:root {
  --bg: #060b16;
  --panel: rgba(12, 20, 44, 0.74);
  --panel-border: rgba(78, 164, 255, 0.18);
  --text: rgba(237, 247, 255, 0.92);
  --muted: rgba(195, 224, 255, 0.72);
  --primary: #2ea3ff;
  --primary2: #00e7ff;
  --danger: #ff4d6d;
  --shadow: 0 18px 70px rgba(0, 0, 0, 0.55);
  --radius: 16px;
  --radius2: 12px;
  --mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
}

* {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
}

body {
  margin: 0;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, PingFang SC, Noto Sans SC,
    "Microsoft YaHei", Arial, sans-serif;
  color: var(--text);
  background:
    radial-gradient(1200px 600px at 12% 12%, rgba(46, 163, 255, 0.22), transparent 58%),
    radial-gradient(900px 520px at 88% 18%, rgba(0, 231, 255, 0.16), transparent 62%),
    radial-gradient(800px 520px at 55% 92%, rgba(124, 77, 255, 0.12), transparent 60%),
    linear-gradient(180deg, #040813 0%, #060b16 50%, #040813 100%);
  overflow: hidden;
}

code {
  font-family: var(--mono);
  font-size: 0.92em;
  color: rgba(237, 247, 255, 0.88);
  background: rgba(0, 231, 255, 0.08);
  border: 1px solid rgba(0, 231, 255, 0.18);
  padding: 0 6px;
  border-radius: 8px;
}

.app {
  height: 100%;
  display: grid;
  grid-template-rows: auto 1fr auto;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 22px;
  border-bottom: 1px solid rgba(78, 164, 255, 0.18);
  background: rgba(6, 11, 22, 0.65);
  backdrop-filter: blur(12px);
}

.brand {
  display: flex;
  gap: 14px;
  align-items: center;
  min-width: 0;
}

.logo {
  width: 34px;
  height: 34px;
  border-radius: 12px;
  background:
    radial-gradient(10px 10px at 30% 30%, rgba(255, 255, 255, 0.95), transparent 60%),
    linear-gradient(135deg, rgba(46, 163, 255, 0.95), rgba(0, 231, 255, 0.7));
  box-shadow: 0 0 0 1px rgba(78, 164, 255, 0.35), 0 18px 34px rgba(0, 0, 0, 0.45);
}

.brand-text {
  min-width: 0;
}

.brand-title {
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.6px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.brand-subtitle {
  font-size: 12px;
  color: var(--muted);
  margin-top: 4px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.btn {
  border: 1px solid rgba(78, 164, 255, 0.25);
  background: rgba(12, 20, 44, 0.65);
  color: var(--text);
  padding: 10px 14px;
  border-radius: 12px;
  cursor: pointer;
  font-weight: 650;
  letter-spacing: 0.4px;
  box-shadow: 0 10px 26px rgba(0, 0, 0, 0.25);
}

.btn:hover {
  border-color: rgba(78, 164, 255, 0.5);
}

.btn:active {
  transform: translateY(1px);
}

.btn-primary {
  border-color: rgba(46, 163, 255, 0.45);
  background: linear-gradient(135deg, rgba(46, 163, 255, 0.18), rgba(0, 231, 255, 0.12));
  box-shadow: 0 14px 38px rgba(46, 163, 255, 0.16);
}

.main {
  display: grid;
  grid-template-columns: 1.02fr 0.98fr;
  gap: 18px;
  padding: 18px;
  overflow: hidden;
}

.panel {
  border-radius: var(--radius);
  border: 1px solid var(--panel-border);
  background: var(--panel);
  box-shadow: var(--shadow);
  overflow: hidden;
  min-height: 0;
  display: grid;
  grid-template-rows: auto 1fr;
}

.panel-preview {
  grid-template-rows: auto 1fr;
}

.panel-header {
  padding: 14px 16px;
  border-bottom: 1px solid rgba(78, 164, 255, 0.16);
  display: grid;
  gap: 6px;
}

.panel-header-tight {
  border-top: 1px solid rgba(78, 164, 255, 0.12);
}

.panel-title {
  font-size: 13px;
  font-weight: 750;
  letter-spacing: 0.8px;
  text-transform: uppercase;
  color: rgba(224, 243, 255, 0.95);
}

.panel-hint {
  font-size: 12px;
  color: rgba(195, 224, 255, 0.7);
  line-height: 1.4;
}

.textarea {
  width: 100%;
  height: 100%;
  border: none;
  outline: none;
  resize: none;
  padding: 16px;
  color: rgba(237, 247, 255, 0.92);
  background: rgba(4, 8, 19, 0.3);
  font-size: 14px;
  line-height: 1.7;
}

.textarea::placeholder {
  color: rgba(195, 224, 255, 0.45);
}

.theme-list {
  padding: 14px 14px 18px;
  display: grid;
  gap: 12px;
  grid-template-columns: 1fr 1fr;
  overflow: auto;
}

.theme-card {
  border-radius: var(--radius2);
  border: 1px solid rgba(78, 164, 255, 0.18);
  background: rgba(4, 8, 19, 0.28);
  padding: 12px;
  cursor: pointer;
  display: grid;
  gap: 10px;
  transition: border-color 120ms ease, transform 120ms ease, background 120ms ease;
}

.theme-card:hover {
  border-color: rgba(78, 164, 255, 0.5);
  transform: translateY(-1px);
}

.theme-card.is-active {
  border-color: rgba(0, 231, 255, 0.65);
  box-shadow: 0 0 0 1px rgba(0, 231, 255, 0.2), 0 18px 44px rgba(0, 231, 255, 0.06);
  background: rgba(0, 231, 255, 0.05);
}

.theme-name {
  font-weight: 750;
  letter-spacing: 0.4px;
  font-size: 13px;
}

.theme-desc {
  color: rgba(195, 224, 255, 0.7);
  font-size: 12px;
  line-height: 1.35;
}

.theme-swatch {
  height: 10px;
  border-radius: 999px;
  background: linear-gradient(90deg, rgba(46, 163, 255, 0.95), rgba(0, 231, 255, 0.85), rgba(124, 77, 255, 0.75));
  border: 1px solid rgba(78, 164, 255, 0.25);
}

.preview-shell {
  padding: 16px;
  overflow: auto;
  background:
    radial-gradient(900px 520px at 30% 20%, rgba(46, 163, 255, 0.08), transparent 52%),
    radial-gradient(700px 520px at 70% 70%, rgba(0, 231, 255, 0.06), transparent 56%),
    rgba(4, 8, 19, 0.22);
}

.preview {
  min-height: 100%;
}

.footer {
  padding: 12px 18px;
  display: flex;
  justify-content: space-between;
  gap: 12px;
  align-items: center;
  border-top: 1px solid rgba(78, 164, 255, 0.18);
  background: rgba(6, 11, 22, 0.65);
  backdrop-filter: blur(12px);
}

.footer-left {
  color: rgba(195, 224, 255, 0.68);
  font-size: 12px;
  line-height: 1.4;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.toast {
  min-width: 0;
  color: rgba(224, 243, 255, 0.92);
  font-size: 12px;
  padding: 8px 10px;
  border-radius: 10px;
  border: 1px solid rgba(78, 164, 255, 0.22);
  background: rgba(4, 8, 19, 0.46);
  opacity: 0;
  transform: translateY(6px);
  transition: opacity 160ms ease, transform 160ms ease;
  pointer-events: none;
}

.toast.is-on {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 980px) {
  body {
    overflow: auto;
  }
  .main {
    grid-template-columns: 1fr;
  }
  .footer-left {
    white-space: normal;
  }
}