/* ===== 基本設定：科技感暗色系 + 霓虹點綴 ===== */
:root{
  --bg: #0b1020;
  --bg-2: #0e1428;
  --card: rgba(255,255,255,0.06);
  --glass: rgba(255,255,255,0.08);
  --stroke: rgba(255,255,255,0.12);
  --text: #e7ecff;
  --muted: #aab4d4;
  --accent: #6fd3ff;
  --accent-2:#8a7dff;
  --success:#3bd3a6;
  --warn:#ffd166;
  --shadow: 0 10px 35px rgba(0,0,0,.45);
  --radius-xl: 20px;
  --radius-md: 12px;
}

/* 使用系統字體；若有引入 Outfit 會自動覆蓋 */
html, body {
  margin: 0;
  color: var(--text);
  background: radial-gradient(1000px 800px at 10% -10%, #12204a 0%, transparent 55%),
              radial-gradient(900px 700px at 110% 20%, #2d1b5f 0%, transparent 60%),
              var(--bg);
  font-family: "Outfit", ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI",
               "Noto Sans TC", "PingFang TC", "Microsoft JhengHei", Roboto, Arial, sans-serif;
}

/* 背後柔光 */
.bg-glow{
  position: fixed; inset: 0; pointer-events: none; z-index: 0;
  background: radial-gradient(600px 450px at 20% 20%, rgba(111,211,255,.15), transparent 60%),
              radial-gradient(700px 520px at 80% 10%, rgba(138,125,255,.12), transparent 60%);
  filter: blur(10px);
}

/* ===== 頂部 ===== */
.app-header{
  position: sticky; top: 0; z-index: 5;
  backdrop-filter: blur(10px);
  background: linear-gradient(180deg, rgba(10,13,30,.85), rgba(10,13,30,.55));
  border-bottom: 1px solid var(--stroke);
  padding: 16px 24px 14px;
}
.app-header .header-top{
  display:flex; align-items:center; justify-content: space-between;
  gap: 16px; flex-wrap: wrap;
}
.app-header .brand{ display:flex; align-items:center; gap:12px; }
.app-header .brand .dot{
  width: 10px; height: 10px; border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  box-shadow: 0 0 14px var(--accent);
  animation: pulse 2.2s ease-in-out infinite;
}
@keyframes pulse { 0%,100%{ transform: scale(1); } 50%{ transform: scale(1.25);} }
.app-header h1{ margin:0; font-size: 22px; letter-spacing: .3px; font-weight: 600; }
.app-header p{ margin: 6px 0 0; color: var(--muted); }
.intro-link{
  display:inline-flex; align-items:center; justify-content:center;
  padding: 8px 16px;
  border-radius: 12px;
  background: linear-gradient(135deg, rgba(111,211,255,.36), rgba(138,125,255,.46));
  border: 1px solid rgba(111,211,255,.6);
  color: #f1f6ff; text-decoration: none;
  font-weight: 600; letter-spacing: .3px;
  box-shadow: 0 10px 28px rgba(111,211,255,.22);
  transition: transform .12s ease, box-shadow .12s ease;
}
.intro-link:hover{
  transform: translateY(-1px);
  box-shadow: 0 12px 32px rgba(111,211,255,.3);
}
.intro-link:active{ transform: translateY(0); }

/* ===== 版面 ===== */
.layout{
  position: relative; z-index: 1;
  display: grid; grid-template-columns: 1.1fr .9fr; gap: 18px;
  padding: 18px;
}
@media (max-width: 1024px){
  .layout{ grid-template-columns: 1fr; }
}

/* ===== 卡片 / 面板 ===== */
.card{
  border-radius: var(--radius-xl);
  background: linear-gradient(180deg, var(--card), rgba(255,255,255,0.04));
  border: 1px solid var(--stroke);
  box-shadow: var(--shadow);
}
.panel{ padding: 16px; }
.panel-title{
  display:flex; align-items:center; justify-content: space-between;
  margin-bottom: 10px;
}
.pill{
  font-size: 12px; letter-spacing: .6px; text-transform: uppercase;
  padding: 6px 10px; border-radius: 999px;
  background: linear-gradient(135deg, rgba(111,211,255,.18), rgba(138,125,255,.18));
  border: 1px solid rgba(111,211,255,.35);
  color: #dff4ff;
}
.status{ color: var(--muted); font-size: 14px; }

