"] #heartbeat {
  background: linear-gradient(90deg, #ff2ea6, #9b00ff); /* 高饱和粉紫 */
  background-size: 200% 200%;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;

  animation: 
    heartbeat 1s infinite,
    heartbeat-glow 1s infinite,
    heartbeat-sway 1s infinite,
    heartbeat-gradient 1s infinite,
    heartbeat-bright 1s infinite,
    heartbeat-rotate 1s infinite;
}

/* -------------------------------
   夜间呼吸光晕 + 缩放随心跳
   ------------------------------- */
@keyframes heartbeat-glow {
  0% {
    text-shadow: 0 0 6px rgba(255,46,166,0.7),
                 0 0 12px rgba(155,0,255,0.5);
  }
  25% {
    text-shadow: 0 0 12px rgba(255,46,166,1),
                 0 0 20px rgba(155,0,255,0.8);
  }
  50% {
    text-shadow: 0 0 18px rgba(255,46,166,1),
                 0 0 30px rgba(155,0,255,0.9);
  }
  75% {
    text-shadow: 0 0 12px rgba(255,46,166,1),
                 0 0 20px rgba(155,0,255,0.8);
  }
  100% {
    text-shadow: 0 0 6px rgba(255,46,166,0.7),
                 0 0 12px rgba(155,0,255,0.5);
  }
}

/* -------------------------------
   Hover 效果：放大 + 夜间光晕增强
   ------------------------------- */
#heartbeat:hover {
  transform: scale(1.5);
}

[data-theme="dark"] #heartbeat:hover {
  transform: scale(1.5);
  text-shadow: 0 0 25px rgba(255,46,166,1),
               0 0 50px rgba(155,0,255,0.9);
}