:root {
  --primary-red: #d92027;
  --secondary-red: #ff4d4d;
  --gold: #ffd700;
  --gold-light: #fff5cc;
  --text-white: #ffffff;
  --shadow-strong: 0 10px 30px rgba(139, 0, 0, 0.5);
}

* {
  box-sizing: border-box;
  -webkit-tap-highlight-color: transparent;
}

body {
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100vh; /* Fallback */
  height: 100dvh;
  overflow: hidden;
  font-family: "Inter", system-ui, sans-serif;
  color: var(--text-white);
  position: relative;
}

/* 动态红色渐变背景 */
.bg-gradient {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, #8b0000 0%, #d92027 50%, #ff4d4d 100%);
  background-size: 200% 200%;
  animation: gradientFlow 8s ease infinite;
  z-index: -2;
}

@keyframes gradientFlow {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

/* Canvas 粒子层 */
#particles {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
  pointer-events: none;
}

/* 静音按钮 */
.mute-btn {
  position: absolute;
  top: 20px;
  right: 20px;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: rgba(0, 0, 0, 0.2);
  border: 1px solid rgba(255, 255, 255, 0.3);
  color: white;
  display: grid;
  place-items: center;
  cursor: pointer;
  z-index: 10;
  backdrop-filter: blur(4px);
}

/* 主内容区 */
.content {
  height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: center; /* 垂直居中 */
  align-items: center;
  padding: 0 24px 100px; /* 底部留出按钮空间 */
  text-align: center;
}

.text-container {
  animation: fadeInUp 0.8s ease-out forwards;
}

.main-title {
  font-family: "Ma Shan Zheng", "Noto Serif SC", serif;
  font-weight: 400; /* Ma Shan Zheng 只有 400 */
  margin: 0 0 24px;
  line-height: 1.3;
  text-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

.line-1 {
  font-size: clamp(32px, 8vw, 48px);
  color: var(--gold-light);
  margin-bottom: 8px;
}

.line-2 {
  font-size: clamp(36px, 10vw, 56px);
  color: white;
}

.highlight {
  color: var(--gold);
  font-size: 1.1em;
  display: inline-block;
  animation: pulseScale 2s infinite ease-in-out;
}

.sub-title {
  font-size: 16px;
  color: rgba(255, 255, 255, 0.9);
  margin: 0;
  font-weight: 500;
  background: rgba(0, 0, 0, 0.2);
  padding: 8px 16px;
  border-radius: 20px;
  border: 1px solid rgba(255, 215, 0, 0.3);
  display: inline-block;
  backdrop-filter: blur(4px);
}

/* 底部按钮区 */
.bottom-action {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  padding: 24px;
  padding-bottom: max(24px, env(safe-area-inset-bottom));
  background: linear-gradient(to top, rgba(0,0,0,0.4) 0%, transparent 100%);
  z-index: 20;
  display: flex;
  justify-content: center;
}

.cta-btn {
  width: 100%;
  max-width: 400px;
  height: 56px;
  border: none;
  border-radius: 28px;
  background: linear-gradient(to right, #ff4d4d, #d92027);
  color: white;
  font-size: 20px;
  font-weight: 700;
  box-shadow: 0 8px 20px rgba(217, 32, 39, 0.4), 
              0 0 0 4px rgba(255, 255, 255, 0.2);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  transition: transform 0.1s;
  animation: heartBeat 1.5s infinite;
}

.cta-btn:active {
  transform: scale(0.96);
}

.btn-icon {
  font-size: 24px;
}

/* 动画定义 */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes pulseScale {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.05); text-shadow: 0 0 15px var(--gold); }
}

@keyframes heartBeat {
  0% { transform: scale(1); }
  14% { transform: scale(1.05); }
  28% { transform: scale(1); }
  42% { transform: scale(1.05); }
  70% { transform: scale(1); }
}

/* 媒体查询适配极小屏幕 */
@media (max-height: 600px) {
  .content {
    justify-content: flex-start;
    padding-top: 80px;
  }
  .line-1 { font-size: 28px; }
  .line-2 { font-size: 32px; }
}