/* ===== 視訊區 ===== */
.video-wrap{
  position: relative; width: 100%;
  border-radius: var(--radius-md);
  overflow: hidden;
  background: #000;
  outline: 1px solid rgba(111,211,255,.2);
  box-shadow: inset 0 0 0 1px rgba(255,255,255,.04);
  aspect-ratio: 16/9;
}
.input_video, .output_canvas{
  position:absolute; inset:0; width:100%; height:100%; object-fit: cover;
}

/* HUD（右上角透明玻璃框） */
.hud{
  position: absolute; right: 12px; top: 12px;
  background: rgba(10,13,30,.35);
  border: 1px solid rgba(111,211,255,.35);
  box-shadow: 0 10px 30px rgba(0,0,0,.35);
  padding: 8px 10px; border-radius: 12px; backdrop-filter: blur(6px);
}
.hud-row{ display:flex; gap:8px; align-items:center; font-size: 12px; }
.hud + .hud-row{ margin-top: 4px; }
.hud-label{ color:#cfeaff; opacity:.85; }
.hud-value{ color:#fff; font-weight:600; }

/* ===== 手勢說明 / 播放清單 ===== */
.card-sub{
  margin-top: 14px; padding: 12px;
  background: linear-gradient(180deg, var(--glass), rgba(255,255,255,0.05));
  border: 1px dashed rgba(255,255,255,.15);
  border-radius: 14px;
}
.gestures h3, .playlist h3{ margin: 6px 0 10px; font-size: 16px; }
.gestures ul{ margin: 8px 0 0 20px; color:#dbeaff; }
.hint{ color: var(--muted); font-size: 13px; margin-top: 8px; }
.muted{ color: var(--muted); }
.list{
  list-style: decimal-leading-zero inside;
  margin: 6px 0 0; padding: 0;
}
.list li{ padding: 4px 0; }
.list a{
  color: #cfe6ff; text-decoration: none; padding: 4px 8px; border-radius: 8px;
  transition: all .2s ease;
}
.list a:hover{
  background: rgba(111,211,255,.12);
  text-shadow: 0 0 6px rgba(111,211,255,.6);
}

/* ===== 播放器皮膚 ===== */
.audio-skin{
  border-radius: 14px;
  background: rgba(12,18,40,.6);
  padding: 10px;
  border: 1px solid rgba(111,211,255,.25);
}
audio{
  width: 100%;
  filter: drop-shadow(0 10px 20px rgba(0,0,0,.3));
}

/* 按鈕樣式 */
.controls{
  display:flex; flex-wrap:wrap; gap:10px; margin-top: 12px;
}
.btn{
  padding: 10px 14px; border-radius: 12px; cursor:pointer;
  font-weight: 600; letter-spacing: .2px;
  border: 1px solid rgba(255,255,255,.14);
  background: linear-gradient(180deg, rgba(255,255,255,.08), rgba(255,255,255,.06));
  color: var(--text);
  transition: transform .12s ease, box-shadow .12s ease, background .2s ease;
  will-change: transform;
}
.btn:hover{ transform: translateY(-1px); box-shadow: 0 8px 22px rgba(0,0,0,.35); }
.btn:active{ transform: translateY(0); }
.btn-primary{
  background: linear-gradient(135deg, rgba(111,211,255,.35), rgba(138,125,255,.35));
  border-color: rgba(111,211,255,.55);
  box-shadow: 0 8px 28px rgba(111,211,255,.15);
}
.btn-ghost{
  background: linear-gradient(180deg, rgba(255,255,255,.06), rgba(255,255,255,.04));
}

/* ===== 畫面提示（flash） ===== */
.flash{
  position: fixed; left: 50%; top: 3%;
  transform: translateX(-50%);
  background: linear-gradient(135deg, rgba(111,211,255,.95), rgba(138,125,255,.95));
  color: #0a0f24; font-weight: 800;
  padding: 10px 14px; border-radius: 14px;
  box-shadow: 0 10px 30px rgba(111,211,255,.35);
  border: 1px solid rgba(255,255,255,.5);
  z-index: 10000;
  transition: opacity .25s ease, transform .25s ease;
}
.flash.hide{ opacity: 0; transform: translateX(-50%) translateY(-6px); }

/* ===== 可調 ===== */
@media (max-width: 900px){
  .panel{ padding: 14px; }
  .video-wrap{ aspect-ratio: 16/10; }
}