/* ============================================
   霓虹贪吃蛇 —— 样式表
   纯 CSS 实现，零外部依赖、零外部字体
   ============================================ */

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
}

html,
body {
  height: 100%;
}

body {
  font-family: system-ui, -apple-system, "Segoe UI", "Microsoft YaHei", sans-serif;
  color: #e6e9ff;
  background: radial-gradient(circle at 50% 30%, #171a3a, #0b0e20);
  background-attachment: fixed;
  min-height: 100vh;
  overflow-x: hidden;
  display: flex;
  justify-content: center;
}

.app {
  width: min(620px, 100%);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  padding: 0 16px;
  user-select: none;
}

/* ---------- 玻璃面板通用规范 ---------- */
.panel {
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 20px;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.hidden {
  display: none !important;
}

/* 主题色文字 */
.c-cyan {
  color: #22d3ee;
}
.c-purple {
  color: #9d88ff;
}
.c-gold {
  color: #ffb347;
}

/* ---------- 顶部栏 ---------- */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 4px 14px;
}

.brand {
  font-size: 22px;
  font-weight: 800;
  letter-spacing: 3px;
  background: linear-gradient(90deg, #22d3ee, #7c5cff);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  filter: drop-shadow(0 0 14px rgba(124, 92, 255, 0.45));
}

.back-link {
  color: #aab0d8;
  text-decoration: none;
  font-size: 14px;
  padding: 8px 14px;
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.06);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  transition: color 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

.back-link:hover {
  color: #ffffff;
  border-color: rgba(124, 92, 255, 0.8);
  box-shadow: 0 0 16px rgba(124, 92, 255, 0.45);
}

/* ---------- 舞台 ---------- */
.stage {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}

/* ---------- 数据栏 ---------- */
.hud {
  width: 100%;
  max-width: 560px;
  display: flex;
  align-items: center;
  padding: 10px 18px;
  gap: 8px;
}

.hud-item {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
}

.hud-label {
  font-size: 12px;
  letter-spacing: 2px;
  color: #8b91bd;
}

.hud-value {
  font-size: 22px;
  font-weight: 800;
  line-height: 1.2;
  text-shadow: 0 0 12px currentColor;
}

.ghost-btn {
  flex: 0 0 auto;
  margin-left: 6px;
  padding: 8px 16px;
  font-size: 13px;
  font-family: inherit;
  color: #cfd4ff;
  background: rgba(124, 92, 255, 0.16);
  border: 1px solid rgba(124, 92, 255, 0.55);
  border-radius: 12px;
  cursor: pointer;
  transition: background 0.2s ease, box-shadow 0.2s ease, color 0.2s ease;
}

.ghost-btn:hover {
  color: #ffffff;
  background: rgba(124, 92, 255, 0.32);
  box-shadow: 0 0 14px rgba(124, 92, 255, 0.5);
}

/* ---------- Canvas 区域 ---------- */
.canvas-wrap {
  position: relative;
  width: min(100%, 560px, calc(100vh - 218px));
  aspect-ratio: 1 / 1;
}

#game {
  display: block;
  width: 100%;
  height: 100%;
  border-radius: 20px;
  background: rgba(9, 11, 26, 0.42);
  border: 1px solid rgba(255, 255, 255, 0.12);
  box-shadow:
    0 0 50px rgba(124, 92, 255, 0.28),
    0 0 120px rgba(34, 211, 238, 0.10),
    inset 0 0 40px rgba(11, 14, 32, 0.6);
  touch-action: none;
}

/* ---------- 遮罩层 ---------- */
.overlay {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 18px;
  border-radius: 20px;
  background: rgba(8, 10, 24, 0.62);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  z-index: 5;
  animation: overlay-in 0.28s ease both;
}

@keyframes overlay-in {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

.overlay-panel {
  width: 100%;
  max-width: 380px;
  padding: 30px 28px;
  text-align: center;
  box-shadow: 0 0 40px rgba(124, 92, 255, 0.25);
}

.title {
  font-size: 30px;
  font-weight: 800;
  letter-spacing: 4px;
  background: linear-gradient(90deg, #22d3ee, #7c5cff, #ff5ca8);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  filter: drop-shadow(0 0 16px rgba(124, 92, 255, 0.5));
}

.subtitle {
  font-size: 24px;
  font-weight: 800;
  letter-spacing: 4px;
  color: #cfd4ff;
  text-shadow: 0 0 16px rgba(124, 92, 255, 0.7);
}

.intro {
  margin: 18px 0 24px;
  font-size: 13.5px;
  line-height: 1.9;
  color: #b9bfe6;
}

.result-row {
  margin-top: 12px;
  font-size: 15px;
  color: #b9bfe6;
}

.result-row .hud-value,
.result-row span {
  font-size: 22px;
  margin-left: 6px;
}

.record-badge {
  margin: 16px auto 4px;
  width: fit-content;
  padding: 6px 18px;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 2px;
  color: #201503;
  background: linear-gradient(90deg, #ffd47a, #ffb347);
  border-radius: 999px;
  box-shadow: 0 0 22px rgba(255, 179, 71, 0.75);
  animation: badge-pulse 1s ease-in-out infinite alternate;
}

@keyframes badge-pulse {
  from {
    transform: scale(1);
  }
  to {
    transform: scale(1.06);
  }
}

/* ---------- 主按钮 ---------- */
.btn-primary {
  margin-top: 6px;
  padding: 12px 38px;
  font-family: inherit;
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 3px;
  color: #ffffff;
  background: linear-gradient(135deg, #7c5cff, #5b8dff);
  border: none;
  border-radius: 14px;
  cursor: pointer;
  box-shadow: 0 0 22px rgba(124, 92, 255, 0.55);
  transition: transform 0.15s ease, box-shadow 0.2s ease, filter 0.2s ease;
}

.btn-primary:hover {
  transform: translateY(-2px);
  filter: brightness(1.12);
  box-shadow: 0 0 32px rgba(124, 92, 255, 0.8), 0 0 60px rgba(34, 211, 238, 0.25);
}

.btn-primary:active {
  transform: translateY(0);
}

/* ---------- 底部说明 ---------- */
.tips {
  text-align: center;
  font-size: 13px;
  letter-spacing: 1px;
  color: #8b91bd;
  padding: 14px 4px 18px;
}

/* ---------- 窄屏适配 ---------- */
@media (max-width: 420px) {
  .brand {
    font-size: 18px;
    letter-spacing: 2px;
  }

  .back-link {
    font-size: 13px;
    padding: 7px 10px;
  }

  .hud-value {
    font-size: 19px;
  }

  .title {
    font-size: 25px;
  }

  .tips {
    font-size: 12px;
  }
}