:root {
  --bg: #101418;
  --panel: #1a222b;
  --text: #f2f5f8;
  --muted: #9aa7b5;
  --accent: #2bb673;
  --warn: #f0a202;
  --danger: #e4572e;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
  background: radial-gradient(1200px 600px at 50% -10%, #243041, var(--bg));
  color: var(--text);
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}

#app {
  max-width: 720px;
  margin: 0 auto;
  padding: 12px 12px 28px;
}

.top h1 {
  margin: 4px 0 0;
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.user-state {
  margin: 6px 0 12px;
  color: var(--accent);
  font-size: 1.05rem;
}

.stage {
  position: relative;
  width: 100%;
  aspect-ratio: 3 / 4;
  background: #000;
  overflow: hidden;
  border-radius: 8px;
}

#video,
#replayImage,
#overlay {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

#video,
#replayImage {
  object-fit: cover;
}

#overlay {
  pointer-events: none;
}

.actions {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
  margin-top: 14px;
}

.dist {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  color: var(--muted);
  font-size: 0.95rem;
}

.dist select {
  flex: 1;
  max-width: 140px;
  padding: 10px;
  border-radius: 8px;
  border: 0;
  background: #243041;
  color: var(--text);
}

button {
  appearance: none;
  border: 0;
  border-radius: 10px;
  padding: 14px 12px;
  font-size: 1rem;
  font-weight: 600;
  color: #04140c;
  background: var(--accent);
}

button:disabled {
  opacity: 0.45;
}

#btnSave {
  background: #4ea1d3;
  color: #041018;
}

.guide {
  margin: 16px 0 8px;
  padding-left: 1.2rem;
  color: var(--muted);
  line-height: 1.55;
}

.dev {
  margin-top: 12px;
  background: var(--panel);
  border-radius: 10px;
  padding: 8px 12px 12px;
}

.dev summary {
  cursor: pointer;
  color: var(--muted);
}

.dev-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-top: 10px;
}

.dev-grid .full {
  grid-column: 1 / -1;
}

.log {
  grid-column: 1 / -1;
  max-height: 240px;
  overflow: auto;
  background: #0b0f14;
  color: #cde3ff;
  padding: 10px;
  border-radius: 8px;
  font-size: 12px;
  white-space: pre-wrap;
}

@media (min-width: 640px) {
  .actions {
    grid-template-columns: 1.1fr 1fr 1fr 1fr;
  }
}