/* ============================================================
   B1 — 全屏 / 深色 / 中文 UI 骨架
   ============================================================ */

:root {
  --bg: #0b0d12;
  --panel: rgba(255, 255, 255, 0.04);
  --panel-border: rgba(255, 255, 255, 0.08);
  --text: #e8eaf0;
  --text-muted: #8a90a0;
  --accent: #6ee7ff;

  --state-idle:    #8a90a0;
  --state-loading: #f6c85f;
  --state-camera:  #4ade80;
  --state-demo:    #6ee7ff;
  --state-error:   #f87171;

  /* 三块滤镜的品牌色（与 QUADS 红/蓝/绿对应） */
  --filter-red:   #ff5d5d;
  --filter-blue:  #5d8bff;
  --filter-green: #5dff9a;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  height: 100%;
  overflow: hidden;
  background: var(--bg);
  color: var(--text);
  font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", system-ui, sans-serif;
  -webkit-font-smoothing: antialiased;
}

/* 全屏底层画布 */
#stage {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
  background: radial-gradient(circle at 50% 40%, #12151d 0%, var(--bg) 70%);
}

/* UI 覆盖层：默认穿透，子元素按需开启交互 */
.ui {
  position: fixed;
  inset: 0;
  pointer-events: none;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: 20px 24px;
}

/* ---- 顶部 ---- */
.ui-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.ui-title {
  margin: 0;
  font-size: 20px;
  font-weight: 600;
  letter-spacing: 0.5px;
}

.ui-status {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px;
  background: var(--panel);
  border: 1px solid var(--panel-border);
  border-radius: 999px;
  font-size: 13px;
  color: var(--text-muted);
  pointer-events: auto;
}

.state-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--state-idle);
  box-shadow: 0 0 6px currentColor;
}

.state-dot[data-state="idle"]    { background: var(--state-idle);    color: var(--state-idle); }
.state-dot[data-state="loading"] { background: var(--state-loading); color: var(--state-loading); }
.state-dot[data-state="camera"]  { background: var(--state-camera);  color: var(--state-camera); }
.state-dot[data-state="demo"]    { background: var(--state-demo);    color: var(--state-demo); }
.state-dot[data-state="error"]   { background: var(--state-error);   color: var(--state-error); }

/* ---- 提示条 ---- */
.ui-notice {
  position: absolute;
  top: 72px;
  left: 50%;
  transform: translateX(-50%);
  max-width: 80vw;
  padding: 10px 16px;
  background: var(--panel);
  border: 1px solid var(--panel-border);
  border-radius: 10px;
  font-size: 14px;
  color: var(--text);
  pointer-events: none;
  transition: opacity 0.2s ease;
}
.ui-notice.is-error {
  border-color: rgba(248, 113, 113, 0.4);
  color: #fca5a5;
}

/* ---- 单手提示 ---- */
.ui-hand-hint {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  padding: 12px 20px;
  background: rgba(246, 200, 95, 0.12);
  border: 1px solid rgba(246, 200, 95, 0.35);
  border-radius: 12px;
  font-size: 15px;
  color: #f6c85f;
  pointer-events: none;
}

/* ---- 底部控制栏 ---- */
.ui-bottom {
  display: flex;
  flex-direction: column;
  gap: 12px;
  pointer-events: auto;
}

.ui-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.btn {
  padding: 10px 18px;
  font-size: 14px;
  font-family: inherit;
  color: var(--text);
  background: var(--panel);
  border: 1px solid var(--panel-border);
  border-radius: 10px;
  cursor: pointer;
  transition: background 0.15s ease, border-color 0.15s ease, transform 0.1s ease;
}
.btn:hover {
  background: rgba(255, 255, 255, 0.08);
  border-color: rgba(255, 255, 255, 0.2);
}
.btn:active { transform: translateY(1px); }
.btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}
.btn-primary {
  background: rgba(110, 231, 255, 0.12);
  border-color: rgba(110, 231, 255, 0.35);
  color: var(--accent);
}
.btn-primary:hover {
  background: rgba(110, 231, 255, 0.2);
  border-color: rgba(110, 231, 255, 0.5);
}

/* ---- 平滑度滑块 ---- */
.ui-smooth {
  display: flex;
  align-items: center;
  gap: 12px;
  width: 100%;
  max-width: 360px;
  font-size: 13px;
  color: var(--text-muted);
}
.ui-smooth label { white-space: nowrap; }
.ui-smooth input[type="range"] {
  flex: 1;
  accent-color: var(--accent);
  cursor: pointer;
}

/* ---- 弱化 UI：idle / error 状态下降低控制栏存在感 ---- */
.ui[data-state="idle"] .ui-bottom,
.ui[data-state="error"] .ui-bottom {
  opacity: 0.55;
  transition: opacity 0.3s ease;
}
.ui[data-state="camera"] .ui-bottom,
.ui[data-state="demo"] .ui-bottom {
  opacity: 1;
  transition: opacity 0.3s ease;
}

/* 窄屏适配 */
@media (max-width: 640px) {
  .ui { padding: 14px 16px; }
  .ui-title { font-size: 16px; }
  .btn { padding: 9px 14px; font-size: 13px; }
}