:root {
  --bg0: #0b1c2c;
  --bg1: #14304a;
  --accent: #2ec4b6;
  --accent-2: #f4a261;
  --text: #f2f7fb;
  --muted: #9db0c3;
  --danger: #e76f51;
  --ok: #2a9d8f;
  --ring: rgba(46, 196, 182, 0.85);
  --panel: rgba(255, 255, 255, 0.06);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  min-height: 100%;
  font-family: "Noto Sans SC", "PingFang SC", sans-serif;
  color: var(--text);
  background:
    radial-gradient(1200px 600px at 20% -10%, #1d4e6b 0%, transparent 55%),
    radial-gradient(900px 500px at 100% 10%, #2a6f6a 0%, transparent 50%),
    linear-gradient(165deg, var(--bg0), var(--bg1));
}

.stage {
  width: min(440px, 100%);
  margin: 0 auto;
  padding: 28px 16px 40px;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.brand .logo {
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  line-height: 1.1;
}

.brand .sub {
  margin: 6px 0 0;
  color: var(--muted);
  font-size: 0.92rem;
}

.section-title {
  margin: 0 0 10px;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--muted);
}

.config {
  padding: 12px 0 2px;
}

.action-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

.chip {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 12px;
  border-radius: 12px;
  background: var(--panel);
  cursor: pointer;
  user-select: none;
  font-size: 0.92rem;
}

.chip input {
  accent-color: var(--accent);
  width: 16px;
  height: 16px;
}

.config-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 18px;
  margin-top: 12px;
}

.switch {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--muted);
  font-size: 0.88rem;
  cursor: pointer;
}

.switch input { accent-color: var(--accent); }

.field {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--muted);
  font-size: 0.88rem;
}

.field input,
.field select {
  width: 96px;
  border: 0;
  border-radius: 8px;
  padding: 8px 10px;
  background: var(--panel);
  color: var(--text);
  font: inherit;
}

.field select {
  width: 108px;
}

.viewport {
  position: relative;
  aspect-ratio: 3 / 4;
  border-radius: 20px;
  overflow: hidden;
  background: #061018;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.35);
}

#video {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transform: scaleX(-1);
}

.mask {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: rgba(4, 12, 20, 0.45);
  mask-image: radial-gradient(ellipse 42% 36% at 50% 42%, transparent 98%, #000 100%);
  -webkit-mask-image: radial-gradient(ellipse 42% 36% at 50% 42%, transparent 98%, #000 100%);
}

.oval {
  position: absolute;
  left: 50%;
  top: 42%;
  width: 72%;
  height: 58%;
  transform: translate(-50%, -50%);
  border: 2px solid var(--ring);
  border-radius: 50%;
  box-shadow: 0 0 0 1px rgba(255, 255, 255, 0.08);
  transition: border-color 0.25s ease;
}

.oval.warn { border-color: var(--accent-2); }
.oval.ok { border-color: var(--ok); }
.oval.err { border-color: var(--danger); }

.hud {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 18px 16px 22px;
  text-align: center;
  background: linear-gradient(transparent, rgba(5, 14, 24, 0.92));
}

.tip {
  margin: 0;
  font-size: 1.05rem;
  font-weight: 500;
  min-height: 1.5em;
}

.progress {
  margin: 8px 0 0;
  color: var(--muted);
  font-size: 0.85rem;
}

.actions {
  display: flex;
  gap: 12px;
}

.btn {
  flex: 1;
  border: 0;
  border-radius: 12px;
  padding: 14px 16px;
  font: inherit;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.15s ease, opacity 0.15s ease;
}

.btn:active { transform: scale(0.98); }
.btn:disabled { opacity: 0.45; cursor: not-allowed; }

.btn.primary {
  background: var(--accent);
  color: #06201d;
}

.btn.ghost {
  background: rgba(255, 255, 255, 0.08);
  color: var(--text);
}

.btn.tiny {
  flex: 0;
  padding: 6px 10px;
  border-radius: 8px;
  font-size: 0.78rem;
  font-weight: 500;
}

.result {
  padding: 6px 4px 0;
  animation: rise 0.35s ease;
}

.result h2 {
  margin: 0 0 8px;
  font-size: 1.15rem;
}

.result p {
  margin: 0;
  color: var(--muted);
}

.result .meta {
  margin-top: 6px;
  font-size: 0.82rem;
}

#resultImg {
  margin-top: 12px;
  width: 100%;
  border-radius: 14px;
  display: block;
}

.base64-box {
  margin-top: 14px;
}

.base64-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  margin-bottom: 8px;
  font-size: 0.88rem;
  color: var(--muted);
}

.base64-ops {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

#base64Out {
  width: 100%;
  resize: vertical;
  border: 0;
  border-radius: 12px;
  padding: 10px 12px;
  background: rgba(0, 0, 0, 0.28);
  color: #c9d7e4;
  font-family: ui-monospace, Consolas, monospace;
  font-size: 0.72rem;
  line-height: 1.4;
}

@keyframes rise {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

@media (max-width: 480px) {
  .stage { padding-top: 18px; }
  .brand .logo { font-size: 1.5rem; }
  .base64-head { flex-direction: column; align-items: flex-start; }
}