:root {
  /* 腾讯会议蓝 */
  --brand: #2b7fff;
  --brand-strong: #1652f0;
  --brand-gradient: linear-gradient(135deg, #3d8bff 0%, #1e5ef5 100%);

  --bg: #eef3fc;
  --card-bg: #ffffff;
  --text: #1a2233;
  --text-muted: #6b7794;
  --border: #e4ebf5;
  --field-bg: #f6f9ff;
  --code-bg: #eef3fd;
  --ok-bg: #e6f5ec;
  --ok-text: #1a7f37;
  --radius: 16px;
  --shadow: 0 1px 2px rgba(22, 82, 240, 0.06), 0 18px 48px rgba(22, 82, 240, 0.1);
}

@media (prefers-color-scheme: dark) {
  :root {
    --brand: #4c8dff;
    --brand-strong: #2f6bff;
    --brand-gradient: linear-gradient(135deg, #4c8dff 0%, #2f6bff 100%);

    --bg: #0b0f17;
    --card-bg: #151b26;
    --text: #e8edf7;
    --text-muted: #93a1bd;
    --border: #263042;
    --field-bg: #1b2330;
    --code-bg: #1e2735;
    --ok-bg: #16281c;
    --ok-text: #6cd08a;
    --shadow: 0 1px 2px rgba(0, 0, 0, 0.4), 0 18px 48px rgba(0, 0, 0, 0.45);
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  background: var(--bg);
  background-image: radial-gradient(
    120% 60% at 50% 0%,
    rgba(43, 127, 255, 0.14) 0%,
    rgba(43, 127, 255, 0) 60%
  );
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  line-height: 1.6;
}

.card {
  width: 100%;
  max-width: 560px;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}

header {
  padding: 28px 28px 24px;
  background: var(--brand-gradient);
  color: #fff;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: 0.5px;
}

.logo {
  width: 30px;
  height: 30px;
  flex: none;
  color: #fff;
}

.subtitle {
  margin: 12px 0 0;
  color: rgba(255, 255, 255, 0.88);
  font-size: 0.85rem;
}

.subtitle code {
  background: rgba(255, 255, 255, 0.18);
  color: #fff;
  padding: 2px 6px;
  border-radius: 6px;
  font-size: 0.82em;
}

.body { padding: 24px 28px 22px; }

.io { margin-bottom: 18px; }

label {
  display: block;
  margin-bottom: 6px;
  font-size: 0.85rem;
  font-weight: 600;
}

textarea {
  width: 100%;
  padding: 12px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--field-bg);
  color: var(--text);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.9rem;
  resize: vertical;
  transition: border-color 0.15s, box-shadow 0.15s;
}

textarea:focus {
  outline: none;
  border-color: var(--brand);
  box-shadow: 0 0 0 3px rgba(43, 127, 255, 0.18);
}

.actions {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 10px;
}

.btn {
  padding: 9px 18px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--card-bg);
  color: var(--text);
  font-size: 0.9rem;
  cursor: pointer;
  transition: filter 0.15s, background 0.15s, border-color 0.15s;
}

.btn:hover { border-color: var(--brand); color: var(--brand); }
.btn:active { filter: brightness(0.96); }

.btn-primary {
  background: var(--brand-gradient);
  color: #fff;
  border-color: transparent;
  font-weight: 600;
  box-shadow: 0 6px 16px rgba(43, 127, 255, 0.32);
}

.btn-primary:hover {
  color: #fff;
  filter: brightness(1.04);
}

.btn-ghost {
  background: transparent;
  border-color: transparent;
  color: var(--text-muted);
}

.btn-ghost:hover { color: var(--brand); border-color: transparent; }

.direction {
  display: inline-block;
  margin-bottom: 10px;
  padding: 4px 12px;
  border-radius: 999px;
  background: var(--ok-bg);
  color: var(--ok-text);
  font-size: 0.8rem;
  font-weight: 600;
}

.copied {
  color: var(--ok-text);
  font-size: 0.85rem;
  font-weight: 600;
}

.hint {
  margin: 4px 0 0;
  color: var(--text-muted);
  font-size: 0.85rem;
}

footer {
  margin-top: 20px;
  padding-top: 16px;
  border-top: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 0.8rem;
  text-align: center;
}